Subsurface investigations of several glacial successions related to engineering construction.ABSTRACT Glacial environments, including subglacial sub·gla·cial adj. Formed or deposited beneath a glacier. sub  gla , supraglacial and
proglacial deposition, yield some of the most complex sedimentary
deposits on Earth. Unsorted deposits of clasts in a finer matrix
(diamictons) are common, both in flow tills and basal (or lodgement lodge·ment n. Variant of lodgment. Noun 1. lodgement - bringing a charge or accusation against someone lodgment ) tills. Using only hand-sized samples these till varieties are difficult to differentiate and may require extensive field investigation to do so. Stratigraphic stra·tig·ra·phy n. The study of rock strata, especially the distribution, deposition, and age of sedimentary rocks. strat detail of glacial deposits has a profound influence on the engineering properties of soil units. Geotechnical studies involve subsurface drilling and sampling, typically using Hollow Stem Auger (HSA HSA Health Savings Account (US) HSA Human Serum Albumin HSA Human Services Agency (Nevada) HSA Health Services Agency HSA Health and Safety Authority (Ireland) ) and Standard Penetration Test The standard penetration test (SPT) is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil. The test procedure is described in the British Standard BS 1377-9:1990 and ASTM D1586. (SPT (Sectors Per Track) The number of sectors in one track. ) methods. Other soil samples are obtained using pushed Shelby tubes. Standard laboratory tests are typically performed on soil samples to determine their engineering properties relative to the geologic conditions and the type of facility to be constructed. Four sites were selected for evaluation, ranging from simple glacial stratigraphy stratigraphy, branch of geology specifically concerned with the arrangement of layered rocks (see stratification). Stratigraphy is based on the law of superposition, which states that in a normal sequence of rock layers the youngest is on top and the oldest on the to a complex glacial succession requiring gamma ray logging Gamma ray logging is a method of using natural gamma radiation to characterize the rock or sediment in a borehole. It is sometimes used in mineral exploration and water-well drilling, but most commonly for formation evaluation in oil- and gas-well drilling. to decipher details. Till features and various types of outwash outwash Deposit of sand and gravel carried by running water from the melting ice of a glacier and laid down in stratified deposits. An outwash may be as much as 330 ft (100 m) thick at the edge of a glacier, and it may extend for many miles. are considered regarding two engineering construction objectives: foundations for buildings and sanitary landfill sanitary landfill: see solid waste. siting. Keywords: Glacial geology, subsurface investigation, engineering geology engineering geology or geological engineering Scientific discipline concerned with the application of geologic knowledge to engineering problems such as reservoir design and location, determination of slope stability for construction purposes, and , geotechnical engineering Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials. Geotechnical engineering includes investigating existing subsurface conditions and materials; assessing risks posed by site conditions; designing earthworks and ********** Much of the Upper Mississippi River
The Upper Mississippi River is the portion of the Mississippi River upstream of Cairo, Illinois, United States. Valley and Great Lakes Great Lakes, group of five freshwater lakes, central North America, creating a natural border between the United States and Canada and forming the largest body of freshwater in the world, with a combined surface area of c.95,000 sq mi (246,050 sq km). was repeatedly covered by massive continental glaciers during the Pleistocene Epoch Pleistocene epoch (plī`stəsēn), 6th epoch of the Cenozoic era of geologic time (see Geologic Timescale, table). According to a classification that considered its deposits to have been formed by the biblical great flood, the epoch was . When the ice melted, layers of eroded materials were deposited, with younger layers overlapping older ones. This glacial debris (unsorted clay, silt, sand, and rock fragments) was either deposited directly by the melting ice or carried away to be deposited by streams formed from meltwater melt·wa·ter n. Water that comes from melting snow or ice. meltwater Noun melted snow or ice Noun 1. . As the source of glaciers shift with time and climatic conditions differ among regions, deposits from various glaciers differ in their physical and mineralogical min·er·al·o·gy n. pl. min·er·al·o·gies 1. The study of minerals, including their distribution, identification, and properties. 2. A book or treatise on mineralogy. properties. These details can be used to distinguish between individual glacial units. Various glacial deposits exhibit a range of properties related to their potential use and limitations for geotechnical aspects. Description and characterization of glacial materials regarding the proposed environmental and construction activity are typically compiled for evaluation. An example data sheet (Fig. 1) illustrates the range of information obtained (after Skempton et al. 1991). British units (feet) are designated in this paper because those are the units normally used in the data gathering process. GLACIAL ENVIRONMENTS AND DEPOSITS Glacial environments yield some of the most complex sedimentary deposits on Earth. Sedimentation occurs in three different environments: beneath the ice as subglacial, atop the ice or supraglacial, or in front of the ice margin as proglacial. The processes of subglacial deposition are the most poorly known as they are inaccessible to direct observation. Deposits formed by supraglacial processes are better known, but more complex, because sedimentation occurs on an unstable substrate (ice) and superglacial deposits commonly undergo several episodes of reworking or resedimentation prior to final deposition. Consequently, the sedimentary record, although conceptually simple, tends to be complex; and detailed description can be challenging. Diamicton, a glacial geology term, refers to unsorted or poorly sorted deposits that are