The Tejas Sequence: Tertiary—Recent

Abstract

At the end of the Maestrichtian Age, seas withdrew from North America and virtually every other continent. The Tejas episode began, as did others before, with high-standing continents; but unlike past times, the seas remained outside of the cratonic interior except for a brief transgression in the Paleocene which probably came from the Arctic Ocean and reached south as far as the Dakotas. The Tejas Sequence name derives from the site of the best-studied Cenozoic units, those of the Texas coastal plain, which feature a rich record of marine and marginal-marine strata (along with the Atlantic, Pacific, and adjacent Gulf coasts). In contrast, the cratonic interior also contains a very sizable Tejas record; but almost all units involved are nonmarine. In addition, substantial areas of the northern craton and Cordillera feature surficial Quaternary glacial deposits, which may obscure uppermost preglacial Tejas depositional events.