Facies description and evolution of a Wolfcampian (Early Permian) shelf margin: Hueco Mountains, west Texas
— Michelle L. Stoklosa, J. A. (Toni) Simo, and Gregory P. Wahlman

The Hueco Mountains of west Texas are situated at the eastern margin of the Late Paleozoic Orogrande Basin. A north-south trending series of outliers lie about 3 mi to the west of the range (19 mi east of El Paso) that are possibly faulted blocks associated with the Rio Grande rift-type graben structure of the present-day Hueco Bolson. The outliers are composed of primarily Upper Pennsylvanian-Lower Permian (Wolfcampian) carbonate strata. The southernmost outlier, which is the subject of this study, is approximately 1 mi in length and consists of about 500 ft of Wolfcampian shelf-margin limestones. Nine different limestone lithofacies have been recognized in this succession, and these have been further grouped into five fades associations, each of which can be placed in a carbonate shelf depositional model. From deepest to shallowest, the fades associations are: Deep Shelf-Basin, Outer Shelf, Buildup, Shallow Shelf, and Breccias. The strata in the outlier show an overall upward-shallowing trend with superimposed, higher-frequency, alternating landwardand seaward-stepping packages. The landward-stepping packages have an erosive base, and consist of the Breccias and the Shallow Shelf associations. A complete seaward-stepping package shows a succession from base to top of Deep Shelf-Basin, Outer Shelf, Buildup and Shallow Shelf associations. Four depositional sequences have also been recognized, each exhibiting a unique succession of landward- and seaward-stepping strata.