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Geological relationships and laser ablation ICP-MS U-Pb geochronology of the Saint George Batholith, southwestern New Brunswick, Canada: implications for its tectonomagmatic evolution.

[Traduit par la redaction]

INTRODUCTION

The Silurian (Ludlovian to Pridolian) to Late Devonian (Famennian) Saint George Batholith in southwestern New Brunswick is a large composite intrusion (2000 [km.sup.2]) that was emplaced into the margin of the peri-Gondwanan microcontinent of Ganderia (Fig. 1). The batholith and associated Silurian volcanic and sedimentary rocks of the Mascarene belt are situated along the boundary between Precambrian Ganderian basement rocks of the New River and Brookville belts to the southeast and Ganderian passive margin Cambrian-Ordovician sedimentary rocks of the St. Croix belt to the northwest (Fyffe and Riva 1990; van Staal et al. 2009; Fyffe et al. 2011). The presence of Proterozoic marble and quartzite in the Brookville belt distinguishes it from the Neoproterozoic volcanic and comagmatic plutonic rocks of the New River belt (Johnson and McLeod 1996; White and Barr 1996). The St. Croix belt is a highly deformed Cambrian-Ordovician (Tremadocian to Sandbian) sequence of shale, wacke, and quartzose sandstone; the Fredericton belt is a thick Silurian (Llandoverian to Ludlovian) sequence of wacke, shale, and calcareous sandstone (Ruitenberg 1967; Fyffe and Riva 2001; Castonguay et al. 2003; Thorne et al. 2008). The precise nature of the contact between the St. Croix and Fredericton belts is difficult to discern in the field due to poor exposure, complex deformation, and similarity of lithotypes. The contact has been interpreted as a northwest-directed thrust, referred to as the Honeydale Fault (Ruitenberg 1967).

Silurian (Llandoverian) volcanic and comagmatic plutonic rocks of the Kingston belt separate the Brookville belt from the New River belt. Felsic volcanic rocks in the Kingston belt have yielded U-Pb zircon ages ranging from 442 to 436 Ma, and associated felsic plutonic rocks, ranging from 437 to 435 Ma (Doig et al. 1990; Barr et al. 2002; McLeod et al. 2003). These volcanic and plutonic rocks are interpreted, based on geochemical characteristics, to represent remnants of a Silurian volcanic arc that formed above a subduction zone dipping to the northwest beneath the New River belt (Fyffe et al. 1999; Barr et al. 2002; White et al. 2006). The shallow marine to subaerial sedimentary and volcanic sequences of the Silurian (Llandoverian to Pridolian) Mascarene belt, lying to the northwest of the Kingston belt, are interpreted to have been deposited in a backarc basin that opened behind the Kingston arc (Fyffe et al. 1999; Barr et al. 2002). Felsic volcanic rocks from the Mascarene belt have yielded U-Pb zircon ages ranging from 438 to 423 Ma (Miller and Fyffe 2002; Van Wagoner et al. 2002).

Based on field relationships and geochronological data, McLeod (1990) divided the Saint George Batholith into the following units from oldest to youngest (Fig. 1): Bocabec Gabbro--greyish green, locally layered, medium-grained gabbro and minor associated granitic rocks; Utopia Granite--typically red, leucocratic, medium--to coarse-grained, equigranular, biotite granite; Welsford, Jake Lee Mountain, and Parks Brook granites--beige to pink, mediumgrained and equigranular to fine-grained and porphyritic, amphibole-bearing, peralkaline granites; Magaguadavic Granite--greyish pink, coarse-grained, megacrystic granite; John Lee Brook Granite--light grey, medium-grained, equigranular, garnetiferous, two-mica granite; and Mount Douglas Granite--light pink, medium-to-coarse-grained and equigranular to fine-grained and porphyritic, rapakivitextured, biotite granite. Geochronological data available to McLeod (1990) included: U-Pb zircon ages from the Utopia (430 [+ or -] 3 Ma), Welsford (422 [+ or -] 1 Ma), and Magaguadavic (396 [+ or -] 1 Ma) granites; an [sup.40]Ar / [sup.39]Ar muscovite age of 384 [+ or -] 7 Ma from the John Lee Brook Granite; and U-Pb monazite ages from the Mount Douglas granite (367 [+ or -] 1 Ma, 366 [+ or -] 1 Ma).

To provide additional crystallization ages for the plutons comprising the Saint George Batholith, six samples were selected for laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) analysis at the University of New Brunswick's Department of Earth Sciences. The U-Pb geochronological work was coordinated with field mapping of the Saint George Batholith by the Geological Surveys Branch of the New Brunswick Department of Energy and Resource Development during the summers of 2015 and 2016. Dated sample sites (Locations 1 through 6, numbered from oldest to youngest age of crystallization) are shown on Figure 1 and Figure 2. Locations 1, 4, 5 and 6 are in the Utopia, Jake Lee Mountain, Wellington Lake (new name), and John Lee Brook granites, respectively. Locations 2 and 3, previously mapped as part of the Mount Douglas Granite and Jake Lee Mountain Granite, respectively (McLeod 1990, McLeod et al. 1998), are here assigned to the Utopia Granite on the basis of new field mapping (see below).

FIELD OBSERVATIONS

In 2015, geochronological analysis of an archived sample from the John Lee Brook Granite indicated that this twomica granite is older than the megacrystic Magaguadavic Granite rather than younger as previously suggested (McLeod 1990). Field work was therefore undertaken in the summers of 2015 and 2016 to resolve the conflict between the previously interpreted intrusive history of the Saint George Batholith and the new geochronological data. Contact relationships between the various plutons comprising the Saint George Batholith were examined and the new findings are reported below and incorporated into the revised regional map of the batholith (Fig. 1). Detailed mapping of contacts between intrusive and country rocks during our recent mapping has also better defined the areal distribution and geometry of the plutons comprising the batholith. Previous maps depicted the Saint George Batholith as a contiguous assemblage of intrusions that were emplaced over an extended period of time to form a single massive body. The new mapping, however, suggests that the batholith is more realistically comprised of a loose cluster of distinctive plutons that intruded mainly into sedimentary and volcanic host rocks rather than into previously consolidated intrusive bodies (Fig. 1).

McLeod (1990) recognized and named the poorly exposed John Lee Brook Granite as a distinct pluton during his mapping of the Saint George Batholith. It is a mediumgrained, equigranular, garnetiferous, two-mica granite, underlying an area of about 50 [km.sup.2] along the northern margin of the batholith just south of the Late Devonian Mount Pleasant Caldera (Thorne et al. 2013). The [sup.40]Ar / [sup.39]Ar muscovite age of 384 [+ or -] 7 Ma from the John Lee Brook Granite together with the reported presence of white microgranitic veins cutting the adjacent Magaguadavic Granite, dated by U-Pb on zircon at 396 [+ or -] 1 Ma (Bevier 1990), suggested that the former was younger than the latter (McLeod 1990). However, dating of sample 85MM-154B, collected by McLeod (1990) from near the headwaters of John Lee Brook, yielded a crystallization age of 413 [+ or -] 2 Ma (Location 6 on Fig. 1) casting doubt on the above interpretation.

Field observations undertaken in the summer of 2015 on a small isolated body of megacrystic granite exposed along the upper reaches of McDougall Inlet, west of South Oromocto Lake (Fig. 1), indicate that the megacrystic granite intrudes and truncates quartz veins and aplitic dykelets within the John Lee Brook Granite (Fig. 3a). This isolated body is considered herein to be part of the larger Jimmy Hill Granite (Fig. 1), which underlies the South Oromocto Lake area to the east of McDougall Inlet; McLeod (1990) previously included the granite in the South Oromocto Lake area as part of the Magaguadavic pluton. A close-up photograph of the outcrop along McDougall Inlet clearly shows pink megacrysts of potassium feldspar with rapakivi mantling characteristic of the Jimmy Hill Granite in contact with the equigranular John Lee Brook Granite (Fig. 3b). The observed cross-cutting relationship confirms that both the megacrystic Jimmy Hill and Magaguadavic plutons, dated at 403 [+ or -] 2 Ma and 396 [+ or -] 1 Ma, respectively (Bevier 1990; Davis et al. 2004), are younger than the John Lee Granite in agreement with new age determination obtained on the latter (see below).

Geophysical maps of the St. George area clearly outline the Magaguadavic pluton in the McDougall Lake area as a prominent, circular magnetic feature (King and Barr 2004). This magnetic signature has been used to draw contacts on previously published bedrock maps that enigmatically suggest that the Early Devonian megacrystic granite of the Magaguadavic pluton cross-cuts the adjacent Late Devonian rapakivi granite of the Mount Douglas pluton. However, the recent field mapping has shown that the two plutons are separated by a screen of sedimentary rocks from 300 to 400 m wide and so do not come into direct contact with one another as shown on earlier maps; thus, the Magaguadavic pluton in this area intruded sedimentary and volcanic rocks along its eastern margin--Ordovician quartzose sandstone of the Kendall Mountain Formation (Cookson Group) in the north and Silurian siltstone and mafic volcanic tuff assigned to the Jones Creek Formation (Mascarene Group) in the south--and the Mount Douglas pluton intruded the same screen of sedimentary and volcanic rocks of Jones Creek Formation along its western margin (Fig. 1). More details on the stratigraphy of the Mascarene Group are given below under the discussion on the tectonic evolution of the Mascarene backarc basin.

The Utopia Granite underlies an area of about 100 [km.sup.2] along the southern margin of the Saint George Batholith. The northern margin of the Utopia pluton is separated from the southern margin of the Magaguadavic pluton by a screen from 300 to 600 m wide of dark grey siltstone and minor mafic tuff of the Silurian Jones Creek Formation exposed above Second Falls on the Magaguadavic River (Figs. 1, 4, and 5). Gabbroic rocks, exposed a short distance down river to the south, are injected by red granitic dykelets characteristic of the Utopia Granite; the granitic dykelets surround clusters of lobate gabbroic enclaves, many of which have fine-grained margins, suggesting that emplacement of the two magma types was essentially contemporaneous (Fig. 6). Similar magma mingling has been observed in the main part of the Bocabec Gabbro in the Oak Bay area (Fig. 1) farther to the southwest and in the Moosehorn Plutonic Suite in adjacent Maine (Fyffe 1971; McLaughlin et al. 2003). Note, however, that the new mapping suggests that a sedimentary screen exists between the Utopia and Bocabec plutons (Fig. 1), casting doubt on previous map interpretations showing a direct physical connection between gabbroic rocks in the Utopia pluton and those of the adjacent Bocabec pluton.

Bevier (1990) and Barr et al. (2010) reported U-Pb zircon ages of 430 [+ or -] 3, 428 [+ or -] 1, and 426 [+ or -] 6 Ma from samples of red Utopia Granite collected near the northern end of Lake Utopia (Fig. 1). These late Wenlockian to Ludlovian ages, according to the time scale of Ogg et al. (2016), seemed too old given that fossil evidence from sedimentary rocks in Maine indicate a Pridolian age (Churchill-Dickson 2004) for the surrounding Eastport Formation (Mascarene Group) and that felsic volcanic rocks in the Eastport Formation in New Brunswick have yielded a preliminary U-Pb zircon age of 423 [+ or -] 1 Ma (Van Wagoner et al. 2002). However, the recent field mapping indicates that the Utopia pluton near the above dated granite may have been emplaced no higher in the stratigraphic section than the Llandoverian to Wenlockian Jones Creek Formation (Mascarene Group). To further investigate the age of the Utopia Granite, sample 171-6 was collected from a distinctive, light pink granite (Martin 2013) exposed on the summit of Dawson Mountain (Fig. 7) to the northwest of Lake Utopia (Location 1 on Fig. 1).

Field mapping was conducted in the Red Rock Lake area to the northeast of Lake Utopia (Fig. 1) to better delineate the contact between the Silurian Utopia Granite and Late Devonian Mount Douglas Granite. Distinguishing between these two granites can be difficult in places as both can vary from red to pink. However, as documented by Cherry and Trembath (1978), the granitic rocks in the Lake Utopia area are homogeneous, equigranular, and medium--to coarse-grained, whereas those in the Mount Douglas area are heterogeneous consisting of about 65% equigranular, medium-to coarse-grained phase and about 35% finegrained porphyritic and aplitic phases. In addition, rapakivi-mantling of potassium feldspar is common in the granitic rocks in the Mount Douglas area (Fig. 8)--a feature that is rare in those of the Lake Utopia area (Cherry and Trembath 1978). These criteria were used to conclude that the Mount Douglas Granite extends farther south in the Red Rock Lake area (Fig. 1) than shown by McLeod (1990). This conclusion was confirmed by preliminary Late Devonian dates of 363.7 [+ or -] 4.1 Ma and 365.0 [+ or -] 3.2 Ma obtained on zircon grains from two samples taken along Red Rock Stream to the west of Red Rock Lake (geochronological data for these samples are not included herein). The location of the contact between the Mount Douglas and Utopia granites could only be limited to within a distance of 500 m due to the scarcity of exposures to the south of Red Rock Lake.

Detailed field mapping was conducted in the Wellington Lake-New River area (Figs. 1 and 2) to better define the contacts between the Utopia, Mount Douglas, and Jake Lee Mountain plutons. Previous mapping in this area by McLeod (1990) had delineated a one km-wide by two kmlong eastward continuation of the Utopia Granite preserved within the Mount Douglas Granite on the east side of New River. Re-examination of exposures along the resource road running south from Victoria Lake revealed the presence of conspicuous rapakivi-mantling of potassium feldspars leaving little doubt that these rocks are part of the Mount Douglas pluton. The next exposure to the south along the resource road, following a gap in exposure of 800 m, is comprised of a medium pink, equigranular granite mapped by McLeod (1990) as part of the Mount Douglas pluton. However, the outcrop at this site lacks rapakivi texture so sample 15-87 was collected for geochronological analysis (Location 2 on Figs. 1 and 2) to determine if this granite is part of the Silurian Utopia pluton. sample 15-104 was collected to the south of Wellington Lake to confirm that the Utopia Granite extends to the west of New River as suggested by the recent mapping (Location 3 on Figs. 1 and 2).

Distinctive, medium-to coarse-grained, light greyishwhite to greyish-pink granite, underlying an area of about 15 [km.sup.2] centered on Wellington Lake, was recognized during the recent mapping on west side of the New River about 19 km northeast of Lake Utopia (Fig. 1). Originally included as part of the Utopia Granite by McLeod (1990), its zirconium-rich geochemistry suggests that it may be a separate pluton (see geochemistry section below) and is herein referred to as the Wellington Lake Granite. It is bordered to the southeast by a narrow band of Mount Douglas Granite consisting of light pink, medium-grained granite grading into a fine-grained porphyry containing rapakivi-mantled potassium feldspar. The Wellington Lake Granite is separated from the main mass of the Mount Douglas Granite to the northwest by a screen from 200 to 400 m wide of light grey siltstone with locally interbedded basalt assigned to the Silurian (Llandoverian to Wenlockian) Jones Creek Formation of the Mascarene Group (Fig. 2). Siltstone inclusions from 10 to 20 cm in diameter are common in the Wellington Lake Granite to the west of Wellington Lake near the unexposed northwestern contact with the sedimentary screen (Fig. 9). Sample 15-72 was collected at this site (Location 5 on Figs. 1 and 2) to define the age of crystallization of the Wellington Lake Granite.

The peralkaline Jake Lee Granite, named by Currie (1988), is an oblong pluton about 20 [km.sup.2] in area intruded into volcanic and sedimentary rocks of the Llandoverian Letete Formation (Mascarene Group) in the southeast, Pridolian sedimentary rocks of the Eastport Formation (Mascarene Group) in the northeast, and granitic rocks of the Utopia pluton in the northwest (Fig. 2). Its core consists of medium-grained, beige, equigranular, riebeckite-bearing granite grading outward to a fine-grained, light grey to light pink, porphyritic margin locally exhibiting rapakivi texture (Fyffe 1998). The fine-grained, northern margin of the Jake Lee Mountain pluton contains abundant, angular blocks of gabbro (Fig. 10). A coherent screen of gabbroic rocks about 300 m wide separates it from the Utopia Granite to the north. Sample JL16-1 was collected from medium-grained, beige granite forming the core of the Jake Lee Mountain pluton in order to determine the age of this previously undated peralkaline granite (Location 4 on Figs. 1 and 2).

LASER ABLATION ICP-MS U-Pb GEOCHRONOLOGY

U-Pb crystallization ages of zircon and monazite were determined by in situ laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) at the University of New Brunswick. Standard polished thin sections were prepared and the zircon and monazite were analyzed using a Resonetics S-155-LR 193 nm ArF Excimer laser ablation (LA) system coupled to an Agilent 7700x quadrupole inductively coupled plasma-mass spectrometer (ICPMS). Only those zircon and monazite grains large enough to accommodate a 25[micro]m and 17[micro]m diameter crater, respectively are measurable using laser ablation. Masses of [sup.31]P, [sup.89]Y, [sup.202]Hg, [sup.204]Pb, [sup.206]Pb, [sup.207]Pb, and [sup.208]Pb, [sup.232]Th, and [sup.238]U were analyzed with 31P used as a guide mass and for internal standardization (assuming ~13 wt. % P in monazite) for calculating Y, Pb, Th, and U concentrations in monazite. 90Zr was used as a guide mass and internal standardization (assuming ~43 wt. % Zr in zircon) for calculating Pb, Th, and U concentrations in zircon. For monazite, U-Pb isotope data was standardized using GSC-8153 monazite and the accuracy of the results confirmed using 44069 monazite (Aleinikoff et al. 2006). Zircon was standardized against 1099 Ma FC-1 zircon (Paces and Miller 1993) and accuracy checked using 337 Ma Plesovice zircon (Slama et al. 2008). Concentrations of U and Th in zircon were calculated relative to NIST610 which was analyzed throughout the analytical sequence. The data have been reduced using the Vizual Age U-Pb geochronology data reduction scheme under Iolite software v. 2.5. Common-Pb correction was applied using Andersen (2002) method. A total between 45 and 82 of zircon and monazite analyses were obtained for each sample; however, of this total number of analyses a subset that are <5% discordant was used to calculate concordia ages using Isoplot version 3.71.09.05.23nx (Ludwig 2009). Details of the method have been described in McFarlane (2015) and Azadbakht et al. (2016). The results of the U-Pb monazite and zircon geochronological studies on the six samples selected for LA ICP-MS analysis (Table 1, Fig. 11) are discussed in detail below.

Utopia Granite (sample 171-6)

Sample 171-6 was collected on the summit of Dawson Mountain at Location 1 on Fig. 1. This light pink variety of Utopia Granite is a medium-grained, moderately altered granite with a slightly seriate texture composed of subhedral potassium feldspar, quartz, plagioclase, and biotite. Fractures and thin veins in the granite are filled with crystalline quartz. The perthitic potassium feldspar occurs as subhedral to euhedral twinned crystals up to 1.25 cm in diameter. Plagioclase occurs as smaller laths and is moderately altered to sericite in the central parts of grains. Quartz crystals are typically rounded and have seriate boundaries with the surrounding groundmass. Biotite grains are present as tabular grains rich in opaques (Fe-Ti oxides), zircon, monazite, and apatite. Monazite crystals occur as subhedral to anhedral and almost rounded grains ranging from very small up to 100 [micro]m in diameter and are mostly in contact with other accessory minerals, such as Fe-Ti oxides, zircon, and apatite (Fig. 12). A total of 82 spot analyses on monazite grains were obtained for the U-Pb geochronological study (Table A1). The results for monazite grains from the Dawson Mountain sample yielded a U-Pb crystallization age of 425.5 [+ or -] 2.1 Ma (Table 1 and Fig. 13), i.e., Ludlovian according to the time scale of Ogg et al. (2016). This age is the same within error as the previously published U-Pb zircon age of 428.3 [+ or -] 1.0 Ma (latest Wenlockian) obtained on a sample of the typically red Utopia Granite exposed on Rte. 785 near the northern end of Lake Utopia (Barr et al. 2010).

Utopia Granite (samples 15-87 and 15-104)

Sample 15-87 was collected on the east side of New River at Location 2 on Figs. 1 and 2. Previously included as part of Mount Douglas Granite (McLeod 1990), recent field observations indicate that it is textually more similar to the Utopia Granite in that rapakivi-mantling is lacking. The sample is a granular, medium-grained, pink granite composed mainly of quartz grains; perthitic potassium feldspar grains up to 0.75 cm in diameter, which are moderately altered to very fine-grained sericite along fractures or twinning planes; plagioclase grains that range from small inclusions hosted by potassium feldspar to moderately large subhedral-euhedral grains with a maximum diameter of 0.5 cm are locally altered to sericite along albite twin planes; and iron-rich biotite laths, which are altered to chlorite along cleavage planes. Zircon and apatite are the most abundant accessory minerals, mostly occurring as inclusions in biotite (Fig. 14a). The zircon crystals occur as subhedral to euhedral grains up to 100 [micro]m in diameter that mostly are in contact with other accessory minerals, such as Fe-Ti oxides, apatite, and xenotime, and exhibit oscillatory zoning (Fig. 14b). Only those zircon crystals large enough to accommodate a 25 [micro]m- diameter crater are measurable using laser ablation, and inclusionand crack-free grains are preferred for analyses. A total of 68 spot analyses of zircon grains were ablated for the U-Pb geochronological study (Table A2). The results for zircon grains from sample 15-87 yielded a U-Pb crystallization age of 420.4 [+ or -] 2.4 Ma (Table 1 and Fig. 15), confirming that it is of Silurian (Pridolian) age and, therefore, part of the Utopia pluton rather than the Late Devonian Mount Douglas pluton.

A sample of medium-grained, pink, biotite granite (sample 15-104) was collected on the west side of New River at Location 3 on Figs. 1 and 2 to confirm that the Utopia Granite extends into the area south of Wellington Lake. The exposures in this area were previously included as part of Jake Lee Mountain Granite (McLeod et al. 1998) but recent field observations indicate that amphibole is not present in these rocks. A total of 62 spot analyses of zircon grains were ablated for the U-Pb geochronological study (Table A3). The analytical results on the zircon grains from sample 15-104 yielded a U-Pb crystallization age of 420.0 [+ or -] 3.5 Ma (Table 1 and Fig. 16) essentially identical to that obtained from sample 15-87.

Jake Lee Mountain Granite (sample JL16-1)

A sample of medium-grained, beige, equigranular, riebeckite-bearing granite (sample JL16-1) was collected along the resource road leading west off the Anthony Lake Road toward Jake Lee Mountain at Location 4 on Figs. 1 and 2. The sample is composed of quartz up to 2 mm in diameter, slightly altered perthitic potassium feldspar grains up to 3 mm in diameter, minor plagioclase with a maximum diameter of 1 mm; and iron-rich biotite laths, which are intensely altered to Fe-Ti oxides. Quartz and alkali feldspar are locally intergrown in a granophyric texture within a mosaic of polygonal, equigranular crystals of quartz and alkali feldspar. Accessory minerals include euhedral to subhedral

zircon crystals that display oscillatory zoning, Fe-Ti oxides, and monazite crystals, which are present as inclusions in zircon or as small grains near or in contact with zircon and Fe-Ti oxide grains. Fine fractures and quartz stringers are present in the specimen.

A total of 60 spot analyses of zircon grains were ablated for the U-Pb geochronological study (Table A4). The analytical results from zircon grains from sample JL16-1 yielded a U-Pb crystallization age of 418.0 [+ or -] 2.3 Ma for the core of the Jake Lee Mountain Granite (Table 1 and Fig. 17). Although this latest Pridolian to earliest Lochkovian age overlaps statistically with the ages obtained from the two samples of Utopia Granite in the New River area, it is consistent with the Jake Lee Mountain Granite being the younger pluton based on the presence of its finer grained northern margin (Fyffe 1998; Barr et al. 2010). The peralkaline Welsford Granite, dated at 422 [+ or -] 1 Ma (Bevier 1990), is not found in contact with the Utopia Granite whereas the undated peralkaline Parks Brook Granite is veined by the Utopia Granite.

