MAPPING LAURENTIDE ICE SHEET POSITIONS IN CENTRAL NEW YORK USING LIDAR

The Laurentide Ice Sheet covered most of Canada and much of the northern United States during the Pleistocene Epoch. Following its last glacial maximum position, it initiated its retreat from northern Pennsylvania about 25,000 to 20,000 years ago. Evidence of ice sheet retreat in the Finger Lakes region of central New York exists as moraines and ice-dammed lake shorelines, first observed by H.L. Fairchild over 100 years ago. We are mapping Pleistocene ice-sheet margins (end moraines) and ice-damned paleo lakes (strandlines and De Geer moraines) in QGIS using LIDAR products down to 1 m resolution. In addition, we are georeferencing historical maps of Glacial Lake Succession in New York State by H.L. Fairchild (1908). Combined, we plan to construct a highly detailed ice-limit and paleo-lake map from which to learn about the style of the last ice-sheet occupation of the Finger Lakes region. Finally, several unpublished ¹⁰Be ages from this region will be placed into context of our new mapping.