About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 63 (1979)

Issue: 3. (March)

First Page: 495

Last Page: 495

Title: Contourite Anticlines as Exploration Objectives: ABSTRACT

Author(s): D. P. McGookey

Article Type: Meeting abstract

Abstract:

Regional seismic profiles off the east coast of the United States gathered by the University of Texas Marine Science Institute and Woods Hole Oceanographic Institute have crossed three types of contourite anticlines. They are symmetric, asymmetric, and half-anticlinal forms and have up to 3,000 ft (1,000 m) of relief. Off the east coast, contourite anticlines have been found in sections of Paleocene to recent age. They are the result of erosion, transport, and deposition by bottom currents that flow along the break between the continental slope and the continental rise. Because of the relation to deep-water currents flowing along this break in slope, the resulting deposits have been named "contourite anticlines." Explorationists should be alert to the presence of contouri e anticlines and realize the limited exploration potential of this type of anticline. Recognition of their true nature early in exploration programs may save millions of dollars.

Seismic reflections from Wilcox (lower Eocene) deep-water sediments of south Texas show that large--more than 10 × 5 mi (16 × 8 km), 2,000± ft (600± m) closure--anticlinal features were developed by deposition basinward from submarine fans. Texaco 1 Rodriguez was drilled in 1968 to 17,752 ft (5,326 m) on one of these contourite anticlines. The section within closure (below a drill depth of 8,700 ft; 2,610 m) penetrated by this test was entirely shale.

Available data on present-day contourite anticlines indicate that the currents that form them are capable of moving only clay-size material. Until stronger currents are documented, sandstones or any other type of reservoir, with the possible exception of fractured chalk, would not be expected in these features. Drape crestal grabens are present over some of the Wilcox contourite anticlines of south Texas. Production has been obtained from the median-depth (9,000 ± 1,000 ft; 2,700 ± 300 m) upthrown fault traps associated with these grabens.

End_of_Article - Last_Page 495------------

Copyright 1997 American Association of Petroleum Geologists