Wellington Lake Granite (sample 15-72)

Sample 15-72 from the Wellington Lake Granite was collected at Location 5 on Fig. 1 and 2 along a resource road running south off the Anthony Lake Road to the west of Wellington Lake. This sample is a holocrystalline, greyish pink, medium-grained, equigranular granite dominated by quartz; perthitic potassium feldspar grains, which are moderately altered to sericite; plagioclase grains, which are altered to sericite in their central parts (Fig. 18a); and biotite laths. Accessory minerals are subhedral zircon (Fig. 18b), apatite, monazite, and xenotime, which are mostly hosted by biotite; and garnet, which occurs as inclusions in plagioclase. A total of 53 spot analyses of zircon grains were ablated for the U-Pb geochronological study. The analytical results on the zircon grains from sample 15-72 (Table A5) yielded a U-Pb crystallization age of 415.5 [+ or -] 2.1 Ma (Table 1 and Fig. 19). This Early Devonian (Lochkovian) age together with its unique textural characteristics (Fig. 9) and chemical composition (see below) supports the recognition of the Wellington Lake Granite as distinct from the Silurian Utopia Granite, to which it was previously assigned (McLeod 1990).

John Lee Brook Granite (sample 85MM-154B)

Sample 85MM-154B from the John Lee Brook Granite was collected by Malcolm McLeod in 1985 during his mapping of the Saint George Batholith (McLeod 1990). The sample site at Location 6 on Figs. 1 and 2 is located along a resource road about 3 km west of Rte. 785 near the headwaters of John Lee Brook. This white, medium-grained, equigranular, twomica granite exhibits hypidiomorphic granular texture and is composed mainly of quartz, moderately altered perthitic potassium feldspar and plagioclase, and biotite (up to 20%), which is partially altered to chlorite. About 5 % primary muscovite is present but no garnet was observed. Zircon, monazite, apatite, xenotime, and Fe-Ti oxides are accessory minerals.

Scanning electron microscope-back scattered electron (SEM-BSE) images of monazite-bearing specimens from the John Lee Brook Granite were taken using software application dPict32 (developed by Geller Microanalytical Laboratories). The abundant accessory monazite in the sample of John Lee Brook Granite occur primarily as inclusions in principal minerals, such as biotite, or in contact with other accessory minerals. To obtain a reliable age of emplacement, monazite grains showing evidence that they were crystallized from a magma and not exhibiting inherited cores need to be chosen for measurement. Thus, monazite grains that are in equilibrium with other accessory minerals, such as apatite and xenotime, were selected for geochronological studies (Figs. 20 a, b, f, and h); disseminated monazite grains hosted as inclusions in biotite appear to be relatively homogeneous and reveal no inherited cores (Figs. 20c-d).

The monazite occurs as subhedral grains from 5 to 80 [micro]m in diameter. Only those grains large enough to accommodate a 17 [micro]m diameter crater are measurable using laser ablation. Chemical discriminants, such as Y vs. U/Th, and P vs. U/Th, indicate that the monazite is chemically homogeneous, although faint patchy zoning was locally evident in SEM-BSE images (Figs. 2ob, g).

A total of 45 spot analyses of monazite grains were ablated for the U-Pb geochronological study (Table A6). The analytical results on the monazite grains from the John Lee Brook Granite yielded a crystallization age of 413.3 [+ or -] 2.1 Ma (Table 1 and Fig. 21). This Early Devonian (Lochkovian) age is significantly older than the previous age of 384 [+ or -] 7 Ma obtained by [sup.40]Ar / [sup.39]Ar dating of muscovite (McLeod 1990). The contact between the John Lee Brook pluton and adjacent Magaguadavic pluton is located about 2 km south of the sample site at Location 6. This site yielded both the monazite age and younger muscovite age for the John Lee Brook Granite so it is likely that the intrusion of the Magaguadavic Granite was responsible for resetting the [sup.40]Ar / [sup.39]Ar isotopic system in the muscovite.

By way of contrast, ages obtained by various geochronological methods from the Magaguadavic Granite in the McDougall Lake area all fall within a relatively narrow range indicating its isotopic systems were not significantly affected by later intrusive events. A sample of megacrystic granite along Rte. 785 just east of McDougall Lake yielded a U-Pb zircon age of 396 [+ or -] 1 Ma (Bevier 1990) and an [sup.40]Ar/[sup.39]Ar biotite age of 400 [+ or -] 4 Ma (McLeod 1990). A porphyritic granitic dyke along the northwestern margin of the Magaguadavic Granite at the Clarence Stream gold deposit (CS on Fig. 1) yielded a U-Pb monazite age of 395.5 [+ or -] 0.5 Ma, and a pegmatitic dyke in the same area yielded a U-Pb monazite age of 390 [+ or -] 8 Ma and a U-Pb zircon age 400 [+ or -] 5 Ma (Thorne et al. 2002, 2008; Davis et al. 2004).

GEOCHEMISTRY

Dated samples from the Utopia Granite (Sample 171-6 and 15-87) and Wellington Lake Granite (Sample 15-72) were analyzed for major elements and selected trace elements, including rare earth elements (REEs). The method used was laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) on fused glass beads at the University of New Brunswick. Standards BCR-2, GSP-2, and SY-4 were used to check precision and accuracy on the fusion beads. Major elements were obtained with a JEOL JSM 6400 Scanning Electron Microscope equipped with an EDAX Genesis X-ray microanalysis system (SEM-EDS). The accelerating voltage was 15 kV and the probe current was approximately 1.5 nA. Spectra were collected for 50 s live-time. Trace element analyses were performed using LA-ICP-MS with a 45[micro]m diameter crater. Standards used were NIST-610 (primary concentration standard), NIST-612 (secondary concentration standard), and BCR-2G (QC standard). The geochemical results are shown in Table 2 together with data on the John Lee Brook Granite (sample 85MM-154B) taken from McLeod (1990). No analysis is available for the dated Jake Lee Mountain Granite (sample J16-1).

Major element characteristics

Sample 15-72 from the Wellington Lake Granite has the lowest silica content (70.3 wt.%) followed by sample 171-6 from the less evolved Utopia Granite (71.7 wt. %), sample 85MM-154B from the John Lee Brook Granite (74.9 wt.%), and sample 15-87 from the more evolved Utopia Granite (77.3 wt.%). All four of the dated samples fall in the peraluminous field (Fig. 22a) and are characterized by high ([Fe.sub.2][O.sub.3] + FeO)/MgO ratio (ranging from 4.7 to 17.9), alkalis with [K.sub.2]O/[Na.sub.2]O >1, and low CaO, [P.sub.2][O.sub.5], Ti[O.sub.2], and MgO (Table 2). On the plot of Si[O.sub.2] versus [K.sub.2]O (Fig. 22b), samples from the John Lee Brook and Utopia granites plot in the fields of high-K; whereas the sample from the Wellington Lake Granite is associated with the shoshonite series.

Trace and rare earth element characteristics

Geochemical data presented by McLeod (1990) and Whalen (1993) indicate that the granite dated on Dawson Mountain and that dated by Barr et al. (2010) on the northern end of Lake Utopia, both of which have yielded Ludlovian ages of emplacement, are less evolved than the granite dated as Pridolian to the east of New River (Sample 15-87). McLeod's and Whalen's data also indicate that granite similar in composition to that east of New River also exists in the southern part of the Lake Utopia area to the east of Lily Lake (Fig. 1), suggesting that the Utopia Granite is a composite pluton composed of an older less evolved component (ave. Si[O.sub.2] = 73.6 wt.%, n = 6), and a younger more evolved component (ave. Si[O.sub.2] = 76.8 wt.%, n = 4). A conspicuous magnetic lineament, located about 1 km north of Lily Lake, trends eastward to Lake Utopia and may represent the boundary between these two components in the western part of the Utopia pluton.

Differences between spider diagrams of the three plutons are highlighted by the contrasting REE patterns of each pluton (Fig. 23a). The REE profiles of the Utopia and Wellington Lake samples are relatively flat with gentle negative slopes. The highly evolved Utopia Granite from east of New River (sample 15-87) has the largest negative Eu anomaly (Eu/[Eu.sup.*] = 0.02), the lowest normalized light (LREE) to heavy (HREE) rare earth ratio [[(La/Yb).sub.N] = 2.3], and most pronounced negative Ba, Sr, and Ti anomalies (Fig. 23b). Sample 15-87 also has lower overall REE abundances reflecting possible fractionation of zircon/xenotime, and monazite/apatite, which have high partition coefficients for HREE and LREE, respectively, and are abundant in this sample. The relatively high negative slope of sample 85MM154B [[(La/Yb).sub.N] = 6.5] from the John Lee Brook Granite (Fig. 23a) is possibly the result of the presence of refractory garnet in the source area or of late-stage fractionation of garnet, which has a high partition coefficient for HREE and is abundant as inclusions mostly hosted by plagioclase in this sample. The prominent negative Nb and Ti anomalies exhibited by the John Lee Granite on the HFSE/primitive mantle spider diagram (Fig. 23b) are likely an inherited signature derived from melting of old granitic basement or arc-derived clastic sedimentary rocks in the source region at 413 Ma.

Sample 15-72 from the Wellington Lake Granite contains the highest overall REE abundances, exhibits the highest normalized LREE enriched pattern [[(La/Yb).sub.N] = 7.73] that is accompanied by a relatively small negative Eu anomalies (Eu/[Eu.sup.*] = 0.06), likely reflecting fractionation in a more oxidized magmatic system where more of the Eu is present as [Eu.sup.+3] and hence would not be incorporated into the crystallizing plagioclase (e.g., Sisson and Grove 1993).

On 'Rb vs Y + Nb', 'Rb vs Yb + Ta', 'Nb vs Y, and 'Ta vs Yb' tectonomagmatic discrimination diagrams (Fig. 24), the dated samples from the Utopia and Wellington Lake granites plot in the within-plate, 'A-type' field whereas the John Lee Brook Granite falls mainly within the syncollisional, 'S-type' field. On the FeO* vs Zr + Nb + Ce + Y discrimination diagram, the Utopia and Wellington Lake samples again fall in the A-type' field (Fig. 25a), whereas the J oh n Lee Brook sample plots in the fractionated granite field (FG). On the ternary Y-Nb-Ce discrimination diagram (Fig. 25b), the dated samples all fall in the crustal A-type' field, although the strongly fractionated Utopia Granite sample from east of New River plots toward a 'mantle-type' granite.

TECTONIC EVOLUTION OF THE MASCARENE BACKARC BASIN

The current plate tectonic model developed for the post-Penobscottian evolution of southern New Brunswick relates Acadian (late Silurian to early Devonian) tectonism in the region to closure of a remnant oceanic tract, referred to as the Acadian Seaway (van Staal et al. 1996; Fyffe et al. 1999; Barr et al. 2002; White et al. 2006; van Staal et al. 2009). This seaway separated the peri-Gondwanan microcontinent of Avalonia (see inset on Fig. 1) from the amalgamated terranes already accreted to the Laurentian continental margin during Early Paleozoic closure of the Iapetus Ocean. The peri-Gondwanan microcontinent of Ganderia, the most outboard of these Iapetan terranes, was accreted to the Laurentian margin during Salinic (late Ordovician to late Silurian) orogenesis. Precambrian rocks of the New River and Brookville belts are considered to underlie the sparsely preserved platform of Ganderia, whereas the Cambrian-Ordovician sedimentary rocks of the St. Croix belt are interpreted to represent its Paleozoic passive margin (van Staal et al. 1996; Fyffe et al. 2011). Subsequent Acadian tectonism and magmatism in southwestern New Brunswick is attributable to accretionary events associated with closure of the Acadian Seaway by northwest-directed subduction beneath the Kingston arc-Mascarene backarc system and its St. Croix-New River substrate (Fig. 1). The arc-backarc system was subsequently extensively dismembered by strike-slip displacement along the Sawyer Brook, St. George, Wheaton Brook, Belleisle, and Kennebecasis faults (Stewart et al. 1995; Fyffe et al. 1999, Fyffe et al. 2011). The Sawyer Brook, St. George, and Wheaton Brook faults were inactive by the Late Devonian as they are cross-cut by the Mount Douglas Granite, emplaced between 367 [+ or -] 1 and 366 [+ or -] 1 Ma (Bevier 1989; McLeod 1990).

The Mascarene backarc basin is situated along the transitional zone between the Ganderian platform comprised of Neoproterozoic basement rocks and its thin cover of Cambrian quartzite (New River belt) in the south and the Ganderian passive margin comprised of a thick succession of Cambrian-Ordovician sedimentary rocks (St. Croix belt) in the north (Fyffe et al. 2011). The Silurian sequences in the dismembered backarc basin, which are all included in the Mascarene Group, have been divided into several formations (i.e., Oak Bay, Waweig, Letete, Long Reach, Jones Creek, and Eastport), described briefly below. The contact between the steeply dipping conglomerate of the Silurian Oak Bay Formation at the base of the Mascarene Group and Cambrian-Ordovician sedimentary rocks of the Cookson Group is generally marked by the Sawyer Brook Fault, along which considerable transcurrent movement has occurred (Park et al. 2008).

Volcanic rocks become abundant up-section in the Oak Bay Formation and the contact with the overlying Waweig Formation, a sequence of moderately dipping, light pink, fossiliferous, fine-grained sandstone and siltstone interbedded with felsic and lesser mafic tuffs, is gradational (Fyffe et al. 1999). A felsic tuff in the Waweig Formation yielded an early Silurian (Llandoverian) U-Pb zircon date of 438 [+ or -] 4 Ma (Miller and Fyffe 2002). The Letete Formation, a complexly deformed, steeply dipping sequence of felsic and mafic tuffs interbedded with dark grey shale, lies along the southern margin of the Mascarene backarc basin between the St. George and Wheaton Brook faults (Fig. 1). Felsic tuff from the Letete Formation yielded an early Silurian (Llandoverian) U-Pb zircon date of 437 [+ or -] 7 Ma (Miller and Fyffe 2002). Mascarene strata to the east of the Saint George Batholith (Fig. 1) include mafic flows and tuffs of the Long Reach Formation and conformably overlying, fine-grained, feldspathic sandstone, siltstone, dacitic flows, and minor mafic tuffs of the Jones Creek Formation. Brachiopods indicate a late Llandoverian to early Wenlockian age for the Long Reach Formation (McCutcheon and Ruitenberg 1987), and associated dacitic volcanic rocks have yielded an early Silurian (early Wenlockian) U-Pb zircon date of 432 [+ or -] 2 Ma (N. Van Wagoner, written communication to M. McLeod, 2001). An equivalent sequence of volcanic rocks lying beneath the late Silurian Eastport Formation in adjacent Maine has suprasubduction-zone geochemical signatures (Llamas and Hepburn 2013).

The early Silurian volcanic sequences of the Oak Bay, Waweig, Long Reach, Jones Creek, and Letete formations, which are at least partially coeval with the volcanic arc rocks in the Kingston Group, are considered here to have been generated in a continental backarc basin in an extensional suprasubduction-zone environment (Fyffe et al. 1999; Barr et al. 2002; White et al. 2006; van Staal et al. 2009). Fossil and geochronological data are consistent with a period of uplift and erosion or non-deposition of Silurian strata in the Mascarene backarc basin in the mid- to Wenlockian. This hiatus, delineated radiometrically by the age of the youngest suprasubduction-zone related volcanism (432 [+ or -] 2 Ma) and oldest non-arc plutonism (428 [+ or -] 1 Ma) constrains the timing of the closure of the Acadian Seaway and collision of Avalonia with the Ganderian margin of composite Laurentia to the mid-Silurian.

The mid-Silurian hiatus in the Mascarene backarc basin was followed by deposition of the shallow-marine to subaerial succession correlated with the Eastport Formation in Maine (Fyffe et al. 1999). The Eastport Formation in New Brunswick, which occurs along the southern margin of the Saint George Batholith to the north of the St. George Fault (Fig. 1), comprises a gently southerly dipping succession of mafic and felsic flows and tuffs interbedded with peritidal to subaerial, red sandstone and siltstone. Felsic flows in the middle section of the Eastport Formation are enriched in Zr (Van Wagoner et al. 2002), suggesting that they may be the extrusive equivalents of the peralkaline Welsford, Jake Lee Mountain, and Parks Brook granites. The Eastport volcanic rocks have within-plate geochemical signatures and have been reported to have a late Ludlovian to early Pridolian age based on the poorly documented, preliminary U-Pb zircon date of 423 [+ or -] 1 Ma (Van Wagoner et al. 2002). The location of the dated felsic flow is not known with certainty but it was likely collected about 1 km above the base of the Eastport Formation.

LATE SILURIAN--EARLY DEVONIAN PLUTONISM

The bulk composition, spatial distribution, and timing of emplacement of the various Silurian (late Wenlockian to Pridolian) to Early Devonian (Lochkovian to Emsian) plutonic rocks in southwestern New Brunswick are discussed below in relationship to the tectonomagmatic evolution of the Kingston arc-Mascarene backarc system (Kingston and Mascarene belts on Fig. 1). As emphasized by Hyndman et al. (2005), convective heat flow in backarc regions can continue for some tens of millions of years after subduction stops; these hot and weak former backarcs can then become the focus of high temperature metamorphism, ductile deformation, and plutonism. Based on previously published geochronological data, the composite Saint George Batholith was emplaced into the Mascarene backarc basin during three separate intervals (428 to 422 Ma; 403 to 390 Ma; and 367 to 366 Ma), covering a time span of approximately 60 million years (Bevier 1989, 1990; McLeod 1990; Whalen et al. 1996; Thorne et al. 2002, 2008; Davis et al. 2004; Barr et al. 2010). The new results reported above indicate magmatic activity also occurred in the backarc between 418 and 413 Ma (Table 1) and indicate that the tectonomagmatic history of the Saint George Batholith was more protracted than previously envisioned. All these intrusive episodes took place after the eruption of suprasubduction--zone related volcanism in the Mascarene backarc basin had ceased at 432 [+ or -] 2 Ma.

Silurian (late Wenlockian to Pridolian) magmatism

The Silurian (late Wenlockian to Pridolian) 'A-type' granite plutons that were emplaced along the southern margin of the Mascarene backarc basin (Welsford, Jake Lee Mountain, Parks Brook, Utopia granites, and felsic components of the Bocabec Gabbro) generally show little evidence of deformation compared to the minor intrusions described below along the northern margin of the basin. Emplacement of the southern Silurian plutons overlapped with the eruption of bimodal flows and tuffs of the Eastport Formation dated at 423 [+ or -] 1 Ma (Van Wagoner et al. 2002). The Welsford and Utopia granites have been previously dated by U-Pb on zircon at 422 [+ or -] 1 and 428.3 [+ or -] 1.0 Ma, respectively (Bevier 1990; Barr et al. 2010). The new results reported here include a U-Pb date on monazite of 425.5 [+ or -] 2.1 Ma for the less evolved phase of the Utopia Granite, U-Pb dates on zircon of 420.4 [+ or -] 2.4 and 420.0 [+ or -] 3.5 Ma for the more evolved phase of the Utopia Granite, and a U-Pb on zircon of 418.0 [+ or -] 2.3 Ma for the Jake Lee Mountain Granite, which straddles the Pridolian-Lochkovian boundary (Fig. 11; Table 1). The undated Parks Brook peralkaline granite must be older than 420 Ma as it is veined by the Utopia Granite.

The elongated shapes of these high-level 'A-type' plutons suggest that their emplacement was at least partly controlled by high heat flow along pre-existing, extensional fault-structures in the basement rocks defining the 'active' southeastern boundary of the Mascarene backarc basin (Fig. 1). Only the Jake Lee Mountain pluton displays evidence of significant shearing, likely attributable to late-stage movement on the St. George Fault (Figs. 1 and 2). More significant fault displacement along the southern margin of the backarc basin appears to have been taken up largely within the highly strained strata of the Letete Formation, located farther to the south between the St. George and Wheaton Brook faults (Fyffe et al. 1999).

The peralkaline, amphibole-bearing Welsford and Jake Lee Mountain granites, and biotite-bearing, Utopia Granite are classified as 'A-type' granites (Whalen 1986; Whalen et al. 1987). The generation of the peralkaline plutons may have involved partial melting of subcontinental lithospheric mantle (Whalen et al. 2006), whereas the generation of the contemporaneous 'aluminous A-type' Utopia Granite likely involved partial melting of dehydrated, granulite-facies, lower continental crust (King et al. 1997). Underplating of the lithosphere with mantle-derived mafic magma is required to produce the high temperatures required to melt the relatively anhydrous protoliths of 'A-type' granites. Neodymium epsilon values [[[epsilon].sub.Nd] (430 Ma)] of + 2.7 for granite from the Bocabec Gabbro, + 2.3 from the Utopia biotite granite, and + 3.4 from the Welsford peralkaline granite indicate some mixing of mantle-derived mafic magma with the partial melts (Whalen et al. 1994; Whalen et al. 2006).

The Sawyer Brook Fault acted as a brittle, normal fault along the northern margin of the Mascarene backarc basin during deposition of the early Silurian Oak Bay conglomerate (Stringer and Burke 1985; Fyffe et al. 1999). Subsequently, a series of mafic dykes were emplaced into this margin of the backarc basin, along a probable splay off the Sawyer Brook Fault. The dykes, each about 30 m in width, occupy a 300 m-wide, northeast-trending dextral shear zone along the northwestern margin of the Magaguadavic pluton. As seen in gold exploration trenches in the Clarence Stream area (CS on Fig. 1), the dykes contain penetrative schistosity of aligned biotite and actinolite that is parallel to the trend of the dykes and cross-cuts an earlier phyllitic cleavage in the Silurian volcanic and sedimentary host rocks of the Waweig Formation; locally the dykes are highly boudinaged. The late schistosity in the sedimentary rocks, defined by muscovite and biotite, wraps around cordierite porphyroblasts, which contain relicts of the earlier phyllitic cleavage (Thorne and Lentz 2001; Park et al. 2008; Thorne et al. 2008). The mafic dykes in the Clarence Stream shear zone are petrochemically similar to, and may represent offshoots from, the Bocabec Gabbro. If this correlation is correct, the dykes were emplaced in the later part of the Silurian (Ludlovian to Pridolian) at about 422.1 [+ or -] 1.3 Ma (Clarke et al. 2017).

High-strain shear zones have also been mapped in the St. Croix and Fredericton belts to the northwest of the Sawyer Brook Fault. The Mohannes Granite, located about 10 km to the west of the area shown in Fig. 1, is light grey, granodiorite to monzogranite that was emplaced into Cambrian-Ordovician sedimentary rocks along the northern margin of the St. Croix belt (Fyffe et al. 1991). This oblong, relatively small, 'I-type' pluton, which yielded a preliminary U-Pb emplacement age on zircon of 420 [+ or -] 5 Ma (Fyffe and Bevier 1992), contains a penetrative, northeast-trending, cataclastic fabric defined by aligned augen of plagioclase and potassium feldspar set in a granulated quartz matrix. Like in the contact aureole of the mafic dykes in the Clarence Stream area, cordierite porphyroblasts in the host rocks of the Mohannes Granite show evidence of growth during deformation.

Early Devonian (Lochkovian to Emsian) magmatism

The John Lee Brook, Jimmy Hill, and Magaguadavic granites, which form the northwestern part of the Saint George Batholith (Fig. 1), are all Early Devonian in age. Both the John Lee Brook and Jimmy Hill plutons appear to be entirely confined to the St. Croix and Fredericton belts on the north side of the Sawyer Brook Fault. The new LA ICP-MS in situ U-Pb age of 413.3 [+ or -] 2.1 Ma indicates that the John Lee Brook Granite was emplaced during the Lochkovian stage (Ogg et al. 2016). Also, the U-Pb zircon crystallization ages of 415.5 [+ or -] 2.1 Ma obtained from the newly recognized Wellington Lake Granite indicates that some high-field-strength-element-enriched magmatic activity was taking place within the Mascarene backarc basin along the southern margin of the Saint George Batholith in early Lochkovian time.

The John Lee Brook pluton has an elongated shape but does not display a fabric, suggesting that its emplacement took place during the waning stages of transpressional tectonic activity. In marked contrast, the Magaguadavic pluton is roughly circular in outline indicating that its emplacement post-dated major fault movement. Like the Tower Hill Granite, which lies entirely in the St. Croix belt, the two-mica John Lee Brook Granite is peraluminous with a high Aluminum Saturation Index (ave. ASI of 1.08) and low [[epsilon].sub.Nd] (400 Ma) value of + 0.3 compared to the other plutons comprising the Saint George Batholith (Whalen et al. 1996). It thus has properties transitional to 'S-type' granites and was likely derived in part by melting or assimilation of supracrustal metasedimentary rocks (Chappell and White 1974). In contrast, the metaluminous megacrystic Magaguadavic Granite, with an ASI of 0.9 and [[epsilon].sub.Nd] (400 Ma) of + 2.0, has 'I-type' characteristics and its generation can be attributed to partial melting of metaigneous rocks in the lower crust (Chappell and White 1974; Whalen et al. 1994, 1996; Yang et al. 2008); the presence of large potassium feldspar phenocrysts indicates that the magma may have been sequestered in the deep crust for some time before rising and solidifying nearer to the surface (McLeod 1990).

