In January 1984, the U. S. Geological Survey research vessel S. P. Lee carried out investigations of the Antarctic continental margin in the Wilkes Land and Victoria Land areas, using 24-channel and high-resolution seismic, sonobuoy refraction, gravity, magnetic, and bottom-sampling methods. This investigation augmented previous surveys of the Dumont d'Urville area by the French Petroleum Institute and explored new areas west and east to the boundary between the onshore Wilkes basin and the Victoria Land highlands. These surveys defined sediment thickness distribution and seismic stratigraphy in this frontier area. The tectonic style of the boundary between the East Antarctic craton and the younger crust of West Antarctica in the Ross Sea is revealed by one multichannel s ismic line across this important boundary.

The initial breakup of Antarctica from Australia occurred as a slowly spreading phase during the middle Cretaceous. According to Deep Sea Drilling Project results on the Tasman Rise, conditions of restricted circulation existed in the growing basin between the continents before the late Eocene. After the late Eocene, the major oceanic circulation pattern was established. Before that time, conditions were favorable for preservation of organic-carbon deposits on the sea floor. Among the questions to be addressed with this data are the following. (1) How do apparent subsidence rates of this passive margin compare with others around the world? (2) Does the onshore subglacial Wilkes basin continue onto the continental shelf? (3) Do Antarctic counterpart basins to the Otway and Ceduna basin of Australia exist? (4) What is the effect of the icecap on the stratigraphy of this margin? (5) Do the two major Tertiary ice advances have conspicuous seismic-stratigraphic signatures?

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