The Diana Formation was named for exposures on Diana Peak, north of July Canyon in the northern Toquima Range (Kay, 1960). At its type section, the Diana disconformably overlies the Ordovician Antelope Valley Limestone and conformably underlies the Masket Shale (Kay and Crawford, 1964).

The Diana Formation was considered Early Silurian in age based upon coral and brachiopod faunas (Kay and Crawford, 1964). Other workers (Berry and Bucout, 1970; Ross, 1970) assigned a Middle to Late Ordovician age to the formation, which in part appears to be the result of sampling Ordovician formations mislabeled as Diana on the original map of Kay and Crawford (1964). McKee (1976b) suggests that the formation is at least in part late Middle or Late Ordovician on the basis of trilobites, graptolites, and conodonts he collected in the Diana Formation.

The Diana is represented by 5 to 10 feet of gray to dark-gray calcarenite which overlies 10-20 feet of thick-bedded dark-gray mottled unfossiliferous limestone that is locally cherty near the base (Kay and Crawford, 1964; McKee, 1976). A few brachiopods, corals, graptolites and trilobites have been found within the Diana Formation (Kleinhampl and Ziony, 1985).

The Diana is about 38 feet at its type locality in the Toquima Range (Kay and Crawford, 1964), and about 77 feet along Ikes Canyon in the Toquima Range (Ross, 1970). Areal Distribution

The Diana is only exposed in a few discontinuous outcrops from Mill to Ikes Canyons in the northern Toquima Range.

The depositional setting of the limited and poorly exposed Diana Formation is poorly understood. The brachiopods and corals found in the limestones suggest a shallow water origin. In general the Diana probably represents shallow marine shelf deposition.