Pg. 8-9, 17-18, 36 (table 6), pl. 27. Pedregosa member of Lowell formation of Bisbee group. Consists of following divisions (ascending): (1f) buff sandstone, 1 foot; (9e) white platy sandstone, 20 feet; (1d) gray and buff limestone, 1 foot; (1c) calcareous sandstone, 25 feet; (1b) white and yellow shale and greenish sandstone, 105 feet; and (1a) thin layers of argillaceous limestone, sandstone, and shale, 30 feet. Total thickness 182 feet. Top member of Lowell formation; overlies Perilla member (new). Underlies Mural limestone. Fossils. Age is Early Cretaceous (Albian); LEYMERIELLA TARDEFURCATA standard ammonite zone.
[Occurs in the Ninety One Hills area, local name for hills in secs. 14 and 23, T. 24 S., R. 24 E., immediately north of International border in vicinity of International Monument No. 91, southeast of Bisbee Junction on Southern Pacific RR, Bisbee 15-min quadrangle, Cochise Co., southeastern AZ. Area includes type locality and standard section of Lowell Formation.]

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 2965).