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

Kenneth L. Pierce·Daniel R. Muhs·Maynard A. Fosberg·Shannon A. Mahan·Joseph G. Rosenbaum·Joseph M. Licciardi·Milan J. Pavich
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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 10 Be accumulation in soils, and cosmogenic 10 Be 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.

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Quaternary ResearchArticle
90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 43.3351671567243° to 43.671844983221604° latitude; -110.96466064453125° to -110.64880371093749° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Kenneth L. Pierce, Daniel R. Muhs, Maynard A. Fosberg, Shannon A. Mahan, Joseph G. Rosenbaum, Joseph M. Licciardi, Milan J. Pavich. 2017-01-20. A loess–paleosol record of climate and glacial history over the past two glacial–interglacial cycles (~ 150 ka), southern Jackson Hole, Wyoming. https://doi.org/10.1016/j.yqres.2011.03.006

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