Differentiation of surficial glacial drift in southeastern Michigan from 7-Å/10-Å X-ray diffraction ratios of clays

Clay Sedimentology

“…On the other hand, clay mineralogy shows systematic differences in the relative abundance of illite compared to chlorite, kaolinite, and vermiculite (Rieck et al 1979). Till and glaciolacustrine materials supplied by both glaciallobes show similar lithology, color, texture, and macrofabric, which prevents the identification of different sourees, glacier progression steps, and local stratigraphy.…”

Composition of till from the Clear Lake Quadrangle, Skagit and Snohomish counties, Washington

“…Some of the clay-fraction minerals (serpentine, talc, stilpnomelane, kaolinite) present in till from the Clear Lake quadrangle are largely derived from local bedrock and provide better indicators of local bedrock composition and ice-flow direction than clasts in the till. The presence of rock units of highly varied mineralogy (Tables 1 & 4) in the Clear Lake quadrangle, each of which contributes a unique suite of minerals to the fine fraction of the tills (Table 4) Distribution and ice-flow direction Chlorite, smectite, mica, and minor amphibole and kaolinite are the principal clay-size minerals in till from the Puget lowland (Pevear et al, unpublished data, 1980;Hepp, 1972;Heller, 1980) (Table 4) The distribution of distinctive rock types has traditionally been used to reconstruct flowlines for continental glaciers (Flint, 1971) and clay minerals have been used to distinguish tills of different ages and source areas in the Midwest and Northeastern United States(cf., Rieck et al, 1979). The present study suggests that clay minerals may provide at least local "markers" for deposits of the Cordilleran ice in northwest Washington.…”

A sediment-mixing process model of till genesis, using texture and clay mineralogy data from Saginaw lobe (Michigan, USA) tills

“…We calculated 7 Å/10 Å ratios to compare our data with data from prior studies (e.g., Rieck et al, 1979; Monaghan and Larson, 1986) that used this parameter as a metric (Table 4). The mean 7 Å/10 Å ratios for till samples is 0.76 ± 0.31, as compared with 0.67 ± 0.35 (2-sigma) for the lake sediment (Table 4).…”

“…1). We included some of the West Branch moraine in the Saginaw lobe terrain, as most consider it to be a Saginaw lobe feature and it is dominated by tills, but excluded most areas within the topographically and sedimentologically diverse interlobate moraine of southeastern Michigan, where glaciofluvial sediments make up most of the landscape (Rieck, 1979; Rieck et al, 1979). The uppermost limit of glacial Lake Saginaw was taken from Lusch et al (2009), and initially all of our sample sites were restricted to areas above this shoreline, that is, till landscapes that had not been covered by the lake.…”