Cretaceous, marine inundations of the San Marcos Platform, Texas

Abstract

During most of the Cretaceous the San Marcos Platform, central Texas, was a low-lying, subaerial terrain. After the Middle Albian it was a low-lying, carbonate terrain, similar to modern Florida, receiving little sediment and yielding little sediment. The Platform was inundated eight times (late early Aptian into middle Aptian, late late Aptian to middle late Albian, earliest Cenomanian, late early Cenomanian, late Cenomanian, earliest Campanian, early middle Campanian, middle(?) Maastrichtian) during the Cretaceous, the last of which is based only on indirect evidence. There are some anomalies. During the latter part of the long normal, magnetostratigraphic interval (34) of the Cretaceous, the San Marco Platform was almost entirely subaerial. Many of the inundations agree neither with the Vail cycles nor with the Kauffman cycles. The conclusion is that transgressions onto the San Marcos Platform are probably associated with sediment-loading of the Gulf Coast Basin.