PSPaleocene-Eocene Deposystems in the Gulf of Mexico: Petroleum System Implications*
Richard H. Fillon1, Arthur S. Waterman2, and Paul N. Lawless3
Search and Discovery Article #10085 (2005)
Posted August 3, 2005
*Poster presentation at AAPG Annual Convention, with SEPM, Calgary, Alberta, June 19-22, 2005.
1 Earth Studies Group, 3730 Rue Nichole, New Orleans, LA 70131, phone: 1-504-0797, [email protected]
2 Paleo-Data, Inc, 6619 Fleur de Lis Drive, New Orleans, LA 70124
3 Dominion Exploration &Production, Inc, 1450 Poydras Street, New Orleans, LA 70112-7219
Synoptic sequence maps based on >200,000 chronostratigraphically correlated wells and published data clarify the history of Paleocene-Eocene deposystems in the Gulf of Mexico. Epeiric carbonates, continental margin banks, and steep continental slopes dominate the Gulf at the end of the Mesozoic. Into this environment Laramide uplift sheds large volumes of siliciclastic detritus, initiating the Paleocene-Eocene depositional cycle (PEDC). Mapped accumulation patterns reveal accommodation created by the calcareous to siliceous basin transition and mobile salt. The PEDC supports expanded shelf margin depocenters in southeastern Texas, thin slope aprons, and a robust Western Gulf Basin fan system fed from the Laramide Uplift in western Canada, the U.S., and Mexico. Fan building is also active in the east-central basin, suggesting sediment transport through southeastern Louisiana. Inclusions of Eocene sediments in salt bodies within the Neogene salt canopy support PEDC salt displacement. The PEDC ends with accelerated uplift of the Colorado Plateau and development of the Rio Grande Rift as a topographic barrier starving East Texas drainage systems and feeding the Missouri-Mississippi system. Reduced deposition across the western basin in the late Eocene and strong Oligocene regression in East Texas point to the decline and virtual cessation of continental margin subsidence. Increased early Oligocene deposition in South Louisiana records the initial eastward shift of the Gulf margin depocenter to its Neogene location. A combination of active shelf margin expansion early in the PEDC and subsequent development of the Rio Grande Rift, suggested by analysis of our synoptic map data, limits optimal reservoir development in the Western Gulf to the early Eocene (ca. 55.2-47.7 Ma).