Overlies Percha shale (Devonian) and underlies andesite in vicinity of Lake Valley mines, Sierra Co, NM, Orogrande basin. In section measured near the mines, Lake Valley is 210 ft thick; it consists of gray limestone filled with nodular chert with shale partings that is overlain by 1) gray-blue limestone with flint fragments, 2) blue shale with crinoids, 3) coarse yellow-white thick-bedded limestone with abundant crinoids and some cherty beds. Fossils (corals, brachiopods, crinoids) listed. Belongs to the Mississippian.

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

Lake Valley revised in report area, west face of Sacramento Mountains, NM in Orogrande basin. Restricted at base to exclude unit previously considered part of Lake Valley--here named Caballero formation--and divided into three lithologic units (all new, ascending): Alamogordo, Arcente, and Dona Ana members. Composite type area for Mississippian rocks in section measured in Deadman Canyon, sec 3, T17S, R10E, Otero Co, NM in Orogrande basin. Dona Ana member of Lake Valley unconformably overlain by Pennsylvanian strata of Magdalena [group]; Alamogordo member of Lake Valley underlain by Caballero formation. The Mississippian beds in Sacramento Mountains area are better developed than in Lake Valley area at Lake Valley, Otero 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, Sierra Co, Orogrande basin. Thickness of revised Lake Valley is 420 ft at Deadman Canyon. Is entirely of Osage (Mississippian) age, based on fauna. Lower portion is of Fern Glen-St. Joe age. Upper, Dona Ana member carries a fauna somewhat comparable to that of the [lower part of] Burlington formation of the Upper Mississippi Valley region. No beds found in Mississippian section in report area that are younger than [lower part of] Burlington age.

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

Lake Valley revised in report area, southwestern NM--divided into six members (ascending): Andrecito (new), Alamogordo (revised), Nunn (new), Tierra Blanca (new), Arcente (revised), and Dona Ana members. Lake Valley is most widespread Mississippian unit in southwest NM, present in Socorro, Sierra, Dona Ana, Otero, Grant, Hidalgo, and Catron Cos, in Orogrande and Pedregosa basins and Basin-and-Range province. Rests unconformably on Caballero formation, or on Devonian sediments where Caballero is missing; unconformably overlain by Kelly formation in western part of report area, by Las Cruces and Rancheria formations (both new) in southern part, and elsewhere by Pennsylvanian sediments. Lake Valley is Osage (Mississippian) in age. Absent from Hueco and Franklin Mountains area, TX, southernmost Orogrande basin. Measured sections, cross sections, areal extent maps.

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

Laudon and Bowsher (1949) have reported 15-30 ft of cherty crinoidal limestone without distinctive fossils overlying the Tierra Blanca member of Lake Valley formation in the southern part of Cooks Range (Luna Co, Basin-and-Range province). These beds were tentatively referred to Kelly limestone. The absence of faunal evidence, and the lack of any definitive break between the formations, has led the author to consider them to be part of Tierra Blanca member of Lake Valley formation, and they were so mapped.

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

Is formation in southwestern NM, and is divided into six members (ascending): Andrecito, Alamogordo, Nunn, Tierra Blanca, Arcente, and Dona Ana Members. Columnar sections at Bear Mountain, Grant Co, and in North Cooks Range, Luna Co (both in southwestern Basin-and-Range province); and at Lake Valley, Sierra Co (western Orogrande basin). Unconformably overlies Upper Devonian (Famennian) Box Member of Percha Shale at Bear Mountain and North Cooks Range; unconformably over Lower Mississippian (Kinderhookian) Caballero Formation at Lake Valley. Arcente and Dona Ana Members missing at Pennsylvanian erosion surface within study area, where Lake Valley underlies Pennsylvanian Oswaldo Limestone of Magdalena Group. Biostratigraphic dating with foraminifers indicates Andrecito and Alamogordo Members are Kinderhookian, and Tierra Blanca Member is Osagean. Stratigraphic position dating places Nunn Member in Osagean. Regional correlations on fig. 2; is correlated with lower part of Escabrosa Group (Keating Formation and lower part of Hachita Formation) in Pedregosa basin. Kinderhookian-Osagean provincial series boundary is questionably placed at the Alamogordo-Nunn contact. Age is Kinderhookian and Osagean (Early Mississippian).

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