During the week of June 28, New York State Museum
geologists will collect sediment cores in the Esopus Valley and its tributary valleys to conduct research relating to climate change, as well as to assist in improving the quality of New York Citys water supply.
The research project, funded by the National Cooperative Geologic Mapping Program, will involve mapping the location and thickness of clay deposits in the Esopus Creek watershed. The clay was deposited in large lakes dammed by glacial ice during the most recent retreat of the continental ice sheet from New York State between 20,000 and 12,000 years ago. During their existence, the glacial lake basins accumulated thick deposits of layered silt and clay that record information about climate change. Geologists hope to extract paleo-climate data from the recovered sediments to help determine the timing of the lakes' existence and the ice retreat.
The second, and more pragmatic, reason for locating the clay deposits in Esopus Creek watershed is because Esopus Creek water flows into the Ashokan Reservoir, one of the Catskill water supply reservoirs for New York Citys drinking water. Floods in the Esopus watershed have caused stream bank erosion and landslides that expose these lake clay sources and increase the amount of clay suspended in the water (turbidity).
Because of the importance of identifying the distribution of these potential turbidity sources in the Ashokan watershed, the New York State Museum has coordinated this effort with the Ashokan Watershed Stream Management Program, a partnership of Cornell Cooperative Extension in Ulster County, the Ulster County Soil and Water Conservation District, and the New York City Department of Environmental Protection. Knowing the location and extent of clay deposits will aid the Ashokan Watershed Stream Management Programs proposed management strategies for improving the quality of New York City's drinking water.