The Magaguadavic Granite was emplaced during the Emsian Stage of the Early Devonian as indicated by previously published U-Pb dates on zircon of 396 [+ or -] 1 Ma (Bevier 1989; Davis et al. 2004). The John Lee Brook and Magaguadavic granites differ markedly in texture, mineralogy, and chemistry, as well as in age. The John Lee Brook Granite generally contains biotite, muscovite, and garnet; and is high in silica (ave. Si[O.sub.2] = 74.0 %). The Magaguadavic Granite contains megacrysts of potassium feldspar, and biotite and hornblende, and is low in silica (ave. Si[O.sub.2] = 68.5 wt.%).

A m-wide granitic dyke in the Clarence Stream shear zone (CS on Fig. 1) has yielded a U-Pb (monazite age) of 395.5 [+ or -] 0.5 Ma (Davis et al. 2004). Its age and the presence of potassium-feldspar phenocrysts (1 to 2 cm in length) suggest that the granitic dyke is an offshoot of the nearby Magaguadavic pluton. However, unlike the main pluton, the dyke exhibits a weak tectonic fabric. It could be concluded from this that dextral shearing associated with the Sawyer Brook Fault may have taken place episodically over a period of at least 25 million years, i.e., between 421 Ma, the presumed age of intrusion of the sheared mafic dykes in the Clarence stream area, and 396 Ma, the age of the associated foliated granitic dyke (Thorne and Lentz 2001; Park et al. 2008; Thorne et al. 2008). Alternatively, the shearing in the granitic dyke may reflect local re-activation of the Sawyer Brook splay within the contact aureole of the Magaguadavic Granite.

The Tower Hill Granite, which transects the core of a late antiform in the St. Croix belt (Fig. 1), is undeformed, except where it is intersected by the northwest-trending Oak Bay Fault (Fyffe et al. 1991, 1999; Castonguay et al. 2003). It contains both biotite and muscovite, is highly peraluminous (ASI of 1.14), and has a negative [[epsilon].sub.Nd] (400 Ma) value of -0.4 (Whalen et al. 1996). A high temperature-low pressure metamorphic assemblage of biotite, andalusite, staurolite, garnet, muscovite, and quartz is developed in the sedimentary rocks up to 500 m from the granite (Ruitenberg 1967; Fyffe et al. 1991). A minimum age of emplacement for the Tower Hill Granite is given by an Rb-Sr muscovite isochron date of 401 [+ or -] 4 Ma (Whalen et al. 1996). An undeformed microgranite dyke, located approximately 2 km east of Tower Hill, yielded a U-Pb zircon age of 409 [+ or -] 2 Ma (Davis et al. 2004).

DISCUSSION AND CONCLUSIONS

Average bulk chemical compositions of plutons comprising the Saint George Batholith and satellite Tower Hill pluton have been calculated using published analyses from McLeod (1990) and Whalen (1993) to supplement the data reported herein for the newly dated samples. These averaged values confirm that the spatial and temporal variations observed from southeast to northwest across the batholith are reflected systematically in the trace-element, REE, and isotopic Nd geochemistry of the clustered plutons (Figs. 23 and 24). On the Pearce et al. (1984) discrimination diagrams, granitic samples from the Bocabec, Utopia, Welsford, Jake Lee Mountain, and Wellington Lake plutons all fall in the 'within -plate' 'field whereas the John Lee Brook, Jimmy Hill, Magaguadavic, and Tower Hill plutons fall mainly on the boundary between the' syn-collisional' and 'volcanic-arc' fields (Fig. 24).

The geochemical variation across the Saint George Batholith can be explained in terms of the transition of the Kinston arc-Mascarene backarc system from an extensional arc to transpressional tectonic environment during the Acadian orogeny, which was caused by closure of the Acadian Seaway and collision of the Avalonian microcontinent with the composite Laurentian margin (van Staal et al. 2009). The initial extensional nature of the Kingston arc is indicated by the early Silurian emplacement of a high-level bimodal intrusive complex into the host volcanic-arc rocks of the Kingston Group. Mafic and granitic dykes in this complex have active-continentalmargin and within-plate signatures, respectively (Eby and Currie 1993). A subsequent change to a compressive environment is indicated by the presence of a zone of low temperature-high pressure metamorphism along the southeastern margin of the Kingston arc, which occurred after emplacement the late Llandoverian intrusive complex at 436 [+ or -] 2 Ma (Doig et al. 1990) and prior to 420 [+ or -] 2 Ma, the oldest [sup.40]Ar / [sup.39]Ar cooling age of metamorphic amphibole defining the foliation in the mafic dykes (Nance and Dallmeyer 1993; Barr et al. 2002; White et al. 2006).

A much later, high temperature-intermediate pressure 'regional contact' metamorphic event associated with emplacement of the Tower Hill Granite at about 401 Ma is evident in the St. Croix belt to the northwest of the Mascarene backarc basin (Fyffe et al. 1991; Whalen et al. 1996). Staurolite and garnet are present in pelitic rocks of both the low-pressure metamorphic assemblage in the St. Croix belt and high-pressure assemblage in the Kingston belt but the garnets in the St. Croix assemblage are significantly lower in magnesium and higher in manganese content (Fyffe et al. 1991; White et al. 2006). The contrast between the penetrative deformation apparent in the Pridolian Mohannes Granite in the St. Croix belt, and the relatively undeformed nature of the late Wenlockian to Pridolian plutons of the Saint George Batholith on opposite sides of the Sawyer Brook Fault (Fig. 1), is likely a reflection of the depth of emplacement and subsequent uplift of the hotter, deeply buried, complexly deformed, Cambrian-Ordovician sedimentary sequence in the northwest, compared to the cooler, near-surface, gently dipping volcanic sequence (Eastport Formation) exposed along the southeastern margin of the Mascarene backarc basin. This strain gradient is evident from the strong ductile fabrics present in the more deeply buried, lower part of the Silurian volcanic sequence (Waweig Formation) and contained mafic dykes now exposed along the northwestern margin of the Mascarene backarc basin in Clarence Stream area (CS on Fig. 1).

Emplacement of late Wenlockian to Pridolian Bocabec, Utopia, Jake Lee Mountain, Parks Brook, and Welsford plutons into the host volcanic rocks of the Mascarene backarc basin coincided with the change from early Silurian suprasubduction-zone influenced volcanism to late Silurian bimodal volcanism in the backarc area. This change in tectonomagmatic environment is attributed to the arrival of the leading edge of Avalonia at the trailing edge of Ganderia of composite Laurentia. The attempted subduction of the buoyant Avalonia microcontinent plate caused a decrease in the angle of subducting slab beneath the Kingston arc leading to increased coupling between the upper Ganderian and lower Avalonian plates, resulting in the cessation of arc-related volcanic activity. Further plate convergence led to partitioning of strain into orthogonal shortening and margin-parallel, strike-slip components focused in the thin, hot and weakened backarc lithosphere (e.g., Hyndman et al. 2005). As the downgoing Avalonian plate reached higher temperatures at greater depths, the dense, dehydrated, subducting oceanic slab ruptured and broke away from the more buoyant continental part of the lower plate, and compressive forces between the Ganderian and Avalonian plates diminished due to the loss of slab pull (Davies and von Blanckenburg. 1995; Ellis et al. 1998; Barnes et al. 1998). Thermomechanical modelling by Gerya et al. (2004) indicates that slab break-off occurs from 5 to 30 million years after collision and that ensuing magmatism can last between 10 to 20 million years. In the Kingston arc-backarc system, slab break-off and the termination of continental subduction is interpreted to have occurred in the mid-Silurian between 432 [+ or -] 2 Ma, the youngest age of arc volcanism, and 428 [+ or -] 1 Ma, the oldest age of post-collision plutonism in the Saint George Batholith. Partial melting of the thin, hot lithosphere inherited from the opening of the Mascarene backarc basin would have been promoted by upwelling and decompressional melting of the asthenospheric mantle following slab-break-off. Such a mechanism accounts for the generation of voluminous bimodal (gabbroic and granitic) magmatism represented by the Bocabec, Utopia, Welsford, Jake Lee Mountain, Parks Brook, and Wellington Lake plutons lasting over a period of about 13 million years (Fig. 11; Tables 1 and 3).

Systematic variation in La/Yb values is evident across the Saint George Batholith: the more southerly group of plutons (Bocabec, Utopia, Welsford, Jake Lee Mountain, and Wellington Lake) typically have (a) a range of La/ Yb values of less than 11, (b) a relatively high isotopically positive epsilon Nd values, and (c) ages ranging from late Wenlockian to early Lochkovian; those to the north (John Lee Brook; Jimmy Hill, Magaguadavic, and satellite Tower Hill pluton) have (a) considerably higher La/Yb values; (b) low positive to slightly negative epsilon Nd values; and (c) ages ranging from late Lochkovian to Emsian (Table 3). Whalen et al. (2006) documented a similar increase in La/Yb and decrease in epsilon Nd in Silurian plutons at increasing distances to west of the Dog Bay Line in central Newfoundland. They interpreted the Dog Bay Line to represent the suture zone between Laurentia and Ganderia that resulted from closure of the intervening Exploits basin by west-directed subduction of backarc oceanic crust. The variation La/Yb and epsilon Nd in these plutons was attributed to slab break-off resulting in a change from shallow-level, garnet-absent melting of juvenile crust proximal to the suture zone and deeper level melting of old granitic basement in the garnet stability field farther to the west.

Hildebrand and Whalen (2014) defined separate 'arc' and 'slab failure' plutonic fields on Nb/Y versus Sr/Y, and La/Yb versus Sr/Y diagrams based the trace-element geochemistry of plutons in the Cretaceous Peninsula Ranges Batholith in coastal California and Mexico. However, they noted that their proposed discrimination fields should not be considered universally applicable because of the inherent tectonic complexities involved in the evolution of orogenic belts; instead the division of the Cretaceous plutons into 'arc' (low La/Yb) and 'slab failure' (high La/Yb) types was determined primarily by the timing of their emplacement with respect to collision and uplift rather than by geochemistry alone. With this in mind, the two fields on Hildebrand and Whalen's discrimination diagrams are used herein to empirically determine which plutons in the Saint George Batholith were likely to have had residual garnet present in their source regions.

The plutons of the Saint George Batholith and satellite Tower Hill pluton fall into the same two groupings on the Hildebrand and Whalen (2014) diagram (Fig. 26) that they do on the Pearce et al. (1984) discrimination diagram (Fig. 24). The Magaguadavic, Jimmy Hill, John Lee Brook, and Tower Hill granites plot in or near the boundary of the 'garnet present' field. The four samples from the John Lee Brook Granite from McLeod (1990), which show wide variation in element ratios (Table 3), have been plotted as individual points rather than as an average; the two samples from the southeastern part of the pluton (ave. La/ Yb of 7.4) appear to be more evolved with higher silica and Rb/Sr values compared to the two samples from the northeast (ave. La/Yb of 14.4). Samples from the younger Jimmy Hill and Magaguadavic plutons (Table 3) plot well into the 'garnet present field (Fig. 26). The transition to deeper level partial melting apparently occurred during the Lochkovian Stage of the Early Devonian based on the emplacement age of 415.5 [+ or -] 2.1 Ma for the Wellington Lake Granite, the youngest 'A-type' pluton, and the emplacement age of 413.3 [+ or -] 2.1 Ma, for the John Lee Brook Granite, the oldest 'S-type' pluton in the backarc region; the former was likely generated at least in part by partial melting of Neoproterozoic volcanic and plutonic rocks underlying the Mascarene belt, and the latter at least in part by granulite-facies dehydration melting of pelitic rocks of the St. Croix belt.

Convective heating and partial melting of the adjacent, thick crust of the St. Criox belt, which marks the northwestern 'passive' boundary of the Mascarene backarc basin, may be responsible for the generation of Early Devonian magmatism at greater depths compared to the Silurian magmatic activity to the southeast. Prograde metamorphism of the bounding thick crust may have led to formation of a dense, eclogitic lower crustal root that had detached from the more buoyant overlying granulitic crust and sank, together with its attached underlying lithospheric mantle, into the convecting asthenosphere of the backarc region (see Krystopowicz and Currie 2013). Subsequent upwelling of the asthenospheric mantle then induced widespread partial melting of the lower crust under 'garnet-present' conditions to generate the 'I-type' Jimmy Hill, Magaguadavic, and 'S-type' Tower Hill plutons (Fig. 24). These plutons then rose to higher levels in the crust, where they solidified during the Emsian between 403 [+ or -] 2 and 396 [+ or -] 1 Ma (Table 3). Isostatic rebound within the St. Croix belt is marked by the domal area of high temperaturelow pressure contact metamorphic zone surrounding the Tower Hill pluton. Deformation of pegmatitic and aplitic dykes and associated auriferous quartz veins located along the northwestern margin of the undeformed, circular, Magaguadavic Granite is focused along reactivated shear fault splays of the Sawyer Brook Fault (Thorne et al. 2008).

The eastern part of the Saint George Batholith was formed 30 million years later with the emplacement of the 600 [km.sup.2], tin-enriched, post-orogenic, Late Devonian Mount Douglas Granite (Fig. 1). The recent mapping and geochronology has shown that the Mount Douglas and other plutons of Silurian to Late Devonian age that comprise the Saint George Batholith actually occur as a cluster of individual intrusions separated by screens of sedimentary and volcanic country rocks, rather than as the continuous mass of amalgamated plutons depicted on earlier maps.

doi:10.4138/atlgeol.2017.008

Date received: 03 November 2016 f Date accepted: 07 April 2017

ACKNOWLEDGEMENTS

The authors would like to thank Malcolm McLeod, Adrian Park, and Dave Stevens for their helpful advice. Dr. Douglas Hall (UNB Microscopy and Microanalyses Facility) is thanked for help with the SEM-BSE imaging. We thank Brandon Boucher for help with the laser ablation ICP-MS data. Serge Allard provide ARCGIS base maps and Terry Leonard drafted the geology maps. Joe Whalen and Jim Mortensen provided insightful suggestions that helped to improve the petrogenetic interpretations presented in the paper. Project funding was provided by New Brunswick Energy and Resource Development, UNB President's Doctoral scholarship (University of New Brunswick), and the New Brunswick Innovation Foundation. Chris McFarlane and David Lentz hold NSERC Discovery grants.

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Nadia Mohammadi (1) *, Les Fyffe (2), Christopher R.M. McFarlane (1), Kay G. Thorne (2), David R. Lentz (1), Brittany Charnley (2), Laurin Branscombe (2), and Sheena Butler (1)

(1.) Department of Earth Sciences, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada

(2.) Geological Surveys Branch, New Brunswick Department of Energy and Resource Development, Fredericton, New Brunswick E3B 5H1, Canada

* Corresponding author <nadia.mohammadi@unb.ca>

Caption: Figure 1. Map of geological belts and plutonic rocks in southwestern New Brunswick, Canada; the Caledonia Fault along the southeast side of the Brookville belt (outside of area of Figure 1) defines the boundary between Ganderia and Avalonia. Inset map shows tectonostratigraphic terranes in the northeastern Appalachians (after Hibbard et al. 2006) with location of Figure 1 outlined by a black block on insert. Location of Figure 2 is shown by outlined rectangle. Major plutons comprising the Saint George Batholith are named in full. Abbreviations: BIF = Belleisle Fault; KCF = Kennebecasis Fault; SGF = St. George Fault; WBF = Wheaton Brook Fault; BH = Beech Hill Granite; MB = McDougall Brook Granite; PR = Pleasant Ridge Granite; SR = Sorrel Ridge Granite; TH = Tower Hill Granite; JH = Jimmy Hill Granite; PB = Parks Brook Granite; WL = Wellington Lake Granite; CS = Clarence Stream gold deposit. Granitic rocks in the Bocabec Gabbro are shown in pink and gabbroic rocks in the Utopia Granite are shown in purple. Asterisk shows location of dated samples in the Saint George Batholith: 1 = 171-6; 2 = 15-87; 3 = 15-104; 4 = JL16-1; 5 = 15-72; 6 = 85MM-154B.

Caption: Figure 2. Detailed geology of Wellington Lake--New River area (see Figure 1 for location). Abbreviations: EP = Eastport Formation; JC = Jones Creek Formation; LT = Letete Formation; JL = Jake Lee Mountain Granite (a) coarse-grained, (b) fine-grained; MD = Mount Douglas Granite; WL = Wellington Lake Granite; UT = Utopia Granite. Asterisk shows location of dated samples: 2 = 15-87; 3 = 15-104; 4 = JL16-1; 5 = 15-72.

Caption: Figure 3. (a) Megacrystic Jimmy Hill Granite intruded into equigranular John Lee Brook Granite along West Branch McDougall Inlet. Quartz vein in the John Lee Granite is truncated by the Jimmy Hill Granite (latitude 45[degrees] 24' 39.7"; longitude 66[degrees] 45' 26.3"). (b) Close-up of the contact between pink rapakivi megacrystic Jimmy Hill Granite and white equigranular John Lee Brook Granite.

Caption: Figure 4. Red, medium-grained, equigranular granite of the Utopia Granite at Second Falls on the Magaguadavic River.

Caption: Figure 5. Inclusions of dark grey siltstone in red Utopia Granite about 2 km above Second Falls on the Magaguadavic River.

Caption: Figure 6. Dark grey, lobate enclaves gabbro injected by veins of red Utopia Granite about 1.8 km above Second Falls on the Magaguadavic River.

Caption: Figure 7. Light pink, medium-grained, equigranular granite of the Utopia Granite on Dawson Mountain (Location 1 on Fig. 1).

Caption: Figure 8. Mount Douglas Granite with abundant rapakivi-mantled alkali feldspar. Location along Lepreau Road west of Munsen Lake (see Fig. 1).

Caption: Figure 9. Greyish-white, medium-grained, equigranular granite of the Wellington Lake Granite containing light grey siltstone inclusion about 2 km southwest of Wellington Lake (Location 5 on Fig. 1).

Caption: Figure 10. Angular blocks of gabbro injected by amphibole-bearing granite along the northern margin of Jake Lee Mountain pluton.

Caption: Figure 11. New U-Pb monazite and zircon geochronological results from the Saint George Batholith. Vertical axis legend is location number for dated samples shown on Figures 1 and 2. Error bars show the concordia age of each sample [+ or -] 2 [sigma] (see Table 1).

Caption: Figure 12. (a) SEM-BSE image of accessory minerals as inclusions in biotite from sample 171-6. (b) Close-up of image (a) showing homogeneous monazite grains with no internal zoning revealed by changing the gamma value (back scatter contrast) of the photograph.

Caption: Figure 13. U-Pb concordia plot for laser ablation ICP-MS analyses of monazite grains from the Sample 171-6 (Utopia Granite). Concordia age = 425.5 [+ or -] 2.1 Ma; data point error ellipses are 2 [sigma]; MSWD of concordance = 0.67; probability of concordance = 0.41. The blue ellipse is weighted-mean error ellipse.

Caption: Figure 14. (a) Photomicrograph of a biotite from sample 15-87; the biotite contains inclusions of zircon and apatite surrounded by zones of radiation damage (in cross-polarized light). (b) SEM-BSE image of a zircon crystal from sample 15-87 exhibiting oscillatory zoning.

Caption: Figure 15. U-Pb concordia plot for laser ablation ICPMS analyses of zircon grains from sample 15-87 (Utopia Granite). Concordia age = 420.4 [+ or -] 2.4 Ma; data point error ellipses are 2 o; MSWD of concordance = 0.18; probability of concordance = 0.67. The blue ellipse is weighted-mean error ellipse.

Caption: Figure 16. U-Pb concordia plot for laser ablation ICPMS analyses of zircon grains from sample 15-104 (Utopia Granite). Concordia age = 420.0 [+ or -] 3.5 Ma; data point error ellipses are 2 [sigma]; MSWD of concordance = 0.20; probability of concordance = 0.66. The blue ellipse is weighted-mean error ellipse.

Caption: Figure 17. U-Pb concordia plot for laser ablation ICPMS analyses of zircon grains from sample JL16-01 (Jake Lee Mountain Granite). Concordia age = 418.0 [+ or -] 2.3 Ma; data point error ellipses are 2 o; MSWD of concordance = 0.40; probability of concordance = 0.53. The blue ellipse is weighted-mean error ellipse.

Caption: Figure 18. (a) Photomicrograph of a plagioclase grain from sample 15-72 with oscillatory zoning and selectively sericitized central part of the grain. (b) SEM-BSE image of a representative zircon crystal from sample 15-72 with oscillatory zoning.

Caption: Figure 19. U-Pb concordia plot for laser ablation ICP-MS analyses of zircon grains from sample 15-72. (Wellington Lake Granite). Concordia age = 415.5 [+ or -] 2.1 Ma; data point error ellipses are 2 o; MSWD of concordance = 1.08; probability of concordance = 0.3. The blue ellipse is weighted-mean error ellipse.

Caption: Figure 20. Representative SEM-BSE images of selected monazite grains from sample 85MM-154B. (a) Two subhedral monazite grains in equilibrium with zircon and apatite. (b) Fractured subhedral monazite that is in equilibrium with apatite. (c) Aggregate of monazite, zircon, and Fe-oxide. (d) Close-up of a fractured homogenous monazite of image (e) hosted within biotite. (e) A biotite with plenty of inclusions, including monazite, apatite, and zircon. (f) Close-up of two homogeneous monazite grains of image (e) that are in equilibrium with apatite. (g) A 60 [micro]m x 40 [micro]m subhedral homogeneous monazite. (h) Monazite grains that are in equilibrium with xenotime and zircon. (i) Fractured homogeneous monazite showing no zoning.

Caption: Figure 21. Concordia plot for laser ablation ICP-MS analyses of monazite grains from sample 85MM-154B (John Lee Brook Granite). Concordia age = 413.0 [+ or -] 2.1 Ma; data point error ellipses are 2 [sigma]; MSWD of concordance = 0.13; probability of concordance = 0.72. The blue ellipse is weighted-mean error ellipse.

Caption: Figure 22. Major element characteristics of granite samples from the Saint George Batholith and satellite Tower Hill pluton. (a) Alumina saturation diagram; fields after Shand (1943); (b) Si[O.sub.2] vs. [K.sub.2]O diagram; fields after Le Maitre et al. (1989). Black non-filled symbols are averaged analyses of plutons from Whalen (1993). Green-filled triangle symbol is analysis of dated John Lee Brook sample from McLeod (1990), and green nonfilled circle is averaged analyses of Jimmy Hill pluton from McLeod (1990).

Caption: Figure 23. Trace-and rare-earth element characteristics of dated granite samples from the Saint George Batholith: (a) Chondrite-normalized REE profiles; normalizing values for C1 chondrite from Sun and McDonough (1989). (b) Primitive mantle-normalized spider diagram; primitive mantle values from Sun and McDonough (1989). See Figure 22 for symbols.

Caption: Figure 24. Tectonomagmatic discrimination diagrams for plutons of the Saint George Batholith and for the satellite Tower Hill pluton. Volcanic arc granite (VAG), syn-collisional granite (syn-COLG), within-plate granite (WPG), and ocean-ridge granite (ORG) fields after Pearce et al. (1984). Christiansen and Keith (1996) equated the VAG, syn-COLG, and WPG fields with I-, S-, and A-type granites, respectively. See Figure 22 for symbols.

Caption: Figure 25. Tectonomagmatic discrimination diagrams for plutons of the Saint George Batholith and for the satellite Tower Hill pluton (a) Zr + Nb + Ce + Y vs. FeO*/ MgO; fields after Whalen et al. (1987); FG = fractionated felsic granites; OGT = unfractionated M-, I-, and S-type granites. (b) Ternary Y-Nb-Ce diagram; fields after Eby (1992); A1 granites are characterized by element ratios similar to the mantle, whereas A2 granites originated from continental crust or arcs. See Figure 22 for symbols.

Caption: Figure 26. Tectonomagmatic discrimination diagrams from Hildebrand and Whalen (2014) for plutons of the Saint George Batholith and satellite Tower Hill pluton. (a) Nb/Y vs. Sr/Y; (b) La/Yb vs. Sr/Y. See Figure 22 for symbols.