massive to crudely stratified stratified /strat·i·fied/ (strat´i-fid) formed or arranged in layers. strat·i·fied adj. Arranged in the form of layers or strata. and consist of a poorly sorted matrix with large clasts (< 2 mm) dispersed throughout. Although a term not typically used in engineering reports, diamicton, as a concept, helps to illustrate the extreme complexity of glacial stratigraphy. They form in a variety of environments--glacial (till, sediment or mudflow mudflow: see landslide. mudflow Flow of water that contains large amounts of suspended particles and silt. Mudflows usually occur on steep slopes where vegetation is too sparse to prevent rapid erosion, but they can also occur on gentle slopes under deposits, ice-slope colluvium col·lu·vi·um n. pl. col·lu·vi·ums or col·lu·vi·a A loose deposit of rock debris accumulated through the action of gravity at the base of a cliff or slope. , glacial lacustrine la·cus·trine adj. 1. Of or relating to lakes. 2. Living or growing in or along the edges of lakes. [French or Italian lacustre (from Latin lacus, lake) + , glacial marine), slopes (colluvium, sediment flow) and volcanic (lahars, volcanic mudflows). Regarding glacial environments, most tills are diamictons; but, as indicated above, not all diamictons have a glacial origin. Till is sediment aggregated by and deposited directly from glacial ice without subsequent disaggregation dis·ag·gre·ga·tion n. 1. A breaking up into component parts. 2. An inability to coordinate various sensations and a failure to observe their mutual relations. and resedimentation. A diagram of the ice-margin environment is shown in Fig. 2 (modified from Edwards 1986); the text by Eyles (1983) describes the complex nature of glacial successions. Till can be subdivided into subglacial (basal) till and supraglacial till. Lodgement and deformation till are found only in the subglacial environment, but melt-out till accumulates in both the subglacial and supraglacial zones. Further consideration yields the following: lodgement till, deposited from or beneath active ice; melt-out till, from inactive or stagnant ice; and deformation till, involving a deforming layer beneath active ice. Melt-out till is sometimes referred to as ablation, till. Lodgement till is massive, poorly sorted, dense and relatively uniform in texture and composition. Sorted sediments, although not common, may occur in thin and irregular bodies or in isolated channel fills. Elongated e·lon·gate tr. & intr.v. e·lon·gat·ed, e·lon·gat·ing, e·lon·gates To make or grow longer. adj. or elongated 1. Made longer; extended. 2. Having more length than width; slender. pebbles in the till show a strong alignment parallel to the direction of ice flow. Subglacial melt-out till is less uniform than lodgement till, contains layers as well as stringers of silt and sand, and has more channel fills; some may have convex upper surfaces, suggesting a tunnel filling. Supraglacial, melt-out till is less dense and may contain more sorted sediment than the subglacial variety. Because of the dynamic nature of its environment, supraglacial melt-out till is less likely preserved than are other till varieties. Deformation till is essentially lodgement till that has undergone squeezing and shearing. In addition to till, there are four other major types of glacial deposits: a) sediment flow deposits and ice-slope colluvium, 2) outwash or glacial fluvial flu·vi·al adj. 1. Of, relating to, or inhabiting a river or stream. 2. Produced by the action of a river or stream. [Middle English, from Latin deposits, 3) glaciolacustrine deposits Sediments deposited into lakes that have come from glaciers are called glaciolacustrine deposits. These lakes include ice margin lakes or other types formed from glacial erosion or deposition. Sediments in the bedload and suspended load are carried into lakes and deposited. , and 4) glacioeolian deposits. Sediment flow deposits and ice-slope colluvium are glacial features formed by mass wasting in a supraglacial environment. They are formed by plastic to viscous, to semi-fluvial flow of sediment/water mixtures. They are also known as flow tills, and typically are diamictions varying from a few centimeters to a few meters in thickness. In small exposures, without the appearance of flow features, flow till commonly cannot be distinguished from basal till. Outwash is sediment deposited from meltwater derived from glacial ice. These are fluvial deposits formed by glacial melt water and commonly consist of sand and gravel that is stratified and crossbedded. Deposits generally become finer in the down-flow direction. Sediment flow deposits (flow tills that are diamictons) are commonly interspersed within the outwash. Glaciolacustrine deposits are formed in lakes in the glacial environments. Lacustrine deposits (Geol.) the deposits which have been accumulated in fresh-water areas. See also: Lacustral are generally sorted, stratified and most are fine grained consisting of silt or clay and occasionally sand. Glacioeolian deposits are deposited by wind in the proglacial or periglacial ''You may be looking for paraglacial, meaning unstable conditions related to local glaciation in the recent past. Periglacial is an adjective referring to places in the edges of glacial areas, normally those related to past ice ages rather than those in the modern era. environment. They are either bedload deposits (dune sand, sheet sand) or suspended load Suspended Load is the term for the fine particles that are light enough to be carried in a stream without touching the stream bed. These particles are generally of the sand, silt and clay size, although they can be larger, es pecially in cases of high discharge, such as during (loess loess (lĕs, lō`əs, Ger. lös), unstratified soil deposit of varying thickness, usually yellowish and composed of fine-grained angular mineral particles mixed with clay. ) of wind systems that were effective in moving sediment. Loess, which is dominantly silt and usually massive, is deposited downwind of major glacial meltwater streams (see West 1995, Chapter 17, p. 397ff). GEOTECHNICAL ASPECTS For engineering geology/geotechnical studies of the Midwest, the drift-covered regions comprise a major portion of the land surface. A simplified designation for the extent of continental glaciation in