BART, PHILLIP J., J. B. ANDERSON, and F. P. SIRINGAN, Rice University, Department of Geology and Geophysics, Houston, TX

ABSTRACT: Seismic Stratigraphic Record of Marine-Based Ice Sheet Decoupling Events Related to Rapid Sea-Level Rise

Decoupling of marine-based ice sheets has been linked to rapid sea-level rises and large concurrent transgressions of coastal environments in the Gulf of Mexico during the Holocene. The decoupling mechanism probably was active throughout the Cenozoic. Approximately 3,200 km of high-resolution seismic datawere collected during the 1988 United States Antarctic Program to investigate the glacial history of the Antarctic Peninsula region. In aid on going seismic stratigraphic analysis of these data, the distribution of glacial-marine isotope facies on the shelf adjacent to Marguerite Bay were mapped. The distribution indicates that at least four decoupling events occurred during the Plio-Pleistocene. After the first retreat, subsequent advances and retreats of the prograding glacial-marin deltas progressively were restricted to the inner portion of the middle shelf. Although the volume of the Palmer Land Ice Sheet draining into Marguerite Bay is small, it probably responds in phase with the larger West Antarctic marine-based ice sheet.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.