The Banner Limestone was first used informally by T. B. Nolan and was later designated the Banner Formation for a lithologically variable type section on the south slope of Banner Hill, northeast of the confluence of Mill Creek and the Owyhee River in the Mountain City Quadrangle (Coats, 1969).

The Banner Formation rests with angular unconformity over the Grossman Formation. It grades up-section as well as laterally into the Nelson Formation and is early Late Mississippian (Meramecian or possibly Osagean) in age (Coats, 1969, 1985).

In the Mountain City Quadrangle, the Banner is composed of a basal peperite breccia composed of volcanic fragments injected into a fossiliferous carbonate mud, and conglomerate composed of subangular to sub-rounded clasts of shale and limestone, and minor well-rounded Valmy quartzite boulders (Coats, 1969; 1985). This is overlain by brown, fine to medium-grained, subangular to sub-rounded quartz sandstone, and about 160 feet of tan-weathering siliceous siltstone. The upper unit is composed of about 260 feet of soft, massive, blue-gray limestone which is arenaceous in the lower 100 feet, and contains minor thin siliceous siltstone interbeds.

In the Owyhee Quadrangle, the Banner is black slate underlain by massive blue-gray limestone with corals, brachiopods, and bryozoans. This grades downward into fine to medium-grained, brown quartz arenite and gray, tan weathering siliceous siltstone and arenaceous limestone, and into conglomerate with rounded white quartzite cobbles as much as 6 inches in diameter (Coats, 1971).

In the northeastern corner of the Mount Velma Quadrangle and in the southwestern portion of the California Mountain Quadrangle at the northeastern tip of the Independence Mountains, the Banner is a calcareous conglomerate exposed in two thin fault slices which rest on the Valmy Formation (Coats, 1985).

In the Rowland Quadrangle, Bushnell (1967) mapped the Diamond A Formation which he suggested may correlate with the Banner Formation. Coats (1985) considers the Diamond A as the Banner Formation. The basal portion is a chert-quartzite pebble conglomerate, with overlying light to medium-gray faintly laminated, fine to medium-grained, sparsely crinoidal limestone that is locally sandy. The limestone is interbedded with black hornfels, and chlorite schist, and 10 foot thick lenses of light gray quartzite-chert pebble conglomerate (Bushnell, 1967). Above the limestone, the formation is dominantly thin layers of greenish-gray to gray shales which probably represent less metamorphosed equivalents of the hornfels and schist. The entire section has been contact metamorphosed and locally contains altered porphyry sills or flows (Bushnell, 1967).

The Banner varies in thickness in the Mountain City Quadrangle where it reaches a thickness of 600 feet (Coats, 1969). It is about 100 feet thick in the California Mountain Quadrangle (Coats, 1985), and 610 to 1,500 feet thick in the northern Rowland Quadrangle (Bushnell, 1967).

The Banner Formation is exposed in the Mountain City and Owyhee Quadrangles, and in small exposures within the northern Rowland, northeastern Mount Velma, and the California Mountain (northeastern Independence Mountains) Quadrangles.

The depositional setting of the Banner Formation is basically unknown as a result of little study and the metamorphosed nature of the unit. Faunal and lithologic evidence suggest a shallow marine shelf setting for the Banner Formation.