the eastern United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. is as follows: the area north of a line from New York City New York City: see New York, city. New York City City (pop., 2000: 8,008,278), southeastern New York, at the mouth of the Hudson River. The largest city in the U.S. across Pennsylvania to Pittsburgh, down the Ohio River Ohio River Major river, eastern central U.S. Formed by the confluence of the Allegheny and Monongahela rivers, it flows northwest out of Pennsylvania, and west and southwest to form the state boundaries of Ohio–West Virginia, Ohio-Kentucky, Indiana-Kentucky, and to the Mississippi River Mississippi River River, central U.S. It rises at Lake Itasca in Minnesota and flows south, meeting its major tributaries, the Missouri and the Ohio rivers, about halfway along its journey to the Gulf of Mexico. , up river to St. Louis, and then along the Missouri River Missouri River River, central U.S. The longest tributary of the Mississippi River, it rises in the Rocky Mountains of southwestern Montana. It flows east to central North Dakota and south across South Dakota, forming sections of the South Dakota–Nebraska boundary, the across the Great Plains into Montana. This boundary is not precise, as there are portions of southern Ohio, Indiana and Illinois that were not glaciated gla·ci·ate tr.v. gla·ci·at·ed, gla·ci·at·ing, gla·ci·ates 1. a. To cover with ice or a glacier. b. To subject to or affect by glacial action. 2. To freeze. . However, it is a useful estimate of the southern extent of glacial advance. For a map view of this area see West 1995, Chapter 12, p. 254. Of primary interest for site characterization in the glacial domain are: 1) landform land·form n. One of the features that make up the earth's surface, such as a plain, mountain, or valley. landform A recognizable, naturally formed feature on the Earth's surface. type, 2) type of unlithifled material (till, river alluvium al·lu·vi·um n. pl. al·lu·vi·ums or al·lu·vi·a Sediment deposited by flowing water, as in a riverbed, flood plain, or delta. Also called alluvion. , outwash, etc.), and 3) engineering properties related to the planned construction project. Subsurface investigations regarding building foundations and sanitary landfill siting in a glaciated domain are considered below. As with all site characterization, description of subsurface conditions is the first order of business. Obtaining background information is the initial step, followed by field reconnaissance, and then a drilling, sampling and laboratory testing program. The common procedure for subsurface geo-technical investigations in the Midwest in glacial terrain involves HSA (hollow stem auger) drilling and split spoon sampling, using the SPT (Standard Penetration Test). This procedure provides N-values, a measure of density or stiffness of a soil, in blows per foot using the Standard Penetration Test. The split spoon sampler (SS) receives the soil sample, and when retrieved from the subsurface, provides a geologic description and soil samples for subsequent testing. Some laboratory tests require an "undisturbed" sample to perform the needed testing. Standard penetration test samples cannot be used to perform these tests. Instead, a pushed Shelby tube (ST) is used to obtain samples for these laboratory procedures. Using Shelby tube samples, tests for density, hydraulic conductivity Hydraulic conductivity, symbolically represented as  , is a property of vascular plants, soil or rock, that describes the ease with which water can move through pore spaces or fractures. , unconfined
compression strength and consolidation are obtained.
Many of the standard engineering tests can also be performed on split spoon samples. These include natural moisture content, Atterberg limits The Atterberg limits are a basic measure of the nature of a fine-grained soil. Depending on the water content of the soil, it may appear in four states: solid, semi-solid, plastic and liquid. , grain size analysis, specific gravity specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the two substances. of solids, and cation exchange capacity In soil science, cation exchange capacity (CEC) is the capacity of a soil for ion exchange of positively charged ions between the soil and the soil solution. A positively-charged ion, which has fewer electrons than protons, is known as a cation due to its attraction to cathodes. (CEC (Central Electronic Complex) The set of hardware that defines a mainframe, which includes the CPU(s), memory, channels, controllers and power supplies included in the box. Some CECs, such as IBM's Multiprise 2000 and 3000, include data storage devices as well. ). This same list can be performed on pushed Shelby tube samples. Tippecanoe County, Indiana Tippecanoe County is a county located in the U.S. state of Indiana. As of 2000, the population was 148,955. The county seat is Lafayette6. History Tippecanoe County was formed March 1, 1826. .--A proposed landfill site landfill site n → vertedero landfill site n → centre m d'enfouissement des déchets landfill site land n in Tippecanoe County was located in an area of a broad, gently rolling ground moraine moraine (mərān`), a formation composed of unsorted and unbedded rock and soil debris called till, which was deposited by a glacier. The till that falls on the sides of a valley glacier from the bounding cliffs makes up lateral moraines, (Tipton Till Plain). The site was eight miles (13 km) south of Lafayette's center-city, at the intersection of US-231 and County Road 800 South. Fourteen, 30-foot (9.1 m) deep borings were obtained on this site. The log for Boring A is provided as Fig. 3. Note that the N-value for sample 3 equals 17, but for sample 7 it equals 47. Both 3 and 7 appear to be diamictons, but the high N-value for sample 7 indicates it is likely lodgment lodg·ment also lodge·ment n. 1. a. The act of lodging. b. The state of being lodged. 2. A place for lodging. 3. An accumulation or a deposit. 