Glacial deposits

Records of past environmental change are preserved in a broad range of Earth materials. Past environments are inferred from "proxy" records, meaning measurements of physical and chemical parameters of marine and terrestrial sediment, polar ice, and other materials that were in some way influenced by their environment during accumulation. Examples of proxy records are the distribution of glacial deposits, the isotopic composition of terrestrial and marine sediments and ice, the abundance and species composition of plant and animal fossils, and the width of tree rings. 

Unconsolidated cover at Pebble consists of 0-50 m of a variety of glacial deposits over Pebble West, where the deposit is partially exposed. At Pebble East, the deposit was partially eroded and is unconformably overlain by an eastward thickening wedge of post-mineralization Late Cretaceous to Eocene volcanosedimentary rocks, up to 600 m in thickness, which in turn are overlain by the glacial deposits. 

Above the bedrock are tundra-covered unconsolidated deposits from two episodes of Pleistocene glaciation. These glacial deposits consist of poorly sorted to unsorted, non-stratified compact till ranging from muddy gravel to sandy... 

The Pebble Cu-Au-Mo porphyry deposit contains one of the largest resources of copper and gold in the world. The Pebble West Zone, partially covered by glacial deposits up to 50 m thick, extends from the surface to 500 m depth (Lang et al. 2007). The East Zone, which extends to at least 1700 m depth, was partially eroded and is concealed by an eastwardly thickening wedge (300-600 m thick) of Late Cretaceous to Eocene volcanic and sedimentary rocks (Bouley et al. 1995 Lang etal. 2007). 

Egli, M. Fitze, P. Mirabella, A. (2001) Weathering and evolution of soils formed on granitic, glacial deposits results from chronose-quences of Swiss alpine environments. Catena 45 19-47... 

Road materials were gathered from 9 locations on unpaved roads in the vicinity of the sampling site. At each location, dust from the roadbed was scraped into a polyethylene sample bag from 5 or more spots over a 10 m area. These materials were also air dried and sieved Identically to the soil materials, but not crushed. Visual inspections of the road surface suggested that samples from 8 of the 9 sites were primarily crushed limestone rock. The remaining site consisted primarily of washed gravel derived from glacial deposits. An inventory of unpaved road surface materials within 5 km of the sampling site indicated that approximately 80% consisted of crushed limestone. 

USA Illinois, Indiana, Ohio, Michigan and Southeastern Wisconsin glacial deposit aquifers... 

Groundwater in glacial deposits often contains high concentrations of arsenic (more than 10 pgL-1 Table 3.13). The presence of abundant fine-grained materials and organic carbon in glacial sediment... 

Thomas, M.A. (2003) Arsenic in Midwestern Glacial Deposits- Occurrence and Relation to Selected Hydrogeo-logic and Geochemical Factors U.S. Geological Survey Water-Resources Investigations Report 03-4228, Columbus, OH. 

Barnes SL (1964) An objective scheme for interpolation of data. J Appl Meteor 3 396-409 Betts AK (1982) Saturation point analysis of moist convective overturning. J Atmos Sci 39 1484-1505 Brook EJ, Brown ET, Kurz MD, Ackert Jr RP, Raisbeck GM, Yiou F (1995) Constraints on age, erosion, and uplift of Neogene glacial deposits in the Transantarctic Mountains determined from in situ cosmogenic 10Be and 26AI. Geology 23 1063-1066... 

Eocke W. W. (1986) Rates of hornblende etching in soils on glacial deposits, Baffin Island, Canada. In Rates of Chemical Weathering of Rocks and Minerals (eds. S. M. Colman and D. P. Dethier). Academic Press, pp. 129-145. 

Hall R. D. and Horn L. L. (1993) Rates of hornblende etching in soils in glacial deposits of the northern Rocky mountains (Wyoming-montana, USA) influence of climate and characteristics of the parent material. Chem. Geol. 105, 17-19. 

The objectives of this study were to develop a method for cave sediment mapping, and to use that method to develop a sedimentary history for the caves of Lime Creek. Cave deposits were mapped using techniques generally applied to unconsolidated surface deposits. Correlation between surface glacial deposits and cave deposits allowed some... 

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