Intraslope basins in Northwest Gulf of Mexico; a key to ancient submarine canyons and fans

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Abstract

The hummocky, diapirically deformed Texas-Louisiana continental slope includes three major types of intraslope basins: blocked-canyon intraslope basin, interdomal basin, and collapse basin. Major sand bodies present in the blocked-canyon intraslope basins are used to determine the sedimentary history of the Tertiary and Quaternary of this area. During relative lowering of sea level, coarse silt and sand temporarily stored near the shelf break were transported by gravity mechanisms and deposited within submarine canyons tending to nullify diapiric movement. Seismic records show these sediments as transparent to semitransparent onlapping seismic reflections. During low stands and rises in sea level, large amounts of mud were transported mainly as mud turbidites (rec rded as indistinct, parallel, onlapping seismic reflections), and it is during this stage that diapiric activity begins. Pelagic and hemipelagic sediments dominate during sea level high stands (recorded as distinct parallel seismic reflections) and drape the canyons and surrounding sea floor. Extensive uplift breaks up the depositional units and eventually disrupts the continuity of canyon systems. Reconstruction of ancient submarine canyons can be achieved by correlating identified blocked-canyon basins; such a correlation is based on the assumption that only a few canyon systems presently exist.

Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Intraslope basins in Northwest Gulf of Mexico; a key to ancient submarine canyons and fans
Year Published 1982
Language English
Publisher Datapages, Inc.
Description 15 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title M 34: Studies in Continental Margin Geology
First page 567
Last page 581