The Schoonover Formation was named by Fagan (1962) for exposures along Schoonover Creek, northwest of McAfee Peak in the Bull Run Quadrangle portion of the northern Independence Mountains.

Fossils found in the Schoonover Formation include brachiopods, bryozoa, coelenterata, and echinoderms that Fagan (1962) considered Mississippian in age. Fossil collections from the lowest portion of the Schoonover are believed to be Late Mississippian (Chesterian) in age (Coats, 1985). Radiolaria from cherts in the formation span Mississippian and Pennsylvanian age (Miller and others, 1981; Coats, 1985). The formation here is considered Late Mississippian to Early Pennsylvanian in age. It is at least partly time equivalent to the lithologically and structurally similar Havallah Sequence (Miller and others, 1981). The base of the Schoonover is a major thrust fault, which places the Schoonover over Ordovician Valmy quartzites and Permian clastics.

The Schoonover is composed of argillaceous shales, cherts, siltstones, limestones, quartzites, conglomerates, and andesitic flows. Both Fagan (1962) and Miller and others (1981) have shown that the entire Schoonover sequence was thrust southeastward in the Independence Mountains as a portion of the Golconda allochthon.

Fagan (1962) divided the Schoonover into 10 members that are described here in ascending order. The Lower Member is olive gray to black, argillitic, medium-bedded chert with quartz sandstone and conglomerates containing boulders of the underlying Ordovician Valmy orthoquartzite. The overlying Dorsey Creek Member is composed of two laterally gradational facies about 650 feet in thickness. One facies is composed of thin-bedded, siliceous, argillaceous, dark gray to green lutites and cherts, with thin interbedded volcanic flows. The second facies is dominantly andesitic flows and agglomerates, with thin beds of conglomerate, fossiliferous limestone, and argillaceous lutite.

The third unit is the Fry Creek Member that is about 450 feet of light to dark green-gray bedded chert. Overlying this is the Mikes Creek Member that is composed of poorly sorted arenite and conglomerate in beds up to 10 feet thick, argillaceous lutite, pebbly mudstone, and thin black chert. This member reaches a maximum thickness of about 2,600 feet (Fagan, 1962). The Harrington Creek Member is composed of folded thin-bedded gray to black argillaceous lutite and black chert, with lesser quartzose siltite and limestone. It reaches a thickness of about 450 feet.

The Cap Winn Member (about 350 feet) is composed of red and gray-green jasperoid chert, and blue-gray and white argillaceous lutite (Fagan, 1962). The overlying Ott Creek Member is composed of as much as 1,600 feet of alternating gray to yellow green, thin-bedded chert, and dark gray, aphanitic limestone with thin quart siltite lenses. The Frost Creek Member is composed of olive-gray siliceous shale, olive-gray chert, and interbedded quartzose siltite beds that are strongly folded and up to 650 feet in thickness. The overlying Bailey Creek Member is predominantly limestone with black chert replacement, and calcareous quartzose cross-laminated siltite. Flute casts and graded beds are also abundant in the arenites of the Bailey Creek Member, which is about 1,100 feet in thickness (Fagan, 1962). The Upper Member of the Schoonover is poorly exposed gray and yellow-green weathering chert with thin lutite interbeds and is up to 750 feet in thickness.

Stanford Geological Survey (1980) mapped the Schoonover Sequence in the northern Independence Mountains using 6 unnamed members that are described in ascending structural-stratigraphic order. The basal unit is formed by discontinuous masses of basaltic greenstone in massive and pillowed flows, and minor laminated tuff. Above these volcanic flows, is a sequence of concordant diabasic intrusions. This is overlain by strongly folded radiolarian chert and interbedded siliceous argillite, with local thin interbeds of sandstone. This is overlain by diamictite with boulder-size clasts of limestone, quartzite and rare greenstone in a mudstone matrix, which is locally interbedded with pebbly mudstone, quartzose arenite, and graded chert-pebble conglomerate (Miller and others, 1981). The overlying member is composed of locally feldspathic and tuffaceous turbiditic sandstone, pebble conglomerate, and siltstone which are interbedded with shale and chert. The upper member of the Schoonover Sequence is composed of turbiditic cherty silty clastic limestone, radiolarian chert and calcareous sandstone interbedded with chert and shale and calcareous sandstone (Miller and others, 1980). The uppermost 8,000 feet of the Schoonover Sequence appear to be a deep-water facies that are thrust over the lower 1,000 feet of shallow-water Chesterian age Schoonover (Miller and others, 1980; Coats, 1985).

The Schoonover is about 9,000 feet thick in the northern Independence Mountains (Fagan, 1962), although intricate folding and thrusting make thicknesses structural and approximate.

The Schoonover is exposed in the northern Independence Mountains within the evaluation area (Fagan, 1962; Coats, 1985).

The allochthonous deep-water Schoonover Formation or Sequence represents the northeasternmost exposures of the Golconda allochthon (Miller and others, 1981). The depositional setting of this sequence is cryptic, although the abundance of sediments deposited by submarine gravity-flow mechanisms suggests moderately deep marine conditions. Fagan (1962) suggested that current flow was within 10 degrees of due east based upon the orientation of convoluted and cross-laminae. Bedded cherts probably represent pelagic accumulations of siliceous organic debris such as radiolarian tests. The presence of tuffaceous turbidites suggests a setting distal to the North American shelf. Siltstones and sandstones in this unit could have been deposited from erosion of the Roberts Mountains allochthon suggesting a source proximal to the North American Shelf.

Miller and others (1981) suggest that if these units from apparent dual sources are stratigraphically interbedded rather than tectonically interleaved, a back-arc setting may be suggested for the Schoonover. They suggest that the Schoonover and Havallah Sequences were most probably deposited in the same paleogeographic setting.