Study area is within Wichita Mountains, southwestern Oklahoma (S. Oklahoma folded belt province). /Wichita Granite Group provisionally revised, from consisting of 5 units (Mount Scott, Headquarters, Reformatory, Lugert, and Quanah) to 10 units (with the addition of Cache, Cooperton, Long Mountain, Medicine Park, and Saddle Mountain). Wichita igneous province divided into eastern and western provinces. Eastern province contains largest area of outcrop, but most of existing nomenclature originated in western part. In the eastern province, the Wichita Granite Group (revised) consists of: Mount Scott Granite, Saddle Mountain Formation, Medicine Park Formation, Cache Formation, and Quanah Granite. In the western province, the Wichita consists of: Mount Scott Granite, Headquarters Granite, Reformatory Granite, Long Mountain Formation, Cooperton Formation, and Lugert Granite. Wichita Granite Group is intrusive equivalent of /Carlton Rhyolite Group. Age of Wichita is Middle Cambrian (525 +/-25 m.y.). Report includes geochemistry, stratigraphic table, map showing distribution of units.
Name Cooperton Formation attributed to Hull (1951, unpub. thesis). Rocks of Cooperton Formation have been included with Lugert or Mount Scott Granite by other workers, however, chemistry and petrography indicate that Cooperton is a separate unit. Biotite is characteristic of Cooperton. Outcrops are isolated thus relationship to other units not determined.
Is the granite composing hills west of Cooperton, Kiowa Co., OK, S. Oklahoma folded belt province. Named from Cooperton.
[Wichita Granite Group preempted by Wichita [Group] of Cummins (1890) in TX; conflicts with nomenclature guidelines stating a group name combines a geographic name with the term "group," and no lithic designation is included (ACSN, 1961, 1970; NACSN, 1983, 2005, 2021).]

Source: Modified from GNU records (USGS DDS-6; Denver GNULEX).