Oxygen and carbon isotopic composition of carbonate rocks of the Permian Qixia Formation, Sichuan basin: thermal effects of Emeishan Basalt/Composicion isotopica de oxigeno y carbon en rocas de carbonato de la formacion de edad permica Qixia, en la Cuenca de Sichuan: efectos termicos del Basalto Emeishan.
The Middle Permian Qixia Formation is widely exposed on the margin of the Sichuan Basin. As a typical lithostratigraphic unit of the upper Paleozoic marine strata, this Formation can be used for stratigraphic correlation. The carbonate rocks of the Qixia Formation gradually change from "black Qixia" to "white Qixia" from the east to the west of the Sichuan Basin. The black Qixia is mainly comprised of medium-thick strata of dark grey limestone interbedded with shale and siliceous rocks, and it generally has dark colors and high contents of organic carbon. It is considered to be one of the four sets of marine source rocks in South China (Chen et al., 2010; Lv et al., 2010; Chen et al., 2012; Liu et al., 2014). The white Qixia is comprised of light grey blocks of limestone containing dolomitic limestone and dolomite, and it is mainly distributed throughout the northern sections of the Micang Mountain and the Longmen Mountain (Sichuan Provincial Bureau of Geology and Mineral Resources, 1991). This finding may reduce the significance of the traditional opinion that "the Qixia Formation is black and the Maokou Formation is while" in the case of western Sichuan Basin. For example, the Qixia Formation in the Qiaoting section in Nanjiang area, northeastern Sichuan, is made of overall grey-black limestone strata (Fig. 1a). Moreover, the Qixia Formation in the Changjianggou section in Jian'ge area, northwestern Sichuan, is generally of dark grey limestone, with grey dolomitic limestone forming the upper part (Fig. 1b). It is widely thought that the black Qixia was deposited in a deep water environment while the white Qixia was deposited in shallow water within a carbon platform (Hu et al., 2010; Chen, 2009). Previous work has shown Qixia Formation has the potential to become a hydrocarbon reservoir rock (Zeng et al., 2010; Hao et al., 2013; Tian et al., 2014). Thus, this regional variation of lithological features have elicited strong academic interest for deciphering the nature and development mechanism of this Formation.
Several studies have noticed abundant saddle dolomite and other types of dolomite that are characterized by curved-face and xenomorphic crystals with high homogenization temperatures (max. > 200[degrees]C) were found to be associated with dissolution pores, vugs and factures in the western part of the Sichuan Basin. The impact of geothermal activity has been invoked to explain the dolomitization mechanism (He and Feng, 1996; Wang and Jin, 1997; Chen et al., 2012; Hao et al., 2012; Li et al., 2012; Shu et al., 2012; Huang et al., 2013; Tian et al., 2014). In this paper, we focus on the influence of the related thermal events on the carbon and oxygen isotopic compositions of the marine carbonates of the Qixia Formation.
The global Permian carbonate rocks have stable and relatively high carbon isotopic compositions (Hermann et al., 2010; Saltzman and Thomas, 2012; Laya et al., 2013). In the carbon isotope curve of the Phanerozoic carbonates (Veizer et al., 1999), the central values of [delta][sup.13]C of the Permian rocks were concentrated in the range of 2.5-4.5[per thousand]. In the carbon isotope record of China's Upper Yangtze Permian, which had a higher resolution than that of the curve reported by Veizer et al. (1999), the [delta][sup.13]C values were also mostly in this range (Fig. 2a, Huang, 1997). A decline in [delta][sup.13]C, resulting from extinctions and replacements of life, was found near the Permian-Triassic boundary (Hiete et al., 2013;Tohver et al., 2013), indicating a high content and rapid burial of organic carbon in the global Permian.
[FIGURE 1 OMITTED]
The [delta][sup.18]O values of the global Permian carbonate rocks are mostly in the range of -3~6.5[per thousand], and the corresponding curve is lower than that of the Carboniferous and Triassic (Veizer et al., 1999). This could have occurred because the Permian seawater had a relatively high temperature, or because the thermal events after the depositional stage had an impact on the Permian carbonate rocks. The oxygen isotopic composition of the Upper Yangtze Permian (Huang, 1997) was lower than that of the same period in the curve reported by Veizer et al. (1999). There are two possible reasons for this. One, the samples used by Veizer et al. were more representative of seawater, as carbon isotopes are more easily preserved in carbonates than oxygen isotopes. The other possible reason is that the carbon isotope curve of China's Upper Yangtze Permian had a higher resolution than that of the curve reported by Veizer et al. (1999). As shown in the previously reported curve, the lower [delta][sup.18]O values of the Permian strata from Upper Yangtze were mainly occurred in: (1) the upper part of the Qixia Formation, (2) the top of the Maokou Formation, and (3) the top of the Permian. These three excursion may be associated with the thermal events related to Emeishan basalt eruption, the karstification related to the Dongwu Movement, and the increase in seawater temperature during the late Permian, respectively (Sun et al., 2012).
[FIGURE 2 OMITTED]
Though the curve of carbon isotope in China's Upper Yangtze Permian had a relatively high resolution, only 8 samples of the Qixia Formation were used in the research (Fig. 2a). For further understanding of the composition and variation in carbon and oxygen isotopes in the Qixia Formation, the research group conducted a study on the carbonate rocks of this Formation in two sections, which were located in the northeast and northwest of the Sichuan Basin. A total of 94 groups of carbon and oxygen isotope data were collected and studied through a comparative analysis. Moreover, the impact of the thermal events related to the Emeishan basalt erruption on the carbon and oxygen isotopic compositions of this Formation was discussed.
2. Geological Setting and Sampling
Samples were collected from the Qiaoting section in the northeast of the Sichuan Basin (Nanjiang County) and from the Changjianggou section in the northwest of the basin (Jian-ge County). According to the tectonic division of the Sichuan Basin (Liu et al., 2000), the two sections are parts of the fault zones of the Micang--Daba the Longmen Mountain--Panxi, respectively (Fig. 3). Currently, the linear distance between the two sections is about 130 km in a north-west direction. The initial distance between the sections was supposed to be significantly greater than 130 km, because the tectonic activities following the depositional stage, especially those related to the Himalayan orogeny, could affect the distance between the sections. For instance, the nappe belt on the front edge of the Longmen Mountain, where the Changjianggou section is located, might decrease this distance.
[FIGURE 3 OMITTED]
The Qixia Formation occurs in the western and northern edges of the Sichuan Basin. The triple division of the Permian has been widely used in stratigraphic studies in China and other countries (e.g. Li et al., 2005; Shen et al., 2005). In this paper, the Qixia and Maokou Formations were included in the Middle Permian in accordance with the triple divisions of the Permian marine facies in the Sichuan Basin (Jin et al.,1999; Li et al.,2005) as well as the stratigraphic classification in International Stratigraphic Chart (2008) (Zhang et al., 2009). In these division plans, however, the lower Permian was poorly developed or even absent in Sichuan basin. The lower Permian, comprised of the Liangshan Formation, is about 1m thick in the Changjianggou section and less than 1m in the Qiaoting section. Due to very thin-bedded layers, this Formation was not marked in the maps in this paper.
The large area of Late Paleozoic basalt (Emeishan basalt) sits along the western margin of the Yangtze Block (Huang and Opdyke,1998) and is supposed to have thermal effect on its underlying carbonate rocks. Zhu et al., (2010) has demonstrated that the paleo-heat flow in the west of the Sichuan Basin reached a maximum at the end of the middle Permian at about 259 Ma (Fig. 4a). In this period, the paleo-heat flows measured in most wells were 60-80 mW/[m.sup.2], while the values in a few wells exceeded 100 mW/[m.sup.2]. The paleo-heat flow characteristics reflected the thermal effect of the Emeishan basalt eruption during the late Paleozoic. When the paleo-heat flow peaked, the Permian Qixia Formation was at the shallow burial stage (Fig. 4b).
[FIGURE 4 OMITTED]
Samples used in the carbon and oxygen isotopic analysis were taken from the limestone matrix and dolomite matrix, avoiding the vug--or vein-filling calcite and dolomite crystals. Previous research indicated that the carbon and oxygen isotopic compositions of calcite and dolomite in vugs are lower than those of carbonate matrix (Huang et al., 2014). This research mainly involved the use of some geochemical methods, including carbon and oxygen isotopic analysis, as well as elemental analysis of some samples. The carbon and oxygen isotopic analysis was carried out at Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, and the CNNC Beijing Research Institute of Uranium Geology, with the use of MAT-252 Mass Spectrometry. The latter was responsible for conducting the test in accordance with the standard of Application of Phosphoric Acid Method to the Measurement of Carbon and Oxygen Isotopic Compositions of Carbonate Minerals or Rocks (DZ/T 0184.17-1997). The former was responsible for analyzing the accuracy of the test results using the Kiel IV Carbonate Device sampling system in accordance with the GBW-04405 standard. The standard deviations of the [delta][sup.13]C (PDB) and [delta][sup.18]O (PDB) values were smaller than 0.040 and 0.080, respectively.
The analysis of the contents of CaO, MgO, Mn, Sr, and Fe contents was performed at the Geological and Mineralogical Testing Center of Huayang in Sichuan province. The CaO and MgO contents were measured using normal chemical analysis, with the limit of detection set at 1%. The relative errors of CaO and MgO measurements were 2% and 5%, respectively. The contents of Mn and Sr were determined by atomic absorption spectrometry, with the limits of detection set at 5 x [10.sup.-6] and 42 x [10.sup.-6], respectively. The relative errors of the measurements were 13% and 14%, respectively. The Fe content was determined by colorimetry, with the limit of detection set at 0.01%. The relative error of the result was less than 8%
4. Results and Discussion
Table 1 exhibits the analysis results pertaining to the carbon and oxygen isotopes in 94 carbonate samples from the Qixia Formation in Qiaoting, Nanjiang, and Changjianggou, Jian'ge. The data of 22 samples marked with '[DELTA]' in table 1 have been published by Lv (2013). In addition to the isotopic data, the contents of Ca, Mg, Sr, Mn, and Fe and the corresponding Mn/Sr ratios of 69 of the 94 samples are also given for an understanding of the mineral compositions (relative contents of calcite and dolomite), representativeness, and diagenetic alteration of the samples.
4.1 Elemental compositions and their implication for diagenetic alteration
According to the elemental analysis, the average values of Mn, Fe, and Sr contents in the 69 samples were 48.8 ppm, 729.1 ppm, and 331.5ppm, respectively. Kaufman et al. (1992; 1993) employed Mn/Sr ratio<2~3 as criterion for selecting carbonate samples in which the isotopic values are considered to be proxy for those of seawater. Most of our samples have rather low Mn and Fe contents and relatively high Sr content and the average Mn/Sr ratio was very low, of only 0.31. However, among the aforementioned 69 samples, there were four samples with Mn content higher than 200ppm, having values at 818 ppm, 278 ppm, 406 ppm and 326ppm. Three of these four samples had very high Fe content as well, having values at 10442 ppm, 2724 ppm, and 14987 ppm, corresponding to the first three high Mn values listed above. The curves of carbon and oxygen isotopes in the subsequent discussion indicated that, among the three samples with both high Mn and Fe contents, two samples exhibited very low [delta][sup.13]C and [delta][sup.18]O values, which deviated from the overall trend. These two samples were collected from the bottom of the Qixia Formation in the Qiaoting section, which was adjacent to the Liangshan Formation. It was speculated that these samples were affected by some [sup.12]C--and [sup.16]O-rich fluids that were associated with the clastic rock strata.
The carbonates of the Qixia Formation in the Qiaoting section and the Changjianggou section did not vary substantially in Fe and Mn contents, except for the aforementioned three samples with high Mn and Fe contents. The average Mn contents of the two sections were 47.3 ppm and 52.1 ppm, and their average Fe contents were 322.7 ppm and 344.2 ppm, respectively. The Sr content in the Qixia Formation was significantly higher in the Qiaoting section than in the Changjianggou section. Their average Sr contents were 421.0 ppm and 140.2 ppm, respectively. The Mn/ Sr ratio of the Qixia Formation in the Qiaoting section was 0.05, which is much lower than the ratio of 0.74 in the Changjianggou section. Overall, it can be concluded that geochemical information of these samples are not significantly affected by non-seawater-like fluids such as meteoric fluids, which would lead to enrichment of Mn, Fe and higher Mn/Sr ratio.
4.2 Carbon and oxygen isotopes
Though the carbonates of the Qixia Formation in the two sections did not vary substantially in terms of elemental composition, their carbon and oxygen isotopic compositions varied greatly from one another (Table 1, Fig. 5, and Fig. 6). Selecting the boundary of Carboniferous-Permian and boundary of Qixia and Maokou Formation as joint, by which the [delta][sup.13]C and [delta][sup.18]O profile of sections in this research and previous study could be compiled. The carbon isotopic compositions of carbonates of the Qixia Formation in the Qiaoting section were relatively stable, except for two samples from the bottom that were affected by the clastic rocks of terrigenous origin in the Liangshan Formation. The [delta][sup.13]C values of the samples ranged from 2.7[per thousand] to 5.2[per thousand], with the average being 4.2[per thousand]. This carbon isotopic composition was close to that of the global seawater of the period (Veizer et al., 1999). The high and stable [delta][sup.13]C values of the marine carbonates in the Qixia Formation reflected a good ecological status of the Earth, stable species and populations of marine invertebrates with calcareous shells, and fast and continuous burial of organic carbon during this period.
In contrast, the Qixia Formation in the Changjianggou section exhibited significant variations and negative excursions in [delta][sup.13]C and [delta][sup.18]O records. The [delta][sup.13]C values were between -1[per thousand] and 3.8[per thousand], and the average was 1.5[per thousand], which was significantly lower than that of the Qixia Formation in the Qiaoting section and the global seawater of the same period (Veizer et al., 1999). The low [delta][sup.13]C values were mainly distributed throughout the middle part of the Qixia Formation (the bottom of the second member of the Formation); the [delta][sup.13]C values of samples from this part were mostly between -1[per thousand] and 1[per thousand]. Despite Qixia Formation in the Changjianggou section and Qiaoting section was deposited in a shallow-water platform facies and an open platform facies, respectively (Huang et al., 2004), such difference could not lead to the observed variation in [delta][sup.13]C values due to its insensitive to spatial factor.
