Mesozoic Structure and Petroleum Systems in the De Soto Canyon Salt Basin in the Mobile, Pensacola, Destin Dome, and Viosca Knoll Areas of the MAFLA Shelf

摘要

Large parts of the De Soto Canyon Salt Basin are unexplored, and structural and petroleum system models may facilitate continued hydrocarbon exploration, as well as the development of geologic CO2 storage programs. The basin contains four structural provinces: (1)Destin fault system, (2)salt pillow province, (3)diapir province, and(4)salt roller province. The Destin fault system bounds half grabens that formed near the updip limit of salt. The faults have variable displacement and were active mainly during the Cretaceous. Broad salt pillows occur basinward of the Destin fault system, and the largest of these structures forms the core of Destin Dome. Salt pillows basinward of Destin Dome began forming shortly after Smackover deposition, whereas Destin Dome largely post-dates the Destin fault system. The diapir province is in the structurally deepest part of the salt basin, and diapirism occurred from the Jurassic into the Tertiary. The salt roller province contains a complex array of normal faults and rollover structures that record gravitational shelf spreading during Jurassic time. Petroleum systems analysis indicates that the basin contains a distinctive suite of source rocks, sealing strata, reservoir strata, and trap types. Exploration efforts have thus far proven successful in structures that formed before or during hydrocarbon expulsion, and many such structures remain untested.