Salt Allochthons in the Deepwater North-Central Gulf of Mexico (SE Green Canyon): Their Role in Hydrocarbon Trap Development and Minibasin Emplacement
Seismic mapping indicates that the southeast portion of the Green Canyon protraction area in the north-central deepwater Gulf of Mexico is underlain by a deep salt allochthon that was emplaced in the Mesozoic (Late Jurassic?-Cretaceous) and a shallow (Sigsbee) salt allochthon that was emplaced in the Neogene-Quaternary. A series of 2D transect interpretations and restorations suggest that the structural development of a number of sub-salt hydrocarbon traps in the region (K2, Mad Dog, Tahiti, Caesar/Tonga, etc.) are related to salt withdrawal from (deflation of) the deep salt allochthon in Neogene-Quaternary time. While much of the salt in the shallow allochthon is interpreted to have emanated from areas to the north of the study area, salt from the deflated deep allochthon is envisioned to have also contributed salt to the shallow allochthon. Large minibasins comprising >10,000 ft (3,000 m) of middle/upper Miocene and younger sediment were translated from the north-northwest on the shallow salt allochthon from 25 mi (40 km), or more, to their present locations near the southern terminus of the shallow allochthon. The minibasins are interpreted to have been emplaced along fairways of thick salt within the shallow allochthon - which developed where the deep allochthon welded at depth, and between subsalt structural highs.
AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019