Pg. 1146 (fig. 3), 1152-1156. Thompson Valley limestone of Cliffield group. Proposed for the thick-bedded, light-gray, commonly variegated coarse-grained limestone originally referred to as zone 6 of Tazewell County classification by Cooper and Prouty [1943, GSA Bull., v. 54, no. 6]. This zone was included by them in their Ward Cove limestone which is here restricted to NIDULITES beds (zone 7). Thickness 75 feet at type section; about 250 to 300 feet in Fountain City, northeastern Tennessee. Underlies Ward Cove limestone; overlies Lincolnshire formation. In Saltville belt, beds similar to Thompson Valley limestone are exposed in McNutt quarry, 1.5 miles southeast of Sharon Springs, Virginia; this was previously referred to as Effna limestone (Cooper, 1944, Virginia Geol. Survey Bull., no. 60). Age is Middle Ordovician.
Type locality: Thompson Valley, Tazewell Co., southwestern VA. Extends into northeastern TN.

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 3871).