It is more difficult to measure the oxygen isotopic compositions of carbonates that can represent seawater in geologic history. In the curve of oxygen isotope in Phanerozoic carbonates reported by Veizer et al. (1999), the oxygen isotopic compositions of marine carbonates showed an overall upward trend over time in the geologic history. In the Qiaoting section, however, the oxygen isotopic compositions of the carbonates of the Qixia Formation were relatively stable overall, ranging from -3.8[per thousand] to 7.8[per thousand] with an average of -5.4[per thousand]. This was slightly lower than that of the global seawater of the same period (Veizer et al., 1999). In contrast, the carbonates of the Qixia Formation in the Changjianggou section showed a significant variation and a negative excursion in oxygen isotopic composition. The [delta][sup.18]O values mostly ranged from -2.1[per thousand] to -9.2[per thousand], and the average was -6.0[per thousand], which is significantly lower than that of both the Qixia Formation in the Qiaoting section and the global seawater of this period reported by Veizer et al. (1999).
[FIGURE 5 OMITTED]
Marine carbonates are the largest inorganic carbon pool in nature. The carbon contents of most diagenetic fluids are relatively low compared to carbonate rock itself, indicating that carbon sources are buffered by the carbonates rather than fluid during diagenesis. As a result, the information about carbon isotope in seawater can be well preserved in carbonate rocks, especially the micritic carbonates that are characterized by low porosity and permeability. Because the possibility of meteoric influence has been ruled out during the sampling and data selecting process, The distinctly low [delta][sup.13]C values of the carbonates of the Qixia Formation in the Changjianggou section indicated that carbon sources with low [delta][sup.13]C values participated in carbonate formation when the rocks still had relatively high porosity and permeability, which lead to high water/rock ratio. Such process could not be involved in the normal thermal evolution of burial diagenesis sequence, because the rock would be highly compacted after high volumes of C[O.sub.2] have been released by the organic matter. In this case, the water/rock ratios were relatively low thus organic carbon's input was not available. Davies (2004) proposed the term "forced maturation" for the alteration of kerogen in host limestones during transient thermal anomalies. Davies and Smith Jr. (2006) pointed out that this process precedes regional burial maturation of organic material. Therefore, we suggested certain unusual thermal events took place in the early stage of diagenesis and caused early forced maturation of organic matter, subsequently decreasing the [delta][sup.13]C values of carbonates by the entrance of carbon sources with low [delta][sup.13]C values. In summary, the lower carbon & isotopic composition of the carbonates of Qixia Formation in the Changjianggou section suggested that the thermal events in the early stage of diagenesis had a greater influence on the Changjianggou section.
[FIGURE 6 OMITTED]
The oxygen isotopic composition of carbonates is quite sensitive to temperature, and the decrease in the [delta]18O values of carbonates is usually caused by isotope fractionation resulting from rising temperature. The lower oxygen isotopic composition of the carbonates of the Qixia Formation in the Changjianggou section suggested that the Qixia Formation in this section had experienced higher temperatures during diagenesis. Due to the influence of the thermal events related to the eruption of the Emeishan basalt, the paleoheat flow in the western Sichuan Basin reached the highest level during the end of the middle Permian. The maximum paleo heat flows experienced by most wells were between 60 and 80 mW/[m.sup.2], and a few wells have exhibited maximum paleo heat flows higher than 100 mW/[m.sup.2] (Zhu et al., 2010). During this period, the Qixia Formation was at the stage of shallow burial (depth=500~100m) (Fig. 1b). The thermal events associated with the Emeishan basalt eruption could reduce the oxygen isotopic composition of the carbonates in the areas affected by the events and cause forced evolution and maturation of the organic matter. This was especially important to the Qixia Formation because of the extremely rapid burial of organic carbon in this Formation. Moreover, the release of C[O.sub.2] by organic carbon sources during the process can further change the carbon isotopic composition of the affected carbonates. Therefore, the Qiaoting section in Nanjiang, which is farther from the basalt area, was less affected by basalt eruption. This could be the major reason for the lower carbon and oxygen isotopic compositions of the carbonates of the Qixia Formation in the Changjianggou section in the west of the Sichuan Basin.
Numerous studies suggest that dolomite formed from seawater would have higher [delta]18O than calcite (eg. Fouke,1994). Several experimental determinations have been carried out for measuring carbonate-water oxygen isotopes fractionation factor and concluded that the fractionation factor of Oxygen will increase during Ca substitution by Mg (eg. Tarutani et al., 1969; Jimenez-Lopez et al., 2004). The rate of change between the [delta][sup.18]O of dolomite and Mg content has been estimated from the difference in [delta][sup.18]O between coprecipitated dolomite and calcite (Vahrenkamp and Swart, 1994). Such estimates for [DELTA][delta][sup.18]Odolo-cal at 25[degrees]C, based on experiments and theoretical calculations, include 4 to 7[per thousand] (Northrop and Clayton, 1966; O'Neil et al., 1969; Matthews and Katz, 1977; Clayton et al., 1989), 2.6 to 4[per thousand] (Fritz and Smith, 1970; Vahrenkamp and Swart, 1994; Schmidt et al., 2005; Vasconcelos et al., 2005;Chacko and Deines, 2008), 3[per thousand] (Land, 1980). Although such values can be translated to 0.05-0.14[per thousand] increase in [delta][sup.18]O per 1%Mg increase, the magnitude of that increase for dolomite is poorly constrained for different temperature condition. Therefore, dolomitization effect are not likely to have significantly contributed to the overall patterns of oxygen isotopic records thus it is not quantified in the current discussion. In addition, given the fact that dolomitization degree in carbonates from Changjianggou section is generally higher than that from Qiaoting section (Li et al., 2015), the difference of temperature effects between these two sections would be higher if we take the effect of A[delta][sup.18]O between dolomite and calcite into account.
The discussion above should lead to the conclusion that, in the areas heavily influenced by the eruption of Emeishan basalt, such as the western part of the Sichuan Basin and some regions in Yunnan and Guizhou Provinces, the organic carbon has experienced forced maturation and oxidation in the early stage of diagenesis due to the thermal effects of the basalt eruption. This might have an adverse impact on hydrocarbon generation in the later stage. Huang and Wang (2008) have noticed that the thermal maturity of bitumen veins in the Kuangshanliang area in Northwestern Sichuan, which is near the Changjianggou section, had high thermal maturities. They proposed that this was caused by thermal alteration and diffusion during deep burial rather than by biodegradation. The thermal events associated with the Emeishan basalt eruption could be another cause of the high thermal maturities of the bitumen veins. Furthermore, the hydrocarbon exploration potential of the areas under the influence of the thermal events may have been reduced due to the early forced maturation and oxidation of organic matter.
The marine carbonates of the global Permian Qixia Formation have very high carbon isotopic composition, indicating an ecological prosperous status, and fast and continuous burial of organic carbon during this period. However, Qixia Formation in two sections, the Qiaoting section in the northeast and the Changjianggou section in the northwest of the Sichuan Basin, varied significantly in carbon and oxygen isotopic compositions.
The carbon and oxygen isotopic compositions of the carbonates of the Qixia Formation in the Qiaoting section vary relatively stable; the [delta][sup.13]C values ranged from 2.7[per thousand] to 5.2[per thousand] (mostly around 4[per thousand]), with an average of 4.2[per thousand], and the [delta][sup.18]O values ranged from -3.8[per thousand] to -7.8[per thousand], with an average of -5.4[per thousand]. Both the carbon and oxygen isotopic compositions of the carbonates were close to those of the global seawater of this period.
