Geologic units in McKinley county, New Mexico

Additional scientific data in this geographic area

Menefee Formation (Campanian to Santonian) at surface, covers 33 % of this area

Mudstone, shale, and sandstone; coal-bearing.

Crevasse Canyon Formation (Santonian to Coniacian) at surface, covers 13 % of this area

Coal-bearing units are Dilco and Gibson Coal Members; other members are Bartlett Barren, Dalton Sandstone, and Borrego Pass Sandstone (or Lentil).

Chinle Group (Upper to middle Triassic) at surface, covers 7 % of this area

Map unit includes Moenkopi Formation (Middle Triassic) at base in many areas; in eastern part of state the following five formations are mapped: TRr, TRb, TRt, TRg, and TRs.

Intertongued Mancos Shale and Dakota Sandstone of west-central New Mexico (Cenomanian) at surface, covers 4 % of this area

Includes the Whitewater Arroyo Tongue of Mancos Shale and the Twowells Tongue of the Dakota.

Alluvium (Holocene to upper Pleistocene) at surface, covers 4 % of this area

Alluvium

Point Lookout Sandstone (Campanian to Santonian) at surface, covers 4 % of this area

Regressive marine sandstone in McKinley and Sandoval Counties; the lower, Hosta Tongue, of Point Lookout is transgressive and is separated from main body by the Satan Tongue of Mancos Shale.

Basaltic to andesitic lava flows (Pliocene) at surface, covers 4 % of this area

Includes minor vent deposits and small shield volcanoes. Flows are commonly interbedded in the Santa Fe and Gila Groups.

Mancos Shale, lower part (Turonian and Cenomanian) at surface, covers 2 % of this area

Mancos Shale, lower part

Upper Tertiary sedimentary units (Pliocene to upper Oligocene) at surface, covers 2 % of this area

Includes Bidahochi Formation (Pliocene to upper Miocene), Picuris Formation (Miocene to Oligocene), Las Feveras Formation (Pliocene), lower Gila Group units in the southwest, and unnamed Pliocene unit in northwestern Socorro County.

Lewis Shale (Campanian) at surface, covers 2 % of this area

Marine shale and mudstone.

Gallup Sandstone (Turonian) at surface, covers 2 % of this area

Generally regressive marine sandstone.

San Rafael Group (Middle Jurassic) at surface, covers 2 % of this area

Consists of Entrada Sandstone, Todilto and Summerville Formations, Bluff Sandstone, and locally Zuni Sandstone (or only Acoma Tongue of Zuni).

Zuni and Entrada Sandstones, undivided (Middle Jurassic) at surface, covers 2 % of this area

Zuni and Entrada Sandstones, undivided

Cliff House Sandstone (Campanian) at surface, covers 2 % of this area

Transgressive marine sandstone.

Satan Tongue of Mancos Shale (Santonian) at surface, covers 2 % of this area

Satan Tongue of Mancos Shale

Pescado Tongue of the Mancos Shale and Gallup Sandstone (Turonian) at surface, covers 2 % of this area

In Zuni Basin only; Pescado is chrono-stratigraphic equivalent of Juana Lopez Member of Mancos Shale.

Kirtland and Fruitland Formations (Campanian) at surface, covers 2 % of this area

Coal-bearing, primarily in the Fruitland.

Morrison Formation (Upper Jurassic) at surface, covers 1 % of this area

Upper Jurassic nonmarine rocks.

Landslide deposits and colluvium (Holocene to Pleistocene) at surface, covers 1 % of this area

Landslide deposits on western flanks of Socorro Mountains not shown for clarity.

Mulatto Tongue of Mancos Shale (Santonian to Coniacian) at surface, covers 1 % of this area

Mulatto Tongue of Mancos Shale

Rio Salado Tongue of the Mancos Shale (Turonian) at surface, covers 1 % of this area

Overlies Twowells Tongue of Dakota Sandstone; mapped only where Tres Hermanos Formation or the Atarque Sandstone is present; mapped as Kdr in parts of Socorro County.

Tres Hermanos Formation (Turonian) at surface, covers 1 % of this area

Formerly designated as Lower Gallup Sandstone in the Zuni Basin.

Chuska Sandstone (Middle to upper Oligocene) at surface, covers 1.0 % of this area

Restricted to Chuska Mountains.

Mancos Shale, upper part (Campanian to Coniacian) at surface, covers 1.0 % of this area

Mancos Shale, upper part

San Andres Formation (Guadalupian and Leonardian) at surface, covers 0.7 % of this area

Limestone and dolomite with minor shale. Guadalupian in south, in part Leonardian to north.

