Samuel W. Gray and Philip J. Bart. Geology and Geophysics, Louisiana State University, E235 Howe Russell Building, Baton Rouge, LA 70803
During the Cenozoic, the climate progressed from global warmth into an icehouse world. The present day cold Antarctic ice sheet produces little basalt melt water, in contrast to temperate glaciers. Therefore, the transition from temperate to polar conditions should have resulted in marked decrease in sediment delivery to adjacent margins. In this study, sediment accumulation rates were calculated from the Ross Sea outer continental shelf and proximal deepwater Ocean Drilling Program and Deep Sea Drilling Project sites. The compilation of sedimentation rates showed that most sites experienced a significant decrease following the middle Miocene cooling and again in the early Pliocene. The abrupt shifts in sediment accumulation rate may represent transitions to largely dry-based conditions for the Antarctic ice sheet at these times, separated by an intervening return to warmer conditions in the Pliocene.
[Manuscript]