4. till. Sample 3 represents a flow till or ablation till. Laboratory test results from the Tippecanoe County site are provided in Table 1. Shelby tube samples rather than split spoon samples were used for testing. Silts and clays are represented, but sand units are not included. Note the high dry densities, ranging from 109.5-133.4 lbs/[ft.sup.3] and the low moisture contents, ranging from 9.2-16.5%. These high density, low moisture contents indicate a very dense, high strength soil that has been densified by the weight of the over-riding ice. Such materials are designated as overconsolidated because the vertical stress at present is significantly less than it was when a great thickness of glacial ice existed above it. This is also consistent with the low values for the hydraulic conductivity, typically in the 10-6 and [10.sup.-7] cm/sec range. Note also that the cation exchange capacity values (CEC) are below 10 meq/l00 grams of dry soil, which are fairly low for clayey soils. Also the plasticity index (PI) values are quite low (1.9-5.0) except for Borings F, M-6 and N-8. A low PI is consistent with low CEC values, both indicating a low clay mineral clay mineral Any of a group of important hydrous aluminum silicates with a layered structure and very small (less than 0.005 mm or microscopic) particle size. They are usually the products of weathering. content. Indianapolis (Marion County Marion County is the name of seventeen counties in the United States of America, mostly named for General Francis Marion:
An upper sand layer (outwash) from 8.5-29 feet, a stiff, silty clay (till) from 29-38 feet and a lower sand layer (outwash) from 38-43 feet are indicated. Seven borings intercepting bedrock, averaging about 50 feet deep, were drilled using HSA and split spoon sampling. The blow counts for the stiff silty clay ranged from 29-57 with an arithmetic mean (mathematics) arithmetic mean - The mean of a list of N numbers calculated by dividing their sum by N. The arithmetic mean is appropriate for sets of numbers that are added together or that form an arithmetic series. of 46 (Table 2). Eleven samples of natural moisture content were obtained for the stiff silty clay, yielding a range from 8.8-11.7%, with an arithmetic mean of 9.8%. Dense, overconsolidated till units are indicated by high blow counts (30 or greater) and low (about 10%) natural moisture contents. This is also indicative of a lodgement till. The Southside Sanitary Landfill, on Kentucky Avenue is located in an area adjacent to the boring site described in Fig. 4. It began operations in 1971 and through a series of expansions now occupies over 200 acres (81 ha). However, it lacks a natural clay barrier below the solid waste. Subsurface geology similar to that indicated in Fig. 4 shows the presence of upper and lower sandy units with a silty clay layer between them. To prevent lateral movement Lateral movements are movements made on a horse that are used for training purposes, that involve the horse moving in a direction other than straight forward. They vary in difficulty, and should be used in a progressive manner, according to the training and physical limitations of of leachate leach·ate n. A product or solution formed by leaching, especially a solution containing contaminants picked up through the leaching of soil. within the upper sand unit, a slurry wall A slurry wall is a type of wall used to build tunnels, to open cuts, and to lay foundations in areas of soft earth close to open water or with a high ground water table. A set of guide walls, typically 1 metre (3.3 ft) deep and 0.5 metre (1. , cut-off trench through the upper unit into the silty clay layer, was proposed. However, the continuity of this silty clay layer throughout the site was questioned based on research by Sudar (1987). If this intermediate clay unit was flow till rather than basal till, it likely would be discontinuous discontinuous /dis·con·tin·u·ous/ (dis?kon-tin´u-us) 1. interrupted; intermittent; marked by breaks. 2. discrete; separate. 3. lacking logical order or coherence. across the site. Therefore, at certain locations, the upper and lower sand units might be directly connected. Field studies were conducted in gravel pit Noun 1. gravel pit - a quarry for gravel stone pit, quarry, pit - a surface excavation for extracting stone or slate; "a British term for `quarry' is `stone pit'" excavations near by, and evidence of both lodgement and fl ow till units was found. Consequently, field studies could not establish the existence of a continuous till section within the sandy outwash. The Indiana Department of Environmental Management (IDEM [Latin, The same.] Used to indicate a reference that has previously been made and typically abbreviated "id." in legal and scholarly bibliographic citations. ) also concluded that the existence of a continuous layer of silty clay beneath the site had not been proven. Hence, they required that the slurry wall extend through the lower sand unit into the New Albany New Albany, city (1990 pop. 36,322), seat of Floyd co., S Ind., near the falls of the Ohio River opposite Louisville, Ky.; inc. 1819. The city was a shipbuilding center in the 19th cent., and the riverboats Robert E. Lee and Eclipse were built there. Shale bedrock. Consistent with IDEM's decision, Sudar (1987) used borings, cross sections, piezometric data and investigation of adjacent active gravel pits to conclude that a high likelihood exists that the silty clay layer is not continuous across the 200 acre (81 ha) site. Chicago, Illinois.--(The Loop area). The Chicago River Chicago River River, northeastern Illinois, U.S. A small river, consisting of a northern and a southern branch, it originally flowed through Chicago into Lake Michigan. and Lake Michigan site are in the Loop area of downtown Chicago, Illinois on a portion of the Calumet Calumet, region, United States Calumet (kăl`y  mĕt'), industrialized region of NW Ind. and NE Ill., along the south shore of Lake Michigan. Lacustrine Plain A Lacustrine plain is a plain that originally formed in a lacustrine environment, that is, as the bed of a lake, but from which the water has disappeared, by natural drainage, evaporation or other geophysical processes. where a high-rise building high-rise buildingMultistory building taller than the maximum height people are willing to walk up, thus requiring vertical mechanical transportation. The introduction of safe passenger elevators made practical the erection of buildings more than four or five stories tall. was to be constructed. Two borings, drilled 155 and 120 feet (47.2 and 36.6 m) deep, intercepted a 15 foot sand layer, with a soft, silty