148-3 Paleoclimatic Constraint on Soil Formation and Survival.

See more from this Division: SSSA Division: Soil Mineralogy
See more from this Session: Poster and 5 Minute Rapid--Soils and Landscapes of the Southwestern United States (includes student competition)

Monday, November 7, 2016: 4:05 PM
Phoenix Convention Center North, Room 132 C

Christopher Shepard, University of Arizona, Tucson, AZ and Craig Rasmussen, 1177 E 4th Street Shantz Bldg, University of Arizona, Tucson, AZ
Abstract:
Soil chronosequences describe how soil properties change with time; however, our understanding of soil chronosequences is typically limited to site- or study-specific basis, lacking global applicability. As such, a global theory of soil property change with time, soil formation, or persistence at the Earth’s surface has yet to be fully developed. Here we propose a global theory of soil formation and survival within the context of past climate change. Using a global synthesis of soil chronosequence data and δ18O records as paleoclimatic proxies we found the rate of change in past climate controlled variability in soil properties and persistence across the Earth’s surface. The vast majority of soils formed during interglacial periods with low rates of climatic change, with few soils forming during periods of rapid climate change at glacial-interglacial periods. Further, climate variability lead to increased variability in soil properties observed at 105 years, coinciding with the glacial-interglacial frequencies throughout much of the mid to late Pleistocene and Holocene. Soils deposited during increased erosion and denudation associated with glacial-interglacial transition, developed and evolved throughout interglacial periods, enabling persistence at the Earth’s surface through later climate shifts. Soils deposited prior to rapid climatic shifts were likely prevented from developing and were removed from the Earth’s surface. Past climate change controlled soil survival throughout the Quaternary, and influenced the distribution of soils that are observed across the modern Earth’s surface.

See more from this Division: SSSA Division: Soil Mineralogy
See more from this Session: Poster and 5 Minute Rapid--Soils and Landscapes of the Southwestern United States (includes student competition)

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