Editorial responsibility: Sandra M. Barr
Table 1. Summary of new U-Pb monazite and zircon concordia ages
obtained by LA ICP-MS from the Saint George Batholith *.

1            2             3               4
Sample    Location     Latitude        Longitude

171-6        1       45[degrees] 12' 54.8"   66[degrees] 51' 28.7"
15-87        2       45[degrees] 16' 15.9"   66[degrees] 36' 31.6"
15-104       3       45[degrees] 15' 03.4"   66[degrees] 38' 59.9"
JL-16-1      4       45[degrees] 13' 57.5"   66[degrees] 38' 08.9"

15-72        5       45[degrees] 14' 58.1"   66[degrees] 40' 55.1"

85MM-        6       45[degrees] 23' 18.0"   66[degrees] 48' 45.0"
  154B

1                5              6         7        8
Sample          Unit         Material   Spot #    Age

171-6      Utopia Granite    Monazite     82     425.5
15-87      Utopia Granite     Zircon      68     420.4
15-104     Utopia Granite     Zircon      62     420.0
JL-16-1       Jake Lee        Zircon      60     418.0
          Mountain Granite
15-72     Wellington Lake     Zircon      53     415.5
              Granite
85MM-      John Lee Brook    Monazite     45     413.3
  154B        Granite

1           9       10        11
Sample    Error   + Error   - Error

171-6      2.1     427.6     423.4
15-87      2.4     422.8     418.0
15-104     3.5     423.5     416.5
JL-16-1    2.3     420.3     415.7

15-72      2.1     417.6     413.4

85MM-      2.1     415.4     411.2
  154B

1          12         13
Sample    MSWD    Probability

171-6     0.67       0.41
15-87     0.18       0.67
15-104    0.20       0.66
JL-16-1   0.40       0.53

15-72     1.08        0.3

85MM-     0.13       0.72
  154B

* Note: (2) = Location of the samples are shown in Figures 1 and
2. (7) = Number of analyzed spots of monazite or zircon grains;
(8) = Concordia ages (Ma) of samples; (9) = Error is two standard
deviations; (10) = Concordia ages plus the error number (Ma);
(11) = Concordia ages minus the error number (Ma); (12) = MSWD
(Mean Squares of Weighted Deviation) of concordance; 13 =
Probability of concordance.

Table 2. LA-ICP-MS analyses of selected granites from the
Saint George Batholith.

Pluton        John Lee Brook    Wellington    Utopia    Utopia
                 Granite       Lake Granite   Granite   Granite
Sample          85MM-154B         15-72        15-87     171-6

Si[O.sub.2]        74.9            70.3        77.26     71.66
  (wt. %)
Ti[O.sub.2]        0.09            0.32        0.08      0.57
[Al.sub.2]        13.97            16.2        12.92     14.13
  [O.sub.3]
FeO                1.09            2.62        1.43      2.16
MnO                0.05            0.06        0.04      0.81
MgO                0.23            0.27        0.08      0.36
CaO                0.5             0.94        0.34      0.83
[Na.sub.2]O        4.1             3.41        2.92      3.63
[K.sub.2]O         4.78            5.57        4.78      5.07
[P.sub.2]          0.03            0.1         0.05      0.05
  [O.sub.5]
Total             100.04           99.7        99.85     99.22
Rb (ppm)           247            132.1        201.2     223.2
Cs                 7.3             2.9           6        7.2
Ba                 132            119.1        23.1       167
Sr                  43             34.2        18.5      40.1
Ga                  --             19.8        20.8      20.6
Ge                  --             1.5          1.9       3.6
Ta                 1.9             1.6          2.2       2.3
Nb                  11             33.9        22.4      25.5
Hf                 3.2             16.1         1.5       7.9
Zr                  83            473.5         44       240.8
Y                   33            118.1        29.6       53
La                  21            101.5        11.1      50.5
Ce                  49            222.5        24.9      98.4
Pr                  --             24.5         2.9      10.5
Nd                  17             95.4        11.9      38.8
Sm                 3.8             22.9         2.5       8.9
Eu                 0.4             0.4         0.02       0.5
Gd                  --             20.6         3.3       7.7
Tb                 0.8             3.5          0.7       1.5
Dy                 4.4             21.5         4.3       9.2
Ho                  --             4.4           1        1.8
Er                  --              12          2.8       5.3
Tm                 0.3             1.6          0.5       0.8
Yb                 2.3             9.4          3.5       6.2
Lu                 0.4             1.4          0.6       0.9
Ni                  0              6.3          5.1       3.2
Co                 1.1             1.7          0.6       1.7
Sc                 3.4             19.5         8.4        9
Cu                  2              6.5         16.5      13.6
Pb                  10             2.9         12.5      57.1
Zn                  47             9.4         21.03      27

Table 3. La/Yb and epsilon Nd (T) values for the Saint George
Batholith and Tower Hill Pluton.

Granitic Pluton       La/Yb     cNd (T)         Age (Ma)

Bocabec             5.8-10.3      2.7     422.1 [+ or -] 1.3 *
Utopia              3.2-10.2      2.2     428.3 [+ or -] 1.0 to
                                           420.4 [+ or -] 2.4
Welsford            7.0-10.0      3.3        422 [+ or -] 1
Jake Lee Mountain    6.3-7.3      --       418.0 [+ or -] 2.3
Wellington Lake       10.7        --       415.5 [+ or -] 2.1
John Lee Brook      5.5-18.0      0.2      413.3 [+ or -] 2.1
Jimmy Hill          20.8-25.3     --         403 [+ or -] 2
Magaguadavic        24.3-29.3     1.5        396 [+ or -] 1
Tower Hill          37.8-40.5    -0.4        401 [+ or -] 4

* The granite is assumed to be coeval with the U-Pb dated Bocabec
Gabbro (Clarke et al. 2017).


APPENDIX
Table A1. Results for in-situ LA-ICP-MS U-Pb monazite
geochronology of Sample 171-6 (Utopia Granite).

                       Approx. conc. (ppm)

spot            C *     U       Th     U/Th
                      (ppm)   (ppm)

171-6-C9-4       1    1990    56150    0.04
171-6-C17-3      1    1116    67000    0.02
171-6-C9-5       3    2330    68700    0.03
171-6-C5-1       1     266    39800    0.01
171-6-C9-3       1     704    64100    0.01
171-6-C6-2       1     825    68700    0.01
171-6-C4-9       3    1058    60100    0.02
171-6-C15-4      1    2726    52100    0.05
171-6-C9-2       1     524    65500    0.01
171-6-C1-3       1    2181    125500   0.02
171-6-C7-5       1    2431    161300   0.02
171-6-C7-1       1     854    67000    0.01
171-6-C18-2      1     779    58500    0.01
171-6-C10-12     1     480    57100    0.01
171-6-C14-7      1     773    61220    0.01
171-6-C10-9      1    1123    44700    0.03
171-6-C7-6       3    2380    68600    0.03
171-6-C10-10     1    1067    58130    0.02
171-6-C10-2      1    1880    65400    0.03
171-6-C18-3      1    1797    108400   0.02
171-6-C4-1       1    2103    127300   0.02
171-6-C15-2      1    2373    69300    0.03
171-6-C17-2      1    2706    122200   0.02
171-6-C14-6      1     815    63000    0.01
171-6-C14-2      1    1662    106900   0.02
171-6-C1-1       1    2613    122500   0.02
171-6-C9-1       1     528    58400    0.01
171-6-C4-4       3    2302    46700    0.05
171-6-C18-4      1    1624    84600    0.02
171-6-C10-4      1    2245    67100    0.03
171-6-C18-5      1    1884    86300    0.02
171-6-C10-8      1    1230    55250    0.02
171-6-C7-3       1    8810     7260    1.21
171-6-C10-5      1    8480     7220    1.17
171-6-C4-7       1    513.3   52660    0.01
171-6-C10-1 #    1    2193    85600    0.03
171-6-C5-3 #     1    370.6   44700    0.01
171-6-C15-1 #    1    2285    53200    0.04
171-6-C10-7 #    1    8740     7340    1.19
171-6-C5-4 #     1    397.1   44970    0.01
171-6-C6-1 #     1     710    62600    0.01
171-6-C6-3 #     1     897    57180    0.02
171-6-C5-2 #     1    379.5   43110    0.01
171-6-C4-8       1    565.8   58300    0.01
171-6-C10-3      1    2346    41100    0.06
171-6-C10-6      1    8440     6970    1.21
171-6-C10-11     1     552    61300    0.01
171-6-C17-1      1    2037    61650    0.03
171-6-C7-4       1    12770   11030    1.16
171-6-C14-1      1    1031    71800    0.01
171-6-C1-2       3    2172    128300   0.02
171-6-C7-2       1    1308    63900    0.02
171-6-C18-1      1    2161    137400   0.02
171-6-C4-3       1    1709    121400   0.01
171-6-C4-12      1     517    53090    0.01
171-6-C4-2       1    1594    110200   0.01
171-6-C5-5       1    1325    103400   0.01
171-6-C15-3      1    2317    83700    0.03
171-6-C4-13      1     802    67800    0.01

                         Approx. conc. (ppm)

spot            C *   [sup.204]Pb   [sup.206]Pb/
                         (cps)      [sup.204]Pb

171-6-C9-4       1        99             44
171-6-C17-3      1        90             45
171-6-C9-5       3        223            36
171-6-C5-1       1        19             69
171-6-C9-3       1        36            106
171-6-C6-2       1        34            140
171-6-C4-9       3        261            35
171-6-C15-4      1        63            201
171-6-C9-2       1         3            883
171-6-C1-3       1        41            274
171-6-C7-5       1        21            547
171-6-C7-1       1        24            136
171-6-C18-2      1        31            135
171-6-C10-12     1         7            369
171-6-C14-7      1        18            219
171-6-C10-9      1         2            2805
171-6-C7-6       3        293            34
171-6-C10-10     1        14            378
171-6-C10-2      1        21            500
171-6-C18-3      1        19            452
171-6-C4-1       1        19            465
171-6-C15-2      1        13            982
171-6-C17-2      1        15            852
171-6-C14-6      1        -4           -1072
171-6-C14-2      1         2            3530
171-6-C1-1       1        -2           -7380
171-6-C9-1       1        -10           -292
171-6-C4-4       3        185            85
171-6-C18-4      1         9            894
171-6-C10-4      1        -10          -1220
171-6-C18-5      1        -6           -1498
171-6-C10-8      1        -17           -374
171-6-C7-3       1        10            4635
171-6-C10-5      1        -7           -6338
171-6-C4-7       1        -7            -390
171-6-C10-1 #    1        -3           -3803
171-6-C5-3 #     1         2            1069
171-6-C15-1 #    1         2            6075
171-6-C10-7 #    1        -13          -3582
171-6-C5-4 #     1        -4            -569
171-6-C6-1 #     1        -7            -581
171-6-C6-3 #     1        -8            -598
171-6-C5-2 #     1         4            521
171-6-C4-8       1         5            659
171-6-C10-3      1         1           12570
171-6-C10-6      1        -9           -4889
171-6-C10-11     1         0             -
171-6-C17-1      1        -8           -1286
171-6-C7-4       1        19            3511
171-6-C14-1      1        -2           -3331
171-6-C1-2       3        135            85
171-6-C7-2       1        15            474
171-6-C18-1      1         2            5671
171-6-C4-3       1        -2           -4745
171-6-C4-12      1        10            287
171-6-C4-2       1        -3           -2977
171-6-C5-5       1        -4           -1618
171-6-C15-3      1         2            7072
171-6-C4-13      1        -4           -1151

                         Final isotope ratios

spot            C *   %Pb      [sup.        2
                      *(a)     207]Pb/   [sigma]
                               [sup.
                               235]U

171-6-C9-4       1    56.70    2.150      0.140
171-6-C17-3      1    60.50    4.940      0.210
171-6-C9-5       3    46.30    0.690      0.840
171-6-C5-1       1    79.70    1.670      0.830
171-6-C9-3       1    82.40    1.650      1.200
171-6-C6-2       1    86.20    1.880      0.210
171-6-C4-9       3    50.70    0.340      0.480
171-6-C15-4      1    91.24    0.968      0.110
171-6-C9-2       1    92.00    1.050      1.200
171-6-C1-3       1    91.21    1.125      0.100
171-6-C7-5       1    92.00    1.010      1.200
171-6-C7-1       1    92.47    1.105      0.058
171-6-C18-2      1    92.40    1.131      0.100
171-6-C10-12     1    93.30    0.947      0.230
171-6-C14-7      1    92.96    1.014      0.048
171-6-C10-9      1    94.43    0.861      0.049
171-6-C7-6       3    54.80    0.300      0.220
171-6-C10-10     1    94.98    0.798      0.062
171-6-C10-2      1    95.16    0.837      0.071
171-6-C18-3      1    96.63    0.744      0.024
171-6-C4-1       1    97.25    0.657      0.034
171-6-C15-2      1    97.44    0.643      0.047
171-6-C17-2      1    97.62    0.633      0.039
171-6-C14-6      1    97.80    0.628      0.037
171-6-C14-2      1    98.13    0.625      0.035
171-6-C1-1       1    98.15    0.602      0.045
171-6-C9-1       1    97.90    0.562      0.490
171-6-C4-4       3    77.40    0.520      0.960
171-6-C18-4      1    98.47    0.559      0.350
171-6-C10-4      1    98.65    0.555      0.110
171-6-C18-5      1    98.55    0.556      0.032
171-6-C10-8      1    99.23    0.518      0.033
171-6-C7-3       1    99.44    0.535      0.012
171-6-C10-5      1    99.62    0.521      0.010
171-6-C4-7       1    99.26    0.502      0.037
171-6-C10-1 #    1    99.42    0.517      0.020
171-6-C5-3 #     1    98.68    0.516      0.059
171-6-C15-1 #    1    99.19    0.522      0.120
171-6-C10-7 #    1    99.78    0.525      0.010
171-6-C5-4 #     1    99.37    0.522      0.280
171-6-C6-1 #     1    99.49    0.506      0.350
171-6-C6-3 #     1    99.36    0.510      0.031
171-6-C5-2 #     1    99.53    0.503      0.045
171-6-C4-8       1    99.44    0.509      0.370
171-6-C10-3      1    99.52    0.501      0.019
171-6-C10-6      1    99.81    0.526      0.011
171-6-C10-11     1    99.17    0.525      0.360
171-6-C17-1      1    99.50    0.496      0.017
171-6-C7-4       1    99.93    0.500      0.009
171-6-C14-1      1    99.36    0.508      0.036
171-6-C1-2       3    78.08    0.490      0.210
171-6-C7-2       1    99.66    0.505      0.024
171-6-C18-1      1    99.48    0.506      0.020
171-6-C4-3       1    99.57    0.490      0.018
171-6-C4-12      1    99.42    0.511      0.040
171-6-C4-2       1    99.63    0.506      0.021
171-6-C5-5       1    99.41    0.527      0.022
171-6-C15-3      1    99.76    0.501      0.190
171-6-C4-13      1    99.46    0.484      0.028

                         Final isotope ratios

spot            C *    [sup.        2      err.
                       206]Pb/   [sigma]   corr.
                        [sup
                       .238]U

171-6-C9-4       1     0.040      0.002    0.465
171-6-C17-3      1     0.102      0.003    0.651
171-6-C9-5       3     0.029      0.013    0.821
171-6-C5-1       1     0.062      0.007    0.035
171-6-C9-3       1     0.068      0.013    0.090
171-6-C6-2       1     0.084      0.002    0.646
171-6-C4-9       3     0.062      0.004    0.861
171-6-C15-4      1     0.061      0.003    0.112
171-6-C9-2       1     0.071      0.012    0.170
171-6-C1-3       1     0.072      0.001    0.285
171-6-C7-5       1     0.067      0.011    0.104
171-6-C7-1       1     0.076      0.002    0.089
171-6-C18-2      1     0.078      0.002    0.424
171-6-C10-12     1     0.070      0.002    0.091
171-6-C14-7      1     0.075      0.002    0.145
171-6-C10-9      1     0.069      0.001    0.158
171-6-C7-6       3     0.042      0.003    0.776
171-6-C10-10     1     0.068      0.002    0.169
171-6-C10-2      1     0.073      0.001    0.360
171-6-C18-3      1     0.072      0.001    0.115
171-6-C4-1       1     0.068      0.001    0.074
171-6-C15-2      1     0.068      0.001    0.096
171-6-C17-2      1     0.069      0.001    0.179
171-6-C14-6      1     0.070      0.001    0.212
171-6-C14-2      1     0.071      0.001    0.022
171-6-C1-1       1     0.070      0.001    0.003
171-6-C9-1       1     0.067      0.005    0.072
171-6-C4-4       3     0.072      0.025    0.798
171-6-C18-4      1     0.067      0.006    0.346
171-6-C10-4      1     0.068      0.002    0.048
171-6-C18-5      1     0.068      0.001    0.062
171-6-C10-8      1     0.066      0.001    0.129
171-6-C7-3       1     0.069      0.001    0.319
171-6-C10-5      1     0.068      0.001    0.282
171-6-C4-7       1     0.067      0.002    0.074
171-6-C10-1 #    1     0.068      0.001    0.015
171-6-C5-3 #     1     0.067      0.002    0.199
171-6-C15-1 #    1     0.069      0.002    0.005
171-6-C10-7 #    1     0.069      0.001    0.402
171-6-C5-4 #     1     0.068      0.004    0.138
171-6-C6-1 #     1     0.067      0.004    0.149
171-6-C6-3 #     1     0.068      0.001    0.094
171-6-C5-2 #     1     0.067      0.002    0.084
171-6-C4-8       1     0.068      0.004    0.059
171-6-C10-3      1     0.068      0.001    0.141
171-6-C10-6      1     0.070      0.001    0.237
171-6-C10-11     1     0.071      0.003    0.190
171-6-C17-1      1     0.068      0.001    0.003
171-6-C7-4       1     0.068      0.001    0.412
171-6-C14-1      1     0.069      0.001    0.098
171-6-C1-2       3     0.065      0.002    0.823
171-6-C7-2       1     0.069      0.001    0.167
171-6-C18-1      1     0.069      0.001    0.044
171-6-C4-3       1     0.068      0.001    0.063
171-6-C4-12      1     0.069      0.002    0.146
171-6-C4-2       1     0.069      0.001    0.055
171-6-C5-5       1     0.072      0.001    0.097
171-6-C15-3      1     0.070      0.003    0.082
171-6-C4-13      1     0.068      0.002    0.112

                                     Age (Ma)

spot            C *   [sup.207]Pb/      2       [sup.
                       [sup.235]U    [sigma]   206]Pb/
                                                [sup.
                                                238]U

171-6-C9-4       1        1168         47        252
171-6-C17-3      1        1807         36        626
171-6-C9-5       3        490          240       186
171-6-C5-1       1        997          140       385
171-6-C9-3       1        974          160       424
171-6-C6-2       1        1021         75        519
171-6-C4-9       3        700          200       389
171-6-C15-4      1        688          42        384
171-6-C9-2       1        779          130       444
171-6-C1-3       1        764          39        448
171-6-C7-5       1        704          160       416
171-6-C7-1       1        753          28        473
171-6-C18-2      1        769          46        486
171-6-C10-12     1        667          83        435
171-6-C14-7      1        714          24        467
171-6-C10-9      1        630          26        430
171-6-C7-6       3        380          150       262
171-6-C10-10     1        595          35        424
171-6-C10-2      1        615          31        452
171-6-C18-3      1        566          14        449
171-6-C4-1       1        509          20        424
171-6-C15-2      1        503          25        426
171-6-C17-2      1        498          23        432
171-6-C14-6      1        489          23        438
171-6-C14-2      1        494          21        444
171-6-C1-1       1        479          24        436
171-6-C9-1       1        459          110       418
171-6-C4-4       3        490          220       447
171-6-C18-4      1        448          110       420
171-6-C10-4      1        446          51        424
171-6-C18-5      1        445          20        424
171-6-C10-8      1        428          21        413
171-6-C7-3       1        435           8        431
171-6-C10-5      1        426           7        423
171-6-C4-7       1        421          25        420
171-6-C10-1 #    1        421          13        421
171-6-C5-3 #     1        419          38        420
171-6-C15-1 #    1        427          50        428
171-6-C10-7 #    1        428           7        430
171-6-C5-4 #     1        418          85        421
171-6-C6-1 #     1        417          120       421
171-6-C6-3 #     1        418          21        423
171-6-C5-2 #     1        411          30        417
171-6-C4-8       1        419          120       426
171-6-C10-3      1        414          13        422
171-6-C10-6      1        428           8        437
171-6-C10-11     1        429          120       440
171-6-C17-1      1        411          12        422
171-6-C7-4       1        411           6        423
171-6-C14-1      1        416          23        429
171-6-C1-2       3        390          150       403
171-6-C7-2       1        414          16        428
171-6-C18-1      1        414          13        429
171-6-C4-3       1        408          13        424
171-6-C4-12      1        411          27        428
171-6-C4-2       1        413          14        430
171-6-C5-5       1        431          15        450
171-6-C15-3      1        411          71        436
171-6-C4-13      1        399          20        424

                           Age (Ma)

spot            C *      2        %
                      [sigma]   conc.
                                (b)

171-6-C9-4       1      11      21.5
171-6-C17-3      1      19      34.6
171-6-C9-5       3      77      38.0
171-6-C5-1       1      40      38.6
171-6-C9-3       1      74      43.5
171-6-C6-2       1      14      50.8
171-6-C4-9       3      26      55.6
171-6-C15-4      1      18      55.8
171-6-C9-2       1      67      57.0
171-6-C1-3       1       8      58.6
171-6-C7-5       1      60      59.1
171-6-C7-1       1      13      62.8
171-6-C18-2      1      13      63.2
171-6-C10-12     1      13      65.2
171-6-C14-7      1       9      65.4
171-6-C10-9      1       8      68.2
171-6-C7-6       3      15      68.9
171-6-C10-10     1       9      71.2
171-6-C10-2      1       9      73.5
171-6-C18-3      1       8      79.4
171-6-C4-1       1       7      83.3
171-6-C15-2      1       7      84.6
171-6-C17-2      1       7      86.6
171-6-C14-6      1       9      89.7
171-6-C14-2      1       7      89.8
171-6-C1-1       1       8      91.0
171-6-C9-1       1      29      91.1
171-6-C4-4       3      130     91.2
171-6-C18-4      1      32      93.8
171-6-C10-4      1       9      95.1
171-6-C18-5      1       6      95.3
171-6-C10-8      1       8      96.6
171-6-C7-3       1       5      99.1
171-6-C10-5      1       4      99.4
171-6-C4-7       1      10      99.8
171-6-C10-1 #    1       6      100.0
171-6-C5-3 #     1      13      100.2
171-6-C15-1 #    1       9      100.3
171-6-C10-7 #    1       5      100.6
171-6-C5-4 #     1      22      100.7
171-6-C6-1 #     1      21      101.0
171-6-C6-3 #     1       9      101.1
171-6-C5-2 #     1      10      101.5
171-6-C4-8       1      24      101.7
171-6-C10-3      1       6      102.0
171-6-C10-6      1       4      102.1
171-6-C10-11     1      18      102.6
171-6-C17-1      1       7      102.7
171-6-C7-4       1       5      102.9
171-6-C14-1      1       8      103.1
171-6-C1-2       3      12      103.3
171-6-C7-2       1       7      103.4
171-6-C18-1      1       5      103.7
171-6-C4-3       1       6      103.8
171-6-C4-12      1      11      104.1
171-6-C4-2       1       7      104.2
171-6-C5-5       1       7      104.5
171-6-C15-3      1      18      106.0
171-6-C4-13      1      10      106.3

Notes: C* = Common Pb correction (1-uncorrected for common-Pb;
2-common-Pb corrected using Andersen (2002) method; 3-common-Pb
corrected using the measured [sup.204]Pb). "calculated from
Andersen (2002) method; bcalculated as 100 x ([sup.206]Pb/
[sup.238]U age/[sup.207]Pb/[sup.235]U age). # signifies the
Samples numbers in bold and italic are used in final age
calculations.

Table A2. Results for in-situ LA-ICP-MS U-Pb zircon geochronology
of Sample 15-87 (Utopia Granite).

