[Gleaned from pre-publication release March 23, 2023.] Frenchman Mountain Dolostone of Tonto Group. Chiefly dolomite. At stratotype [principal reference section], thickness 371 m [1,200+ ft]. Overlies Havasu Member of Muav Formation of Tonto Group; contact placed between dark gray, burrow-mottled, erosion-resistant dolostone (Havasu) and overlying light-gray, less resistant dololaminite (Frenchman Mountain). Underlies Dunderberg Shale Member of Nopah Formation; contact placed between reddish weathering, glauconitic, bioclastic, echinoderm plate-rich grainstone (Frenchman Mountain) and overlying brownish gray-weathering, ledge-forming, interbedded shale and dolostone (Dunderberg). Traced eastward into Marble Canyon area, eastern Grand Canyon, Coconino County, northern Arizona, where it is a few meters thick; overlies Muav Formation (undivided) and unconformably underlies Devonian Temple Butte Formation. Is correlative with most of Banded Mountain Member of Bonanza King Formation (geographically restricted). Age is considered late Middle to Late Cambrian (Marjuman to Steptoean Laurentian Stages) based on stratigraphic relations. Report includes measured sections.
[Principal reference section]: measured section just east of Las Vegas, in a prominent unnamed canyon 0.7 km south of East Lake Mead Blvd. on western face of Frenchman Mountain. The mouth of this canyon is at Lat. 36 deg. 11 min. 29 sec. N., Long. 115 deg. 00 min. 28 sec. W., [approx. bdry. btw. secs. 23 and 24, T. 20 S., R. 62 E.], Las Vegas NE 7.5-min quadrangle, Clark Co., southern NV. Section extends into adjacent Frenchman Mountain 7.5-min quadrangle. Named from Frenchman Mountain, Clark Co., southern NV (name credited to V.S. Korolev, 1997, Univ. Nevada-Las Vegas MS thesis).
[Additional locality information from USGS historical topographic map collection TopoView, accessed April 11, 2023.]

Source: pre-publication version.