A loess-paleosol record of climate and glacial history over the past two glacial-interglacial cycles (similar to 150 ka), southern Jackson Hole, Wyoming

Academic Article

Abstract

  • Abstract Loess accumulated on a Bull Lake outwash terrace of Marine Oxygen Isotope Stage 6 (MIS 6) age in southern Jackson Hole, Wyoming. The 9 m section displays eight intervals of loess deposition (Loess 1 to Loess 8, oldest), each followed by soil development. Our age-depth model is constrained by thermoluminescence, meteoric 10Be accumulation in soils, and cosmogenic 10Be surface exposure ages. We use particle size, geochemical, mineral-magnetic, and clay mineralogical data to interpret loess sources and pedogenesis. Deposition of MIS 6 loess was followed by a tripartite soil/thin loess complex (Soils 8, 7, and 6) apparently reflecting the large climatic oscillations of MIS 5. Soil 8 (MIS 5e) shows the strongest development. Loess 5 accumulated during a glacial interval (~ 76–69 ka; MIS 4) followed by soil development under conditions wetter and probably colder than present. Deposition of thick Loess 3 (~ 43–51 ka, MIS 3) was followed by soil development comparable with that observed in Soil 1. Loess 1 (MIS 2) accumulated during the Pinedale glaciation and was followed by development of Soil 1 under a semiarid climate. This record of alternating loess deposition and soil development is compatible with the history of Yellowstone vegetation and the glacial flour record from the Sierra Nevada.
  • Authors

  • Pierce, Kenneth L
  • Muhs, Daniel R
  • Fosberg, Maynard A
  • Mahan, Shannon A
  • Rosenbaum, Joseph G
  • Licciardi, Joseph
  • Pavich, Milan J
  • Status

    Publication Date

  • July 2011
  • Has Subject Area

    Published In

    Keywords

  • Bull Lake
  • Cosmogenic Be-10
  • Jackson Hole
  • Loess
  • MIS-3
  • MIS-4
  • MIS-6
  • Meteoric Be-10
  • Paleosols
  • Thermoluminescence
  • Digital Object Identifier (doi)

    Start Page

  • 119
  • End Page

  • 141
  • Volume

  • 76
  • Issue

  • 1