Loess accumulation and soil formation in central kansas, United States, during the past 400 000 years

Abstract

Based on interpolation of thermoluminescence dates and the mean accumulation rate of 0.034 mm yr-' , four cycles of pedogenic CaC03 accumulation are found within the Loveland Loess: 41 5-325 ka, 325-250 ka, 250-195 ka and 195-95 ka. The four CaC03 peaks correspond chronologically to marine oxygen isotope stages 11, 9, 7 and 5, respectively. The early Wisconsin (95-70 ka) was characterized by sand dune activity. The reddish pedocomplex was formed from 70 to 35ka under relatively warm and moist climatic conditions with a very slow rate of silt accumulation (0.016 mm yr-'). The Gilman Canyon pedocomplex, enriched in organic matter and dated at 35-20 ka, was formed under a strong physical weathering regime and a relatively high rate of silt accumulation (0.15mmyr-'), indicating a windy, relatively moist, probably cool environment. It developed when the Laurentide ice sheet was advancing and dust content in Greenland ice core was low. The Peoria Loess was accumulated at a rate of 0.3 mm yr-I in central Kansas under cold dry conditions when the ice sheet fluctuated around its maximum position and the dust content in the Greenland ice core was the highest. Even the warm substage around 13 ka has some corresponding evidence in the central Great Plains. The welldeveloped Brady Soil, dated at 10.5-8.5 ka, indicates that the early Holocene was the optimal time for soil development since 20 ka. The poorly weathered Bignell Loess might have been deposited during the Altithermal Period from 8.5 to 6 ka.

Late Quaternary environmental reconstructions of playa-lunette system evolution on the central High Plains of Kansas, United States

“…On the central High Plains, the Sangamon Soil is widespread, and development occurred throughout all of marine isotope stage (MIS) 5 and most of MIS 4 (Forman et al, 1992;Forman and Pierson, 2002;Maat and Johnson, 1996). Previous research on the Great Plains indicates that during Sangamon Soil formation, regional climate was warm and dry (Feng et al, 1994) or warm and humid (Karlstrom et al, 2008;Muhs and Bettis, 2003). In the Lower Mississippi River Valley, the soil formed under a warm to hot climate with seasonal or longer periods of drought (Markewich, 2008).…”

“…Loess deposition occurred predominantly during MIS 2, ca. 25-12 ka, and accumulated more rapidly than underlying loess units (Feng et al, 1994;Maat and Johnson, 1996;Martin, 1993) under a colder and/or drier climate than today Muhs et al, 1999). Mason et al (2007) asserted there is little evidence of pedogenic alteration below the surface soil within the loess unit, although Ruhe et al (1971) identifi ed several "dark bands" in Peoria Loess of western Iowa, which they interpreted as a series of incipient paleosols.…”

“…Regionally, Peoria Loess accumulated rapidly during MIS 2, between ca. 25 and 12 ka, under a cold and/ or dry climate (Feng et al, 1994;Mason et al, 2007;Muhs et al, 2008). This interval is characterized by the thickest sedimentary units within most playa-lunette system zones.…”

“…Stable carbon isotope data from Wilson Ridge indicate that temperature increased and effective precipitation decreased toward the end of pedogenesis. The Pleistocene-Holocene transition is poorly preserved in Cheyenne Bottoms, though the Brady Soil is preserved on surrounding uplands, indicating the landscape stabilized during the Pleistocene-Holocene transition (Feng et al, 1994;Fredlund, 1995).…”

Evidence of Saharan dust in upper Pleistocene reworked palaeosols of North‐west Sardinia, Italy: palaeoenvironmental implications

“…Red or reddish‐brown palaeosols are observed in the Quaternary sedimentary successions worldwide (Feng et al. , 1994; Marx et al.…”