Five main depositional systems of the Jackson Group in Texas are delineated through regional outcrop and subsurface investigation.
This report presents stratigraphic data and interpretations pertaining to the origin of a continental shelf-ocean basin sedimentary complex developed during Lower Cretaceous time in northern Coahuila, Mexico.
Primary sedimentary structures in modern point-bar deposits of the Amite River in Louisiana and the Colorado River in Texas are analogous to features observed in Eocene Simsboro and Pleistocene Colorado River deposits of the Texas Gulf Coastal Plain.
Trilobites collected during the past 20 years from the Morgan Creek, Point Peak, and San Saba Members of the Wilberns Formation comprise 89 species assigned to 45 genera belonging to zones of the upper Franconian and Trempealeauan Stages of the Upper Cambrian Croixan Series.
The Bofecillos Mountains area of Trans-Pecos Texas contains a Tertiary volcanic vent and a varied sequence of lava flows, tuff, ash-flow tuff, and associated conglomerate, sandstone, and mudrock; after most of the volcanic activity had ceased, the area was block faulled and later dissected into a