Delaware Basin

By earliest Permian time, during the Wolfcampian Epoch, the ovoid shaped subsiding Delaware Basin extended over 10,000 square miles (26,000 km2) in what is now western Texas and southeast New Mexico.

[2] Structurally the Delaware, Midland and Marfa were foreland basins created when the Ouachita Mountains were uplifted as the southern continent Gondwana collided with Laurasia, forming the supercontinent Pangea in the Late Carboniferous (Pennsylvanian).

The sediments responsible for creating the Yeso were deposited in nearshore areas that graded into the carbonate banks of the Victorio Peak Formation in the deeper waters.

The facies were:[1]: 195§5 Capitan Reef was built primarily from calcareous sponges, encrusting algae such as stromatolites, and directly from seawater as a limey mud.

In stark contrast, Cenozoic (current era), Mesozoic (age of the dinosaurs), and even middle Paleozoic (well before the Permian) reefs are mainly composed of corals.

[4] Sea level dropped as the late Permian glaciation intensified and locked increasing amounts of water in distant ice caps.

The Castile consists of 1⁄16 inch (1.6 mm) thick laminae of alternating gray anhydrite and gypsum, brown calcite, and halite.

Rivers migrated over its surface and deposited the red silt and sand that now constitute the siltstone and sandstone of the Rustler and Dewey Lake Formations.

[1]: 184§2 Uplift associated with the Laramide orogeny in the late Mesozoic and early Cenozoic created a major fault along which the Guadalupe Mountains were thrust into existence.

Due to the semiarid climate, the karst topography that was created lacks the characteristic depressions, sink holes, pits, and solutional fissures on the surface.