| Summary: | Piston cores from the western Ross Sea reveal a stratigraphy consisting of basal tills overlain by glacial-marine sediments, succeeded seaward by glacial-marine deposits with abundant microfossils and IRD. The glacigenic sediments are succeeded at the shelf margin by coarse bioclastic sands and gravels. Seismic and core data indicate that the grounding line for the late Wisconsinan glacial maximum was just north of Coulman Island. Carbonate sediments from the outer shelf were grouped into four distinct facies. Radiocarbon dates indicate that carbonate deposition was occurring during much of the late Wisconsin. The pre-mid Miocene unconformity identified in DSDP Site 273 (Hayes and Frakes, 1975) was tied to the seismic data in the western Ross Sea. The data suggests that this event was responsible for the general physiography of the western shelf. Turbidites, including calcarenites, litharenites and quartz arenites, were recovered from the slope and the data suggests that outer shelf banks are the source for these deposits.
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