Fitzhugh Member, upper member of Clarita Formation of Chimneyhill subgroup [informal] of Hunton Group. Thickness 0 to 45 feet. Gradationally overlies Prices Falls Member (new) of Clarita Formation. Unconformably underlies Henryhouse Formation. Described as an evenly bedded limestone composed largely of fossil debris. The most common fossils are crinoid plates, many with an orange-pink color, but other fossils are well represented and in several places the Fitzhugh is an ostracode coquina. At type, and in northern and eastern exposures, the matrix is part spar, part micrite, but in central Arbuckles is mostly biomicrite. Brachiopods indicate early Wenlockian age.
Type locality: along bed of Chimneyhill Creek, in SE/4 sec. 5, T. 2 N., R. 6 E., Pontotoc Co., OK. Named from town of Fitzhugh in southern Pontotoc Co., OK. Strata do not crop out in the town but are well exposed in Lawrence uplift a few mi toward the east.
["Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Considered informal and should not be capitalized.]

Source: US geologic names lexicon (USGS Bull. 1350, p. 259); supplemental information from GNU records (USGS DDS-6; Denver GNULEX).