This award supports continuing study of the late Pliocene- early Pleistocene terrestrial glacigene Sirius Group of the Transantarctic Mountains. The program consists of a six week field season in the Dominion Range-Beardmore Glacier region in the 1990-91 austral season, followed by laboratory data reduction. The following are among the principal targets to be addressed during the field and laboratory studies: (1) pre- Sirius paleotopography and structural geology; (2) section measurement, lateral and vertical facies changes; (3) collection of interglacial beech forest (Nothofagus) and other macro-and microplant material; (4) search for fossil insect, crustacean, bivalve, and fish material in the finer-grained lacustrine facies; (5) collect additional matrix and microclast samples from the Sirius Group with the aim of expanding the collection of Cretaceous-Paleogene-Neogene microfossils which were transported from the interior basins of East Antarctica during the late Plicoene-early Pleistocene; and (6) continue to test the hypothesis that Pliocene glaciation in this part of Antarctica involved high frequency variations of relatively small ice sheets, the development of interglacials of protracted warm periods, and major marine invasions of the antarctic interior by transgressions associated with higher stands of sea level.
