ABSTRACT

Outcrops in the Victorio Flexure area of the Sierra Diablo Mountains, West Texas, provide evidence that suggests that Ouachita-related tectonism remained active throughout latest Wolfcampian time and line-sourced, carbonate debris aprons can be composed of channel architectural elements, as well as sheet architectural elements. The Victorio Flexure is a deep-rooted structural feature that reactivated during late Paleozoic deformation. In the early Permian (Wolfcampian), uplifted pre-Permian strata along the Victorio Flexure were eroded and were the source of clastic alluvial and fluvial systems (Powwow Formation). Marine transgression followed and flooded the landscape, clastic influx waned, and carbonate production ensued. Outer ramp wackestones and packstones were initially deposited, followed by the accumulation of thick platform packstones as sea level stabilized (lower to middle Hueco 'C' Formation). The progradational extent of the platform sediments was controlled by subtle topography associated with the Victorio Flexure. This carbonate depositional profile can be characterized as a structurally modified ramp with a fringing carbonate sand belt.

In the latest Wolfcampian, tectonic movement along the Victorio Flexure increased slope height by over 1,000 ft and slope gradient by more than 7°. This structural modification triggered the mobilization of large volumes of platform- and upper-slope-derived carbonate material basinward. The allochthonous debris formed a slope-centered apron composed of slide mass, debrite, hemipelagite, and sediment gravity flow packages (upper Hueco 'C' Formation). Platform-derived slide masses and fine-grained periplatform hemipelagic drapes dominate proximal, upper slope settings. Debrite-filled channel complexes and topography-filling, high-and low-concentration sediment gravity flow packages occupy more distal, lower slope, and toe-of-slope environments. The internal stacking patterns of the debrite complexes imply focusing of flows (channelization) from updip point sources. Proximal-to-distal changes are observed in channel architecture, including the degree of amalgamation and erosion/incision vs. deposition. In the Victorio Flexure area, the upper Hueco 'C' debris apron marks the final phase of deposition in the Wolfcampian.