                           Approx. conc. (ppm)

spot               C *     U       Th     U/Th
                         (ppm)   (ppm)

15-87-03-28         3    3305     2090    1.58
15-87-03-28         3    3305     2090    1.58
15-87-5-C4-2-204    3    42200   881000   0.05
15-87-5-C4-2-204    3    42200   881000   0.05
15-87-03-30         2    1463     1980    0.74
15-87-03-30         2    1463     1980    0.74
87-3-11-204         3    2626    20900    0.13
87-3-11-204         3    2626    20900    0.13
15-87-3-7-204       2    2441     1556    1.57
15-87-3-7-204       2    2441     1556    1.57
15-87-03-23         1    3260     1200    2.72
15-87-03-16         3    545.5    1550    0.35
15-87-5-C2-2-204    3    1005    169.7    5.92
15-87-4-D-9-204     1     935     479     1.95
15-87-3-3-204       1     945     1200    0.79
15-87-4-D-7-204     1    14880    671     22.18
15-87-4-D-11-204    2    4540     2126    2.14
15-87-5-C1-2-204    2    2360     792     2.98
15-87-3-13-204      3    2499     2277    1.10
15-87-03-22         2    4961     1511    3.28
15-87-3-9-204       1    2110     2059    1.02
15-87-3-14-204      3    2036     1080    1.89
15-87-3-10-204      1    2672     7080    0.38
15-87-4-D-14-204    1    5933     2060    2.88
15-87-5-C4-1        1    1386    22210    0.06
15-87-5-1-204       3    7190     4240    1.70
15-87-5-9-204       2    4210     2259    1.86
15-87-03-17         2     890     530     1.68
15-87-5-C2-4        3    2498     573     4.36
15-87-03-12         2    1954     3030    0.64
15-87-5-C2-3-204    3    5960     423     14.09
15-87-03-06         2    1467     1573    0.93
15-87-03-25         3    12980    1219    10.65
15-87-4-D-10-204    1    6637     1272    5.22
15-87-03-20         2    6100     700     8.71
15-87-5-C1-1        1    1963     1326    1.48
15-87-05-06         3    3953     1269    3.12
15-87-03-05         1    612.2    779     0.79
15-87-03-26         3    3317     633     5.24
15-87-03-27         2     495    527.1    0.94
15-87-3-1-204       1    4121     2301    1.79
15-87-05-05         3    1193     756     1.58
15-87-4-D-12        1    2964     652     4.55
15-87-3-18-204      3    5490     4930    1.11
15-87-03-04         2     666     634     1.05
15-87-03-19         3    5210     8260    0.63
15-87-03-24         3    5400     1090    4.95
15-87-4-D-6         3    1664     425     3.92
15-87-4-D-8         1    6810     2032    3.35
15-87-05-02         1    2724     1396    1.95
15-87-03-15         3    6895     723     9.54
15-87-2-C1-1 #      1    4442     572     7.77
15-87-4-D-13 #      1    510.3    75.9    6.72
15-87-05-03 #       2    1292    118.4    10.91
15-87-2-C2-3 #      1    3914     453     8.64
15-87-2-C2-2 #      1    3721    319.3    11.65
15-87-05-04 #       3    1370    110.9    12.35
15-87-5-C2-1        3    1105    216.9    5.09
15-87-03-21 #       1    333.8   607.9    0.55

                            Approx. conc. (ppm)

spot               C *   [sup.204]Pb   [sup.206]Pb/
                            (cps)      [sup.204]Pb

15-87-03-28         3       5500            49
15-87-03-28         3       5500            49
15-87-5-C4-2-204    3        235           1047
15-87-5-C4-2-204    3        235           1047
15-87-03-30         2         7            5514
15-87-03-30         2         7            5514
87-3-11-204         3        54            1462
87-3-11-204         3        54            1462
15-87-3-7-204       2        129           855
15-87-3-7-204       2        129           855
15-87-03-23         1        38            5026
15-87-03-16         3        25            1324
15-87-5-C2-2-204    3        127           1632
15-87-4-D-9-204     1        156           1592
15-87-3-3-204       1        12            1593
15-87-4-D-7-204     1        56            4623
15-87-4-D-11-204    2        29            3814
15-87-5-C1-2-204    2        40            1084
15-87-3-13-204      3        100           792
15-87-03-22         2        361           229
15-87-3-9-204       1        74            997
15-87-3-14-204      3        46            5443
15-87-3-10-204      1        368           206
15-87-4-D-14-204    1        29            2521
15-87-5-C4-1        1        767           150
15-87-5-1-204       3        -4           -20400
15-87-5-9-204       2        -27          -1716
15-87-03-17         2        60            2778
15-87-5-C2-4        3        70            2280
15-87-03-12         2        115           836
15-87-5-C2-3-204    3        48            1915
15-87-03-06         2        320           231
15-87-03-25         3        51            2396
15-87-4-D-10-204    1        327           505
15-87-03-20         2        -2           -6425
15-87-5-C1-1        1        144           620
15-87-05-06         3        17           11835
15-87-03-05         1        31            1926
15-87-03-26         3         5            3662
15-87-03-27         2       1404            97
15-87-3-1-204       1        203           1255
15-87-05-05         3        59            2366
15-87-4-D-12        1        -11          -1789
15-87-3-18-204      3        44            4193
15-87-03-04         2        24            963
15-87-03-19         3        103           2034
15-87-03-24         3        138           2714
15-87-4-D-6         3        833           522
15-87-4-D-8         1        162           246
15-87-05-02         1        -1           -52270
15-87-03-15         3         1           20460
15-87-2-C1-1 #      1        -2           -78700
15-87-4-D-13 #      1        177           1200
15-87-05-03 #       2        -8           -6911
15-87-2-C2-3 #      1         7            6114
15-87-2-C2-2 #      1        34            3053
15-87-05-04 #       3        21            2295
15-87-5-C2-1        3        131           279
15-87-03-21 #       1        204           809

                             Final isotope ratios

spot               C *   %Pb     [sup.207]Pb/      2
                         *(a)    [sup.235]5U    [sigma]

15-87-03-28         3    77.20      2.370        0.140
15-87-03-28         3    77.20      2.370        0.140
15-87-5-C4-2-204    3    98.37      1.459        0.052
15-87-5-C4-2-204    3    98.37      1.459        0.052
15-87-03-30         2    99.45      1.270        0.069
15-87-03-30         2    99.45      1.270        0.069
87-3-11-204         3    98.89      1.324        0.061
87-3-11-204         3    98.89      1.324        0.061
15-87-3-7-204       2    97.50      1.107        0.032
15-87-3-7-204       2    97.50      1.107        0.032
15-87-03-23         1    99.42      1.085        0.040
15-87-03-16         3    98.72      1.154        0.050
15-87-5-C2-2-204    3    98.79      0.949        0.036
15-87-4-D-9-204     1    99.10      1.080        0.041
15-87-3-3-204       1    99.26      0.633        0.023
15-87-4-D-7-204     1    99.51      0.498        0.016
15-87-4-D-11-204    2    99.39      0.830        0.023
15-87-5-C1-2-204    2    98.14      0.689        0.024
15-87-3-13-204      3    97.87      0.704        0.019
15-87-03-22         2    92.36      0.705        0.018
15-87-3-9-204       1    98.02      0.663        0.021
15-87-3-14-204      3    99.66      0.656        0.026
15-87-3-10-204      1    90.83      0.638        0.020
15-87-4-D-14-204    1    99.14      0.619        0.018
15-87-5-C4-1        1    88.31      0.655        0.024
15-87-5-1-204       3    99.64      0.614        0.016
15-87-5-9-204       2    99.86      0.598        0.016
15-87-03-17         2    99.43      0.613        0.023
15-87-5-C2-4        3    99.37      0.550        0.017
15-87-03-12         2    97.58      0.586        0.019
15-87-5-C2-3-204    3    98.76      0.548        0.016
15-87-03-06         2    92.21      0.609        0.020
15-87-03-25         3    99.14      0.440        0.013
15-87-4-D-10-204    1    96.42      0.562        0.015
15-87-03-20         2    99.78      0.519        0.014
15-87-5-C1-1        1    96.95      0.549        0.016
15-87-05-06         3    99.77      0.571        0.016
15-87-03-05         1    98.84      0.571        0.021
15-87-03-26         3    99.27      0.539        0.015
15-87-03-27         2    81.00      0.529        0.019
15-87-3-1-204       1    98.43      0.563        0.015
15-87-05-05         3    99.19      0.571        0.017
15-87-4-D-12        1    99.64      0.530        0.014
15-87-3-18-204      3    99.45      0.544        0.014
15-87-03-04         2    99.08      0.581        0.021
15-87-03-19         3    99.12      0.540        0.014
15-87-03-24         3    99.06      0.496        0.014
15-87-4-D-6         3    96.84      0.533        0.017
15-87-4-D-8         1    92.92      0.509        0.014
15-87-05-02         1    99.77      0.525        0.015
15-87-03-15         3    99.70      0.510        0.013
15-87-2-C1-1 #      1    99.76      0.512        0.015
15-87-4-D-13 #      1    98.31      0.525        0.020
15-87-05-03 #       2    99.85      0.513        0.015
15-87-2-C2-3 #      1    99.60      0.512        0.015
15-87-2-C2-2 #      1    99.80      0.507        0.014
15-87-05-04 #       3    99.35      0.513        0.015
15-87-5-C2-1        3    93.08      0.520        0.018
15-87-03-21 #       1    97.76      0.502        0.021

                             Final isotope ratios

spot               C *   [sup.206]Pb/     2a     err.
                          [sup.238]U             corr.

15-87-03-28         3       0.0816      0.0017   0.871
15-87-03-28         3       0.0816      0.0017   0.871
15-87-5-C4-2-204    3       0.0702      0.0012   0.330
15-87-5-C4-2-204    3       0.0702      0.0012   0.330
15-87-03-30         2       0.0684      0.0014   0.485
15-87-03-30         2       0.0684      0.0014   0.485
87-3-11-204         3       0.0737      0.0015   0.474
87-3-11-204         3       0.0737      0.0015   0.474
15-87-3-7-204       2       0.0687      0.0010   0.018
15-87-3-7-204       2       0.0687      0.0010   0.018
15-87-03-23         1       0.0680      0.0011   0.575
15-87-03-16         3       0.0713      0.0014   0.389
15-87-5-C2-2-204    3       0.0623      0.0011   0.227
15-87-4-D-9-204     1       0.0705      0.0012   0.265
15-87-3-3-204       1       0.0506      0.0008   0.506
15-87-4-D-7-204     1       0.0467      0.0008   0.585
15-87-4-D-11-204    2       0.0724      0.0012   0.438
15-87-5-C1-2-204    2       0.0638      0.0010   0.396
15-87-3-13-204      3       0.0684      0.0009   0.707
15-87-03-22         2       0.0694      0.0011   0.504
15-87-3-9-204       1       0.0664      0.0011   0.476
15-87-3-14-204      3       0.0666      0.0014   0.320
15-87-3-10-204      1       0.0655      0.0010   0.420
15-87-4-D-14-204    1       0.0654      0.0010   0.644
15-87-5-C4-1        1       0.0689      0.0012   0.159
15-87-5-1-204       3       0.0653      0.0009   0.227
15-87-5-9-204       2       0.0645      0.0009   0.544
15-87-03-17         2       0.0677      0.0010   0.321
15-87-5-C2-4        3       0.0624      0.0009   0.075
15-87-03-12         2       0.0662      0.0010   0.357
15-87-5-C2-3-204    3       0.0628      0.0013   0.836
15-87-03-06         2       0.0689      0.0010   0.247
15-87-03-25         3       0.0525      0.0009   0.591
15-87-4-D-10-204    1       0.0654      0.0008   0.344
15-87-03-20         2       0.0614      0.0012   0.786
15-87-5-C1-1        1       0.0644      0.0008   0.341
15-87-05-06         3       0.0667      0.0010   0.680
15-87-03-05         1       0.0674      0.0010   0.004
15-87-03-26         3       0.0644      0.0010   0.115
15-87-03-27         2       0.0639      0.0009   0.316
15-87-3-1-204       1       0.0679      0.0011   0.718
15-87-05-05         3       0.0685      0.0010   0.521
15-87-4-D-12        1       0.0644      0.0007   0.203
15-87-3-18-204      3       0.0662      0.0008   0.406
15-87-03-04         2       0.0698      0.0011   0.260
15-87-03-19         3       0.0660      0.0008   0.442
15-87-03-24         3       0.0613      0.0013   0.578
15-87-4-D-6         3       0.0658      0.0010   0.345
15-87-4-D-8         1       0.0633      0.0010   0.514
15-87-05-02         1       0.0659      0.0012   0.536
15-87-03-15         3       0.0644      0.0007   0.586
15-87-2-C1-1 #      1       0.0666      0.0014   0.289
15-87-4-D-13 #      1       0.0681      0.0014   0.079
15-87-05-03 #       2       0.0671      0.0009   0.059
15-87-2-C2-3 #      1       0.0671      0.0014   0.174
15-87-2-C2-2 #      1       0.0670      0.0014   0.396
15-87-05-04 #       3       0.0679      0.0009   0.340
15-87-5-C2-1        3       0.0694      0.0011   0.470
15-87-03-21 #       1       0.0675      0.0010   0.340

                                       Age (Ma)

spot               C *   [sup.207]Pb/      2       [sup.
                          [sup.235]U    [sigma]   206]Pb/

                                                   [sup.
                                                   238]U

15-87-03-28         3        1226         40        506
15-87-03-28         3        1226         40        506
15-87-5-C4-2-204    3        912          21        437
15-87-5-C4-2-204    3        912          21        437
15-87-03-30         2        830          30        427
15-87-03-30         2        830          30        427
87-3-11-204         3        854          27        458
87-3-11-204         3        854          27        458
15-87-3-7-204       2        756          15        429
15-87-3-7-204       2        756          15        429
15-87-03-23         1        744          20        424
15-87-03-16         3        777          24        444
15-87-5-C2-2-204    3        676          19        390
15-87-4-D-9-204     1        746          22        439
15-87-3-3-204       1        499          14        318
15-87-4-D-7-204     1        410          11        295
15-87-4-D-11-204    2        614          13        451
15-87-5-C1-2-204    2        532          14        398
15-87-3-13-204      3        541          11        427
15-87-03-22         2        542          11        433
15-87-3-9-204       1        516          13        415
15-87-3-14-204      3        512          16        416
15-87-3-10-204      1        502          13        409
15-87-4-D-14-204    1        489          11        408
15-87-5-C4-1        1        511          15        429
15-87-5-1-204       3        486          10        408
15-87-5-9-204       2        476          10        403
15-87-03-17         2        486          15        422
15-87-5-C2-4        3        445          11        390
15-87-03-12         2        468          12        413
15-87-5-C2-3-204    3        444          10        393
15-87-03-06         2        482          12        429
15-87-03-25         3        370           9        330
15-87-4-D-10-204    1        453          10        408
15-87-03-20         2        424          10        384
15-87-5-C1-1        1        444          10        402
15-87-05-06         3        458          10        416
15-87-03-05         1        458          13        421
15-87-03-26         3        438          10        402
15-87-03-27         2        431          13        399
15-87-3-1-204       1        454          10        423
15-87-05-05         3        458          11        427
15-87-4-D-12        1        431           9        403
15-87-3-18-204      3        441           9        413
15-87-03-04         2        464          14        435
15-87-03-19         3        438           9        412
15-87-03-24         3        409          10        385
15-87-4-D-6         3        433          11        411
15-87-4-D-8         1        418           9        396
15-87-05-02         1        428          10        411
15-87-03-15         3        419           9        403
15-87-2-C1-1 #      1        420          10        416
15-87-4-D-13 #      1        428          13        425
15-87-05-03 #       2        420          10        419
15-87-2-C2-3 #      1        419          10        419
15-87-2-C2-2 #      1        417          10        418
15-87-05-04 #       3        420          10        423
15-87-5-C2-1        3        425          12        432
15-87-03-21 #       1        412          14        421

                             Age (Ma)

spot               C *      2        %
                         [sigma]   conc.
                                    (b)

15-87-03-28         3      10      41.3
15-87-03-28         3      10      41.3
15-87-5-C4-2-204    3       7      47.9
15-87-5-C4-2-204    3       7      47.9
15-87-03-30         2       8      51.4
15-87-03-30         2       8      51.4
87-3-11-204         3       9      53.7
87-3-11-204         3       9      53.7
15-87-3-7-204       2       6      56.7
15-87-3-7-204       2       6      56.7
15-87-03-23         1       7      57.0
15-87-03-16         3       8      57.2
15-87-5-C2-2-204    3       7      57.6
15-87-4-D-9-204     1       7      58.9
15-87-3-3-204       1       5      63.7
15-87-4-D-7-204     1       5      71.9
15-87-4-D-11-204    2       7      73.4
15-87-5-C1-2-204    2       6      74.9
15-87-3-13-204      3       6      78.9
15-87-03-22         2       7      79.9
15-87-3-9-204       1       7      80.3
15-87-3-14-204      3       8      81.2
15-87-3-10-204      1       6      81.5
15-87-4-D-14-204    1       6      83.5
15-87-5-C4-1        1       7      84.0
15-87-5-1-204       3       5      84.0
15-87-5-9-204       2       6      84.7
15-87-03-17         2       6      86.9
15-87-5-C2-4        3       5      87.7
15-87-03-12         2       6      88.3
15-87-5-C2-3-204    3       8      88.5
15-87-03-06         2       6      89.0
15-87-03-25         3       6      89.2
15-87-4-D-10-204    1       5      90.2
15-87-03-20         2       7      90.4
15-87-5-C1-1        1       5      90.5
15-87-05-06         3       6      90.7
15-87-03-05         1       6      91.8
15-87-03-26         3       6      91.9
15-87-03-27         2       6      92.5
15-87-3-1-204       1       6      93.3
15-87-05-05         3       6      93.3
15-87-4-D-12        1       4      93.4
15-87-3-18-204      3       5      93.7
15-87-03-04         2       7      93.7
15-87-03-19         3       5      94.0
15-87-03-24         3       7      94.1
15-87-4-D-6         3       6      94.7
15-87-4-D-8         1       6      94.8
15-87-05-02         1       7      96.1
15-87-03-15         3       5      96.2
15-87-2-C1-1 #      1       9      99.0
15-87-4-D-13 #      1       8      99.2
15-87-05-03 #       2       5      99.7
15-87-2-C2-3 #      1       9      99.8
15-87-2-C2-2 #      1       8      100.1
15-87-05-04 #       3       5      100.7
15-87-5-C2-1        3       7      101.8
15-87-03-21 #       1       6      102.2

Notes: C* = Common Pb correction (1-uncorrected for common-Pb;
2-common-Pb corrected using Andersen (2002) method; 3-common-Pb
corrected using the measured [sup.204]Pb). acalculated from
Andersen (2002) method; bcalculated as 100 x ([sup.206]Pb/
[sup.238]U age/[sup.207]Pb/[sup.235]U age). # signifies the
Samples numbers in bold and italic are used in final age
calculations.

Table A3. Results for in-situ LA-ICP-MS U-Pb zircon geochronology
of sample 15-104 (Utopia Granite).

                       Approx. conc. (ppm)

spot            C *     U      Th     U/Th
                      (ppm)   (ppm)

104-3-C7-1       1     751     767    0.98
104-1-C1-2       1    1071    591.1   1.81
104-3-C7-3       1    1268     928    1.37
104-3-C4-2       3    2641    2954    0.89
104-1-C11-2      1    1127    1033    1.09
104-1-C6-1       3    3340    2780    1.20
104-1-C1-6       3    4390    1428    3.07
104-2-C8-1       3    4707    2592    1.82
104-2-C5-4       1    1726     991    1.74
104-1-C1-5       1    5100    2549    2.00
104-1-C5-4       1    2893    1432    2.02
104-1-C1-4       3    2249     859    2.62
104-1-C6-3       3    4880    3400    1.44
104-1-C1-1       1    2770    1544    1.79
104-2-C2-3       1    1090     527    2.07
104-1-C4-3       3    4016    3860    1.04
104-2-C5-3       3    1113     715    1.56
104-3-C7-2       1    1065     867    1.23
104-1-C4-1       1    1402    1090    1.29
104-1-C3-6       3    7680    9620    0.80
104-1-C3-8       3    1595    1187    1.34
104-3-C2-3       3    2268    1334    1.70
104-2-C4-2       1    2430     317    7.67
104-1-C3-2       1    7330    1424    5.15
104-3-C5-2       1    3823    1387    2.76
104-1-C3-4       2    1772    3200    0.55
104-2-C4-1       1    2409    1248    1.93
104-3-C2-1       1     876     604    1.45
104-1-C1-7       3    3634    1464    2.48
104-3-C2-2       3     627     439    1.43
104-3-C2-4       3    1937    1710    1.13
104-1-C3-1 #     1    7240     673    10.76
104-1-C4-2 #     3    1781     856    2.08
104-1-C5-3 #     3    8380    5850    1.43
104-1-C2-2 #     1    1702     921    1.85
104-1-C11-1 #    1    2481    1128    2.20
104-2-C5-2       3    2575    1345    1.91
104-1-C5-1 #     3    5580    4250    1.31
104-1-C1-3 #     1    1283     641    2.00
104-1-C5-2       3    10170   5310    1.92
104-3-C3-1 #     3    2174    1120    1.94
104-2-C4-3       3    4460     621    7.18
104-3-C5-1 #     1    1039    547.5   1.90
104-1-C3-7       3    1454    1159    1.25
104-1-C3-5 #     3    7660    5960    1.29
104-1-C4-4 #     3    2859    1179    2.42
104-2-C8-2 #     3    3919    1532    2.56
104-2-C2-1       3    667.4   371.9   1.79
104-1-C7-1 #     3    3043     759    4.01
104-2-C5-5       2    1260     702    1.79
104-1-C2-1       3    1515    1022    1.48
104-1-C3-9       3    1897    1883    1.01
104-1-C3-3       3    2503    12300   0.20
104-3-C4-1       3    1444    1308    1.10
104-2-C2-2       3    1316     672    1.96
104-3-C7-4       3     777    1077    0.72
104-1-C7-2       3    2861     598    4.78
104-1-C6-2       3    2952    1530    1.93
104-2-C5-1       3    3061    1478    2.07

                         Approx. conc. (ppm)

spot            C *   [sup.204]Pb   [sup.206]Pb/
                         (cps)      [sup.204]Pb

104-3-C7-1       1        89            199
104-1-C1-2       1        84            319
104-3-C7-3       1        86            377
104-3-C4-2       3       1417            45
104-1-C11-2      1        72            528
104-1-C6-1       3       3110            31
104-1-C1-6       3       1124            40
104-2-C8-1       3       4090            33
104-2-C5-4       1        40            1460
104-1-C1-5       1        96            1178
104-1-C5-4       1        84            993
104-1-C1-4       3        631            86
104-1-C6-3       3        309           263
104-1-C1-1       1        55            1287
104-2-C2-3       1        22            1405
104-1-C4-3       3        556           137
104-2-C5-3       3       1302            45
104-3-C7-2       1        18            1248
104-1-C4-1       1        14            3238
104-1-C3-6       3       2501            74
104-1-C3-8       3        240           227
104-3-C2-3       3       1760            59
104-2-C4-2       1        30            2530
104-1-C3-2       1        63            3254
104-3-C5-2       1        44            2984
104-1-C3-4       2        154           381
104-2-C4-1       1        22            3761
104-3-C2-1       1         5            6020
104-1-C1-7       3        211           433
104-3-C2-2       3        124           155
104-3-C2-4       3        142           320
104-1-C3-1 #     1        25           10120
104-1-C4-2 #     3       1001            72
104-1-C5-3 #     3       1383           137
104-1-C2-2 #     1        19            3451
104-1-C11-1 #    1        12            7792
104-2-C5-2       3        756            84
104-1-C5-1 #     3        170           982
104-1-C1-3 #     1         5            9420
104-1-C5-2       3        142           2238
104-3-C3-1 #     3        467           130
104-2-C4-3       3        282           353
104-3-C5-1 #     1        -1           -39520
104-1-C3-7       3        478           123
104-1-C3-5 #     3       1176           222
104-1-C4-4 #     3        179           415
104-2-C8-2 #     3        273           438
104-2-C2-1       3        189           151
104-1-C7-1 #     3        309           255
104-2-C5-5       2        123           352
104-1-C2-1       3        478           124
104-1-C3-9       3        702            89
104-1-C3-3       3        378           199
104-3-C4-1       3        526           103
104-2-C2-2       3        175           262
104-3-C7-4       3        119           209
104-1-C7-2       3        495            79
104-1-C6-2       3       1007            54
104-2-C5-1       3       1241            50

                            Final isotope ratios

spot            C *     %Pb     [sup.207]Pb/      2
                       *(a)     [sup.235]5U    [sigma]

104-3-C7-1       1     92.24       1.824        0.071
104-1-C1-2       1     94.13       0.891        0.063
104-3-C7-3       1     95.60       1.054        0.075
104-3-C4-2       3     64.70       1.550        0.340
104-1-C11-2      1     96.81       0.722        0.021
104-1-C6-1       3     58.49       1.580        0.320
104-1-C1-6       3     52.66       0.400        0.130
104-2-C8-1       3     58.20       1.350        0.220
104-2-C5-4       1     98.14       0.665        0.033
104-1-C1-5       1     98.37       0.584        0.054
104-1-C5-4       1     98.39       0.621        0.017
104-1-C1-4       3     76.60       0.449        0.070
104-1-C6-3       3     92.04       0.543        0.042
104-1-C1-1       1     98.66       0.592        0.062
104-2-C2-3       1     98.79       0.569        0.019
104-1-C4-3       3     85.39       0.345        0.050
104-2-C5-3       3     62.60       1.050        0.270
104-3-C7-2       1     98.94       0.628        0.026
104-1-C4-1       1     98.99       0.577        0.017
104-1-C3-6       3     74.96       0.623        0.087
104-1-C3-8       3     91.31       0.586        0.100
104-3-C2-3       3     69.60       0.633        0.089
104-2-C4-2       1     99.30       0.561        0.016
104-1-C3-2       1     99.41       0.509        0.015
104-3-C5-2       1     99.41       0.572        0.019
104-1-C3-4       2     94.50       0.652        0.081
104-2-C4-1       1     99.40       0.578        0.015
104-3-C2-1       1     99.36       0.533        0.016
104-1-C1-7       3     95.28       0.557        0.041
104-3-C2-2       3     86.20       0.530        0.170
104-3-C2-4       3     93.84       0.465        0.064
104-1-C3-1 #     1     99.78       0.531        0.022
104-1-C4-2 #     3     75.40       0.562        0.082
104-1-C5-3 #     3     86.51       0.526        0.130
104-1-C2-2 #     1     99.73       0.525        0.015
104-1-C11-1 #    1     99.80       0.503        0.019
104-2-C5-2       3     77.00       0.590        0.110
104-1-C5-1 #     3     98.15       0.520        0.042
104-1-C1-3 #     1     99.77       0.507        0.015
104-1-C5-2       3     99.19       0.414        0.013
104-3-C3-1 #     3     86.38       0.538        0.091
104-2-C4-3       3     95.23       0.540        0.046
104-3-C5-1 #     1     99.80       0.508        0.014
104-1-C3-7       3     85.11       0.604        0.093
104-1-C3-5 #     3     91.95       0.487        0.030
104-1-C4-4 #     3     95.68       0.494        0.049
104-2-C8-2 #     3     96.03       0.500        0.051
104-2-C2-1       3     88.00       0.594        0.098
104-1-C7-1 #     3     92.86       0.481        0.053
104-2-C5-5       2     94.60       0.526        0.058
104-1-C2-1       3     85.30       0.544        0.084
104-1-C3-9       3     79.81       0.632        0.097
104-1-C3-3       3     91.33       0.599        0.066
104-3-C4-1       3     83.71       0.710        0.110
104-2-C2-2       3     93.86       0.444        0.060
104-3-C7-4       3     92.30       0.650        0.130
104-1-C7-2       3     77.91       0.460        0.860
104-1-C6-2       3     68.00       0.590        0.150
104-2-C5-1       3     66.14       0.530        0.190

                          Final isotope ratios

spot            C *   [sup.206]Pb/     2       err.
                       [sup.238]U    [sigma]   corr.

