[Named] for exposures in vicinity of Ibex Spring. Type locality designated about 2 km southwest of Ibex Spring and south of jeep road that connects spring area with Buckwheat Wash to west, southwestern Shoshone 15' quad, Death Valley region, San Bernardino Co, CA. Also mapped in northern half of Confidence Hills 15' quad, Inyo Co, CA. Called "basin facies" of Noonday Dolomite (Williams and others, 1976). [Composite] type section consists of (ascending); conglomerate, arkose, limestone, shaly limestone, and dolomite members. Estimated thickness is 200 m at type locality. At southern end of Saddle Peak Hills thickness is more than 700 m. Unconformably overlies Kingston Peak Formation; underlies Johnnie Formation. Age is Late Proterozoic based on stratigraphic relations.

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