20 Lake Sediments as Archives of Environmental Change (Posters)

Sunday, 17 March 2019
1:30 PM - 5:30 PM
Casco Bay Hall

POST-GLACIAL STRATIGRAPHY AND HUMAN IMPACTS IN UPPER BOLTON LAKE, EASTERN CONNECTICUT: IMPLICATIONS FOR AN ATLANTIC WHITE CEDAR STAND

Paper number: 20-9
Program: Theme Sessions
Time: 1:30 PM – 5:30 PM

Authors

Abstract

Lakes contain valuable sedimentary archives that can be used to interpret environmental change through time. We present the results of an investigation of Upper Bolton Lake in eastern Connecticut, located in the headwaters (205 m elevation) of the Hop River, a tributary of the Willimantic River and part of Thames River watershed in eastern Connecticut. It is shallow (<2.3 m), being the northernmost of three connected lakes, the others being Middle and Lower Bolton Lakes. Each lake has been dammed as a water reservoir, creating a 200-year history of anthropogenic fluctuations in lake levels. Prior to damming, the valley likely hosted a combination of floodplains, swamps, and wetlands within glacial lake basins.

Presently, Upper Bolton Lake is dammed at its southern edge by a causeway and derelict culvert system, and in the northeast, transitions into a tree stand of Atlantic White Cedar. State government plans to modify the lake’s water levels, which may impact this protected tree stand. Concerned about such impacts, local interest groups asked that we investigate the geologic context and history of water level change. Multiple vibracores will be collected at the site to characterize Holocene and Anthropogenic stratigraphy near the cedar swamp. These cores will be described and sampled for 14C dating, grain size, organic content (measured by loss-on-ignition) and heavy metal content (Pb, Zn, and Cu), measured using a handheld XRF. Investigation results will be combined with a Ground Penetrating Radar (GPR) survey coordinated by the Natural Resources Conservation Service. Overall, this project contributes to research regarding Holocene environmental change and human impacts within the New England landscape while also informing the questions of local residents.

Geological Society of America Abstracts with Programs. Vol. 51, No. 1

doi: 10.1130/abs/2019NE-328656

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