Paleopedologic and geomorphic evidence for Holocene climate variation, Shortgrass Steppe, Colorado, USA

摘要: Abstract Radiocarbon dates of paleosols in northeastern Colorado indicate distinct periods stability and soil formation with intervening instability resulting truncation or burial. A combination pedologic geomorphic indicators were used to resolve the duration of, prevailing climate during, these periods. Five sites, each having a paleosol, examined using both traditional analyses grain-size statistics, latter decipher mode parent material deposition. Twenty local stream, dune bedrock deposits analyzed statistics establish benchmarks for comparison soils. Field investigation supported by frequency early Holocene, middle Holocene contemporary soils all formed alluvium. Organic C phytolith data suggest climatic conditions more favorable plant productivity than present climate. Soil development suggests wetter moisture regimes present. Low carbonate contents an eolian source Bk Btk horizons. The presence paleosol horizons decrease precipitation at end soil-forming intervals followed drought subsequent