24 Lake Sedimentary Records of Past Climate and Environment (Posters)

This session will focus on lacustrine archives and reconstructions of past environmental changes through the use of geochemical, biological, and sedimentological proxies. Both modern and paleo proxy datasets are welcome.

Monday, 23 March 2026
8:00 AM - 12:00 PM
CCC, Ballroom C

Interrogating the Nature and Timing of the Clastic-Organic Transition in Lake Sediment Cores as an Indicator of Landscape Stabilization in New England

Paper number: 24-17
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

The transition from the last glacial period to the current interglacial represents a period of profound climatic and environmental change in North America. In New England, this transition is recorded in lake sediments as a distinctive shift from clastic to organic sediments, reflecting changes in both the aquatic and surrounding terrestrial systems. While this transition is ubiquitous, its timing and character are variable. As such, this study aims to examine the timing of the clastic-organic transition, describe the sedimentologic nature of this transition, and investigate the spatial, temporal, and stratigraphic patterns among 8 lake sediment records from New England. We present new data from 7 lake cores in Maine (Rock Pond, Midway Pond, Eddy Pond, Upper McNalley Pond, Wadleigh Pond, Squirrel Pond, and Hale Pond), three lakes in New Hampshire (Sky Pond, Smith Pond Enfield, and Smith Pond Washington), and one lake in Vermont (May Pond), as well as consider several existing high resolution records from prior work. We present initial radiocarbon dates, sedimentological descriptions, and a range of proxy data (e.g., magnetic susceptibility, loss-on-ignition). Initial results demonstrate that the transition is temporally heterogeneous, spanning over two millennia from ~13.7 ka at Sky Pond (NH) to ~11.6 ka at May Pond (VT), with intermediate ages of 13.2 ka (Smith Pond Enfield, NH) and 13.0 ka (Smith Pond Washington, NH). Ongoing analyses of the Maine lake cores will extend the transect of study northward, broadening the evaluation of the clastic-organic transition, and ultimately strengthening paleoclimatic and paleoecological reconstructions of New England during the last period of deglaciation. Understanding the clastic-organic transition is critical to interpreting landscape evolution and ecological and climate changes across the Pleistocene–Holocene transition and may help in understanding the deglaciation and succession of modern regions.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411292

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