Abstract

Four depositional sequences of 4 to 15 million years' duration have been recognized in Lower Cretaceous strata of the Mississippi Interior Salt Basin. These are the LKEGR-1 (Lower Cretaceous, Eastern Gulf Region) (132 to 117 Ma), LKEGR-2 (117 to 109 Ma), LKEGR-3 (109 to 103 Ma), and LKEGR-4 (103 to 99 Ma) depositional sequences. The LKEGR-1 depositional sequence includes the Hosston and Sligo formations (Hauterivian to Aptian age). The LKEGR-2 depositional sequence includes the Pine Island, James, Rodessa, and Ferry Lake formations (Aptian to Albian age). The LKEGR-3 depositional sequence includes the Mooringsport and Paluxy formations (Albian age). The LKEGR-4 depositional sequence includes the Andrew and Dantzler formations (Late Albian age). These depositional sequences can be identified and mapped throughout the basin. They are interpreted to be the result of a combination of post-rift tectonics, variations in siliciclastic sediment supply and dispersal systems, and eustasy.

To date, 3.3 Tcf of natural gas and 791 million barrels of oil have been produced from Lower Cretaceous petroleum reservoirs in the Mississippi Interior Salt Basin. Most of the oil production is from the LKEGR-2 depositional sequence, and the majority of the natural gas is from the LKEGR-1 depositional sequence. Based on sequence stratigraphic analysis, these reservoirs have considerable petroleum potential for continued exploration and production.