18 Limnogeology and Paleoclimatology—Investigating Past Environments and Reconstructing Past Climates (Posters)

Monday, 18 April 2016
1:30 PM - 5:30 PM
Illinois Ballroom AB

LATE PLEISTOCENE TO HOLOCENE CLIMATE VARIABILITY AS RECORDED IN THE SEDIMENT OF SILVER LAKE, OHIO

Paper number: 18-7
Program: Theme Sessions
Time: 1:30 PM – 5:30 PM

Authors

Abstract

In order to provide greater spatial coverage of late Pleistocene to Holocene environmental change in the Midwest, a 13.5-m long sediment core was collected from Silver Lake in northeast OH. Age control is provided by radiocarbon dating and correlation to a dated kettle lake record from western OH. Lithologic descriptions and loss-on-ignition profiles allow the history of the lake to be divided into three periods. The first period spans 13.5 to 8.24 m core depth (~17,000-7,000 cal year BP) and is characterized by low organic content (average 13%), occurrences of silty layers and high dry bulk density. Within this period at Younger Dryas time, organic content is low (average 6%) and a silty sediment is present possibly reflecting increased terrigenous sediment input to the lake during cold conditions. Above the Younger Dryas interval, the organic content increases to 19%, likely reflecting a moderation of the climate at the onset of the Holocene. The second period spans 8.24 to 1.07 m core depth (~7,000-200 cal year BP), and is characterized by mud having no visible silty layers, and a pronounced increase in organic content (average 51%). Within this period there are 6 intervals of decreased organic content suggestive of millennial-scale variability in terrigenous input and/or lake productivity. The upper 1.07 m is the third period and is characterized by a pronounced decrease in organic content (average 19%) and a corresponding increase in dry bulk density. These sediment characteristics are interpreted as enhanced soil erosion resulting from Euro-American settlement and land clearance.

Geological Society of America Abstracts with Programs. Vol. 48, No. 5

doi: 10.1130/abs/2016NC-275083

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