Glacial drift

Shilts, W.W. 1975. Principles of geochemical exploration for sulphide deposits using shallow samples of glacial drift. Canadian Institute of Mining and Metallurgy Bulletin, 68, 73-80. 

Shilts, W.W. 1996. Glacial drift exploration. In Menzies, J. (ed) Past Glacial Environments Sediment Forms and Techniques. Butterworth-Heineman, 411-438. 

Sharp, J. M., 1984, Hydrogeologic Characteristics of Shallow Glacial Drift Aquifers in Dissected Till Plains (North-Central Missouri) Ground Water, Vol. 22, No. 6, pp. 683-689. 

A general term for the entire layer or mantle of fragmental and loose, incoherent, or unconsolidated rock material, of whatever origin (residual or transported) and of a much varied character, that nearly everywhere forms the surface of the land and overlies or covers the more coherent bedrock. It includes rock debris (weathered in place) of all kinds, volcanic ash, glacial drift, alluvium, loess and aeolian deposits, vegetal accumulations, and soils. 

Szramek, K Walter, L.M. and McCall, P. (2004) Arsenic mobility in groundwater/surface water systems in carbonate-rich Pleistocene glacial drift aquifers (Michigan). Applied Geochemistry, 19(7), 1137-55. 

Warner, K.L. (2001) Arsenic in glacial drift aquifers and the implication for drinking water — Lower Illinois River Basin. Ground Water, 39(3), 433-42. 

Quite recently... to be exact, Within a billion years, in fact... Some time before the glacial drift Had given the planet s face a lift, A group of shameless molecules... 

The Crandon massive sulphide deposit is found in Precambrian volcanic rocks of the Rhinelander-Ladysmith greenstone belt, which trends east-west across the northern part of Wisconsin. Mineralisation occurs in a sequence of volcanic and associated sedimentary rocks which strike about N85 W, dip 70-90 Tl, and consists of laminae of sphalerite in pyrite with minor amounts of galena and chalcopyrite. Stringer sulphide mineralisation underlies the massive sulphide ore and consists of quartz-chalcopyrite-pyrite and pyrite-chalcopyrite-sphalerite veins. The deposit is covered by up to 65 m of glacial drift. 

The Milk River Formation conformably overlies the Colorado Group and consists of up to 100 m of very fine- to medium-grained sandstone, siltstone and shale. More detailed geological descriptions of the aquifer are presented by Meyboom (1960). The Milk River aquifer, which comprises the lower part of the formation, crops out in the southernmost part of Alberta and northern Montana. Overlying the Milk River Formation is the Pakowki Shale. This unit consists entirely of marine shale with some very thin sandstone and bentonite beds (McCrossan and Glaister, 1964). Other bedrock and glacial drift units overlying the Pakowki have not been further subdivided (Fig. 2). 

Core samples of the glacial drift were retrieved during the installation of wells and piezometers in the study area. In order to avoid contamination of the core samples, a hollow-stem auger and split-spoon sampler were used. 

Samples of drill cuttings from the glacial drift and the Belly River Formation were analyzed by means of the X-ray powder camera method in an attempt to find laumontite. The results were negative. The only location in Alberta where laumontite has been found is in the Cretaceous Blairmore Group in the folded foothills in the southwestern corner of the province (MUler, 1972). What these observations indicate is that somewhat higher temperatures and pressures are required to form significant quantities of the zeolite laumontite than are avaUable in the study area. 

The Ca—Mg—HCO3- and Ca—Mg—SO4-type groundwater from the glacial drift aquifers reflects the dissolution of calcite and dolomite by carbonic acid formed in the soil zone, and the production and leaching of secondary gypsum through oxidation of sulfide in the presence of calcite or dolomite under conditions of partial saturation. In cases where the content of carbonates is low, silicate mineral weathering potentially occurs. 

The present configuration of the surface of the glacial drift in Long Island Sound is a deep central basin bounded by sills on the east and west. The submergence history of the Sound depends on the elevations of the lowest points on these sills relative to the sea level curve. On the Mattituck sill (to the east) this elevation is now -25 m. Sand is now being transported from east to west across the Mattituck sill and it is possible that the sill is now at a higher elevation than it was immediately after retreat of the ice. (More detailed acoustic reflection profile studies of the internal structure of the sill may answer this question.) The lowest point on the sill to the west (which has not yet been surveyed in as much detail) is higher than -20 m. (The locations of the saddle points on the eastern... 

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