3-7 New Insights from an Old Archive: Abrupt Hydroclimate Shifts Across the Pleistocene-Holocene Transition, Browns Lake, Ohio

Session: Lakes of the World Through Space and Time: Archives of Climate, Paleoenvironments, Ecosystems, Geohazards, and Economic Resources

Presenting Author:

Eva Lyon

Authors:

Lyon, Eva C.¹, Gately, Damien², Miller, Elliot³, Corcoran, Meg⁴, Diefendorf, Aaron⁵, Lowell, Thomas⁶, Wiesenberg, Nick⁷, Wiles, Greg⁸

(1) The College of Wooster, Wooster, OH, USA, (2) The College of Wooster, Wooster, OH, USA, (3) The College of Wooster, Wooster, OH, USA, (4) University of Cincinnati, Cincinnati, OH, USA, (5) University of Cincinnati, Cincinnati, OH, USA, (6) University of Cincinnati, Cincinnati, OH, USA, (7) The College of Wooster, Wooster, OH, USA, (8) The College of Wooster, Wooster, OH, USA,

Abstract:

The Pleistocene-Holocene transition has been observed in lake sediment and ice core records across the northern hemisphere. Few archives from northern Ohio record the relatively rapid swings in hydroclimate that typify this time. Brown’s Lake in northeast Ohio is one such record. A seven-meter core collected in 2021 includes virtually the entire Holocene, and the final few millennia of the Pleistocene. Preliminary lithologic, magnetic susceptibility, and pXRF data support the interpretation that abrupt hydroclimate swings were happening in this part of North America at the end of the Pleistocene. With radiocarbon dates at 12,620-12,720 and 13,350-13,450 cal BP (1-sigma), this interval is marked by pronounced lithologic and magnetic changes across the Younger Dryas and Bolling-Allerod; the core includes abrupt changes from tan-gray fine-medium sand in the Younger Dryas and at least two other pulses, to light-medium brown sandy mud across the bulk of the Bolling-Allerod. Spikes in calcium and magnetic susceptibility accompany the sand layers, suggesting erosional events, perhaps driven by enhanced storminess. In contrast, Holocene sediments immediately following the transition are uniformly dark brown muds, with low magnetic susceptibility, consistent with a relatively quiescent hydroclimate regime. Further radiocarbon dates are needed to better constrain a “mystery interval” that precedes the Bolling-Allerod. We are also in the process of describing biotic changes across these intervals through smear slide analysis.

 

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7875

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