Gravity studies of the Victoria Land Basin and Iselin Bank

Author(s): Davey, Frederick J.; Cooper, Alan K.
Author Affiliation(s): Primary:
Dep. Sci. and Ind. Res., Wellington, New Zealand
Other:
Dep. Sci. and Ind. Res., New Zealand
U. S. Geol. Surv., United States
Volume Title: Antarctic continental margin; geology and geophysics of the western Ross Sea
Volume Author(s): Cooper, Alan K., editor; Davey, Frederick J.
Source: The Antarctic continental margin; geology and geophysics of the western Ross Sea, edited by Alan K. Cooper and Frederick J. Davey. Earth Science Series, Vol.(5B), p.119-137. Publisher: Circum-Pacific Council for Energy and Mineral Resources, Houston, TX, United States. ISSN: 1068-6517. ISBN: 0-933687-05-2
Note: In English. 14 refs.; illus. incl. 3 tables, sects., sketch maps
Summary: New gravity and bathymetry maps are presented for the west and central Ross Sea. The gravity data show a large negative anomaly trending north-south along the axis of the Victoria Land basin. Gravity models demonstrate that this negative anomaly can be accounted for by increased water depth and thicker low density and velocity sediments along the basin axis, as noted on seismic data. The gravity models also indicate that thin crust lies under the basin. This thin crustal section thickens rapidly at the coast between McMurdo Sound and Cape Washington to about 40 km under the Transantarctic Mountains. The northern boundary of the Victoria Land basin near Cape Washington marks the northern boundary of the region of thin crust. This coincidence suggests that the thin crust formed as a result of extensional tectonics associated with the older, major episode of basin formation of the Victoria Land basin rather than with the younger extensional episode causing active rifting along the basin axis. Gravity models over Iselin Bank show a crustal thickness of 21-24 km. Several graben structures occur on top of the bank, trending parallel to the axis of the bank. A sedimentary trough and associated thinned crustal section indicate extensional tectonics has occurred off the western margin of the bank. (Auth.)
Year of Publication: 1987
Research Program: DSDP Deep Sea Drilling Project
Key Words: 16 Structural Geology; 20 Geophysics, Applied; Antarctic Ocean; Antarctica; Bathymetry; Beacon Supergroup; Cape Washington; Crust; DSDP Site 270; Deep Sea Drilling Project; Extension; Geophysical methods; Geophysical surveys; Grabens; Gravity anomalies; Gravity methods; Iselin Bank; Leg 28; McMurdo Sound; Ross Sea; Seismic methods; Southern Ocean; Structural geology; Surveys; Tectonics; Transantarctic Mountains; Velocity; Victoria Land Basin
Record ID: 1988075274
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from the Antarctic Bibliography, United States

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