clay and a stiff, silty clay below. A summary of laboratory test results is provided in Table 3. Soft lacustrine deposits extend from 23.5 to between 48-50 feet deep. Natural moisture contents for these softer soils range from 16.2- 24.6% (arithmetic mean 21.4%). A plasticity index of 19 or 20 was indicated. From 48.5-120 feet the natural moisture content ranged from 8.8-22.2 (arithmetic mean = 15.1%) and the plasticity index ranged from 5-18 (arithmetic mean = 10.2%). The unit extending from 53.5 to 115 or 120 feet is an overconsolidated, basal or lodgement till. Evaluation of N-values for the two borings indicated that three distinct silty clay layers can be discerned: lacus trine from 23.5-50 feet, stiff glacial till from 50-80 feet and a hard glacial till from about 80-120 feet. Boring logs reveal that the subsurface consists of a surface sand layer (likely beach or dune sand) to a depth of 23 feet with a silty bed (lacustrine) below that to a depth of about 50 feet and an extremely dense silty clay (lodgement till) below, extending to a depth of 120 feet. N-values and natural moisture contents were the primary engineering data used to delineate these contrasting glacial deposits. High-rise buildings in Chicago are founded today on the overconsolidated, basal till or on bedrock. Elkhart County, Indiana Elkhart County is a county located in the U.S. state of Indiana. As of 2000, the population was 182,791. The county seat is Goshen. Geography According to the U.S. Census Bureau, the county has a total area of 1,212 km² (468 mi²). .--(Steuben Morainal Lake Section). The Earthmover's Solid Waste facility, south of the city of Elkhart (Elkhart County, Indiana), is located six miles (3.7 km) northeast of Wakarusa and eight miles (12.8 km) northwest of Goshen. It involves a 45-acre (18.2 hectare) expansion near a complex geologic boundary within the Maxinkukee Moraine. The site is part of the Steuben Morainal Lake Section, with intersecting deposits of the Lake Michigan Lobe from the north and the Huron-Erie (Saginaw) Lobe, from the northeast. For this boundary area, with its complicated glacial stratigraphy, the subsurface is best characterized using the megasequence procedure proposed by Bleuer & Melhorn (1989). Earthmover's facility, displaying Wisconsin age till at the surface, was only a few miles southeast of the St. Joseph Aquifer System (Reussow & Rohne 1975; DNR See dynamic noise reduction and domain name resolver. 1987), a major regional outwash aquifer, which had to be protected from contamination. Bleuer & Melhorn (1989) proposed that the uppermost unit at the facility is the Post Wakarusa Fan Complex and below it lies the Wakarusa megasequence, consisting of a Wisconsin age till and kame-fan sequence. Underlying are pre-Wisconsin deposits, the Nappanee-Bremen megasequence. Interpretations were made using gamma-ray logs conducted in existing water wells. Details of the Wakarusa megasequence depict an upper clay-rich blocky till with a coarse sandy interval below. The Nappanee-Bremen megasequence consists of clay-rich tills and a clay-free (clean) coarse sand interval. The clay-free coarse interval within the Nappanee-Bremen megasequence apparently corresponds to the Nappanee aquifer discussed by DNR (1987). The coarse sand intervals (Bleuer & Melhorn 1989) typically occur between elevations 750-780 feet (229-247 m), MSL See multiple single-level. , with the base of the landfill ranging from 794-811 feet (242-274 m). Bedrock below the site is the green-to-black Ellsworth Shale (Reussow & Rohne 1975), Devonian to Mississippian age. Based on regional data, the depth to bedrock ranges from 200-250 feet (61-76 m) and the ground surface elevation, prior to landfilling, ranged from 806-820 feet (245-250 m). An idealized i·de·al·ize v. i·de·al·ized, i·de·al·iz·ing, i·de·al·iz·es v.tr. 1. To regard as ideal. 2. To make or envision as ideal. v.intr. 1. gamma ray gamma ray Penetrating very short-wavelength electromagnetic radiation, similar to an X-ray but of higher energy, that is emitted spontaneously by some radioactive substances (see gamma decay; radioactivity). log and stratigraphic section for the site are provided in Fig. 5. Shown chronologically are the Post-Wakarusa Fan Complex, Wakarusa Megasequence and Nappanee-Bremen Megasequence. Gamma ray logging responds to the clay content because of the increase in radiation typically occurring in clay minerals Clay minerals are hydrous aluminium phyllosilicates, sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths and other cations. Clays have structures similar to the micas and therefore form flat hexagonal sheets. . The Post-Wakarusa fan complex, prevalent in the north central portion of the landfill extends offsite to the north. According to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. test borings it exists from the ground surface (typically about 810 feet) to an elevation of about 796 feet. Sands in the unit are fairly clean, but gamma ray response (Fig. 5) suggests a significant presence of silt and clay. The deposit is interpreted as a pro-glacial fan complex with a typical braided stream braided stream A stream consisting of multiple small, shallow channels that divide and recombine numerous times forming a pattern resembling the strands of a braid. pattern. Because of its relatively small extent, the fan complex likely was deposited by a small, lingering lobe of melting ice during final glacial retreat. Initially, meltwater eroded the underlying Wakarusa megasequence; and, as melting progressed, the cut was backfilled with these fan deposits. A laboratory hydraulic conductivity of 2.3 X [10.sup.-5] cm/sec was obtained at the base of this fan, at elevation 798 feet (243 in). This is too permeable to provide a suitable barrier below the waste, and a 10-foot thick, recompacted clay, base liner was required where this unit occurred. This silty material, was suitable, however, for daily cover of trash during landfilling. Hydraulic conductivities for soils samples taken below the landfill base are given in Table 4. Boring WB-25 intercepted the Post-Wakarusa fan complex. Underlying this fan complex is the Wakausa Megasequence (Fig. 5), typically consisting of a till overlying overlying suffocation of piglets by the sow. The piglets may be weak from illness or malnutrition, the sow may be clumsy or ill, the pen may be inadequate in size or poorly designed so that piglets cannot escape. a coarser sequence of silty and clayey sand. Till below the base of the facility (at 810 feet) is gray to blue-gray, homogeneous silty clay. Percentage of fines (silt and clay combined) typically ranges between 50- 90%. Blow counts varied from 20-70 per foot, suggesting that the unit is supraglacial rather than subglacial (or lodgement), which in this area sustains blow counts exceeding 100 per foot. Clay and silt facies facies /fa·ci·es/ (fa´she-ez) pl. fa´cies [L.] 1. the face. 2. surface; the outer aspect of a body part or organ. 