104-3-C7-1       1       0.1058      0.0029    0.753
104-1-C1-2       1       0.0637      0.0015    0.439
104-3-C7-3       1       0.0827      0.0030    0.142
104-3-C4-2       3       0.1057      0.0070    0.776
104-1-C11-2      1       0.0657      0.0014    0.113
104-1-C6-1       3       0.1096      0.0044    0.760
104-1-C1-6       3       0.0360      0.0019    0.694
104-2-C8-1       3       0.1111      0.0036    0.700
104-2-C5-4       1       0.0695      0.0016    0.701
104-1-C1-5       1       0.0630      0.0020    0.812
104-1-C5-4       1       0.0665      0.0014    0.201
104-1-C1-4       3       0.0505      0.0024    0.391
104-1-C6-3       3       0.0614      0.0013    0.583
104-1-C1-1       1       0.0654      0.0015    0.456
104-2-C2-3       1       0.0644      0.0014    0.031
104-1-C4-3       3       0.0420      0.0015    0.377
104-2-C5-3       3       0.1060      0.0070    0.710
104-3-C7-2       1       0.0714      0.0018    0.193
104-1-C4-1       1       0.0666      0.0016    0.467
104-1-C3-6       3       0.0691      0.0015    0.447
104-1-C3-8       3       0.0672      0.0016    0.588
104-3-C2-3       3       0.0719      0.0016    0.470
104-2-C4-2       1       0.0671      0.0015    0.686
104-1-C3-2       1       0.0622      0.0016    0.831
104-3-C5-2       1       0.0691      0.0019    0.701
104-1-C3-4       2       0.0751      0.0013    0.592
104-2-C4-1       1       0.0701      0.0019    0.574
104-3-C2-1       1       0.0656      0.0014    0.022
104-1-C1-7       3       0.0683      0.0020    0.379
104-3-C2-2       3       0.0628      0.0018    0.811
104-3-C2-4       3       0.0570      0.0025    0.506
104-1-C3-1 #     1       0.0680      0.0018    0.639
104-1-C4-2 #     3       0.0693      0.0017    0.612
104-1-C5-3 #     3       0.0665      0.0024    0.494
104-1-C2-2 #     1       0.0679      0.0015    0.269
104-1-C11-1 #    1       0.0662      0.0024    0.237
104-2-C5-2       3       0.0722      0.0020    0.505
104-1-C5-1 #     3       0.0678      0.0020    0.570
104-1-C1-3 #     1       0.0667      0.0014    0.304
104-1-C5-2       3       0.0561      0.0014    0.265
104-3-C3-1 #     3       0.0690      0.0019    0.650
104-2-C4-3       3       0.0698      0.0018    0.369
104-3-C5-1 #     1       0.0677      0.0015    0.100
104-1-C3-7       3       0.0732      0.0021    0.613
104-1-C3-5 #     3       0.0652      0.0014    0.600
104-1-C4-4 #     3       0.0652      0.0019    0.595
104-2-C8-2 #     3       0.0662      0.0017    0.503
104-2-C2-1       3       0.0744      0.0019    0.549
104-1-C7-1 #     3       0.0641      0.0018    0.676
104-2-C5-5       2       0.0694      0.0018    0.617
104-1-C2-1       3       0.0706      0.0016    0.687
104-1-C3-9       3       0.0788      0.0021    0.405
104-1-C3-3       3       0.0811      0.0030    0.403
104-3-C4-1       3       0.0896      0.0025    0.632
104-2-C2-2       3       0.0670      0.0018    0.735
104-3-C7-4       3       0.0847      0.0027    0.598
104-1-C7-2       3       0.0677      0.0100    0.667
104-1-C6-2       3       0.0793      0.0023    0.716
104-2-C5-1       3       0.0834      0.0026    0.556

                                     Age (Ma)

spot            C *   [sup.207]Pb/      2       [sup.
                       [sup.235]U    [sigma]   206]Pb/
                                                [sup.
                                                238]U

104-3-C7-1       1        1049         25        650
104-1-C1-2       1         636         33        398
104-3-C7-3       1         730         31        512
104-3-C4-2       3         880         120       645
104-1-C11-2      1         553         13        410
104-1-C6-1       3         880         130       669
104-1-C1-6       3         298         93        228
104-2-C8-1       3         812         100       679
104-2-C5-4       1         517         20        433
104-1-C1-5       1         466         32        393
104-1-C5-4       1         490         11        415
104-1-C1-4       3         370         52        318
104-1-C6-3       3         444         29        384
104-1-C1-1       1         472         32        409
104-2-C2-3       1         457         12        402
104-1-C4-3       3         297         36        265
104-2-C5-3       3         720         130       647
104-3-C7-2       1         494         16        445
104-1-C4-1       1         462         11        415
104-1-C3-6       3         476         52        431
104-1-C3-8       3         458         64        419
104-3-C2-3       3         486         56        448
104-2-C4-2       1         453         11        419
104-1-C3-2       1         417         10        389
104-3-C5-2       1         459         12        431
104-1-C3-4       2         496         50        467
104-2-C4-1       1         463         10        437
104-3-C2-1       1         433         11        410
104-1-C1-7       3         445         27        426
104-3-C2-2       3         410         110       393
104-3-C2-4       3         371         45        357
104-1-C3-1 #     1         432         14        424
104-1-C4-2 #     3         440         57        432
104-1-C5-3 #     3         422         84        415
104-1-C2-2 #     1         428         10        424
104-1-C11-1 #    1         414         14        413
104-2-C5-2       3         450         73        449
104-1-C5-1 #     3         423         28        423
104-1-C1-3 #     1         416         10        416
104-1-C5-2       3         351          9        352
104-3-C3-1 #     3         428         58        430
104-2-C4-3       3         432         31        435
104-3-C5-1 #     1         417         10        422
104-1-C3-7       3         448         64        455
104-1-C3-5 #     3         400         20        407
104-1-C4-4 #     3         400         34        407
104-2-C8-2 #     3         406         35        414
104-2-C2-1       3         449         64        463
104-1-C7-1 #     3         388         38        401
104-2-C5-5       2         419         41        433
104-1-C2-1       3         421         54        440
104-1-C3-9       3         461         64        489
104-1-C3-3       3         460         41        502
104-3-C4-1       3         501         70        553
104-2-C2-2       3         366         42        418
104-3-C7-4       3         456         84        524
104-1-C7-2       3         350         210       422
104-1-C6-2       3         407         100       492
104-2-C5-1       3         360         140       516

                          Age (Ma)

spot            C *      2        %
                      [sigma]   conc.
                                 (b)

104-3-C7-1       1      18      62.0
104-1-C1-2       1       9      62.6
104-3-C7-3       1      18      70.2
104-3-C4-2       3      40      73.3
104-1-C11-2      1       9      74.2
104-1-C6-1       3      25      76.0
104-1-C1-6       3      12      76.5
104-2-C8-1       3      21      83.6
104-2-C5-4       1      10      83.7
104-1-C1-5       1      12      84.3
104-1-C5-4       1       9      84.7
104-1-C1-4       3      15      85.9
104-1-C6-3       3       8      86.5
104-1-C1-1       1       9      86.6
104-2-C2-3       1       8      88.1
104-1-C4-3       3       9      89.3
104-2-C5-3       3      40      89.9
104-3-C7-2       1      11      90.0
104-1-C4-1       1      10      90.0
104-1-C3-6       3       9      90.5
104-1-C3-8       3      10      91.5
104-3-C2-3       3       9      92.1
104-2-C4-2       1       9      92.4
104-1-C3-2       1      10      93.3
104-3-C5-2       1      12      93.9
104-1-C3-4       2       8      94.1
104-2-C4-1       1      11      94.3
104-3-C2-1       1       9      94.5
104-1-C1-7       3      12      95.7
104-3-C2-2       3      11      95.8
104-3-C2-4       3      15      96.2
104-1-C3-1 #     1      11      98.1
104-1-C4-2 #     3      10      98.1
104-1-C5-3 #     3      14      98.4
104-1-C2-2 #     1       9      98.9
104-1-C11-1 #    1      14      99.8
104-2-C5-2       3      12      99.8
104-1-C5-1 #     3      12      100.0
104-1-C1-3 #     1       9      100.1
104-1-C5-2       3       8      100.2
104-3-C3-1 #     3      12      100.5
104-2-C4-3       3      11      100.7
104-3-C5-1 #     1       9      101.2
104-1-C3-7       3      13      101.6
104-1-C3-5 #     3       8      101.8
104-1-C4-4 #     3      11      101.8
104-2-C8-2 #     3      10      101.8
104-2-C2-1       3      12      103.0
104-1-C7-1 #     3      11      103.3
104-2-C5-5       2      11      103.3
104-1-C2-1       3       9      104.5
104-1-C3-9       3      12      106.1
104-1-C3-3       3      18      109.1
104-3-C4-1       3      15      110.4
104-2-C2-2       3      11      114.2
104-3-C7-4       3      16      114.9
104-1-C7-2       3      62      120.6
104-1-C6-2       3      14      120.9
104-2-C5-1       3      15      143.3

Notes: C* = Common Pb correction (1-uncorrected for common-Pb;
2-common-Pb corrected using Andersen (2002) method; 3-common-Pb
corrected using the measured [sup.204]Pb). "calculated from
Andersen (2002) method; bcalculated as 100 x ([sup.204]Pb/
[sup.238]U age/[sup.207]Pb/[sup.235]U age). # signifies the
Samples numbers in bold and italic are used in final age
calculations.

Table A4. Results for in-situ LA-ICP-MS U-Pb zircon geochronology
of Sample JL16-01 (Jake Lee Mountain Granite)

                              Approx. conc. (ppm)

spot                 C *     U        Th      U/Th
                           (ppm)     (ppm)

JL-16-01-3-C8-2       1    228.9     159.4    1.44
JL-16-01-2-C1-3       1    295.2     277.4    1.06
JL-16-01-2-C6-3       1    196.3     125.8    1.56
JL-16-01-1-C6-2       1    335.1     355.9    0.94
JL-16-01-2-C6-2       1    262.3     249.0    1.05
JL-16-01-2-C6-1       1    689.9     721.0    0.96
JL-16-01-1-C5-3       1    291.4     224.3    1.30
JL-16-01-1-C15-1      1    272.1     233.9    1.16
JL-16-01-2-C9-3       1    237.6     151.8    1.57
JL-16-01-3-C5-2       1    1183.0   1025.0    1.15
JL-16-01-1-C2-3       3    218.1     187.3    1.16
JL-16-01-1-C1-2       1    1012.0   1458.0    0.69
JL-16-01-2-C2-2       3    311.6     529.0    0.59
JL-16-01-1-C15-2      1    341.3     317.7    1.07
JL-16-01-3-C1-1       3    314.3     219.1    1.43
JL-16-01-2-C1-4       1    205.0     146.3    1.40
JL-16-01-3-C7-2       1    404.0     467.0    0.87
JL-16-01-3-C8-3       1    290.0     204.7    1.42
JL-16-01-2-C5-1       3    224.6     182.6    1.23
JL-16-01-3-C7-3       1    258.3     181.4    1.42
JL-16-01-2-C5-3       1    359.5     374.0    0.96
JL-16-01-1-C2-2       1    251.7     184.5    1.36
JL-16-01-1-C15-4      1    285.3     199.1    1.43
JL-16-01-1-C6-3       1    1523.0   1201.0    1.27
JL-16-01-1-C6-4       1    346.0     230.0    1.50
JL-16-01-3-C2-2       1    235.6     157.4    1.50
JL-16-01-1-C3-3 #     1    223.7     136.1    1.64
JL-16-01-2-C5-2       1    178.4     139.0    1.28
JL-16-01-1-C3-1       1    527.7     776.0    0.68
JL-16-01-1-C2-1 #     1    243.3     158.2    1.54
JL-16-01-3-C5-1       1    656.0     519.0    1.26
JL-16-01-2-C1-2 #     1    265.3     190.6    1.39
JL-16-01-3-C7-1 #     1    278.1     225.1    1.24
JL-16-01-2-C1-1 #     1    231.2     149.0    1.55
JL-16-01-1-C15-3 #    1    322.1     272.6    1.18
JL-16-01-1-C2-4 #     1    346.3     292.8    1.18
JL-16-01-3-C1-2       1    257.6     186.3    1.38
JL-16-01-1-C6-1 #     1    214.1     127.8    1.68
JL-16-01-1-C3-2       1    416.5     347.6    1.20
JL-16-01-3-C2-1 #     1    387.0     314.0    1.23
JL-16-01-1-C5-2 #     1    335.0     254.8    1.31
JL-16-01-3-C8-1       1    416.8     314.3    1.33
JL-16-01-2-C5-5 #     1    258.6     168.9    1.53
JL-16-01-2-C9-1 #     1    212.7     137.0    1.55
JL-16-01-2-C11-2      3    3790.0   4360.0    0.87
JL-16-01-2-C11-2      3    3790.0   4360.0    0.87
JL-16-01-2-C2-1       1    151.2     82.8     1.83
JL-16-01-1-C1-4 #     2    3182.0   4550.0    0.70
JL-16-01-1-C1-3 #     1    7160.0   11790.0   0.61
JL-16-01-3-C1-3       3    411.2     454.0    0.91
JL-16-01-3-C1-3       3    411.2     454.0    0.91
JL-16-01-1-C3-4       3    307.7     245.0    1.26
JL-16-01-1-C3-4       3    307.7     245.0    1.26
JL-16-01-2-C6-4       3    735.0    1078.0    0.68
JL-16-01-2-C6-4       3    735.0    1078.0    0.68
JL-16-01-2-C11-1      3    2823.0   2474.0    1.14
JL-16-01-2-C11-1      3    2823.0   2474.0    1.14
JL-16-01-2-C9         2    305.1     380.3    0.80
JL-16-01-2-C9-2       2    305.1     380.3    0.80

                              Approx. conc. (ppm)

spot                 C *   [sup.204]Pb   [sup.206]Pb/
                              (cps)      [sup.204]Pb

JL-16-01-3-C8-2       1        59            121
JL-16-01-2-C1-3       1        57            186
JL-16-01-2-C6-3       1        61            130
JL-16-01-1-C6-2       1        37            312
JL-16-01-2-C6-2       1        53            187
JL-16-01-2-C6-1       1        81            330
JL-16-01-1-C5-3       1        25            388
JL-16-01-1-C15-1      1         3            2790
JL-16-01-2-C9-3       1        29            288
JL-16-01-3-C5-2       1        54            725
JL-16-01-1-C2-3       3        145            63
JL-16-01-1-C1-2       1        21            1719
JL-16-01-2-C2-2       3        109           100
JL-16-01-1-C15-2      1        10            1076
JL-16-01-3-C1-1       3        217            53
JL-16-01-2-C1-4       1        17            402
JL-16-01-3-C7-2       1         9            1428
JL-16-01-3-C8-3       1        -3           -3417
JL-16-01-2-C5-1       3        186            52
JL-16-01-3-C7-3       1        -9            -966
JL-16-01-2-C5-3       1         4            3073
JL-16-01-1-C2-2       1         5            1792
JL-16-01-1-C15-4      1         0             -
JL-16-01-1-C6-3       1        33            1738
JL-16-01-1-C6-4       1        -1           -12240
JL-16-01-3-C2-2       1        -16           -509
JL-16-01-1-C3-3 #     1         9            803
JL-16-01-2-C5-2       1         0             -
JL-16-01-1-C3-1       1        10            1835
JL-16-01-1-C2-1 #     1         4            2115
JL-16-01-3-C5-1       1        16            1493
JL-16-01-2-C1-2 #     1        -3           -2887
JL-16-01-3-C7-1 #     1        -6           -1625
JL-16-01-2-C1-1 #     1        -3           -2680
JL-16-01-1-C15-3 #    1        14            844
JL-16-01-1-C2-4 #     1         3            4187
JL-16-01-3-C1-2       1        -4           -2198
JL-16-01-1-C6-1 #     1        -11           -698
JL-16-01-1-C3-2       1         2            7250
JL-16-01-3-C2-1 #     1        -1           -13200
JL-16-01-1-C5-2 #     1        19            607
JL-16-01-3-C8-1       1        -5           -2982
JL-16-01-2-C5-5 #     1        -2           -4455
JL-16-01-2-C9-1 #     1        -6           -1212
JL-16-01-2-C11-2      3        344           203
JL-16-01-2-C11-2      3        344           203
JL-16-01-2-C2-1       1         6            927
JL-16-01-1-C1-4 #     2        106           1112
JL-16-01-1-C1-3 #     1        117           1140
JL-16-01-3-C1-3       3        161            80
JL-16-01-3-C1-3       3        161            80
JL-16-01-1-C3-4       3        171            78
JL-16-01-1-C3-4       3        171            78
JL-16-01-2-C6-4       3        133           191
JL-16-01-2-C6-4       3        133           191
JL-16-01-2-C11-1      3       1101            61
JL-16-01-2-C11-1      3       1101            61
JL-16-01-2-C9         2        134            93
JL-16-01-2-C9-2       2        134            93

                               Final isotope ratios

spot                 C *    %Pb    [sup.207]Pb/     2a
                           * (a)    [sup.235]U    [sigma]

JL-16-01-3-C8-2       1    81.60      2.490        0.170
JL-16-01-2-C1-3       1    89.75      1.367        0.056
JL-16-01-2-C6-3       1    90.30      1.327        1.100
JL-16-01-1-C6-2       1    93.55      0.977        0.044
JL-16-01-2-C6-2       1    94.16      1.050        0.080
JL-16-01-2-C6-1       1    94.90      0.923        0.160
JL-16-01-1-C5-3       1    95.02      0.908        0.210
JL-16-01-1-C15-1      1    95.66      0.788        0.034
JL-16-01-2-C9-3       1    95.82      0.878        0.052
JL-16-01-3-C5-2       1    97.99      0.647        0.023
JL-16-01-1-C2-3       3    72.40      0.420        0.380
JL-16-01-1-C1-2       1    98.31      0.633        0.019
JL-16-01-2-C2-2       3    81.07      0.510        0.280
JL-16-01-1-C15-2      1    98.38      0.649        0.028
JL-16-01-3-C1-1       3    66.00      0.650        0.370
JL-16-01-2-C1-4       1    98.55      0.628        0.080
JL-16-01-3-C7-2       1    98.79      0.562        0.026
JL-16-01-3-C8-3       1    98.79      0.587        0.031
JL-16-01-2-C5-1       3    65.70      0.480        0.380
JL-16-01-3-C7-3       1    98.79      0.586        0.032
JL-16-01-2-C5-3       1    99.03      0.561        0.027
JL-16-01-1-C2-2       1    99.08      0.585        0.031
JL-16-01-1-C15-4      1    99.28      0.521        0.026
JL-16-01-1-C6-3       1    99.39      0.565        0.057
JL-16-01-1-C6-4       1    99.29      0.567        0.024
JL-16-01-3-C2-2       1    99.51      0.548        0.023
JL-16-01-1-C3-3 #     1    99.60      0.518        0.039
JL-16-01-2-C5-2       1    99.67      0.546        0.029
JL-16-01-1-C3-1       1    99.66      0.486        0.093
JL-16-01-1-C2-1 #     1    99.71      0.516        0.023
JL-16-01-3-C5-1       1    99.64      0.529        0.022
JL-16-01-2-C1-2 #     1    99.74      0.513        0.025
JL-16-01-3-C7-1 #     1    99.74      0.519        0.026
JL-16-01-2-C1-1 #     1    99.72      0.522        0.031
JL-16-01-1-C15-3 #    1    99.69      0.509        0.072
JL-16-01-1-C2-4 #     1    99.82      0.516        0.021
JL-16-01-3-C1-2       1    99.75      0.513        0.025
JL-16-01-1-C6-1 #     1    99.67      0.518        0.027
JL-16-01-1-C3-2       1    99.72      0.537        0.024
JL-16-01-3-C2-1 #     1    99.84      0.504        0.023
JL-16-01-1-C5-2 #     1    99.83      0.507        0.023
JL-16-01-3-C8-1       1    99.85      0.563        0.024
JL-16-01-2-C5-5 #     1    99.85      0.510        0.026
JL-16-01-2-C9-1 #     1    99.93      0.506        0.027
JL-16-01-2-C11-2      3    90.97      0.282        0.053
JL-16-01-2-C11-2      3    90.97      0.282        0.053
JL-16-01-2-C2-1       1    99.88      0.520        0.034
JL-16-01-1-C1-4 #     2    98.48      0.496        0.082
JL-16-01-1-C1-3 #     1    98.61      0.496        0.026
JL-16-01-3-C1-3       3    77.15      0.560        0.260
JL-16-01-3-C1-3       3    77.15      0.560        0.260
JL-16-01-1-C3-4       3    77.17      0.480        0.300
JL-16-01-1-C3-4       3    77.17      0.480        0.300
JL-16-01-2-C6-4       3    90.52      0.450        0.130
JL-16-01-2-C6-4       3    90.52      0.450        0.130
JL-16-01-2-C11-1      3    70.69      0.500        0.100
JL-16-01-2-C11-1      3    70.69      0.500        0.100
JL-16-01-2-C9         2    81.10      0.440        0.260
JL-16-01-2-C9-2       2    81.10      0.440        0.260

                               Final isotope ratios

spot                 C *   [sup.206]Pb/     2a      err.
                            [sup.238]U    [sigma]   corr.