Triassic rocks, undivided (Triassic) at surface, covers 0.6 % of this area

Continental red beds.

Nacimiento Formation (Paleocene) at surface, covers 0.5 % of this area

San Juan Basin

Dakota Sandstone (Cenomanian) at surface, covers 0.4 % of this area

Includes Oak Canyon, Cubero, and Paguate Tongues; includes Clay Mesa Tongue of Mancos Shale.

Glorieta Sandstone (Leonardian) at surface, covers 0.4 % of this area

Texturally and mineralogically mature, high-silica quartz sandstone.

Mancos Shale (Cenomanian to Campanian) at surface, covers 0.4 % of this area

Divided into Upper and Lower parts by Gallup Sandstone.

Hosta Tongue of Point Lookout Sandstone (Santonian) at surface, covers 0.4 % of this area

Transgressive marine sandstone.

Upper and Middle Jurassic rocks, undivided (Upper and Middle Jurassic) at surface, covers 0.3 % of this area

In southwest includes the basalt-bearing Broken Jug Formation.

Pictured Cliffs Sandstone (Campanian) at surface, covers 0.3 % of this area

Prominent cliff-forming marine sandstone.

Yeso Formation (Leonardian) at surface, covers 0.3 % of this area

Sandstones, siltstones, anhydrite, gypsum, halite, and dolomite.

Basaltic to andesitic lava flows (Middle to lower Pleistocene) at surface, covers 0.2 % of this area

Includes vent deposits.

Basaltic to andesitic lava flows (Holocene to middle Pleistocene) at surface, covers 0.2 % of this area

Flows south of Grants and west of Carrizozo are Holocene. Includes minor vent deposits.

Abo Formation (Wolfcampian) at surface, covers 0.2 % of this area

Red beds, arkosic at base, finer and more mature above; Wolfcampian; may include limestone beds of Pennsylvanian age (Virgilian) in Zuni Mountains. In Robledo Mountains the Abo may be considered a member of the Hueco Formation.

Ojo Alamo Formation (Paleocene) at surface, covers 0.1 % of this area

San Juan Basin

Upper Cretaceous rocks of southwestern New Mexico, undivided (Maastrichtian to Cenomanian) at surface, covers 0.1 % of this area

Beartooth and Sarten Formations are in part Albian. Includes Virden Formation in northern Hidalgo County, Ringbone Formation in Hidalgo, Luna and Grant Counties, Mancos Shale in Silver City area.

Paleoproterozoic granitic plutonic rocks (Paleoproterozoic) at surface, covers 0.1 % of this area

Variably foliated granites and granitic gneisses; 1.71 - 1.65 Ga in northern New Mexico; 1.66 - 1.65 Ga in central and southern New Mexico.

Eolian deposits (Holocene to middle Pleistocene) at surface, covers < 0.1 % of this area

Eolian deposits.

Rock Point Formation of Chinle Group (Upper Triassic) at surface, covers < 0.1 % of this area

May locally include Wingate Sandstone.

Basaltic to andesitic lava flows (Neogene) at surface, covers < 0.1 % of this area

Includes minor vent deposits. Flows are commonly interbedded in the Santa Fe and Gila Groups.

Tertiary intrusive rocks of intermediate to silicic composition (Pliocene to Eocene) at surface, covers < 0.1 % of this area

Includes monzonitic to granitic plutons, stocks, laccoliths, and porphyritic dikes in deeply eroded magmatic centers; and andesitic, dacitic, or rhyolitic plugs and dikes near cauldrons or stratovolcanoes. In the Latir field, fine-grained rhyolitic dikes commonly cut coarse-grained granitic plutons. Includes alkaline laccoliths, plugs, and dikes in Colfax County. North-trending dikes near Capitan include some mafic diabase dikes.

Tertiary mafic intrusive rocks (Pliocene to upper Eocene) at surface, covers < 0.1 % of this area

Includes many long basaltic andesite dikes of Oligocene age near Pie Town, Acoma, Riley, Chupadera, Truth or Consequences, Roswell, Raton, and Dulce; and several elongate or shoestring-like sills of basalt or basaltic andesite. Also includes basaltic necks of Pliocene age that dot the landscape northeast of Mount Taylor. Where dikes extend into Quaternary alluvium the contact is an unconformity.

Intermediate to silicic volcanic rocks (Neogene) at surface, covers < 0.1 % of this area

Mostly andesitic to dacitic strato volcanoes. Includes rhyolite lavas and tuffs in the Jemez Mountains, Volcanoes in Jemez Mountains and eastern Colfax County are upper Miocene. Mount Taylor and composite volcanoes in the Taos Plateau volcanic field are Pliocene.