In the subsurface and at the outcrop, waters in argillaceous deposits of the Calvert Bluff Formation (lower Eocene, Wilcox Group) are brackish to saline.

Cores from deep stratigraphic test wells provide an excellent basis for determination of source-rock quality and thermal maturity of potential hydrocarbon source rocks in the Palo Duro Basin. Total organic carbon (TOC) content in Pennsylvanian and Wolfcampian rocks is highest in basinal shales.

Topographically controlled ground-water-basin divides, established during the Pleistocene by erosion of the Pecos and Canadian River valleys, prevent ground-water recharge in the outcrop of the Triassic Dockum Group from entering the confined part of the aquifer in the Dockum Group beneath the So

These cross sections numerically correspond to previously published onshore cross sections (CS0002--Dodge and Posey, 1981) and extend those sections across the continental shelf into the Miocene, a recent target of renewed petroleum exploration.

Many modern shore zones comprise a continuum of depositional environments that encompass both strandplain and barrier-island systems. Strandplains are further subdivided into two classes: sand-rich beach-ridge plains and mud-rich chenier plains.

Pre-Pennsylvanian rocks in the Palo Duro Basin include (1) basal transgressive marine Cambrian(?) sandstones deposited over Precambrian basement, (2) overlying Lower Ordovician dolomites of the Ellenburger Group that formed when shallow seas covered much of the North American continent, and(3) Mi

Salt dissolution has affected parts of the Upper Permian Salado, Seven Rivers, San Andres, Glorieta, and upper Clear Fork Formations beneath the Pecos River valley in eastern New Mexico and has been active beneath the Canadian River valley and the Rolling Plains of the Texas Panhandle.