POSSIBLE POST-LAURENTIDE ALPINE GLACIATION IN THE GREAT GULF CIRQUE, PRESIDENTIAL RANGE, NEW HAMPSHIRE - AN UPDATE

The possibility that active local glaciers existed in the cirques on the Presidential Range (PR) after the departure of the Late Wisconsinan Laurentide Ice Sheet (LIS) continues to be debated because the surficial geologic features of the cirques are not consistent with those usually considered together as evidence for recent cirque glaciation: fresh sharply defined cirque basins and associated moraines within and below them. The cirques on the PR are sharply defined, but so far associated moraines have not been found. Recently however, surficial mapping and laboratory-based stone clast provenance study in and below the Great Gulf cirque have identified landforms there that may be moraines, but dense vegetation and rugged field access have made it difficult to specifically relate their emplacement to a localized ice mass. As a result, alternative interpretations related to deposition by the LIS itself persist. New LiDAR data currently being processed for the Great Gulf area will be presented that may better inform ongoing debate, at least as it relates to the Great Gulf cirque.