Pg. 40-41. Name proposed for the uppermost of three formations of /Tintic Mountain Volcanic Group (new). Consists of a lower, poorly exposed air-fall tuff (informally called tuff member) of moderately to strongly altered, well-bedded, fine-grained, white clay stained brown, yellow, and black, 38 m thick; and an upper medium- to dark-gray, compact, finely porphyritic latite (informally called flow member) with planar partings, 29 m thick. Magnetite abundant. Unconformably overlies Latite Ridge Latite (new) of Tintic Mountain Volcanic Group or Packard Quartz Latite; unconformably underlies North Standard Latite (new) or Pinyon Queen Latite, both of /Laguna Springs Volcanic Group. Age is considered middle Oligocene. Big Canyon Latite of /Tintic Mountain Volcanic Group adopted by the USGS. [US geologic names lexicon (USGS Bull. 1564, p. 12-13) indicates the tuff is white-stained (not brown, yellow, and black stained). --unresolved.]
Type section: exposures capping the east-trending ridge that marks south entrance to Big Canyon, in NW/4 sec. 13, T. 10 S., R. 2 W., East Tintic Mountains, 16 km southwest of East Tintic mining district, Juab and Utah Cos., central UT. Named from Big Canyon.
[Tintic Mountain Volcanic Group and Laguna Springs Volcanic Group conflict with nomenclature guidelines stating a group name combines a geographic name with the term "group," and no lithic designation is included (ACSN, 1961, 1970; NACSN, 1983, 2005, 2021).]

Source: US geologic names lexicon (USGS Bull. 1564, p. 12-13); Changes in stratigraphic nomenclature, 1979 (USGS Bull. 1502-A, p. A7); GNU records (USGS DDS-6; Denver GNULEX).