Results of Geophysical Research in Ross Sea

K. Hinz

The Ross Sea is underlain from the east to the west by three north-south-trending sedimentary basins: the Eastern basin (east of the 180° meridian), the Central basin (along 175°), and the Victoria Land basin.

In the center of the Eastern basin, the thickness of the sediments generally ranges between 3,000 and 6,000 m. The pre-late Oligocene sediments occur only in the center of the basin. There are no indications of block faulting in the sedimentary sequence, indicating that synsedimentary subsidence has been the dominant tectonic process.

A broad basement high, the Central High, lies to the west of the Eastern basin. The top of basement is a peneplain over large parts of the high. The overlying sediments are mostly younger than Oligocene.

The Central basin lies to the west of the Central High, extends approximately north-south through the central Ross Sea. Sedimentary thicknesses in excess of 6,000 m were observed. A relatively narrow basement high, trending north-south, separates the Central basin from the complex Victoria Land basin.

The Victoria Land basin is a 150-km wide basin that extends from the Ross Ice Shelf to 75°S. It is bounded to the north by a shallow and characteristically planated basement high, the Coulman High, and to the west by the uplifted Transantarctic Mountains. The Victoria Land basin is subdivided by north-south-trending zones of volcanic/magmatic intrusions, probably equivalents of the Neogene Hallett Volcanics and McMurdo Volcanics, respectively, that affected the Victoria Land basin, resulting in uplift and inversion of parts of the basin.

AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.