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.
- Stoklosa, Michelle L.; Simo, J. A. (Toni); Wahlman, Gregory P., 1998, Facies description and evolution of a Wolfcampian (Early Permian) shelf margin: Hueco Mountains, west Texas, in: Las Cruces Country II, Mack, G. H.; Austin, G. S.; Barker, J. M., New Mexico Geological Society, Guidebook, 49th Field Conference, pp. 177-186.