LATE AND POST-GLACIAL DEPOSITIONAL ENVIRONMENTS, NORTHERN WHITE MOUNTAINS, NEW HAMPSHIRE

Complex sequences of deposition in regionally adjacent north-facing drainages in the northern part of the White Mountains provide clues to the nature of local deglaciation processes as Late-Wisconsinan ice retreated, and sometimes locally readvanced, during its otherwise systematic recession to the north. Drainages located at lower elevations, such as the Peabody River valley, are often characterized by variable complexes of systematically interbedded till, glaciolacustrine, and slope-process deposits, while those at more intermediate and higher elevations, such as the Wild River valley and in and below King Ravine, are characterized by chaotically interbedded often collapsed deposits of till, ice-contact and glaciolacustrine sediments, and mountain-slope colluvium. These depositional records suggest relatively rapid deglaciation and active erosion on higher and steeper mountainsides with complex deposition related to slower recessional deglaciation at transitional and lower elevations. In spite of evidence of rapid deglaciation on higher mountain slopes, evidence in the valleys confirms that systematic retreat of a sometimes oscillating ice front prevailed over widespread ice mass stagnation in the region during the latter phases of the Late Wisconsinan.