ABSTRACT

The sequence stratigraphy of northwestern Green Canyon has been studied using 900 mi of multifold seismic data and 39 wells with biostratigraphic data (14 with high-resolution analysis). Variations in fossil abundance and diversity were used in the recognition of condensed sections.

Eight depositional sequences (2.4, 1.9, 1.4, 0.8, 0.7, 0.5, 0.6, and 0.4 Ma) have been recognized. Paleobathymetry indicates that sequences were deposited primarily in bathyal water depths. Most of the sediments compose lowstand systems tracts and consist of basin-floor fan, slope fan, and prograding complex. Thick bathyal sandstones are present in three major sequences (1.9, 1.4, and 1.1 Ma) and represent potential reservoirs in the area. These are interpreted as basin-floor fan deposits. Slope-fan complexes compose most of the sediment in the area; levee channel complexes, overbank deposits, slope fills, slump-debris flows, and canyon fills were recognized in these turbidite complexes. Transgressive and highstand systems tracts are thin across the area and are well developed in the younger sequences (<0.6 Ma).

Syndepositional structures characterize the study area. Growth faults and salt diapirism play a role important in the geometry and distribution of the depositional units, as well as creating structural features for petroleum entrapment.