The carbonates of the Qixia Formation in the Changjianggou section exhibited significant variations and negative excursions in [delta][sup.13]C and [delta][sup.18]O records. The [delta][sup.13]C values were between -1[per thousand] and 3.8[per thousand], and the average was 1.5[per thousand], which is significantly lower than that of the global seawater of the period. The [delta][sup.18]O values were mostly in the -2.1 to -9.2[per thousand] range, and the average was -6.0[per thousand], which is also significantly lower than that of the global seawater of the period.
Most of the carbonate samples from the Changjianggou and Qiaoting sections had very low Mn and Fe contents and a relatively high Sr content. The elemental composition characteristics indicated that the samples from both sections have been diagenetically altered to a small degree and thus were representative of seawater of that period. Therefore, it is unreasonable to attribute the differences between the carbon and isotopic compositions in the two sections of the Qixia Formation to only diagenetic alteration.
The low carbon and oxygen isotopic compositions of the samples from the Changjianggou section were associated with the proximity to the eruption center of the Emeishan basalt. The thermal effect of the related thermal events reduced the oxygen isotopic composition of the carbonates. The high temperature forced the organic matter to mature rapidly, and the C[O.sub.2] released by organic carbon sources during the thermal evolution entered the carbonates, thus resulting in a decline in the [delta][sup.13]C values.
The early forced maturation and oxidation of organic matter may have reduced the hydrocarbon exploration potential of the areas heavily influenced by the eruption of Emeishan basalt, such as western Sichuan Basin and some regions in Yunnan and Guizhou Provinces.
This study was supported by the National Natural Science Foundation of China (41272130, 41172099). We also wish to acknowledge the support provided by Key Laboratory for Sedimentary Basin and Oil and Gas Resources of MLR, Grant zdsys2014003 as well as State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Grant PLC201308. In addition, Lv Jie and Lan Yefang are thanked for helpful discussion during field work.
Chacko, T. and Deines, P. (2008). Theoretical calculation of oxygen isotope fractionation factors in carbonate systems: Geochimica et Cosmochimica Acta. 72, 3642-3660.
Chen, H.; Xie, X.N.; Li, H.J.; Su, M.; Peng, W.; Hu, C.Y. (2010). Evaluation of the Permian marine hydrocarbon source rocks at Shangsi section in Sichuan Province using multi-proxies of paleoproductivity and paleoredox. Journal of Palaeogeography. 12, 324-333 (in Chinese with English abstract).
Chen, J.P.; Liang, Q.G.; Zhang, S.C.; Deng, C.P.; Zhao, Z.; Zhang, D.J. (2012). Evaluation criterion and methods of the hydrocarbon generation potential for China's Paleozoic marine source rocks. Acta Geologica Sinica. 86, 1132-1142 (in Chinese with English abstract).
Chen, X.; Zhao, W.Z.; Zhang, L.P.; et al. (2012). Discovery and exploration significance of structure-controlled hydrothermal dolomites in the Middle Permian of the central Sichuan Basin. Acta Petrolei Sinica, 33 (4), 562-569 (in Chinese with English abstract).
Chen, Z.Q. (2009). Discussion on Gas Exploration of Middle Permian Qixia Formation, Sichuan Basin. Natural gas geoscience. 20 (3), 325-334 (in Chinese with English abstract).
Clayton, R.N.; Goldsmith, J.R.; Mayeda, T.K. (1989). Oxygen isotope fractionation in quartz, albite, anorthite and calcite. Geochimica et Cosmochimica Acta. 53, 725-733.
Davies, G.R. (2004). Hydrothermal (thermobaric) dolomitization: Rock fabrics and organic petrology, in R. McAuley, ed., Dolomites--The spectrum: Mechanisms, models, reservoir development: Canadian Society of Petroleum Geologists, Seminar and Core Conference. January 13-1. Calgary, Extended Abstracts, CD format.
Davies, G.R. and Smith, Jr., L.B. (2006). Structurally controlled hydrothermal dolomite reservoir facies:an overview. AAPG Bulletin. 90/11, 1641-1690.
Fouke, B.W. (1994). Deposition, diagenesis and dolomitization of Neogene Seroe Domi Formation coral reef limestones on Curacao, Netherlands Antilles: Foundation for Scientific Research in the Caribbean Region. 133, 1-182.
Fritz, P. and Smith, D.G.W. (1970). The isotopic composition of secondary dolomites. Geochimica et Cosmochimica Acta. 34, 1161-1173.
Hao, Y.; Lin, L.B.; Zhou, J.G.; Ni, C.; Zhang, J.Y. Chen, W. (2012). Characteristics and genesis of leopard limestone in Middle Permian Qixia Formation, Northwest Sichuan, China. Journal of Chengdu University of Technology (Science & Technology Edition). (6), 651-656 (in Chinese with English abstract).
He, YB. and Feng, Z.Z. (1996). Origin of Fine--to Coarse-grained Dolostones of Lower Permian in Sichuan Basin and Its Peripheral Regions. Journal of Jianghan Petroleum Institute, 18 (4), 5-20 (in Chinese with English abstract).
Hermann, E.; Hochuli, P.A.; Bucher, H.; Vigran, J.O.; Weissert, H.; Bernasconi, S.M. (2010). A close-up view of the Permian-Triassic boundary based on expanded organic carbon isotope records from Norway (Trondelag and Finnmark Platform). Global and Planetary Change, 74, 156-167.
Hiete, M.; Roehling, H.; Heunisch, C.; Berner, U. (2013). Facies and climate changes across the Permian-Triassic boundary in the North German Basin; insights from a high-resolution organic carbon isotope record Paleozoic climate cycles; their evolutionary and sedimentological impact. Special Publication-Geological Society of London. 376, 549-574.
Hu, M.Y; Wei, G.Q.; Hu, Z.G.; Yang, W.; Hu, J.Z.; Liu, M.C.; Wu, L.Q.; Xiang, J. (2010). Sequence-lithofacies palaeogeography of the Middle Permian Qixia Formation in Sichuan Basin. Journal of Palaeogeography. 12 (5), 515-526 (in Chinese with English abstract).
Huang, D.F.; Wang, L.S. (2008). Geochemical characteristics of bituminous dike in Kuangshanliang area of the Northwestern Sichuan Basin and its significance. Acta Petrolei Sinica, 29 (1), 23-28 (in Chinese with English abstract).
Huang, K.; Opdyke, N.D.; Huang, K.N.; Opdyke, N.D. (1998). Magnetostratigraphic investigations on an Emeishan basalt section in western Guizhou province, China. Earth & Planetary Science Letters. 163 (1-4), 1-14.
Huang, S.J. (1997). A study of Carbon and Strontium Isotope of Late Paleozoic Carbonate Rocks in the Upper Yangtze Platform. Acta Geologica Sinica, 71 (1), 45-53 (in Chinese with English abstract).
Huang, S.J.; Lan, Y.F.; Huang, K.K.; Lv, J. (2014). Vug fillings and records of hydrothermal activity in Qixia Formation of Middle Permian, western Sichuan Basin. Acta Petrologica Sinica. 30 (3), 687-698 (in Chinese with English abstract).
Huang, S.J.; Pan, X.Q.; Lv, J.; Qi, S.C.; Huang, K.K.; Lan, Y.F.; Wang, C.M. (2013). Hydrothermal dolomitization and subsequent retrograde dissolution in Qixia Formation, West Sichuan: a case study of incomplete and halfway-back dolomitization. Journal of Chengdu University of Technology (Science & Technology Edition). 40 (3), 288-300 (in Chinese with English abstract).
