T120 Where Does the Wind Blow? Aeolian Systems in Time and Space (Posters)

Monday, 5 November 2018
9:00 AM - 6:30 PM
Halls J-K

TRACE ELEMENTS IN LAMINATED SOIL CARBONATES: FIRST STEPS TOWARDS UNDERSTANDING THE SIGNAL

Paper number: T120-8
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

Laminated soil carbonate rinds are an emerging proxy that has been used to describe late Quaternary paleoclimate and ecologic change in the western US. However, their trace element composition has not yet been explored. As trace elements in soils relate to soil composition and dust input as modified by climate and soil processes, changes in the trace element composition of rinds from a single soil should relate to changes in soil processes and climate through time. Here we show preliminary results in understanding the controls on trace element composition at a field site near Torrey, southern UT, USA. We are investigating local vs. regional controls on rind composition by comparing trace element profiles (e.g., Mg/Ca) of a suite of soil carbonate rinds from a single surface. Rinds were collected from a variety of depths and boulder sizes (20->100 cm). If local controls dominate (such as clast size or nearby vegetation) then different rind profiles will exhibit strong variability and climate information will be obscured. On the other hand, if regional climate controls rind trace element chemistry, then rinds may serve as a proxy for, for example, wind direction and thus dust source. Initial results from two rinds showed that trace element profiles of Mg/Ca and Sr/Ca replicates within the same rind. However, there was considerable variability in profiles between the rinds, suggesting local controls dominated trace element composition. We are examining several other rinds to determine if this result is pervasive or if it is possible to elucidate a climate signal from a composite record of several rinds.

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-320053

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