JL-16-01-3-C8-2       1       0.0872      0.0027    0.542
JL-16-01-2-C1-3       1       0.0724      0.0017    0.205
JL-16-01-2-C6-3       1       0.0726      0.0081    0.005
JL-16-01-1-C6-2       1       0.0669      0.0015    0.095
JL-16-01-2-C6-2       1       0.0738      0.0018    0.362
JL-16-01-2-C6-1       1       0.0695      0.0028    0.740
JL-16-01-1-C5-3       1       0.0695      0.0025    0.133
JL-16-01-1-C15-1      1       0.0646      0.0015    0.275
JL-16-01-2-C9-3       1       0.0717      0.0018    0.321
JL-16-01-3-C5-2       1       0.0662      0.0016    0.176
JL-16-01-1-C2-3       3       0.0656      0.0041    0.890
JL-16-01-1-C1-2       1       0.0676      0.0016    0.060
JL-16-01-2-C2-2       3       0.0596      0.0033    0.879
JL-16-01-1-C15-2      1       0.0693      0.0017    0.131
JL-16-01-3-C1-1       3       0.0692      0.0041    0.917
JL-16-01-2-C1-4       1       0.0686      0.0018    0.122
JL-16-01-3-C7-2       1       0.0641      0.0015    0.221
JL-16-01-3-C8-3       1       0.0666      0.0015    0.196
JL-16-01-2-C5-1       3       0.0645      0.0038    0.891
JL-16-01-3-C7-3       1       0.0670      0.0016    0.247
JL-16-01-2-C5-3       1       0.0660      0.0016    0.136
JL-16-01-1-C2-2       1       0.0686      0.0016    0.201
JL-16-01-1-C15-4      1       0.0634      0.0015    0.051
JL-16-01-1-C6-3       1       0.0686      0.0017    0.382
JL-16-01-1-C6-4       1       0.0689      0.0016    0.178
JL-16-01-3-C2-2       1       0.0687      0.0017    0.315
JL-16-01-1-C3-3 #     1       0.0661      0.0016    0.109
JL-16-01-2-C5-2       1       0.0697      0.0017    0.005
JL-16-01-1-C3-1       1       0.0636      0.0015    0.081
JL-16-01-1-C2-1 #     1       0.0671      0.0017    0.133
JL-16-01-3-C5-1       1       0.0689      0.0019    0.228
JL-16-01-2-C1-2 #     1       0.0664      0.0016    0.010
JL-16-01-3-C7-1 #     1       0.0676      0.0016    0.197
JL-16-01-2-C1-1 #     1       0.0676      0.0016    0.005
JL-16-01-1-C15-3 #    1       0.0663      0.0016    0.059
JL-16-01-1-C2-4 #     1       0.0672      0.0015    0.282
JL-16-01-3-C1-2       1       0.0668      0.0015    0.065
JL-16-01-1-C6-1 #     1       0.0672      0.0016    0.152
JL-16-01-1-C3-2       1       0.0695      0.0016    0.304
JL-16-01-3-C2-1 #     1       0.0664      0.0015    0.302
JL-16-01-1-C5-2 #     1       0.0668      0.0016    0.073
JL-16-01-3-C8-1       1       0.0735      0.0019    0.359
JL-16-01-2-C5-5 #     1       0.0675      0.0016    0.132
JL-16-01-2-C9-1 #     1       0.0673      0.0017    0.097
JL-16-01-2-C11-2      3       0.0394      0.0013    0.517
JL-16-01-2-C11-2      3       0.0394      0.0013    0.517
JL-16-01-2-C2-1       1       0.0690      0.0020    0.007
JL-16-01-1-C1-4 #     2       0.0667      0.0012    0.088
JL-16-01-1-C1-3 #     1       0.0672      0.0021    0.335
JL-16-01-3-C1-3       3       0.0673      0.0033    0.856
JL-16-01-3-C1-3       3       0.0673      0.0033    0.856
JL-16-01-1-C3-4       3       0.0655      0.0036    0.891
JL-16-01-1-C3-4       3       0.0655      0.0036    0.891
JL-16-01-2-C6-4       3       0.0618      0.0018    0.548
JL-16-01-2-C6-4       3       0.0618      0.0018    0.548
JL-16-01-2-C11-1      3       0.0678      0.0019    0.732
JL-16-01-2-C11-1      3       0.0678      0.0019    0.732
JL-16-01-2-C9         2       0.0624      0.0024    0.895
JL-16-01-2-C9-2       2       0.0624      0.0024    0.895

                                         Age (Ma)

spot                 C *   [sup.207]Pb/     2a       [sup.
                            [sup.235]U    [sigma]   206]Pb/
                                                     [sup.
                                                     238]U

JL-16-01-3-C8-2       1        1260         59        539
JL-16-01-2-C1-3       1        870          24        450
JL-16-01-2-C6-3       1        852          170       452
JL-16-01-1-C6-2       1        688          22        417
JL-16-01-2-C6-2       1        715          39        459
JL-16-01-2-C6-1       1        660          61        433
JL-16-01-1-C5-3       1        648          75        433
JL-16-01-1-C15-1      1        590          20        404
JL-16-01-2-C9-3       1        632          28        446
JL-16-01-3-C5-2       1        506          14        413
JL-16-01-1-C2-3       3        490          230       409
JL-16-01-1-C1-2       1        497          12        421
JL-16-01-2-C2-2       3        440          180       373
JL-16-01-1-C15-2      1        505          18        432
JL-16-01-3-C1-1       3        500          210       431
JL-16-01-2-C1-4       1        491          42        428
JL-16-01-3-C7-2       1        450          17        401
JL-16-01-3-C8-3       1        467          20        416
JL-16-01-2-C5-1       3        450          190       403
JL-16-01-3-C7-3       1        464          21        418
JL-16-01-2-C5-3       1        450          18        412
JL-16-01-1-C2-2       1        464          20        427
JL-16-01-1-C15-4      1        423          17        396
JL-16-01-1-C6-3       1        454          31        427
JL-16-01-1-C6-4       1        454          16        429
JL-16-01-3-C2-2       1        442          15        428
JL-16-01-1-C3-3 #     1        421          25        412
JL-16-01-2-C5-2       1        439          19        434
JL-16-01-1-C3-1       1        401          23        398
JL-16-01-1-C2-1 #     1        423          15        419
JL-16-01-3-C5-1       1        433          14        430
JL-16-01-2-C1-2 #     1        417          17        415
JL-16-01-3-C7-1 #     1        424          17        421
JL-16-01-2-C1-1 #     1        424          20        422
JL-16-01-1-C15-3 #    1        416          41        414
JL-16-01-1-C2-4 #     1        421          14        419
JL-16-01-3-C1-2       1        418          17        417
JL-16-01-1-C6-1 #     1        420          18        419
JL-16-01-1-C3-2       1        434          15        433
JL-16-01-3-C2-1 #     1        414          16        415
JL-16-01-1-C5-2 #     1        414          16        417
JL-16-01-3-C8-1       1        451          16        457
JL-16-01-2-C5-5 #     1        415          17        421
JL-16-01-2-C9-1 #     1        413          18        421
JL-16-01-2-C11-2      3        244          41        249
JL-16-01-2-C11-2      3        244          41        249
JL-16-01-2-C2-1       1        421          23        430
JL-16-01-1-C1-4 #     2        407          49        416
JL-16-01-1-C1-3 #     1        407          18        419
JL-16-01-3-C1-3       3        380          170       420
JL-16-01-3-C1-3       3        380          170       420
JL-16-01-1-C3-4       3        360          180       409
JL-16-01-1-C3-4       3        360          180       409
JL-16-01-2-C6-4       3        330          87        387
JL-16-01-2-C6-4       3        330          87        387
JL-16-01-2-C11-1      3        360          66        422
JL-16-01-2-C11-1      3        360          66        422
JL-16-01-2-C9         2         80          180       390
JL-16-01-2-C9-2       2         80          180       390

                              Age (Ma)

spot                 C *     2a        %
                           [sigma]   conc.

                                      (b)
JL-16-01-3-C8-2       1      16      42.8
JL-16-01-2-C1-3       1      10      51.8
JL-16-01-2-C6-3       1      51      53.0
JL-16-01-1-C6-2       1       9      60.6
JL-16-01-2-C6-2       1      11      64.2
JL-16-01-2-C6-1       1      17      65.6
JL-16-01-1-C5-3       1      15      66.9
JL-16-01-1-C15-1      1       9      68.4
JL-16-01-2-C9-3       1      11      70.6
JL-16-01-3-C5-2       1      10      81.6
JL-16-01-1-C2-3       3      25      83.5
JL-16-01-1-C1-2       1      10      84.7
JL-16-01-2-C2-2       3      20      84.8
JL-16-01-1-C15-2      1      10      85.6
JL-16-01-3-C1-1       3      25      86.2
JL-16-01-2-C1-4       1      11      87.1
JL-16-01-3-C7-2       1       9      89.0
JL-16-01-3-C8-3       1       9      89.0
JL-16-01-2-C5-1       3      23      89.6
JL-16-01-3-C7-3       1      10      90.0
JL-16-01-2-C5-3       1      10      91.6
JL-16-01-1-C2-2       1      10      92.1
JL-16-01-1-C15-4      1       9      93.6
JL-16-01-1-C6-3       1      10      94.1
JL-16-01-1-C6-4       1      10      94.6
JL-16-01-3-C2-2       1      10      96.9
JL-16-01-1-C3-3 #     1      10      98.0
JL-16-01-2-C5-2       1      10      98.9
JL-16-01-1-C3-1       1       9      99.0
JL-16-01-1-C2-1 #     1      10      99.0
JL-16-01-3-C5-1       1      11      99.2
JL-16-01-2-C1-2 #     1      10      99.4
JL-16-01-3-C7-1 #     1      10      99.4
JL-16-01-2-C1-1 #     1      10      99.4
JL-16-01-1-C15-3 #    1      10      99.5
JL-16-01-1-C2-4 #     1       9      99.6
JL-16-01-3-C1-2       1       9      99.8
JL-16-01-1-C6-1 #     1      10      99.8
JL-16-01-1-C3-2       1      10      99.8
JL-16-01-3-C2-1 #     1       9      100.1
JL-16-01-1-C5-2 #     1       9      100.6
JL-16-01-3-C8-1       1      12      101.4
JL-16-01-2-C5-5 #     1      10      101.5
JL-16-01-2-C9-1 #     1      10      101.9
JL-16-01-2-C11-2      3       8      102.0
JL-16-01-2-C11-2      3       8      102.0
JL-16-01-2-C2-1       1      12      102.2
JL-16-01-1-C1-4 #     2       7      102.3
JL-16-01-1-C1-3 #     1      13      103.0
JL-16-01-3-C1-3       3      20      110.5
JL-16-01-3-C1-3       3      20      110.5
JL-16-01-1-C3-4       3      22      113.6
JL-16-01-1-C3-4       3      22      113.6
JL-16-01-2-C6-4       3      11      117.1
JL-16-01-2-C6-4       3      11      117.1
JL-16-01-2-C11-1      3      12      117.2
JL-16-01-2-C11-1      3      12      117.2
JL-16-01-2-C9         2      15      487.5
JL-16-01-2-C9-2       2      15      487.5

Notes: C* = Common Pb correction (1-uncorrected for common-Pb;
2-common-Pb corrected using Andersen (2002) method; 3-common-Pb
corrected using the measured [sup.204]Pb). acalculated from
Andersen (2002) method; bcalculated as 100 x ([sup.206]Pb/
[sup.238]U age/[sup.207]Pb/[sup.235]U age). # signifies the
Samples numbers in bold and italic are used in final age
calculations.

Table A5. Results for in-situ LA-ICP-MS U-Pb zircon
geochronology of Sample 15-72 (Wellington Lake Granite).

                              Approx. conc. (ppm)

spot                 C *     U        Th     U/Th
                           (ppm)    (ppm)

15-72-03-12           2    355.1    997.0    0.36
15-72-03-12           2    355.1    997.0    0.36
15-72-03-06           2    822.0    3350.0   0.25
15-72-03-06           2    822.0    3350.0   0.25
15-72-03-11           2    338.9    251.0    1.35
15-72-03-11           2    338.9    251.0    1.35
15-72-03-10           1    326.5    265.0    1.23
15-72-03-10           1    326.5    265.0    1.23
15-72-03-07           1    1127.0   3720.0   0.30
15-72-03-07           1    1127.0   3720.0   0.30
15-72-03-19           3    494.5    428.0    1.16
15-72-03-19           3    494.5    428.0    1.16
15-72-03-04           1    713.0    1580.0   0.45
15-72-03-04           1    713.0    1580.0   0.45
15-72-S2-C1-4         1    517.0    520.0    0.99
15-72-03-20           1    353.8    3031.0   0.12
15-72-03-15           2    411.1    560.0    0.73
15-72-03-03           1    819.0    621.0    1.32
15-72-S1-C1-core-1    1    1732.0   4580.0   0.38
15-72-S2-C1-3         1    307.9    205.4    1.50
15-72-03-25           1    248.0    308.0    0.81
15-72-S2-C2-3         1    508.0    621.0    0.82
15-72-S1-C3-2         1    422.0    1311.0   0.32
15-72-S2-C2-1         1    1096.0   4031.0   0.27
15-72-S1-C2-9         1    1348.0   650.0    2.07
15-72-03-14           1    604.0    1810.0   0.33
15-72-S2-C1-6         1    2380.0   1803.0   1.32
15-72-S2-C1-2         1    923.0    769.0    1.20
15-72-S1-C2-5         1    426.8    140.0    3.05
15-72-03-08           1    655.0    156.6    4.18
15-72-03-24           1    755.0    2485.0   0.30
15-72-S1-C2-7         2    458.0    121.0    3.79
15-72-03-09           1    926.0    1358.0   0.68
15-72-03-17           1    1054.0   1858.0   0.57
15-72-S2-C1-7         1    735.1    245.0    3.00
15-72-03-22           2    396.6    438.3    0.90
15-72-S2-C1-1 #       1    712.3    102.7    6.94
15-72-03-18           1    749.2    1890.0   0.40
15-72-S1-C2-6 #       1    875.0    476.0    1.84
15-72-S2-C1-5         1    883.6    187.8    4.71
15-72-S1-C1-3         1    1499.0   242.5    6.18
15-72-03-23           1    776.9    1283.0   0.61
15-72-S2-C2-4 #       1    866.0    221.0    3.92
15-72-S1-C3-1 #       1    574.0    123.0    4.67
15-72-S1-C2-1 #       1    473.0    307.0    1.54
15-72-S1-C2-4 #       1    358.2    105.7    3.39
15-72-S2-C4-1 #       1    971.0    405.0    2.40
15-72-S1-C2-3 #       1    539.0     88.8    6.07
15-72-03-16           1    761.4    192.5    3.96
15-72-03-01 #         1    385.2    400.0    0.96
15-72-S1-C3-1         1    327.5     81.8    4.00
15-72-S1-C2-8         2    1205.0   266.0    4.53
15-72-03-21           2    581.0    664.0    0.88
15-72-S2-C4-2 #       1    681.4    208.2    3.27
15-72-03-02 #         1    597.0    270.0    2.21
15-72-03-13           1    158.5     76.6    2.07
15-72-03-13           3    158.5     76.6    2.07
15-72-S1-C2-2         1    389.8    236.5    1.65

                              Approx. conc. (ppm)

spot                 C *   [sup.204]Pb   [sup.206]Pb/
                              (cps)      [sup.204]Pb

15-72-03-12           2        -3           -2147
15-72-03-12           2        -3           -2147
15-72-03-06           2        131           294
15-72-03-06           2        131           294
15-72-03-11           2        78            164
15-72-03-11           2        78            164
15-72-03-10           1        48            232
15-72-03-10           1        48            232
15-72-03-07           1        12            2093
15-72-03-07           1        12            2093
15-72-03-19           3        28            470
15-72-03-19           3        28            470
15-72-03-04           1        150           126
15-72-03-04           1        150           126
15-72-S2-C1-4         1         6            3518
15-72-03-20           1        11            2174
15-72-03-15           2        -6           -4902
15-72-03-03           1        42            622
15-72-S1-C1-core-1    1         5            4684
15-72-S2-C1-3         1        27            430
15-72-03-25           1         5            5756
15-72-S2-C2-3         1        14            1321
15-72-S1-C3-2         1        -3           -4443
15-72-S2-C2-1         1        27            1011
15-72-S1-C2-9         1         6            1578
15-72-03-14           1        23            679
15-72-S2-C1-6         1        -5           -3678
15-72-S2-C1-2         1         9            944
15-72-S1-C2-5         1         4            5705
15-72-03-08           1         3           11220
15-72-03-24           1        18            499
15-72-S1-C2-7         2         5            6354
15-72-03-09           1        29            425
15-72-03-17           1        -11          -2623
15-72-S2-C1-7         1        14            2013
15-72-03-22           2        13            2244
15-72-S2-C1-1 #       1         4            6870
15-72-03-18           1        48            407
15-72-S1-C2-6 #       1        -10          -1155
15-72-S2-C1-5         1        33            1382
15-72-S1-C1-3         1        22            1810
15-72-03-23           1         6            5082
15-72-S2-C2-4 #       1        29            916
15-72-S1-C3-1 #       1        -5           -3398
15-72-S1-C2-1 #       1        41            272
15-72-S1-C2-4 #       1        -16           -773
15-72-S2-C4-1 #       1         4            4295
15-72-S1-C2-3 #       1        -2           -4645
15-72-03-16           1         7            5619
15-72-03-01 #         1         6            3912
15-72-S1-C3-1         1        12            838
15-72-S1-C2-8         2         9            3650
15-72-03-21           2        10            1544
15-72-S2-C4-2 #       1        -5           -24540
15-72-03-02 #         1        48            651
15-72-03-13           1         4            5533
15-72-03-13           3         4            5533
15-72-S1-C2-2         1        -24           -902

                               Final isotope ratios

spot                 C *    %Pb    [sup.207]Pb/     2ct
                           * (a)    [sup.235]U    [sigma]

15-72-03-12           2    99.66      1.579        0.062
15-72-03-12           2    99.66      1.579        0.062
15-72-03-06           2    94.30      1.036        0.041
15-72-03-06           2    94.30      1.036        0.041
15-72-03-11           2    86.72      1.094        0.040
15-72-03-11           2    86.72      1.094        0.040
15-72-03-10           1    92.84      1.095        0.091
15-72-03-10           1    92.84      1.095        0.091
15-72-03-07           1    99.20      0.936        0.077
15-72-03-07           1    99.20      0.936        0.077
15-72-03-19           3    97.09      0.883        0.036
15-72-03-19           3    97.09      0.883        0.036
15-72-03-04           1    84.80      0.725        0.025
15-72-03-04           1    84.80      0.725        0.025
15-72-S2-C1-4         1    99.67      0.722        0.042
15-72-03-20           1    99.70      0.727        0.031
15-72-03-15           2    99.69      0.718        0.029
15-72-03-03           1    96.97      0.705        0.028
15-72-S1-C1-core-1    1    98.58      0.633        0.024
15-72-S2-C1-3         1    97.21      0.652        0.044
15-72-03-25           1    99.80      0.622        0.028
15-72-S2-C2-3         1    99.82      0.597        0.035
15-72-S1-C3-2         1    99.71      0.553        0.023
15-72-S2-C2-1         1    98.64      0.604        0.019
15-72-S1-C2-9         1    99.57      0.573        0.020
15-72-03-14           1    97.37      0.576        0.021
15-72-S2-C1-6         1    99.44      0.564        0.034
15-72-S2-C1-2         1    98.00      0.574        0.026
15-72-S1-C2-5         1    99.60      0.564        0.035
15-72-03-08           1    99.55      0.579        0.020
15-72-03-24           1    98.20      0.583        0.021
15-72-S1-C2-7         2    99.76      0.516        0.022
15-72-03-09           1    93.26      0.504        0.015
15-72-03-17           1    99.63      0.530        0.016
15-72-S2-C1-7         1    98.72      0.534        0.021
15-72-03-22           2    99.73      0.546        0.020
15-72-S2-C1-1 #       1    99.22      0.508        0.019
15-72-03-18           1    95.30      0.532        0.016
15-72-S1-C2-6 #       1    99.44      0.511        0.017
15-72-S2-C1-5         1    98.96      0.504        0.017
15-72-S1-C1-3         1    97.99      0.499        0.022
15-72-03-23           1    99.21      0.517        0.017
15-72-S2-C2-4 #       1    99.64      0.508        0.019
15-72-S1-C3-1 #       1    99.65      0.495        0.020
15-72-S1-C2-1 #       1    99.99      0.505        0.024
15-72-S1-C2-4 #       1    99.04      0.499        0.022
15-72-S2-C4-1 #       1    99.69      0.510        0.023
15-72-S1-C2-3 #       1    99.83      0.502        0.024
15-72-03-16           1    99.58      0.525        0.017
15-72-03-01 #         1    99.75      0.512        0.019
15-72-S1-C3-1         1    98.55      0.531        0.030
15-72-S1-C2-8         2    98.74      0.522        0.016
15-72-03-21           2    99.51      0.540        0.018
15-72-S2-C4-2 #       1    99.83      0.508        0.017
15-72-03-02 #         1    97.30      0.518        0.018
15-72-03-13           1    98.67      0.538        0.031
15-72-03-13           3    98.67      0.538        0.031
15-72-S1-C2-2         1    99.73      0.486        0.036

                               Final isotope ratios

spot                 C *   [sup.206]Pb/     2ct     err.
                            [sup.238]U    [sigma]   corr.

