Late Quaternary glacier fluctuations and vegetation change in the northwestern Ahklun Mountains, southwestern Alaska

This research examines moraine and lacustrine records of late Quaternary glacier and vegetation fluctuations in the northwestern Ahklun Mountains of southwestern Alaska.; Moraine mapping reveals that ice-cap outlet glaciers in the study area extended ca. 60 km from the center of the Ahklun Mountains ice dome during the early Wisconsin (sensu lato), and ca. 40 km during the late Wisconsin. This indicates asymmetry of glaciation over the range, particularly during the early Wisconsin (s.l.).; Lacustrine records from Little Swift Lake extend back to ca. 13.4 cal ka. Most vegetation changes resulted from the post-glacial spread of trees and shrubs, but there is also evidence for climatic change. Most notably, palynological and sedimentological data indicate a reversal, to dry (and possibly cool) climate at the onset of the Younger Dryas chronozone, followed by a period of exceptionally productive mesic conditions during the early Holocene.