Gulf of Mexico-Orca Basin - United States of America

Gulf of Mexico

United States of America

The Orca Basin is a mid-slope, silled, mini-basin in the northern Gulf of Mexico some 300 km southwest of the Mississippi River mouth on the Louisiana continental slope. It is unique amongst the mini-basins in this area, in containing a large brine pool of anoxic salt brine. The lake is approximately 123 km2 (47 sq mi) in area and up to 220 m (720 ft) deep under 2,400 m (7,900 ft) depth of Gulf water and is derived from dissolution of underlying Jurassic age Louann Salt. With a volume of 13.3 km3 (3.2 cu mi) the pool results from the dissolution of about 3.62 billion tonnes of the Louann Salt bed into seawater. The basin owes its shape to ongoing salt tectonics and is surrounded by salt diapirs.

Gas hydrates were detected in a number of cores collected in the Orca basin during Leg 96 of the Deep Sea Drilling Program (DSDP). The cores were recovered from a water depth of 2,412 m (7,913 ft) at Holes 618 and 618A, with first evidence of gas hydrate occurring in Hole 618. Hydrates were observed in the top section of Core 618-4 at 85 fbsf (26 mbsf) in gray mud and consisted... read more on Wikipedia

This information was updated on 14/07/2011

Recorded Datafields


Deep Sea Driliing Programme


Leg 96






Hydrates occurring as inclusions, white crystals a few millimeters in diameter.


27° 00.68' N - 91° 15.73' W

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