PEEL, FRANK J., CHRISTOPHER J. TRAVIS, JAKE R. HOSSACK, and DORIE B. McGUINNESS, BP Exploration Inc., Houston, TX

ABSTRACT: Structural Provinces in the Cover Sediments of the US Gulf of Mexico Basin: Linked Systems of Extension, Compression and Salt Movement

Jurassic-Quaternary strata of the northern Gulf of Mexico basin form discrete structural provinces of differing age, extent and style. Major controls on the development of these provinces include variations in the age and locus of sediment input to the shelf/slope, distribution of autochthonous salt and salt canopies, and basement topography.

Mesozoic gravity sliding in the eastern Gulf was controlled by regional basement slope and local basement morphology. Basement morphology and the distribution of autochthonous salt determined structural style.

Tertiary structuring was driven by sediment loading. Each major sediment influx during the Tertiary resulted in updip extension coupled with downdip compression. Salt canopy spreading appears to have occurred at the end of periods of compression.

Structural style within provinces was controlled by the distribution of autochthonous and autochthonous salt. Where sediment input loaded the top of a salt canopy, movement was accommodated within that canopy. Local extensional systems were balanced by local compression at the canopy front (e.g., lower Pleistocene system of West Cameron). In contrast, where shallow canopies were absent, sediment loading drove large, deep growth faults, which often cut down to autochthonous salt. The compression was transferred far downdip into mid-lower slope fold belts (e.g., Eocene-Oligocene and Oligocene-Miocene systems of the western Gulf). Combination of structural styles was also possible. early Pliocene sediment loading around the Mississippi Delta was taken up partly within a canopy, and partl by deep growth faulting balanced downdip by the Atwater thrust belt.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.