Type section designated as south-dipping sequence on ridge between Whirlwind and Soda Creeks, sec.23 T24S R23E, Medfra B-3 quad, west-central AK. Supplemental section is on north flank of syncline, secs. 29-30 T23S R25E, Medfra B-3 quad. Main outcrop extends northeastward for about 100 km. Consists of relatively thick cycles of dolomite and limestone with some silty intervals and reefoid units containing corals. Thickness ranges from 1000 to 1500 m. North of Stone Mountain apparently overlies(?) Paradise Creek Formation; unconformably overlies Telsitna Formation west of region. West of White Mountain unconformably underlies Permian through Lower Cretaceous strata. Age of lower part (0 to 800 m) is Silurian and Early Devonian (probably Siegenian) based on ostracodes (J.M. Berdan, written commun., 1976). Upper part is Emsian to Frasnian based on corals identified by W.A. Oliver, Jr. (written commun., 1977). Age is Late Silurian to Late Devonian.

Source: GNU records (USGS DDS-6; Menlo GNULEX).