Huang, X.P.; Yang, T.Q.; Zhang, H.M. (2004). Research on the sedimentary faces and exploration potential areas of lower Permian in Sichuan Basin. Natural Gas Industry, 24 (1), 10-12 (in Chinese with English abstract).
Jimenez-Lopez, C.; Romanek, C.S.; Huertas, F.J.; Ohmoto, H.; Caballero, E. (2004). Oxygen isotope fractionation in synthetic magnesian calcite. Geochimica et Cosmochimica Acta. 68, 3367-3377.
Jin, Y.G.; Wang, X.D.; Shang, Q.H.; Wang, Y; Sheng, J.Z. (1999). Chronostratigraphic subdivision and correlation of The Permian in China. Acta geologica Sinica. 73 (2), 97-108 (in Chinese with English abstract).
Kaufman, A.J.; Jacobsen, S.B.; Knoll, A.H. (1993). The Vendian record of Srand C-isotope variations in seawater: implications for tec-tonics and paleoclimate. Earth and Planetary Science Letters, 120, 409-430.
Kaufman, A.J.; Knoll, A.H.; Awramik, S.M. (1992). Biostratigraphic and chemostratigraphic correlation of Neoproterozoic sedimentary successions: Upper Tindir Group, northwestern Canada, as a test case. Geology, 20, 181-185.
Land, L.S. (1980). The isotopic and trace element geochemistiy of dolomite: The state of the art, in Zenger, D.H., Dunham, J.B., and Ethington, R.L., eds., Concepts and models of dolomitization: Society of Economic Paleontologists and Mineralogists Special Publication. 28, 87-110.
Laya, J.C.; Tucker, M.E.; Groecke, D.R.; Perez-Huerta, A. (2013).Carbon, oxygen and strontium isotopic composition of low-latitude Permian carbonates (Venezuelan Andes); climate proxies of tropical Pangea (in Paleozoic climate cycles; their evolutionary and sedimentological impact. Special Publication-Geological Society of London. 376 (1): 367-385.
Li, B.; Yan, J.X.; Xue, W.Q.; Ma, Z.X.; Li, A.Z. (2012). Origin of patchy dolomite and Its Geological Signification from Middle Permian, Guangyuan, Sichuan Province. Earth Science-Journal of China University of Geosciences. (Suppl.2), 136-146 (in Chinese with English abstract).
Li, G.H.; Li, X.; Song, S.Y; Song, W.H.; Yang, X.N. (2005). Dividing Permian into 3 series and its significance in Sichuan basin. Natural Gas Exploration and Development. 28 (3), 20-25 (in Chinese with English abstract).
Liu, D.L.; Song, Y.; Xue, A.M.; Li, Y.P.; Luo, Z.L.; Shen, X.Z.; Yang, X.Y.; Zhang, Z.W.; Tao, S.Z. (2000). A comprehensive research on tectonic and gas accumulation zone of Sichuan basin. Publishing House of Oil Industry (in Chinese).
Liu, X.T.; Yan, J.X.; Xue, W.Q.; Ma, Z.X.; Li, B. (2014). The geobiological formation process of the marine source rocks in the Middle Permian Chihsia Formation of South China. Science China: Earth Science 44 (6), 1185-1192.
Lv, B.Q.; Cai, J.G.; Liu, F.; Shao, L.; Wang, H.G.; Quan, S.Q. (2010). Upwelling deposits at the marginal slope of a carbonate platform in Qixia stage and its relation with hydrocarbon source rocks. Marine Geology& Quaternary Geology. 30 (5), 109-118 (in Chinese with English abstract).
Lv, J. (2013). Formation mechanism of the lower Permian dolomites in western Sichuan Basin. Chengdu university of technology (in Chinese with English abstract).
Matthews, A. and Katz, A. (1977). Oxygen isotope fractionation during the dolomitization of calcium carbonate. Geochimica et Cosmochimica Acta. 41, 1431-1438.
Northrop, D.A. and Clayton, R.N. (1966). Oxygen isotope fractionation in systems containing dolomite. J. Geol. 74, 174-196.
O'Neil, J.R.; Mayeda, T.K.; Clayton; R.N. (1969). Oxygen isotope fractionation in divalent metal carbonates. J. Chem. Phys. 51, 5547-5558.
Saltzman, M.R.; Thomas, E. (2012). Carbon isotope stratigraphy. In: Gradstein F M, Ogg J M, Schmidt M D, Ogg G (Eds). The Geologic Time scale, Elsevier. 207-232.
Schmidt, M.; Xeflide, S.; Botz, R.; Mann, S. (2005). Oxygen isotope fractionation during synthesis of CaMg-carbonate and implications for sedimentary dolomite formation: Geochimica et Cosmochimica Acta. 69, 4665-4674.
Shen, S.Z.; Wang, Y.; Jin, Y.G. (2005). Progress Report on the Global Stratotype Sections and Points (GSSPs) of the Permian system. Journal of Stratigraphy, 2, 138-146 (in Chinese with English abstract).
Shu, X.H.; Zhang, J.T.; Li, G.R.; Long, S.X.; Wu, S.X.; Li, H.T. (2012). Characteristics and genesis of hydrothermal dolomites of Qixia and Maokou Formations in northern Sichuan Basin. Oil& Gas Geology. 33 (3), 442-448, 458 (in Chinese with English abstract).
Sichuan Provincial Bureau of Geology and mineral resources. (1991). Sichuan Province geological map of the people's Republic of China (1:1 000 000). Beijing:Geological Publishing House (in Chinese).
Sichuan Provincial Bureau of Geology and mineral resources. (1991). Regional geology of Sichuan Province. Beijing: Geological Publishing House 186 (in Chinese).
Song, W.H. (1985). Distribution pf Permian dolomite and natural gas exploration in Sichuan Basin. Natural Gas Industry, 5 (4), 16-23 (in Chinese with English abstract).
Sun, Y.D.; Joachimski, M.M.; Wignall, P.B.; Yan, C.B.; Chen, Y.L.; Jiang, H.S.; Wang, L.; Lai, X.l. (2012). Lethally hot temperatures during the early Triassic greenhouse. Science, 338 (6105), 366-370.
Tarutani, T.; Clayton, R.N; Mayeda, T.K. (1969). The effect of polymorphism and magnesium substitution on oxygen isotope fractionation between calcium carbonate and water. Geochim. Cosmochim. Acta. 33, 987-996.
Tian, J.C.; Lin, X.B.; Zhang, X.; Peng, S.F.; Yang, C.Y.; Luo, S.B.; Xu, L. (2014). The genetic mechanism of shoal facies dolomite and its additive effect of Permian Qixia Formation in Sichuan Basin. Acta Petrological Sinica. 30 (3), 679-686 (in Chinese with English abstract).
Tohver, E.; Cawood, P.A.; Riccomini, C.; Lana, C.; Trindade, RIF. (2013). Shaking a methane fizz; seismicity from the Araguainha impact event and the Permian-Triassic global carbon isotope record. Palaeogeography, Palaeoclimatology, Palaeoecology. 387, 66-75.
Vahrenkamp, V.C. and Swart, P.K. (1994). Late Cenozoic dolomites of the Bahamas: metastable analogues for the genensis of ancient platform dolomites, in Purser, B., Tucker, M. and Zenger D., eds., Dolomites: A volume in honor of Dolomieu: International Association of Sedimentologists Special Publication. 21, 133-153.