3. expression (1). of the Wakarusa Megasequence are extensive throughout the site, absent only where the Post-Wakarusa Fan complex occurs and the Wakarusa was eroded away. The base of the till unit was found between 770-789 feet elevation. Laboratory hydraulic conductivity values for this zone (Table 4) ranged from 3 x [10.sup.-8] to 1 x [10.sup.-6] cm/sec (geometric mean (mathematics) geometric mean - The Nth root of the product of N numbers. If each number in a list of numbers was replaced with their geometric mean, then multiplying them all together would still give the same result. = 8 x [10.sup.-8]; arithmetic mean = 1.4 x [10.sup.-7]). In Table 4 the last entry, 2.3 x [10.sup.-5] cm/sec, as indicated above, pertai ns to the Post-Wakarusa Fan Complex. The Wakarusa sand facies, a discontinuous silty, clayey, sand body, lies beneath the Wakarusa clay and silt facies. It represents a meltout feature of Wisconsin glaciation and is probably a fan complex much like the PostWakarusa Fan Complex described above. However, it is more widespread. The top of the Wakarusa sand ranges in elevation between 778-804 feet, whereas the bottom elevation ranges from 775-783 feet. Since it is unsuitable barrier material for preventing leachate migration, where the sand occurs less than 10 feet below the bottom of the base grade, a 10-foot recompacted clay liner was added. The Nappanee-Bremen Megasequence differs from the Wakarusa Megasequence in two major ways: 1) based on its gamma ray signature (Fig. 5) and on borings, it is more variable and not as well defined, and 2) the sand sequences are much cleaner than the Wakarusa sand. The clayey and silty facies of this megasequence have less clay and more silt than the Wakarusa till, but still show low hydraulic conductivities, from 8 x [10.sup.-8] to 2 x [10.sup.-7] cm/sec. The sand facies are generally continuous from about elevations 775-730 feet, on the eastern half of the site. Groundwater maps for the Nappanee aquifer at the Earthmover's facility were obtained on a monthly basis. The Wakarusa sand was unsaturated unsaturated /un·sat·u·rat·ed/ (un-sach´ur-at?ed) 1. not holding all of a solute which can be held in solution by the solvent. 2. denoting compounds in which two or more atoms are united by double or triple bonds. , and groundwater piezometer pi·e·zom·e·ter n. An instrument for measuring pressure, especially high pressure. pi·e zo·met data from other units were used
to find horizontal and vertical gradients. Groundwater pressure in sand
units below the landfill base was a concern. If uplift pressures exceed
the downward stress of the overlying soil, a soil popup can occur,
yielding a spring-like feature in the base of the excavation.
Cation exchange capacity (CEC) data for the site (Table 4) ranged from 12.9-20.8 meq/100g of dry soil, with an average of 15.6. These values are relatively high for clayey soils in Indiana. Recall, for the clayey silt samples in the Tippecanoe County study (Table 1) the CEC values averaged 7.6 meq/100g, which, by contrast, is below average for cohesive, Indiana soils. Using the megasequence procedure of Bleuer & Melhorn (1989) to develop geologic detail, Wehran Engineering was able to depict the complicated stratigraphy of the site to the satisfaction of IDEM. The landfill extension was designed based on this geologic interpretation, and landfill expansion was accomplished. As indicated above, a 10 foot (3 m) thick, recompacted clay liner was added in areas where sandy zones were found immediately below the landfill base.
Table 1
Test results, Tippecanoe County study.
Dry
density
Boring, Sample, (lbs./
Depth Visual classification [ft.sup.3])
A, 4-ST, 11.5-14.5' Gray silty clay to clayey silt, 128.9
little sand, trace gravel
B, 4-ST, 15'-16'4" Gray sandy clayey silt, little 122.2
gravel
C, 4-ST, 12'-13'6" Gray brown sandy clayey silt, 127.9
little gravel
E, 6-ST, 18'-20' Gray clayey silt, some sand, little 133.4
gravel
F, 3-ST, l0'-12'9" Brown clayey silt, little sand and 109.5
gravel
G, 5-ST, 20'-21'2" Gray clayey silt, some sand, trace 127.5
gravel
H, 5-ST, 20'-21'2" Gray clayey silt, some sand, trace 131.1
gravel
I, 5-ST, 20'-22'9" Gray silty clay to clayey silt, 130.8
little sand and gravel
J, 4-ST, 15'-15'l0" Gray clayey silt, some sand, little
gravel
M, 4-ST, 12'-13'8" Gray clayey silt, some sand, trace 122.2
gravel
M, 6-ST, 17'-18'8" Gray clayey silt, some sand, trace 128.2
gravel
N, 6-ST, 17'-18'4" Gray clayey silt, some sand, little 125.1
gravel
N, 8-ST, 25'-26' Gray clayey silt, some sand, little 121.4
gravel
Natu-
ral Atterberg limits
mois- Liq- Plas- Plas-
Boring, Sample, ture uid tic ticity
Depth (%) limit limit index
A, 4-ST, 11.5-14.5' 11.8 18.4 13.4 5.0
B, 4-ST, 15'-16'4" 14.3 18.9 14.2 4.7
C, 4-ST, 12'-13'6" 9.2
E, 6-ST, 18'-20' 10.3
F, 3-ST, l0'-12'9" 16.5 38.4 22.9 15.5
G, 5-ST, 20'-21'2" 8.5
H, 5-ST, 20'-21'2" 8.7
I, 5-ST, 20'-22'9" 10.3 17.3 13.4 2.9
J, 4-ST, 15'-15'l0" 13.5 16.7 13.2 4.5
M, 4-ST, 12'-13'8" 10.2 15.1 13.2 1.9
M, 6-ST, 17'-18'8" 10.8 20.6 13.1 7.5
N, 6-ST, 17'-18'4" 11.8 17.9 14.4 3.5
N, 8-ST, 25'-26' 11.4 21.0 12.7 8.3
Hydraulic
Boring, Sample, conductivity *
Depth (cm/sec)
A, 4-ST, 11.5-14.5' 1.75 X [10.sup.-7]
B, 4-ST, 15'-16'4" 2.43 X [10.sup.-6]
C, 4-ST, 12'-13'6"
E, 6-ST, 18'-20'
F, 3-ST, l0'-12'9"
G, 5-ST, 20'-21'2"
H, 5-ST, 20'-21'2"
I, 5-ST, 20'-22'9" 1.55 X [10.sup.-7]
J, 4-ST, 15'-15'l0" 1.01 X [10.sup.-7]
M, 4-ST, 12'-13'8" 7.62 X [10.sup.-7]
M, 6-ST, 17'-18'8" 2.64 X [10.sup.-7]
N, 6-ST, 17'-18'4" 4.9 X [10.sup.-5]
N, 8-ST, 25'-26' 1.45 X [10.sup.-5]
* Falling head method, ST = Shelby Tube. CEC results: A, 15', 6.9
meq/100 g; D, 20', 8.3 meq/100 g, Avg. = 7.6 meq/100 g.
