Pg. 8-19, 36 (table 6), pl. 27. Lowell formation of Bisbee group. Series of alternating sandstones, shales, and limestones. Includes following members (new) in ascending order: Pacheta, Joserita, Saavedra, Cholla, Quajote, Perilla, and Pedregosa. Total thickness 1,104 feet. Overlies Morita formation; underlies Mural limestone (restricted to upper part of Ransome's Mural limestone; lower part of Ransome's Mural limestone = Lowell formation). Age is Early Cretaceous (Aptian to Albian); PARAHOPLITES MELCHIORIS to LEYMERIELLA TARDEFURCATA standard ammonite zone.
Type locality: 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 [formerly El Paso and Southwestern RR], and southwest of Schlandt Ranch, [Bisbee 15-min quadrangle], Cochise Co., southeastern AZ. Named from community of Lowell [now a part of Bisbee].
[Misprint (US geologic names lexicon, USGS Bull. 1200, p. 2251): the listed alternate usage is incorrect; the Lowell Limestone in Allegheny Formation = Newberry's (1878) Pennsylvanian Lowell Limestone of Ohio.]

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 2251).

Not used. Name applied by Stoyanow (1949) to the lower member of Mural limestone and upper beds of Morita formation of Ransome (1904). The base of Lowell formation found to not be readily traceable, whereas the base of Mural limestone as originally defined by Ransome (1904) can be mapped readily within narrow stratigraphic units. Rocks at Lowell type section duplicated by a fault. Several writers assumed that Lowell was a replacement name only for the lower member of the Mural. Stoyanow did not clearly state that several hundred ft of Morita were also included in Lowell.

Source: GNU records (USGS DDS-6; Denver GNULEX).