|Geologic age||Late Jurassic|
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Clastic > Mixed-clastic > Sandstone-mudstone (Bed)
Sedimentary > Chemical > Evaporite > Gypsum (Bed)
|Comments||Limestone, shale, siltstone, sandstone, gypsum and conglomerate. Upper part--mostly limestone aphanitic up to 25 ft of brownish-yell sandst. and limest at top. Lower part--complexly interfingered sandstone, siltstone, shale, limestone, and conglomerate., some impure gypsum. short-distance lateral facies changes common. Mostly sandy shale and siltstone at NW end of Malone Mtns, grades SE to mostly sandst. Jurassic ammonites. Thickness 150-1,000 + ft. Malone Mtns in Hudspeth Co. are only about 10 sq. mi in area just north of I-80 midway between El Paso and Van Horn. Only Jurassic outcrops in west Trans-Pecos. According to Albritton (1937) the Malone consists of a lower division of ls., conglo., sandst., sandy shale, and impure ls., and upper division dominantly impure ls. Max. thickness about 1,000 ft. Unconformably overlies Permian strata.|
Bureau of Economic Geology, 1976, Pecos Sheet, Geologic Atlas of Texas: University of Texas at Austin, Bureau of Economic Geology, scale 1:250,000.
Albritton, C.C., Jr., 1937, Field and Laboratory, v. 5, no. 2. p. 48-50.
Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000.