Table 2
Natural moisture contents and N values, stiff, silty clay samples,
Indianapolis, Indiana. Tsf = tons per square foot, N value = number of
blows to drive sample one foot.
Unconfined
Natural moisture compression N value
Boring No. Depth (ft) content, % strength (Tsf) (blows/ft)
1 28.5-30.0 11.7 40
33.5-35.0 10.8 56
2 33.5-35.0 8.9 53
3 33.5-35.0 10.4 45
4 38.5-40.0 10.0 40
5 28.5-30.0 8.8 29
33.5-35.0 9.6 7.91 47
6 33.5-35.0 9.7 57
38.5-40.0 9.3 47
7 33.5-35.0 9.5 32
38.5-40.0 9.4 53
Table 3
Laboratory test results and N values for silty, clay samples, chicago,
Illinois.
Natural
moisture Atterberg limits
Boring No. Depth (ft) content, % LL PL PI
1 23.5-25.0 18.0
28.5-30.0 16.2
33.5-35.0 19.7
38.5-40.0 21.3
43.5-45.0 22.3 39 19 20
48.5-50.0 19.4
53.5-55.0 19.1
58.5-60.0 19.6 35 17 18
63.5-65.0 19.6
68.5-70.0 17.6
73.5-75.0 18.4 27 16 11
78.5-80.0 16.1
83.5-85.0 16.0
88.5-90.0 14.7 28 16 12
93.5-95.0 8.8
98.5-100.0 11.0 21 16 5
103.5-105.0 11.4 NP
108.5-110.0 9.5
113.5-115.0 9.3
2 23.5-25.0 23.0
28.5-30.0 23.5
33.5-35.0 20.3
38.5-40.0 23.3
43.5-45.0 24.6 37 18 19
48.5-50.0 23.0
58.5-60.0 17.1 32 18 14
63.5-65.0 16.3
68.5-70.0 15.2 28 17 11
73.5-75.0 12.8
78.5-80.0 11.8
83.5-85.0 12.5
88.5-90.0 18.7
93.5-95.0 12.1
98.5-100.0 22.2 19 13 6
103.5-105.0 14.0
108.5-110.0 11.7
113.5-115.0 10.8 19 14 5
118.5-120.0 20.8 39 19 10
N value
Boring No. (blows/ft)
1 12
5
11
8
8
24
18
34
38
23
52
41
>121
65
>124
>110
>120
>200
>200
2 2
7
12
9
8
10
22
25
40
35
60
>100
>100
>100
>100
>100
>100
>100
>100
Table 4
Earthmover's Facility, Elkhart County, Indiana. Hydraulic conductivity
(k) and Cation exchange capacity (CEC) tests. Tests taken below landfill
base.
Depth below
Gound elev Landfill base Test elev landfill base,
Boring (ft) elev (ft) (ft) (ft)
B-14 817 808 798 10
B-14 817 808 798 10
B-15 817 809 798 11
B-17 807 794 791 3
B-17 807 794 790 4
B-17a * 807 794 791 3
B-18 806 798 795 3
B-19 806 800 795 5
B-19b # 806 800 794 6
WB-6 808 800 785 15
WB-9 813 802 792 10
WB-9 813 802 792 10
WB-10 808 798 793 5
WB-10 808 798 792 6
WB-11 812 804 791 13
WB-22 804 798 789 9
WB-23 806 803 796 7
WB-24 819 811 805 6
WB-25 820 808 798 10
k CEC
Boring (cm/sec) Meq/100 g
B-14 4.7 x [10.sup.-8]
B-14 3.3 x [10.sup.-8] 13.9
B-15 13.2
B-17 3.3 x [10.sup.-8]
B-17 20.8
B-17a * 2.0 x [10.sup.-7]
B-18 15.2
B-19 16.8
B-19b # 10.0 x [10.sup.-6]
WB-6 12.9
WB-9 7.5 x [10.sup.-8]
WB-9 16.0
WB-10 2.0 x [10.sup.-7]
WB-10 16.7
WB-11 15.2
WB-22 3.5 x [10.sup.-8]
WB-23 5.1 x [10.sup.-8]
WB-24 6.9 x [10.sup.-8]
WB-25 2.3 x [10.sup.-5]
* In-situ test.
