Sequence Stratigraphy of Cenozoic Deepwater Deposits in the Perdido Fold Belt, Northwestern Deep Gulf of Mexico

Joseph C. Fiduk, Paul Weimer, Bruce D. Trudgill, Mark G. Rowan, Peter E. Gale, Bryant E. Korn, Ronald L. Phair, Geneva R. Roberts, William T. Gafford, James B. Dischinger, and Kevin L. Putney

Analysis of 12,000 km of 2-D multifold seismic data shows three large Cenozoic wedges of deepwater deposits in the Perdido fold belt that differ in seismic facies, areal distribution, and potential reservoir geometries. Together, these three wedges reflect the changing positions of Cenozoic depocenters and record the evolution of the Perdido structural province. Lithologic interpretation is based upon seismic facies and analogous facies in other drilled areas in the Gulf of Mexico.

1) The Paleocene to middle Oligocene interval, which is strongly folded, reflects pre-growth deposition. Paleocene and Oligocene strata thicken westward and consist of medium to high amplitude, subparallel reflections of varying continuity. Broad channels and channel-levee systems are interpreted, suggesting turbidite deposition. These strata are interpreted as the down-dip equivalent of the Wilcox and Frio shallow- water depo-centers and are potentially sand-prone. Eocene strata are low amplitude, discontinuous, subparallel reflections interpreted to be shale-prone. 2) The upper Oligocene to upper Miocene interval consists of multiple well-developed sequences with variable amplitude, divergent reflections, many of which onlap against the fold crests. Sequences within this interval are often modified by erosion, faulting, and/or slumping against the folds. 3) The upper Miocene to Recent interval, which overlies most folds, consists of channel-levee, overbank, slump, and layered or amalgamated turbidite sheet deposits. These are similar to other coeval submarine fan sediments in the northern deep Gulf. Thus, the Cenozoic section in the Perdido fold belt is interpreted as mostly shale-prone, with some sand-prone intervals, based upon seismic facies, isopach thickening to the west, and similar producing facies elsewhere in the Gulf of Mexico.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California