A CONTINUOUS RECORD OF HOLOCENE PALEOENVIRONMENTS AND NEOGLACIATION IN THE TETON RANGE, WYOMING, FROM ALPINE LAKE SEDIMENTS

Lake basins in the Teton Mountain Range, WY, sensitively record environmental and glacial change through the constant accumulation of sediment. Continuous sediment records are especially valuable as current evidence of Holocene glacier activity in the western United States is primarily derived from moraine chronologies, which often fail to capture Neoglacial advance and retreat. In this study, we present sediment core analyses from Lake Solitude (0.15 km²; 2761 m a.s.l), a currently non-glacial cirque lake situated at the head of the north fork of Cascade Canyon in the central Tetons. We compare a suite of sedimentary indicators including magnetic susceptibility, bulk density, grain size distributions, geochemical abundance, percent organic matter, and clastic sediment flux. Radiocarbon dating and tephrochronology are used to establish age control of the sediments. The resulting ~14,000-year record captures deglaciation of the cirque basin at the end of the last Ice Age and suggests small Teton glaciers persisted until the Pleistocene-Holocene transition and subsequently experienced phases of Neoglacial expansion and retreat. Our results complement regional evidence of multi-phase Neoglacial expansion and retreat. Paleoclimate records suggest Neoglacial activity was largely driven by winter snowpack trends and long-term Holocene summer cooling. The sedimentary record presented in this study spans past periods of abrupt and rapid climate and glacial change that can provide analogues to contemporary environmental change and ultimately improve our understanding of sensitive alpine ecosystems in a changing climate.