First use of name; intent to name not stated. Area of report is west face of Sacramento Mountains; type area measured in Deadman Canyon, sec 3, T17S, R10E, Otero Co, NM in Orogrande basin. Mississippian formations are underlain by Percha formation of Late Devonian age. Mississippian rocks formerly called Percha removed from Percha and divided into: (ascending): Caballero formation (new) and Lake Valley formation (revised)--itself divided into three new units (ascending): Alamogordo, Arcente, and Dona Ana members. Dona Ana consists of very cherty, gray to brown, thin-bedded, crinoidal limestone. Local bioherm masses sometimes found within member. Is 60 ft thick at type. Is unconformably overlain by Pennsylvanian Magdalena [group] strata; overlies Arcente member (new) of Lake Valley. Is of Osage (Mississippian) age; carries a fauna somewhat comparable to that of the [lower part of] Burlington formation of Upper Mississippi Valley region. No beds found in Mississippian section in report area that are younger than [lower part of] Burlington age. The Mississippian beds in Sacramento Mountains area are better developed than in Lake Valley area at Lake Valley, Sierra Co, Orogrande basin. Caballero formation is present in both areas, but Lake Valley beds at Lake Valley are all correlated with Alamogordo member as developed in Sacramento Mountains. Arcente and Dona Ana members not present at Lake Valley. Is Osage (Mississippian) age.

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