15-72-03-12           2       0.0714      0.0014    0.265
15-72-03-12           2       0.0714      0.0014    0.265
15-72-03-06           2       0.0664      0.0011    0.065
15-72-03-06           2       0.0664      0.0011    0.065
15-72-03-11           2       0.0707      0.0013    0.199
15-72-03-11           2       0.0707      0.0013    0.199
15-72-03-10           1       0.0714      0.0014    0.623
15-72-03-10           1       0.0714      0.0014    0.623
15-72-03-07           1       0.0672      0.0010    0.560
15-72-03-07           1       0.0672      0.0010    0.560
15-72-03-19           3       0.0689      0.0010    0.248
15-72-03-19           3       0.0689      0.0010    0.248
15-72-03-04           1       0.0664      0.0010    0.250
15-72-03-04           1       0.0664      0.0010    0.250
15-72-S2-C1-4         1       0.0670      0.0017    0.057
15-72-03-20           1       0.0677      0.0012    0.110
15-72-03-15           2       0.0677      0.0012    0.309
15-72-03-03           1       0.0672      0.0010    0.027
15-72-S1-C1-core-1    1       0.0650      0.0020    0.467
15-72-S2-C1-3         1       0.0680      0.0020    0.044
15-72-03-25           1       0.0655      0.0011    0.248
15-72-S2-C2-3         1       0.0639      0.0019    0.522
15-72-S1-C3-2         1       0.0614      0.0016    0.164
15-72-S2-C2-1         1       0.0670      0.0020    0.168
15-72-S1-C2-9         1       0.0642      0.0019    0.039
15-72-03-14           1       0.0645      0.0011    0.061
15-72-S2-C1-6         1       0.0646      0.0015    0.008
15-72-S2-C1-2         1       0.0670      0.0020    0.173
15-72-S1-C2-5         1       0.0663      0.0016    0.003
15-72-03-08           1       0.0687      0.0009    0.120
15-72-03-24           1       0.0690      0.0011    0.390
15-72-S1-C2-7         2       0.0647      0.0016    0.004
15-72-03-09           1       0.0634      0.0008    0.193
15-72-03-17           1       0.0670      0.0009    0.118
15-72-S2-C1-7         1       0.0680      0.0020    0.224
15-72-03-22           2       0.0693      0.0010    0.256
15-72-S2-C1-1 #       1       0.0664      0.0014    0.172
15-72-03-18           1       0.0685      0.0009    0.082
15-72-S1-C2-6 #       1       0.0664      0.0014    0.329
15-72-S2-C1-5         1       0.0660      0.0020    0.206
15-72-S1-C1-3         1       0.0650      0.0020    0.236
15-72-03-23           1       0.0669      0.0010    0.339
15-72-S2-C2-4 #       1       0.0660      0.0016    0.213
15-72-S1-C3-1 #       1       0.0650      0.0015    0.033
15-72-S1-C2-1 #       1       0.0660      0.0016    0.015
15-72-S1-C2-4 #       1       0.0652      0.0015    0.010
15-72-S2-C4-1 #       1       0.0667      0.0017    0.116
15-72-S1-C2-3 #       1       0.0656      0.0016    0.011
15-72-03-16           1       0.0684      0.0009    0.174
15-72-03-01 #         1       0.0671      0.0011    0.140
15-72-S1-C3-1         1       0.0690      0.0020    0.014
15-72-S1-C2-8         2       0.0680      0.0010    0.205
15-72-03-21           2       0.0701      0.0011    0.045
15-72-S2-C4-2 #       1       0.0666      0.0014    0.117
15-72-03-02 #         1       0.0678      0.0010    0.236
15-72-03-13           1       0.0699      0.0014    0.014
15-72-03-13           3       0.0699      0.0014    0.014
15-72-S1-C2-2         1       0.0660      0.0020    0.060

                                     Age (Ma)

spot                 C *    [sup.      2ct      [sup.
                           207]Pb/   [sigma]   206]Pb/
                            [sup                [sup.
                           .235]U               238]U

15-72-03-12           2      960       24        444
15-72-03-12           2      960       24        444
15-72-03-06           2      722       21        415
15-72-03-06           2      722       21        415
15-72-03-11           2      753       18        440
15-72-03-11           2      753       18        440
15-72-03-10           1      740       44        445
15-72-03-10           1      740       44        445
15-72-03-07           1      668       41        419
15-72-03-07           1      668       41        419
15-72-03-19           3      643       19        429
15-72-03-19           3      643       19        429
15-72-03-04           1      553       14        415
15-72-03-04           1      553       14        415
15-72-S2-C1-4         1      551       23        418
15-72-03-20           1      555       19        422
15-72-03-15           2      550       17        423
15-72-03-03           1      544       17        419
15-72-S1-C1-core-1    1      499       15        405
15-72-S2-C1-3         1      508       26        426
15-72-03-25           1      488       17        409
15-72-S2-C2-3         1      473       22        399
15-72-S1-C3-2         1      445       15        384
15-72-S2-C2-1         1      479       12        418
15-72-S1-C2-9         1      460       14        401
15-72-03-14           1      461       13        403
15-72-S2-C1-6         1      454       20        404
15-72-S2-C1-2         1      462       16        422
15-72-S1-C2-5         1      452       23        414
15-72-03-08           1      463       13        428
15-72-03-24           1      466       13        430
15-72-S1-C2-7         2      423       15        404
15-72-03-09           1      414       10        396
15-72-03-17           1      432       11        418
15-72-S2-C1-7         1      433       14        422
15-72-03-22           2      441       13        432
15-72-S2-C1-1 #       1      421       13        415
15-72-03-18           1      433       11        427
15-72-S1-C2-6 #       1      420       12        414
15-72-S2-C1-5         1      416       12        411
15-72-S1-C1-3         1      411       14        406
15-72-03-23           1      423       11        418
15-72-S2-C2-4 #       1      416       13        412
15-72-S1-C3-1 #       1      409       14        406
15-72-S1-C2-1 #       1      415       16        412
15-72-S1-C2-4 #       1      410       15        407
15-72-S2-C4-1 #       1      418       15        416
15-72-S1-C2-3 #       1      412       17        410
15-72-03-16           1      429       11        427
15-72-03-01 #         1      420       13        418
15-72-S1-C3-1         1      434       20        432
15-72-S1-C2-8         2      428       11        427
15-72-03-21           2      438       12        437
15-72-S2-C4-2 #       1      416       12        416
15-72-03-02 #         1      423       12        423
15-72-03-13           1      433       21        436
15-72-03-13           3      433       21        436
15-72-S1-C2-2         1      401       26        413

                                Age (Ma)

                             2ct       %
                           [sigma]   conc.
spot                 C *              (b)

15-72-03-12           2       8      46.3
15-72-03-12           2       8      46.3
15-72-03-06           2       7      57.4
15-72-03-06           2       7      57.4
15-72-03-11           2       8      58.5
15-72-03-11           2       8      58.5
15-72-03-10           1       8      60.1
15-72-03-10           1       8      60.1
15-72-03-07           1       6      62.8
15-72-03-07           1       6      62.8
15-72-03-19           3       6      66.8
15-72-03-19           3       6      66.8
15-72-03-04           1       6      75.1
15-72-03-04           1       6      75.1
15-72-S2-C1-4         1       10     75.9
15-72-03-20           1       7      76.1
15-72-03-15           2       7      76.8
15-72-03-03           1       6      77.1
15-72-S1-C1-core-1    1       9      81.2
15-72-S2-C1-3         1       11     83.8
15-72-03-25           1       7      83.9
15-72-S2-C2-3         1       12     84.4
15-72-S1-C3-2         1       9      86.3
15-72-S2-C2-1         1       9      87.1
15-72-S1-C2-9         1       11     87.2
15-72-03-14           1       7      87.4
15-72-S2-C1-6         1       9      88.9
15-72-S2-C1-2         1       9      91.3
15-72-S1-C2-5         1       10     91.5
15-72-03-08           1       6      92.4
15-72-03-24           1       7      92.4
15-72-S1-C2-7         2       10     95.6
15-72-03-09           1       5      95.7
15-72-03-17           1       5      96.8
15-72-S2-C1-7         1       9      97.4
15-72-03-22           2       6      97.9
15-72-S2-C1-1 #       1       9      98.5
15-72-03-18           1       5      98.6
15-72-S1-C2-6 #       1       9      98.7
15-72-S2-C1-5         1       9      98.7
15-72-S1-C1-3         1       9      98.7
15-72-03-23           1       6      98.8
15-72-S2-C2-4 #       1       9      98.9
15-72-S1-C3-1 #       1       9      99.2
15-72-S1-C2-1 #       1       10     99.2
15-72-S1-C2-4 #       1       9      99.3
15-72-S2-C4-1 #       1       11     99.5
15-72-S1-C2-3 #       1       10     99.5
15-72-03-16           1       5      99.5
15-72-03-01 #         1       7      99.6
15-72-S1-C3-1         1       11     99.6
15-72-S1-C2-8         2       9      99.7
15-72-03-21           2       7      99.7
15-72-S2-C4-2 #       1       9      99.9
15-72-03-02 #         1       6      99.9
15-72-03-13           1       8      100.6
15-72-03-13           3       8      100.6
15-72-S1-C2-2         1       11     102.9

Notes: C* = Common Pb correction (1-uncorrected for common-Pb;
2-common-Pb corrected using Andersen (2002) method; 3-common-Pb
corrected using the measured [sup.204]Pb). "calculated from
Andersen (2002) method; bcalculated as 100 x ([sup.206]Pb/
[sup.238]U age/[sup.207]Pb/[sup.235]U age). 3 signifies the
Samples numbers in bold and italic are used in final age
calculations.

Table A6. Results for in-situ LA-ICP-MS U-Pb monazite
geochronology of a Sample 85MM-154B (John Lee Brook Granite).

                             Approx. conc. (ppm)

spot                 C *     U       Th     U/Th
                           (ppm)   (ppm)

85-MM-154B-C2-1       3     814    29500    0.03
85-MM-154B-C6-2       1     692    40440    0.02
85-MM-154B-C4-2       1    1313    51700    0.03
85-MM-154B-C4-3       1     907    49480    0.02
85-MM-154B-C4-1       1     916    44620    0.02
85-MM-154B-C10-2      1     954    43990    0.02
85MM154B-mz6-3        1     760    48300    0.02
85MM154B-mz3-3        3     490    22100    0.02
85-MM-154B-C4-4       1    1596    40240    0.04
85-MM-154B-C12-2      1     489    43210    0.01
85MM154B-mz5-3        1     818    55320    0.01
85-MM-154B-C6-1       1     658    49720    0.01
85-MM-154B-C3-4       1    386.2   45590    0.01
85MM154B-mz4-1        1    1714    71500    0.02
85-MM-154B-C3-3       1     686    48450    0.01
85-MM-154B-C1-2       1     974    45900    0.02
85-MM-154B-C5-1       1    1164    48690    0.02
85MM154B-mz1-1        1    4140    45100    0.09
85MM154B-mz5-2        1     848    49580    0.02
85-MM-154B-C10-3      1    1071    47280    0.02
85MM154B-mz7-2        1     410    41500    0.01
85MM154B-mz6-1        1     358    40600    0.01
85-MM-154B-C7-1 #     1    1072    48840    0.02
85-MM-154B-C9-1 #     1    1915    51600    0.04
85MM154B-mz7-1        1     738    73400    0.01
85-MM-154B-C1-1 #     1    607.7   46870    0.01
85MM154B-mz2-2 #      1     600    24700    0.02
85-MM-154B-C4-5 #     1    1219    48490    0.03
85MM154B-mz5-6        1    1339    65410    0.02
85-MM-154B-C3-2 #     1     553    45030    0.01
85-MM-154B-C10-4 #    1     982    49010    0.02
85-MM-154B-C10-1 #    1     980    49170    0.02
85MM154B-mz6-4 #      1     425    46900    0.01
85-MM-154B-C9-3 #     1     798    46420    0.02
85MM154B-mz2-1 #      1     980    25200    0.04
85MM154B-mz3-1        3     470    20900    0.02
85-MM-154B-C9-2 #     1    1111    50980    0.02
85MM154B-mz6-2 #      1     360    43500    0.01
85-MM-154B-C12-3      1     891    51680    0.02
85-MM-154B-C12-1      1    1202    46850    0.03
85MM154B-mz5-4        3     946    58810    0.02
85MM154B-mz4-2        2    11290   116900   0.10
85-MM-154B-C3-1       2     964    50200    0.02
85MM154B-mz5-1        3     882    51600    0.02
85MM154B-mz3-2        3     802    44020    0.02

                             Approx. conc. (ppm)

spot                 C *   [sup.204]Pb   [sup.206]Pb/
                              (cps)      [sup.204]Pb

85-MM-154B-C2-1       3        139            30
85-MM-154B-C6-2       1        44            172
85-MM-154B-C4-2       1        47            154
85-MM-154B-C4-3       1        27            341
85-MM-154B-C4-1       1        45            205
85-MM-154B-C10-2      1        37            263
85MM154B-mz6-3        1        45            288
85MM154B-mz3-3        3       1100            36
85-MM-154B-C4-4       1        29            499
85-MM-154B-C12-2      1        18            294
85MM154B-mz5-3        1        15            995
85-MM-154B-C6-1       1         2            4260
85-MM-154B-C3-4       1         1            2576
85MM154B-mz4-1        1        23            1061
85-MM-154B-C3-3       1        13            500
85-MM-154B-C1-2       1        -4           -1963
85-MM-154B-C5-1       1         6            1727
85MM154B-mz1-1        1        39            2000
85MM154B-mz5-2        1         6            2645
85-MM-154B-C10-3      1        -4           -2554
85MM154B-mz7-2        1        -8           -1061
85MM154B-mz6-1        1         2            3565
85-MM-154B-C7-1 #     1        -7           -1463
85-MM-154B-C9-1 #     1        -2           -8061
85MM154B-mz7-1        1        12            724
85-MM-154B-C1-1 #     1        -4           -1378
85MM154B-mz2-2 #      1        -2           -11250
85-MM-154B-C4-5 #     1         6            1907
85MM154B-mz5-6        1         8            2681
85-MM-154B-C3-2 #     1        11            469
85-MM-154B-C10-4 #    1         4            2475
85-MM-154B-C10-1 #    1         5            2006
85MM154B-mz6-4 #      1        -7           -1003
85-MM-154B-C9-3 #     1        10            817
85MM154B-mz2-1 #      1         3            9833
85MM154B-mz3-1        3        171           135
85-MM-154B-C9-2 #     1        -1           -10500
85MM154B-mz6-2 #      1         6            1137
85-MM-154B-C12-3      1        11            812
85-MM-154B-C12-1      1         1           10809
85MM154B-mz5-4        3        329            66
85MM154B-mz4-2        2        99            1448
85-MM-154B-C3-1       2        109            84
85MM154B-mz5-1        3        182           112
85MM154B-mz3-2        3        92            175

                                Final isotope ratios

spot                 C *    %Pb    [sup.207]Pb/      2
                           * (a)    [sup.235]U    [sigma]

85-MM-154B-C2-1       3    41.80      1.570        0.860
85-MM-154B-C6-2       1    87.28      1.444        0.061
85-MM-154B-C4-2       1    87.57      1.510        0.110
85-MM-154B-C4-3       1    91.60      1.062        0.039
85-MM-154B-C4-1       1    91.61      1.156        0.048
85-MM-154B-C10-2      1    92.04      1.058        0.041
85MM154B-mz6-3        1    93.70      0.929        0.026
85MM154B-mz3-3        3    57.60      1.240        2.500
85-MM-154B-C4-4       1    95.38      0.740        0.026
85-MM-154B-C12-2      1    96.50      0.730        0.059
85MM154B-mz5-3        1    97.10      0.671        0.033
85-MM-154B-C6-1       1    97.23      0.626        0.029
85-MM-154B-C3-4       1    97.41      0.636        0.037
85MM154B-mz4-1        1    97.82      0.601        0.017
85-MM-154B-C3-3       1    98.20      0.587        0.029
85-MM-154B-C1-2       1    98.15      0.549        0.025
85-MM-154B-C5-1       1    98.32      0.549        0.021
85MM154B-mz1-1        1    98.67      0.503        0.089
85MM154B-mz5-2        1    98.92      0.511        0.023
85-MM-154B-C10-3      1    98.98      0.528        0.022
85MM154B-mz7-2        1    99.16      0.520        0.019
85MM154B-mz6-1        1    99.08      0.544        0.023
85-MM-154B-C7-1 #     1    99.20      0.506        0.023
85-MM-154B-C9-1 #     1    99.19      0.496        0.016
85MM154B-mz7-1        1    99.19      0.501        0.130
85-MM-154B-C1-1 #     1    99.13      0.502        0.022
85MM154B-mz2-2 #      1    99.28      0.524        0.048
85-MM-154B-C4-5 #     1    99.29      0.504        0.019
85MM154B-mz5-6        1    99.40      0.489        0.013
85-MM-154B-C3-2 #     1    99.14      0.507        0.025
85-MM-154B-C10-4 #    1    99.29      0.497        0.019
85-MM-154B-C10-1 #    1    99.45      0.505        0.024
85MM154B-mz6-4 #      1    99.44      0.517        0.023
85-MM-154B-C9-3 #     1    99.28      0.504        0.021
85MM154B-mz2-1 #      1    99.57      0.506        0.045
85MM154B-mz3-1        3    84.40      0.450        0.110
85-MM-154B-C9-2 #     1    99.42      0.493        0.018
85MM154B-mz6-2 #      1    99.13      0.509        0.024
85-MM-154B-C12-3      1    99.52      0.491        0.020
85-MM-154B-C12-1      1    99.45      0.491        0.017
85MM154B-mz5-4        3    70.30      0.480        0.160
85MM154B-mz4-2        2    98.29      0.409        0.015
85-MM-154B-C3-1       2    80.10      0.392        0.010
85MM154B-mz5-1        3    81.83      0.460        0.130
85MM154B-mz3-2        3    90.81      0.300        0.380

                                Final isotope ratios

spot                 C *   [sup.206]Pb/      2      err.
                            [sup.238]U    [sigma]   corr.

85-MM-154B-C2-1       3       0.0479      0.0064    0.87
85-MM-154B-C6-2       1       0.0718      0.0013    0.137
85-MM-154B-C4-2       1       0.0757      0.0021    0.189
85-MM-154B-C4-3       1       0.0691      0.0013    0.155
85-MM-154B-C4-1       1       0.0744      0.0017    0.458
85-MM-154B-C10-2      1       0.0714      0.0014    0.367
85MM154B-mz6-3        1       0.0706      0.0014    0.146
85MM154B-mz3-3        3       0.0923      0.0220    0.816
85-MM-154B-C4-4       1       0.0653      0.0010    0.234
85-MM-154B-C12-2      1       0.0697      0.0016    0.232
85MM154B-mz5-3        1       0.0663      0.0012    0.228
85-MM-154B-C6-1       1       0.0662      0.0013    0.042
85-MM-154B-C3-4       1       0.0673      0.0017    0.132
85MM154B-mz4-1        1       0.0664      0.0010    0.009
85-MM-154B-C3-3       1       0.0651      0.0012    0.091
85-MM-154B-C1-2       1       0.0644      0.0013    0.362
85-MM-154B-C5-1       1       0.0646      0.0011    0.108
85MM154B-mz1-1        1       0.0626      0.0063    0.469
85MM154B-mz5-2        1       0.0639      0.0009    0.154
85-MM-154B-C10-3      1       0.0665      0.0012    0.055
85MM154B-mz7-2        1       0.0667      0.0012    0.095
85MM154B-mz6-1        1       0.0700      0.0015    0.031
85-MM-154B-C7-1 #     1       0.0658      0.0011    0.153
85-MM-154B-C9-1 #     1       0.0650      0.0010    0.369
85MM154B-mz7-1        1       0.0651      0.0029    0.007
85-MM-154B-C1-1 #     1       0.0657      0.0014    0.023
85MM154B-mz2-2 #      1       0.0680      0.0029    0.124
85-MM-154B-C4-5 #     1       0.0660      0.0011    0.162
85MM154B-mz5-6        1       0.0646      0.0008    0.141
85-MM-154B-C3-2 #     1       0.0661      0.0015    0.114
85-MM-154B-C10-4 #    1       0.0653      0.0011    0.295
85-MM-154B-C10-1 #    1       0.0661      0.0011    0.044
85MM154B-mz6-4 #      1       0.0682      0.0014    0.22
85-MM-154B-C9-3 #     1       0.0669      0.0013    0.156
85MM154B-mz2-1 #      1       0.0669      0.0038    0.49
85MM154B-mz3-1        3       0.0682      0.0029    0.464
85-MM-154B-C9-2 #     1       0.0659      0.0013    0.091
85MM154B-mz6-2 #      1       0.0679      0.0012    0.125
85-MM-154B-C12-3      1       0.0665      0.0013    0.045
85-MM-154B-C12-1      1       0.0665      0.0012    0.103
85MM154B-mz5-4        3       0.0689      0.0016    0.706
85MM154B-mz4-2        2       0.0625      0.0019    0.752
85-MM-154B-C3-1       2       0.0610      0.0014    0.949
85MM154B-mz5-1        3       0.0650      0.0013    0.695
85MM154B-mz3-2        3       0.0652      0.0042    0.605

                                         Age (Ma)

spot                 C *   [sup.207]Pb/      2       [sup.
                           [sup.235]5U    [sigma]   206]Pb/
                                                     [sup.
                                                    238]8U

85-MM-154B-C2-1       3        1120         250       304
85-MM-154B-C6-2       1        905          27        447
85-MM-154B-C4-2       1        935          38        470
85-MM-154B-C4-3       1        732          20        430
85-MM-154B-C4-1       1        775          23        463
85-MM-154B-C10-2      1        729          20        444
85MM154B-mz6-3        1        668          14        440
85MM154B-mz3-3        3        840          280       569
85-MM-154B-C4-4       1        562          15        408
85-MM-154B-C12-2      1        550          34        434
85MM154B-mz5-3        1        521          21        414
85-MM-154B-C6-1       1        494          18        413
85-MM-154B-C3-4       1        498          23        419
85MM154B-mz4-1        1        477          11        414
85-MM-154B-C3-3       1        467          18        407
85-MM-154B-C1-2       1        445          16        402
85-MM-154B-C5-1       1        444          14        403
85MM154B-mz1-1        1        413          47        392
85MM154B-mz5-2        1        418          15        399
85-MM-154B-C10-3      1        430          15        415
85MM154B-mz7-2        1        427          13        416
85MM154B-mz6-1        1        444          15        437
85-MM-154B-C7-1 #     1        416          15        412
85-MM-154B-C9-1 #     1        410          11        406
85MM154B-mz7-1        1        410          52        406
85-MM-154B-C1-1 #     1        413        15 410
85MM154B-mz2-2 #      1        427          24        424
85-MM-154B-C4-5 #     1        414          13        412
85MM154B-mz5-6        1        405           9        403
85-MM-154B-C3-2 #     1        413          17        413
85-MM-154B-C10-4 #    1        408          13        408
85-MM-154B-C10-1 #    1        412          16        413
85MM154B-mz6-4 #      1        424          15        425
85-MM-154B-C9-3 #     1        415          14        418
85MM154B-mz2-1 #      1        415          26        418
85MM154B-mz3-1        3        420          79        424
85-MM-154B-C9-2 #     1        407          12        411
85MM154B-mz6-2 #      1        415          16        424
85-MM-154B-C12-3      1        406          14        415
85-MM-154B-C12-1      1        404          12        415
85MM154B-mz5-4        3        400          120       429
85MM154B-mz4-2        2        348          10        391
85-MM-154B-C3-1       2        336           7        381
85MM154B-mz5-1        3        290          110       406
85MM154B-mz3-2        3        240          120       407

                               Age (Ma)

spot                 C *      2        %
                           [sigma]   conc.
                                      (b)

85-MM-154B-C2-1       3      39      27.1
85-MM-154B-C6-2       1       8      49.4
85-MM-154B-C4-2       1      12      50.3
85-MM-154B-C4-3       1       8      58.8
85-MM-154B-C4-1       1      10      59.7
85-MM-154B-C10-2      1       9      60.9
85MM154B-mz6-3        1       9      65.8
85MM154B-mz3-3        3      140     67.7
85-MM-154B-C4-4       1       6      72.6
85-MM-154B-C12-2      1      10      78.9
85MM154B-mz5-3        1       7      79.5
85-MM-154B-C6-1       1       8      83.6
85-MM-154B-C3-4       1      10      84.1
85MM154B-mz4-1        1       6      86.9
85-MM-154B-C3-3       1       7       87
85-MM-154B-C1-2       1       8      90.4
85-MM-154B-C5-1       1       7      90.9
85MM154B-mz1-1        1      38      94.8
85MM154B-mz5-2        1       5      95.5
85-MM-154B-C10-3      1       7      96.5
85MM154B-mz7-2        1       8      97.5
85MM154B-mz6-1        1       9      98.4
85-MM-154B-C7-1 #     1       7       99
85-MM-154B-C9-1 #     1       6      99.1
85MM154B-mz7-1        1      17      99.1
85-MM-154B-C1-1 #     1       8      99.2
85MM154B-mz2-2 #      1      17      99.3
85-MM-154B-C4-5 #     1       7      99.6
85MM154B-mz5-6        1       5      99.6
85-MM-154B-C3-2 #     1       9       100
85-MM-154B-C10-4 #    1       7       100
85-MM-154B-C10-1 #    1       7      100.2
85MM154B-mz6-4 #      1       8      100.3
85-MM-154B-C9-3 #     1       8      100.6
85MM154B-mz2-1 #      1      23      100.6
85MM154B-mz3-1        3      18       101
85-MM-154B-C9-2 #     1       8      101.1
85MM154B-mz6-2 #      1       7      102.1
85-MM-154B-C12-3      1       8      102.2
85-MM-154B-C12-1      1       7      102.6
85MM154B-mz5-4        3      10      107.3
85MM154B-mz4-2        2      12      112.2
85-MM-154B-C3-1       2       9      113.4
85MM154B-mz5-1        3       8      140.1
85MM154B-mz3-2        3      26      169.6

Notes: C* = Common Pb correction (1-uncorrected for common-Pb;
2-common-Pb corrected using Andersen (2002) method; 3-common-Pb
corrected using the measured [sup.204]Pb). "calculated from
Andersen (2002) method; bcalculated as 100 x ([sup.206]Pb/
[sup.238]U age/[sup.207]Pb/[sup.235]U age). # signifies the
Samples numbers in bold and italic are used in final age
calculations.
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Author:Mohammadi, Nadia; Fyffe, Les; McFarlane, Christopher R.M.; Thorne, Kay G.; Lentz, David R.; Charnley
Publication:Atlantic Geology
Geographic Code:1U1ME
Date:Jan 1, 2017
Words:29335
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