# = Sample gotten by redrilling B-19 to the specified elevation and
obtaining a Shelby tube.
B = Early borings
WB = Wehran Company borings.
Figure 3
Boring log, subsurface exploration, for a proposed landfill in
Tippeconoe County. The site was located in an area of a broad,
gently-rolling ground moraine.
Project Name: Proposed Landfill
Date of Boring: November 11, 1981
Boring: A
Drilling Method: HSA
File: Southwest corner-SR 231 & CR 800 South Tippecanoe County
Project No.:
Sampling: AU, SS and ST
Description Depth Sample N [Q.sub.u]
Surface 1-AU - -
Dark brown clayey silt to
silty clay, trace organic mat.
Brown silty clay, trace sand
5
2-SS 8 -
Brown silty fine to medium sand
10
3-SS 17 3.3
Gray silty clay to clayey silt, 4-ST
little sand, trace small gravel
15
5-SS 21 -
Gray brown fine to coarse snad,
trace small gravel
20
6-SS 50/5" 10
Gray clayey silt, some sand,
Trace gravel (Till) 25 7-SS 47 7.0
30
8-SS 50/5" 6.5
Description [Q.sub.p] [w.sub.c]
Surface - 25
Dark brown clayey silt to
silty clay, trace organic mat.
Brown silty clay, trace sand
- 18
Brown silty fine to medium sand
4.0 10
Gray silty clay to clayey silt,
little sand, trace small gravel
- 16
Gray brown fine to coarse snad,
trace small gravel
4.5+ 8
Gray clayey silt, some sand,
Trace gravel (Till) 4.5+ 8
4.5+ 7
Description Remarks
Surface
Dark brown clayey silt to
silty clay, trace organic mat.
Brown silty clay, trace sand
Water level, 6 ft. @ 24HR
Brown silty fine to medium sand
Gray silty clay to clayey silt, Taken 11'6" to 14'6"
little sand, trace small gravel
Gray brown fine to coarse snad,
trace small gravel
[w.sub.c] = Natural moisture
Content
Gray clayey silt, some sand, AU = Auger
Trace gravel (Till) ST = Shelby Tube
SS = Split Spoon Sample
from SPT
SPT = Standard Penetration
Test, N values
End of Boring
ACKNOWLEDGMENTS Tim Bannister and Steve Reuter, Andrews Environmental Engineering Company in Indianapolis, Indiana (formerly with Wehran Engineering Corp.) provided literature and information on till megagroups for northcentral Indiana. David Warder, Chief Engineer, ATC ATC Air Traffic Control ATC Average Total Cost ATC Certified Athletic Trainer ATC At the Center (Hartford, Maine retreat center) ATC Applied Technology Council ATC All Things Considered Associated, Inc., Midcontinent Division, provided valuable information on the nature of subsurface evaluations of glacial deposits. Ned Bleuer, glacial geologist, Indiana Geological Survey Created in 1837, the Indiana Geological Survey (IGS) is an official agency of the U.S. state of Indiana charged with geological research and the dissemination of information about the state's energy, mineral and water resources. , Bloomington, provided a publication and discussion on the complexities of glacial deposits and the use of megagroups to decipher till stratigraphy. K.H. Cho helped to prepare the illustrations. The valuable contributions of these individuals is greatly appreciated. Manuscript received 28 August 2001, revised 5 March 2002. LITERATURE CITED Bleuer, N. & W. Melhorn. 1989. Glacial Terrain Models, North-central Indiana--The Application of Downhole Logging to Analysis of Glacial Vertical Sequences, Geological Society of America The Geological Society of America (or GSA) is a nonprofit organization dedicated to the advancement of the geosciences. The society was founded in New York in 1888 by James Hall, James D. , North-Central Section, Field Trip 2, South Bend, Indiana This article is about the city in Indiana, US. For other uses of the name South Bend, see South Bend (disambiguation). South Bend is a city in St. Joseph County, Indiana, United States. , April. Department of Natural Resources Many sub-national governments have a Department of Natural Resources or similarly-named organization:
Edwards, M.B. 1986. Glacial Environments, Sedimentary Environment and Facies (H.G. Reading, ed.). Pp. 45-471. Eyles, N. 1983. Glacial Geology, An Introduction for Engineers and Earth Scientists. Pergamon Press. 409 pp. Reussow, J.P. & P.B. Rohne. 1975. Water Resources of the St. Joseph River Basin in Indiana. Hydrolic Investigation Atlas, HA-0537. U.S. Geological Survey, Reston, Virginia. Skempton, J.P., R.C. Berg & D.R. Soller. 1991. Glacial Geology of the Midwest. Framework and Applications, Short Course, 34th Annual meeting, Association of Engineering Geologists, Chicago. Illinois. Sudar, Susan A. 1987. Subsurface and Hydrogeologic Investigation of the Existing Operations and Proposed Expansion of South Side Sanitary Landfill, Marion County, Indiana Marion County is a county located in the U.S. state of Indiana. As of 2000, the population was 860,454. The estimated population in 2006 was 865,504. The county seat is Indianapolis6. Geography According to the U.S. . M.S. Thesis, Purdue University. 148 pp. Wehran Engineering Corporation. 1989. Permit Amendments for Solid Waste Disposal Facility, Expansion for Earthmover's Incorporated, Elkhart, Indiana. West, T.R. 1995. Geology Applied to Engineering, Prentice-Hall. 560 pp. |
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