Abstract

The Powwow Conglomerate is the time-transgressive, sporadically distributed, basal, fluvial and marine, clastic unit of a regional, Early Permian (Wolfcampian) marine transgression. It was deposited in the lows of a technically disturbed, subaerially exposed surface of varying topographic relief on rocks ranging in age from Pennsylvanian to Riphean (Precambrian). The unit is intimately associated with the Diablo platform positive area. Where present it forms the basal unit of the Hueco Group (Wolfcampian-Leonardian ?, Lower Permian) in Texas.

The intensity of the pre-Permian structural disturbance increases southward toward the Ouachita tectonic belt and reflects the collision tectonics taking place during the latest Pennsylvanian and earliest Permian. The event is recorded in the Franklin Mountains of Texas (El Paso County) and New Mexico (Doña Ana County) in the disconformity between the Late Pennsylvanian (Missourian-Virgilian) Panther Seep Formation and the Early Permian (middle-late Wolfcampian) Hueco Group. An earlier Ouachita tectonic belt event is recorded also in the Franklin and Hueco Mountains between the latest Mississippian (Chesterian) Helms Formation and the earliest Pennsylvanian (Morrowan) La Tuna Formation of the Magdalena Group (Franklin Mountains) and Magdalena Formation (Hueco Mountains). Ouachita movement influenced is interpreted to have initiated in the medial Osagian (Lower Mississippian) and ceased within the Leonardian (Lower Permian).

The northward extension of the unit into the Sacremento Mountains of New Mexico is complexly interrelated with the tectonically derived sedimentation sequences resulting from movements associated with the Pedernal Uplift. West and northwest of the Sacremento Mountains in New Mexico, it is represented by apparently continuous sedimentation in the Bursum Formation.