35-17 Glacial Lake Evenson: Geomorphic and Sedimentologic Evidence for a Previously Unrecognized Ice Age Pro-Glacial Lake, Mercer County, Pennsylvania

Session: Ice sheets, glaciers, and landscapes, oh my! (Posters)

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Observation of a homestead on a semi-circular flat-topped hillock in glaciated terrain prompted speculation that the underlying landform was a delta. Field reconnaissance quickly recorded a landscape with geomorphic evidence for a lake plain, surrounded by a shoreline that included multiple deltas. High resolution LIDAR acquisition permitted inquiry concerning potential morphosequences of the expected lacustrine and fluvial landforms. Analysis of derived bare ground elevation surfaces confirmed the presence of the morphologies expected to remain after the eventual draining of a pro-glacial lake, including several potential spillways, perhaps associated with a progression of lowering lake stages. Subsequent ground truthing with sediment sampling confirmed both silty clay lacustrine gyttja, as well as pebbly sand alluvium in the deltas. These investigations remain ongoing with aspirations for installing trenches to describe the sedimentology and to capture materials suitable for radiocarbon analyses. We named these Ice Age features Glacial Lake Evenson after the esteemed professor of Quaternary Science at Lehigh University, Dr Edward Bernard Evenson. Without his mentoring and deep commitment to field investigations, we would have continued driving by these features, as countless others have done, thinking no more than, “That sure is a pretty house on a nice lot.”

Geological Society of America Abstracts with Programs. Vol. 58, No. 2, 2026

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