Geological Society of America

65 D4. Geochemistry (Posters)

Sunday, 22 March 2020
1:30 PM - 5:30 PM
Grand Ballroom E–G

SEDIMENT CORES FROM WHITE POND, SOUTH CAROLINA, CONTAIN A PLATINUM ANOMALY, PYROGENIC CARBON PEAK, AND COPROPHILOUS SPORE DECLINE AT 12.8 KA

Paper number: 65-2
Program: Technical Sessions
Time: 1:30 PM – 5:30 PM

Authors

Christopher R. Moore Presenting Author
Savannah River Archaeological Research Program, South Carolina Institute of Archaeology and Anthropology, USC, New Ellenton, SC
Chad S. Lane
University of North Carolina Wilmington, Wilmington, NC
Josh D. Kapp
University of California, Santa Cruz, Santa Cruz, CA
Allen West
Prescott, AZ
David L. Carlson
Texas A&M University, College Station, TX
Wendy S. Wolbach
DePaul University, Chicago, IL
Theodore Them
College of Charleston, Charleston, SC
M. Harris
College of Charleston, Charleston, SC
Sean Pyne-O'Donnell
NanyangTechnological University, Singapore
Mark J. Brooks
Savannah River Archaeological Research Program, South Carolina Institute of Archaeology and Anthropology, USC--Retired, Batesburg, SC
Albert C. Goodyear
University of South Carolina, Columbia, SC
Terry Ferguson
Wofford College Environmental Studies, Spartanburg, SC
Angelina G. Perrotti
University of Wisconsin, Madison, WI
Siddhartha Mitra
East Carolina University, Greenville, NC
Ashlyn M. Listecki
East Carolina University, Greenville, NC
Bailey C. King
East Carolina University, Greenville, NC
David Mallinson
East Carolina University, Greenville, NC

Abstract

A widespread platinum (Pt) anomaly was recently documented in Greenland ice and 11 North American sedimentary sequences at the onset of the Younger Dryas (YD) event (~12,800 cal yr BP), consistent with the YD Impact Hypothesis. We report high-resolution analyses of a 1-meter section of a lake core from White Pond, South Carolina, USA. After developing a Bayesian age-depth model that brackets the late Pleistocene through early Holocene, we analyzed and quantified the following: 1) Pt and palladium (Pd) abundance, 2) geochemistry of 58 elements, 3) coprophilous spores, 4) sedimentary organic matter (OC and sedaDNA), 5) stable isotopes of C (δ¹³C) and N (δ¹⁵N), 6) soot, 7) aciniform carbon, 8) cryptotephra, 9) mercury (Hg), and 10) magnetic susceptibility. We identified large Pt and Pt/Pd anomalies within a 2-cm section dated to the YD onset (12,785 ± 58 cal yr BP). These anomalies precede a decline in coprophilous spores and correlate with an abrupt peak in soot and C/OC ratios, indicative of large-scale regional biomass burning. We also observed a relatively large excursion in δ¹⁵N values, indicating rapid climatic and environmental/hydrological changes at the YD onset. Our results are consistent with the YD Impact Hypothesis and impact-related environmental and ecological changes.

Geological Society of America Abstracts with Programs. Vol. 52, No. 2

doi: 10.1130/abs/2020SE-345064

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