Katherine A. Giles¹, Robert K. Goldhammer²
(1) New Mexico State University, Las Cruces, NM
(2) Texaco Exploration, Bellaire, TX

Abstract: Patterns of Reef Accretion Associated with Salt Diapirism, La Popa Basin

Stratal geometries and lithofacies distribution of carbonate buildups in La Popa basin of NE Mexico record the interplay of eustatic, salt tectonic,and paleogeographic controls. Strata adjacent to La Popa salt weld record three major phases of carbonate reef formation including: (1) El Toro lentil, Early Cretaceous; (2) San Jose lentil, Late Cretaceous; and (3) La Popa lentil, Mid-Paleocene that are separated by siliciclastic deltaic/shoreface deposition. The carbonate lentils formed during eustatic sea level maxima and reduced regional sediment accumulation rates when near-surface salt rise created substantial bathymetric relief. Carbonate buildup distribution shifted along the trace of La Popa weld from a SE position in the Early Cretaceous, to a central position in the Late Cretaceous, and a NW position in the Paleocene and presumably tracks the migrating position of salt diapir induced bathymetric highs. Parasequence sets within La Popa lentil display progradation on the eastern/windward reef margin where forereef clinoforms prograded into salt withdrawal depositional lows (i.e. rim synclines) and are coeval with retrogradational sets on the western/leeward margin generated by decreased sedimentation rates relative to subsidence in the rim syncline.

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