Geological Society of America

23 D7. Quaternary Geology (Posters)

Sunday, 18 March 2018
1:30 PM - 5:30 PM
Lake Champlain Exhibition Hall

CHARACTERIZING HOLOCENE SEDIMENT ACCUMULATION AND HUMAN IMPACTS IN AN UPLAND KETTLE POND IN EASTERN CONNECTICUT

Paper number: 23-3
Program: Technical Sessions
Time: 1:30 PM – 5:30 PM

Authors

William B. Ouimet Presenting Author
University of Connecticut, Storrs, CT
Kervelle Baird
University of Connecticut, Storrs, CT
Kyle Farrell
University of Connecticut, Storrs, CT
Scott Rowan
University of Connecticut, Storrs, CT
Joseph Wilcox
University of Connecticut, Storrs, CT
Caitlin T. McManimon
University of Connecticut, Storrs, CT
Heather Scofield
University of Connecticut, Storrs, CT
Billy Stansfield
University of Connecticut, Storrs, CT
Sean Gonzales
University of Connecticut, Storrs, CT
Yulio Araya
University of Connecticut, Storrs, CT
Benjamin Lee
University of Connecticut, Storrs, CT
Liam Nangle
University of Connecticut, Storrs, CT
Fernanda Mastroluca
University of Connecticut, Storrs, CT

Abstract

Lakes contain valuable sedimentary archives that can be used to understand landscape and environmental change through time. Here, we present the results of a project focused on examining Echo Lake in eastern Connecticut. Echo Lake (elevation ~78 m) is a kettle pond located within the upper reaches of the Thames River watershed. It lies adjacent the Fenton and Mount Hope Rivers and lake levels are controlled by groundwater - there are no side streams flowing in and no dam. A high-resolution sonar scan of Echo Lake indicates that lake bathymetry is characterized by an elongated bowl shape, maximum water depths of 4.8-5.5 m, and steep edges. To characterize sediment in the lake, we collected 3 shallow surfaces cores ranging 65-90 cm in length, one deeper push core that recovered sediments lying ~1m to 5m below the sediment-water interface, and 10 lake bottom grab samples. The long core was sampled for ¹⁴C dating and all samples were analyzed for organic content (measure by loss-on-ignition) and heavy metals such as Pb, Zn and Cu (measured by handheld XRF). Surface and shallow cores highlight the influence of human activities, with high levels of Pb, Zn and Cu in all surface sediments and the uppermost 40 cm of sediment cores marking regional industrialization and other activities over the past 150 years. Deeper stratigraphy (>1 m) highlights a transition from high sediment input in the late Pleistocene/early Holocene to high organic input punctuated by small sand lenses inferred to reflect storms that mobilized sediment from nearby kettle walls into the deepest areas of the lake. The Holocene stratigraphy observed at Echo Lake reflects either a transition from colder environment to a warmer one that supported nearby lake vegetation, or shifting lake levels through time.

Geological Society of America Abstracts with Programs. Vol. 50, No. 2

doi: 10.1130/abs/2018NE-311353

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