Late Pleistocene glacial chronology of the western Ahklun Mountains, southwest Alaska

Late Pleistocene glacial chronology of the western Ahklun Mountains, southwest Alaska
Briner, J. P.
1998
Utah State University, Logan
106 p.
Geophysical Institute Library: THESIS NOT UAF
New glacial mapping and 35 cosmogenic $\sp{36}$Cl surface exposure ages constrain the extent and timing of late Pleistocene glacial fluctuations in the western Ahklun Mountains, southwestern Alaska. Morphometric and soil relative-age data characterize two main drift units deposited during the Arolik Lake and Klak Creek glaciations, named herein. During the Arolik Lake glaciation, outlet glaciers emanated from an ice cap over the central portion of the Ahklun Mountains and deposited moraines at or beyond the modern coast at 53.6 $\pm$ 2.0 $\sp{36}$Cl ka. During the Klak Creek glaciation, ice-cap outlet glaciers deposited moraines 20-80 km up-valley from Arolik Lake moraines during two phases, one from $\sim$25 to 23 $\sp{36}$Cl ka, and another from $\sim$19 to 15 $\sp{36}$Cl ka. The restricted extent of Klak Creek glaciers might reflect a lack of available moisture as sea ice covered the Bering Sea during the peak of the last global glacial maximum.
M.S. thesis
Minerals Data and Information Rescue in Alaska (MDIRA)