Arnold H. Bouma¹
(1) Louisiana State University, Baton Rouge, LA

Abstract: Deep marine depositional systems

Our understanding about deep marine sandy depositional environments has not advanced as rapidly as the engineering developments and computer modeling. Several models have been developed but the varying interactions of tectonics, climate, sediment, and sea-level fluctuations clearly demonstrate that no two deposits are completely similar. Two end members - sand rich, coarse-grained (common for active margins) and mud-rich, fine-grained (common for passive margins) - were analyzed and it can be demonstrated that the differences between the two are significant. When dealing with a sand/mud-rich system one should use parts of each end member to construct a model most suitable for the deposits of interest. The fine-grained systems are most susceptible to glacially-controlled sea-level fluctuations, and it is possible that most of the fan construction takes place during the first part of the transgressive systems tract.

The sand-rich turbidite systems have been well studied in the subsurface and in outcrop. The mud-rich fans (e.g., GOM, offshore West Africa, some fields in the North Sea) are less known. They are bypassing systems and have a different sand distribution. Integrated studies, using the various seismic attributes, well logs and outcrops, are required to obtain a better understanding of these important deposits.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana