Neogene Shelf, Slope, and Basin-Floor Gas Plays, Laguna Madre-Tuxpan Continental Shelf, Eastern Mexico

Neogene shelf, slope-fan, and basin-floor-fan plays in the Laguna Madre-Tuxpan (LM-T) continental shelf reflect a variety of structural and stratigraphic controls, including gravity sliding and extension, strike-slip motion, salt evacuation, and lowstand canyon and fan systems associated with major uplift of carbonate and volcanic terrains. In a 16- month study of the eastern Mexico continental shelf, conducted jointly by the Bureau of Economic Geology (BEG) and PEMEX Exploración y Producción, more than 30 plays were defined and mapped over a 50,000-km 2 area that links the Veracruz and Burgos basins. The south part of the LM-T area in the Veracruz Basin contains deep-seated basement faults that provided upward migration for hydrocarbons potentially to charge upper and middle Miocene canyon, slope-fan, and basin-floor-fan systems. In contrast, the Lankahuasa area north of the Veracruz Basin contains major shallow- detachment, listric faults associated with thick Pliocene shelf and inner-slope depocenters. Lower and middle Miocene plays on the Tuxpan Platform northwest of the Lankahuasa area contain thick successions of steeply dipping slope deposits, consisting of narrow slope-channel and lobate slope-fan sandstones encased in siltstones and mudstones. Plays in the north end of the LM-T area in the Burgos Basin contain intensely deformed strata associated with diapirism, salt withdrawal, and salt welds. Plays in this area are mud-rich and internally complex, including debris-flow, slump, and canyon-fill deposits.