Paleoclimatic interpretations of buried paleosols within the pre-Illinoian till sequence in northern Missouri, USA

摘要: Abstract Northern Missouri preserves shallow buried paleosols ranging in age from Early to Late Pleistocene that are developed six pre-Illinoian tills beneath Illinoian (MIS 6) and Wisconsinan 4-2) loess. The morphology of these changes with age, reflecting a changing climate during the Pleistocene, cosmogenic-nuclide burial dates respective sola provide control on timing changes. depth secondary calcium carbonate nodules within weathering profiles increases younger indicating transition moister conditions absent entirely modern soils. After approximately 0.4 Ma, became distinctly redder, even as time available for pedogenesis shorter, culminating bright red Sangamon Geosol 5). This trend is consistent increasing interglacial temperatures and/or precipitation. Finally, erosion rates determined concentrations also increase systematically age. may be due some combination climate, more-frequent glaciations deposition thick cover unconsolidated glacial sediment above stable residuum-dominated preglacial landscape.