Vasconcelos, C.; McKenzie, J.A.; Warthmann, R.; Bernasconi, S.M. (2005). Calibration of the [delta]18O paleothermometer for dolomite precipitated in microbial cultures and natural environments: Geology. 33, 317-320.
Veizer, J.; Ala, D.; Azmy, K.; Bruckschen, P.; Buhl, D.; Bruhn, F.; Carden, G.A.F; Diener, A.; Ebneth, S.; Godderis, Y.; Jasper, T.; Korte, C.; Pawellek. F.; Podlaha, O.G.; Stauss, H. (1999). 87Sr/86Sr, [delta]13C and [delta]18O evolution of Phanerozoic seawater. Chemical Geology, 161, 59-88.
Wang, Y.S. and Jin, Y.Z. (1997). The formation of dolomite and paleokarst of the Lower Permian series in Sichuan Basin and the relation to the Emei taphrogenesis. Journal of Chengdu University of Technology, 24 (1), 8-16 (in Chinese with English abstract).
Zeng, D.M.; Shi, X.; Wang, X.Z.; Huang, Y.; Yang, Y.M. (2010). Features and distribution of Shoal facies reservoirs in the Lower Permian Qixia Formation, northwest Sichuan, China. Natural Gas Industry. 30 (12), 25-28, 122 (in Chinese with English abstract).
Zhang, S.G.; Zhang, Y.B.; Yan, H.J. (2009). A Brief introduction to the "International Stratigraphic Chart" (2008).Journal of Stratigraphy. 33 (1), 1-10 (in Chinese with English abstract).
Zhu, C.Q.; Xu, M.; Shan, J.N.; Yuan, Y.S.; Zhao, Y.Q.; Hu, S.B. (2009). Quantifying the denudations of major tectonic events in Sichuan basin. Constrained by the paleothermal records. Geology in China. 36 (6), 1268-1277 (in Chinese with English abstract).
Zhu, C.Q.; Xu, M.; Yuan, Y.S.; Zhao, Y.Q.; Shan, J.N.; He, Z.G.; Tian, Y.T.; Hu, S.B. (2010). Palaeo-geothermal response and record of the effusing of Emeishan basalts in Sichuan Basin. Chinese Science Bulletin. 55 (6), 474-482 (in Chinese with English abstract).
Huang Keke (1,2), Zhong Yijiang (1,2) *, Li Xiaoning (1,2) and Hu Zuowei (1,2)
(1) State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, CDUT, Chengdu 610059 China
(2) Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China
* Corresponding author. E-mail:email@example.com
Manuscript received: 08/08/2015
Accepted for publication: 09/10/2015
How to cite item
Table 1. Carbon and oxygen isotopic compositions of carbonates of the Qixia Formation in Qiaoting, Nanjiang and Changjianggou, Jian'ge, and contents of Ca, Mg, Sr, Mn and Fe in the samples and corresponding Mn/Sr ratio Changjianggou, Jian'ge, and contents of Ca, Mg, Sr, Mn and Fe in the samples and corresponding Mn/Sr ratios Section Sample No. Sample type Thickness (m) Changjianggou JG1 limestone 0 Changjianggou JG6 limestone 3.74 Changjianggou JG7 limestone 4.37 Changjianggou JG8 limestone 4.84 Changjianggou JG9 limestone 5.53 Changjianggou JG10 limestone 6.22 Changjianggou JG11 limestone 8.09 Changjianggou JG12 limestone 9.8 Changjianggou JG13 limestone 10.8 Changjianggou JG15 limestone 12.5 Changjianggou JG16 limestone 13.12 Changjianggou JG18 limestone 15.98 Changjianggou JG22 limestone 24.51 Changjianggou JG23 limestone 27.22 Changjianggou JG25 limestone 31.57 Changjianggou JG26 dolomitized limestone 32.66 Changjianggou JG27 limestone 34.36 Changjianggou JG28 limestone 35.04 Changjianggou JG29 limestone 35.76 Changjianggou JG30 limestone 36.15 Changjianggou JG31 limestone 38.1 Changjianggou JG32 limestone 39.49 Changjianggou JG34 limestone 42.64 Changjianggou JG35 limestone 43.19 Changjianggou JG36 limestone 44.58 Changjianggou JG37 limestone 45.88 Changjianggou JG39-2 limestone 48.32 Changjianggou JG41 limestone 49.92 Changjianggou JG43 limestone 51.58 Changjianggou JG44 limestone 53.5 Changjianggou JG45-1 limestone 54.33 Changjianggou JG47 dolomitized limestone 58.06 Changjianggou JG48 dolomitized limestone 59.2 Changjianggou JG49 calcitic dolomite 60.13 Changjianggou JG50 dolomitized limestone 62.03 Changjianggou JG51-1 dolomitized limestone 63.29 Changjianggou JG52 calcitic dolomite 66.57 Changjianggou JG53 dolomitized limestone 69.09 Changjianggou JG54-1 dolomitized limestone 69.78 Changjianggou JG55-1 limestone 72.75 Changjianggou JG56 limestone 79.06 Changjianggou JG57 dolomitized limestone 79.95 Changjianggou JG58 limestone 80.46 Changjianggou JG59 dolomitized limestone 80.67 Changjianggou JG60 limestone 82.46 Changjianggou JG61 dolomitized limestone 83.7 Changjianggou JG62 limestone 83.7 Qiaoting LJ-A limestone 1.67 Qiaoting LJ-B limestone 3.35 Qiaoting LJ-D limestone 16.74 Qiaoting LJ-F limestone 19.69 Qiaoting LJ-B2 limestone 22.72 Qiaoting LJ-B4 limestone 24.9 Qiaoting LJ-B5-1 dolomitized limestone 25.34 Qiaoting LJ-B6 limestone 25.86 Qiaoting LJ6 limestone 27.45 Qiaoting LJ7-1 calcitic dolomite 28.33 Qiaoting LJ7 dolomitized limestone 28.33 Qiaoting LJ8A-1 dolomite 28.49 Qiaoting LJ8A calcitic dolomite 28.49 Qiaoting LJ08 limestone 28.49 Qiaoting LJ09 limestone 28.64 Qiaoting LJ10 limestone 28.72 Qiaoting LJ11 limestone 28.92 Qiaoting