184-1 Environmental Conditions and Landscape Development in Central New York During the Glacial to Interglacial Transition

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

Presenting Author:

Authors:

Abstract:

While the retreat of the Laurentide Ice Sheet (LIS) and post-glacial environmental change have been extensively studied in New England, high-resolution records from the Finger Lakes region of New York remain sparse. To address this gap, we developed a record of deglaciation and postglacial environmental conditions since ~14.7 cal ka BP using sediment cores from two ponds, Mud Pond and Round Pond. Magnetic susceptibility (MS), high-resolution sediment geochemical data (μ-XRF core scanning), loss-on-ignition, and smear slide analyses revealed how the landscape responded to LIS retreat and subsequent climate change. Both cores preserve a basal, well-sorted siliciclastic silt (80–90% lithogenous, <10% organic matter) with high Ti, Zr, K, and MS values, consistent with detrital input from recently deglaciated, sparsely vegetated terrain. These silt units were likely deposited in proglacial lakes—Lake Warren (Round Pond) and Lake Iroquois (Mud Pond). In Round Pond, the transition from siliciclastic silt to laminated, carbonate-rich (15-30%; higher Ca, Sr) silty sand with mollusk fragments, followed by a 0.5-cm thick very coarse sand at  ~13.5 cal ka BP, reflects a shallowing lake environment and change in sediment source. A thick sapropel bed (80% organic matter) above this transitions to bedded carbonate mud (30-40% carbonate) with mollusks, indicating warm summers, higher aquatic productivity, and reduced detrital input. This shift signals increased vegetation cover and stabilization of the landscape. Mud Pond preserves a basal silt abruptly overlain by herbaceous peat with high organic content (60-80%) and low MS and elemental values, signaling an unconformity. The lower detrital input (20–30% lithogenous) suggests denser vegetation cover and warmer conditions after ~11.62 cal ka BP. Differences in post-glacial landscape evolution between the two sites likely reflects contrasting basin morphologies. Round Pond occupies a deep kettle hole whereas Mud Pond occupies a relatively flat lowland between drumlins. These results highlight the interplay between regional climate forcing and local geomorphic controls on post-glacial environmental changes in the Finger Lakes region.

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

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.