LJ12 limestone 29.12 Qiaoting LJ13-1 dolomite 29.36 Qiaoting LJ13 limestone 29.36 Qiaoting LJ14-1 dolomite 31.03 Qiaoting LJ14 limestone 31.03 Qiaoting LJ15-1 dolomite 32.23 Qiaoting LJ15 limestone 32.23 Qiaoting LJ16-2 dolomite 33.42 Qiaoting LJ18 limestone 36.42 Qiaoting LJ20 limestone 37.44 Qiaoting LJ22 limestone 39.53 Qiaoting LJ24 limestone 42.86 Qiaoting LJ26 limestone 44.56 Qiaoting LJ28 limestone 45.88 Qiaoting LJ30 limestone 47.6 Qiaoting LJ32 limestone 48.75 Qiaoting LJ34 limestone 51.15 Qiaoting LJ35-1 calcitic dolomite 51.9 Qiaoting LJ35 calcitic dolomite 51.9 Qiaoting LJ38-1 calcitic dolomite 53.79 Qiaoting LJ38 calcitic dolomite 53.79 Qiaoting LJ41 limestone 57.06 Qiaoting LJ43 limestone 59.06 Qiaoting LJ45 limestone 61.38 Qiaoting LJ46 limestone 66.48 Qiaoting LJ48 limestone 69.93 Qiaoting LJ50 limestone 76.37 Qiaoting LJ51 limestone 78.83 Qiaoting LJ52 limestone 81.76 Qiaoting LJ54-1 dolomite 83.98 Section Sample No. [delta][sup.13]C [delta][sup.18]O PDB ([per thousand]) PDB ([per thousand]) Changjianggou JG1 -0.48 -4.08 Changjianggou JG6 1.4 -4.4 Changjianggou JG7 2.2 -3.7 Changjianggou JG8 2.3 -4.7 Changjianggou JG9 1.9 -6.2 Changjianggou JG10 1.9 -4.1 Changjianggou JG11 2.7 -3.58 Changjianggou JG12 1.4 -5.9 Changjianggou JG13 2.4 -7.7 Changjianggou JG15 2.9 -4.8 Changjianggou JG16 3.3 -7.1 Changjianggou JG18 2.8 -5.1 Changjianggou JG22 3.84 -7.22 Changjianggou JG23 -1 -6.2 Changjianggou JG25 0.5 -6.5 Changjianggou JG26 1.8 -4.5 Changjianggou JG27 0.8 -6 Changjianggou JG28 0.3 -5.9 Changjianggou JG29 0.9 -6.5 Changjianggou JG30 0.7 -5.9 Changjianggou JG31 0.1 -6.6 Changjianggou JG32 -0.18 -8.37 Changjianggou JG34 0.4 -7 Changjianggou JG35 -0.66 -9.11 Changjianggou JG36 -0.4 -6.6 Changjianggou JG37 -1 -6.7 Changjianggou JG39-2 0.1 -7.51 Changjianggou JG41 -0.4 -6.6 Changjianggou JG43 0.16 -7.03 Changjianggou JG44 0.7 -6.5 Changjianggou JG45-1 0.77 -7.29 Changjianggou JG47 2.51 -6.14 Changjianggou JG48 2.74 -6.91 Changjianggou JG49 1.89 -9.16 Changjianggou JG50 2.99 -6.11 Changjianggou JG51-1 2.89 -6.68 Changjianggou JG52 2.24 -8.04 Changjianggou JG53 2.35 -6 Changjianggou JG54-1 1.59 -7.35 Changjianggou JG55-1 2.06 -6.2 Changjianggou JG56 2.09 -5.42 Changjianggou JG57 3.28 -3.96 Changjianggou JG58 2.05 -5.72 Changjianggou JG59 2.41 -5.04 Changjianggou JG60 2.78 -5.37 Changjianggou JG61 3.3 -2.1 Changjianggou JG62 2 -3.8 Qiaoting LJ-A -0.02 -9.86 Qiaoting LJ-B 1.67 -9.11 Qiaoting LJ-D 2.67 -7.35 Qiaoting LJ-F 3.65 -5.29 Qiaoting LJ-B2 4.21 -7.17 Qiaoting LJ-B4 4.13 -5.78 Qiaoting LJ-B5-1 4.12 -4.58 Qiaoting LJ-B6 3.71 -3.65 Qiaoting LJ6 3.8 -6.32 Qiaoting LJ7-1 4.86 -5.5 Qiaoting LJ7 4.11 -7.34 Qiaoting LJ8A-1 5.22 -4.27 Qiaoting LJ8A 4.47 -6.32 Qiaoting LJ08 4.16 -7.5 Qiaoting LJ09 4 -7.79 Qiaoting LJ10 4.19 -6.33 Qiaoting LJ11 4.16 -6.29 Qiaoting LJ12 4.12 -6.37 Qiaoting LJ13-1 4.94 -4.69 Qiaoting LJ13 4.14 -6.67 Qiaoting LJ14-1 4.47 -4.44 Qiaoting LJ14 4.17 -5.96 Qiaoting LJ15-1 5.21 -4.42 Qiaoting LJ15 4.12 -5.32 Qiaoting LJ16-2 4.42 -6.28 Qiaoting LJ18 4 -3.97 Qiaoting LJ20 4.05 -5.3 Qiaoting LJ22 4.17 -5.04 Qiaoting LJ24 4.27 -5.35 Qiaoting LJ26 4.29 -5.7 Qiaoting LJ28 4.42 -5.32 Qiaoting LJ30 4.23 -5.41 Qiaoting LJ32 4.35 -4.96 Qiaoting LJ34 4.36 -4.47 Qiaoting LJ35-1 4.62 -4.81 Qiaoting LJ35 3.84 -5.61 Qiaoting LJ38-1 3.97 -4.73 Qiaoting LJ38 3.81 -4.8 Qiaoting LJ41 4.39 -4.58 Qiaoting LJ43 4.52 -3.88 Qiaoting LJ45 4.89 -4.88 Qiaoting LJ46 4.84 -4.78 Qiaoting LJ48 4.41 -3.96 Qiaoting LJ50 4.74 -5.24 Qiaoting LJ51 4.83 -3.79 Qiaoting LJ52 3.52 -4.59 Qiaoting LJ54-1 3.12 -3.87 Section Sample No. CaO (%) MgO (%) Sr (ppm) Mn (ppm) Changjianggou JG1 54.91 0.17 84 25 Changjianggou JG6 Changjianggou JG7 Changjianggou JG8 Changjianggou JG9 Changjianggou JG10 Changjianggou JG11 53.84 0.94 279 29 Changjianggou JG12 Changjianggou JG13 Changjianggou JG15 Changjianggou JG16 Changjianggou JG18 Changjianggou JG22 54.08 0.09 553 7 Changjianggou JG23 Changjianggou JG25 Changjianggou JG26 Changjianggou JG27 Changjianggou JG28 Changjianggou JG29 Changjianggou JG30 Changjianggou JG31 Changjianggou JG32 51 3.83 68 102 Changjianggou JG34 Changjianggou JG35 54.98 0.39 56 49 Changjianggou JG36 Changjianggou JG37 Changjianggou JG39-2 55.5 0.09 76 32 Changjianggou JG41 Changjianggou JG43 55.5 0.26 67 22 Changjianggou JG44 Changjianggou JG45-1 55.76 0.13 76 30 Changjianggou JG47 31.6 5.19 86 64 Changjianggou JG48 30.93 9.35 28 47 Changjianggou JG49 29.94 10.89 23 40 Changjianggou JG50 31.83 9.27 75 49 Changjianggou JG51-1 31.12 10.29 69 326 Changjianggou JG52 30.84 11.08 606 70 Changjianggou JG53 32.78 9.61 68 83 Changjianggou JG54-1 52.54 8.85 101 38 Changjianggou JG55-1 55.03 0.26 95 19 Changjianggou JG56 55.74 0.09 149 20 Changjianggou JG57 35.66 7.45 92 36 Changjianggou JG58 55.3 0.35 150 21 Changjianggou JG59 48.07 6.32 168 23 Changjianggou JG60 51.14 3.68 117 14 Changjianggou JG61 Changjianggou JG62 Qiaoting LJ-A 49.61 0.4 426 818 Qiaoting LJ-B 52.96 0.48 1007 278 Qiaoting LJ-D 54.97 0.32 1206 38 Qiaoting LJ-F 50.61 3.93 606 15 Qiaoting LJ-B2 55.63 0.08 308 10 Qiaoting LJ-B4 55.52 0.08 301 9 Qiaoting LJ-B5-1 42.23 10.28 823 15 Qiaoting LJ-B6 54.6 0.99 517 9 Qiaoting LJ6 55.29 0.25 470 7 Qiaoting LJ7-1 42.12 16.3 290 13 Qiaoting LJ7 49.88 4.46 322 7 Qiaoting LJ8A-1 32.51 19.27 328 13 Qiaoting LJ8A 36.55 16.19 290 12 Qiaoting LJ08 53.56 1.82 419 8 Qiaoting LJ09 54.94 0.33 410 8 Qiaoting LJ10 54.71 0.74 550 7 Qiaoting LJ11 55.17 0.33 430 8 Qiaoting LJ12 55.63 0.08 355 9 Qiaoting LJ13-1 33.52 18.47 430 32 Qiaoting LJ13 54.71 0.66 503 9 Qiaoting LJ14-1 34.97 18.15 382 36 Qiaoting LJ14 54.25 0.83 474 8 Qiaoting LJ15-1 32.4 18.23 297 19 Qiaoting LJ15 55.63 0.08 339 7 Qiaoting LJ16-2 32.4 18.79 142 20 Qiaoting LJ18 55.29 0.08 171 8 Qiaoting LJ20 54.1 0.79 793 406 Qiaoting LJ22 54.83 0.74 265 11 Qiaoting LJ24 55.29 0.33 418 15 Qiaoting LJ26 55.06 0.33 234 7 Qiaoting LJ28 54.83 0.41 333 10 Qiaoting LJ30 55.4 0.08 192 9 Qiaoting LJ32 55.75 0.08 334 10 Qiaoting LJ34 54.83 0.41 346 9 Qiaoting LJ35-1 36.87 15.1 214 26 Qiaoting LJ35 40 13.55 219 28 Qiaoting LJ38-1 37.99 13.65 377 19 Qiaoting LJ38 39.77 12.97 234 26 Qiaoting LJ41 54.6 1.16 321 11 Qiaoting LJ43 55.29 0.25 366 10 Qiaoting LJ45 55.52 0.08 523 12 Qiaoting LJ46 54.71 0.66 857 18 Qiaoting LJ48 54.48 0.74 382 9 Qiaoting LJ50 55.63 0.08 462 12 Qiaoting LJ51 54.83 0.66 381 13 Qiaoting LJ52 54.25 0.91 346 37 Qiaoting LJ54-1 32.51 17.26 395 101 Section Sample No. Mn/Sr Fe (ppm) Remark Changjianggou JG1 0.29 1147 [DELTA] Changjianggou JG6 Changjianggou JG7 Changjianggou JG8 Changjianggou JG9 Changjianggou JG10 Changjianggou JG11 0.1 186 [DELTA] Changjianggou JG12 Changjianggou JG13 Changjianggou JG15 Changjianggou JG16 Changjianggou JG18 Changjianggou JG22 0.01 202 [DELTA] Changjianggou JG23 Changjianggou JG25 Changjianggou JG26 Changjianggou JG27 Changjianggou JG28 Changjianggou JG29 Changjianggou JG30 Changjianggou JG31 Changjianggou JG32 1.5 337 [DELTA] Changjianggou JG34 Changjianggou JG35 0.88 135 [DELTA] Changjianggou JG36 Changjianggou JG37 Changjianggou JG39-2 0.43 186 [DELTA] Changjianggou JG41 Changjianggou JG43 0.33 202 [DELTA] Changjianggou JG44 Changjianggou JG45-1 0.4 354 [DELTA] Changjianggou JG47 0.74 152 [DELTA] Changjianggou JG48 1.68 261 [DELTA] Changjianggou JG49 1.74 337 [DELTA] Changjianggou JG50 0.65 455 [DELTA] Changjianggou JG51-1 4.72 590 [DELTA] Changjianggou JG52 0.12 NG [DELTA] Changjianggou JG53 1.21 253 [DELTA] Changjianggou JG54-1 0.38 186 [DELTA] Changjianggou JG55-1 0.2 152 [DELTA] Changjianggou JG56 0.13 219 [DELTA] Changjianggou JG57 0.4 599 [DELTA] Changjianggou JG58 0.14 202 [DELTA] Changjianggou JG59 0.14 472 [DELTA] Changjianggou JG60 0.12 599 [DELTA] Changjianggou JG61 Changjianggou JG62 Qiaoting LJ-A 1.92 10442 * Qiaoting LJ-B 0.28 2724 * Qiaoting LJ-D 0.03 374 Qiaoting LJ-F 0.02 757 Qiaoting LJ-B2 0.03 92 Qiaoting LJ-B4 0.03 82 Qiaoting LJ-B5-1 0.02 983 Qiaoting LJ-B6 0.02 212 Qiaoting LJ6 0.02 128 Qiaoting LJ7-1 0.05 242 Qiaoting LJ7 0.02 109 Qiaoting LJ8A-1 0.04 293 Qiaoting LJ8A 0.04 149 Qiaoting LJ08 0.02 424 Qiaoting LJ09 0.02 212 Qiaoting LJ10 0.01 144 Qiaoting LJ11 0.02 101 Qiaoting LJ12 0.02 86 Qiaoting LJ13-1 0.07 463 Qiaoting LJ13 0.02 155 Qiaoting LJ14-1 0.1 677 Qiaoting LJ14 0.02 143 Qiaoting LJ15-1 0.06 712 Qiaoting LJ15 0.02 93 Qiaoting LJ16-2 0.14 123 Qiaoting LJ18 0.05 20 Qiaoting LJ20 0.51 14987 * Qiaoting LJ22 0.04 636 Qiaoting LJ24 0.03 255 Qiaoting LJ26 0.03 76 Qiaoting LJ28 0.03 196 Qiaoting LJ30 0.05 160 Qiaoting LJ32 0.03 286 Qiaoting LJ34 0.03 160 Qiaoting LJ35-1 0.12 602 Qiaoting LJ35 0.13 309 Qiaoting LJ38-1 0.05 516 Qiaoting LJ38 0.11 365 Qiaoting LJ41 0.03 506 Qiaoting LJ43 0.03 124 Qiaoting LJ45 0.02 220 Qiaoting LJ46 0.02 276 Qiaoting LJ48 0.02 304 Qiaoting LJ50 0.03 284 Qiaoting LJ51 0.03 197 Qiaoting LJ52 0.11 458 Qiaoting LJ54-1 0.25 1490 Note: Blank cells in the table represent without detection; NG=below the limit of detection; 22 samples marked with '[DELTA]' have been published by Lv, 2013; 3 samples marked with * have both high Mn content (>200ppm) and high Fe content (>2000ppm).
|Printer friendly Cite/link Email Feedback|
|Author:||Keke, Huang; Yijiang, Zhong; Xiaoning, Li; Zuowei, Hu|
|Publication:||Earth Sciences Research Journal|
|Date:||Mar 1, 2016|
|Previous Article:||Geospatial analysis for the determination of hydro-morphological characteristics and assessment of flash flood potentiality in arid coastal plains: a...|
|Next Article:||GIS-based assessment of aquifer vulnerability using DRASTIC model: a case study on Kodaganar basin/Evaluacion basada en el Sistema De Informacion...|