Geologic units in Taos county, New Mexico

Additional scientific data in this geographic area

Basaltic to andesitic lava flows (Pliocene) at surface, covers 25 % of this area

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

Permian and Pennsylvanian rocks, undivided (Permian and Pennsylvanian) at surface, covers 16 % of this area

Includes Concha, Scherrer, Colina, Epitaph, and Earp Formations (Permian) and Horquilla Limestone (Permian to Pennsylvanian).

Piedmont alluvial deposits (Holocene to lower Pleistocene) at surface, covers 10 % of this area

Includes deposits of higher gradient tributaries bordering major stream valleys, alluvial veneers of the piedmont slope, and alluvial fans. May locally include uppermost Pliocene deposits.

Alluvium (Holocene to upper Pleistocene) at surface, covers 7 % of this area

Alluvium

Paleoproterozoic granitic plutonic rocks (Paleoproterozoic) at surface, covers 5 % 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.

Intermediate to silicic volcanic rocks (Neogene) at surface, covers 4 % 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.

Lower Santa Fe Group (Upper Miocene to uppermost Oligocene) at surface, covers 4 % of this area

Includes Hayner Ranch, Rincon Valley, Popotosa, Cochiti, Tesuque, Chamita, Abiquiu, Zia, and other formations.

Paleoproterozoic mafic metavolcanic rocks with subordinate felsic metavolcanic rocks (Paleoproterozoic) at surface, covers 3 % of this area

Includes the 1.78-1.72 Ga Moppin (Tusas Mountains), Gold Hill (Taos Range), and Pecos (Sangre de Cristo Mountains) complexes; interpreted to be supracrustal part of juvenile volcanic arc basement.

Lower-upper middle Tertiary basaltic andesites and andesites of the Mogollon Group (Upper Oligocene (26-29 Ma)) at surface, covers 3 % of this area

Includes La Jara Peak Basaltic Andesite, Uvas Basaltic Andesite, basaltic andesites of Poverty Creek and Twin Peaks, Squirrel Springs Canyon Andesite, Razorback Basalt, Bear Springs Basalt, flows of Gila Flat, Salt Creek Formation, Middle Mountain Formation, and the Alum Mountain Group. Pre-Amalia-Tuff lavas in the Questa caldera are dominantly silicic andesites and dacites; elsewhere silicic lavas are a minor component of Tual.

Tertiary intrusive rocks of intermediate to silicic composition (Pliocene to Eocene) at surface, covers 3 % 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.

Paleoproterozoic calc-alkaline plutonic rocks (Paleoproterozoic) at surface, covers 2 % of this area

Granodiorite, diorite, and gabbro complexes; 1.78-1.71 Ga; interpreted to be intrusive part of juvenile volcanic arc basement.

Eolian deposits (Holocene to middle Pleistocene) at surface, covers 2 % of this area

Eolian deposits.

Upper Santa Fe Group (Middle Pleistocene to uppermost Miocene) at surface, covers 2 % of this area

Includes Camp Rice, Fort Hancock, Palomas, Sierra Ladrones, Arroyo Ojito, Ancha, Puye, and Alamosa Formations.

Silicic to intermediate volcanic rocks (Neogene, mostly Miocene) at surface, covers 2 % of this area

Rhyolite and dacite flows with associated minor tuffs. Commonly interbedded with Santa Fe or Gila Group sedimentary units. Dacitic lavas in northern Jemez Mountains are Pliocene.

Paleoproterozoic quartzite (Paleoproterozoic) at surface, covers 2 % of this area

Includes 1.70 Ga Ortega Quartzite and equivalents in northern New Mexico and 1.67 Ga quartzites in central New Mexico.

Santa Fe Group, undivided (Middle Pleistocene to uppermost Oligocene) at surface, covers 1 % of this area

Basin fill of the Rio Grande rift. Locally represents upper Miocene formations of the middle Santa Fe Group in the northern Albuquerque Basin.

Upper middle Tertiary rhyolitic lavas and local tuffs (Upper Oligocene (24-29 Ma)) at surface, covers 1 % of this area

Includes Taylor Creek Rhyolite, Fanney Rhyolite, rhyolite of Rocky Canyon, rhyolite of Hardy Ridge, and upper rhyolite members of the Luis Lopez and Sawmill Canyon formations.

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.

Upper middle Tertiary rhyolitic pyroclastic rocks of the Mogollon Group, ash-flow tuffs (Upper Oligocene (24-30 Ma)) at surface, covers 1.0 % of this area

Regional ash-flow tuffs include the La Jencia, Vick's Peak, Lemitar, South Canyon, Bloodgood Canyon, Shelley Peak, Davis Canyon, Park, Rhyolite Canyon, Apache Springs, and Amalia Tuffs; the tuffs of Horseshoe Canyon, Diamond Creek, Garcia Camp, Caronita Canyon, Turkey Springs, and Little Mineral Creek; and the Jordan Canyon Formation. Includes some locally erupted lavas and tuffs within thick intra-caldera units; includes minor volcaniclastic sedimentary units between thin outflow sheets.

Paleoproterozoic metasedimentary rocks (Paleoproterozoic) at surface, covers 1.0 % of this area

Pelitic schist, quartz-muscovite schist, immature quartzite, and subordinate amphibolite; includes parts of Vadito Group in northern New Mexico, immature metasedimentary rocks of central New Mexico, and Bullard Peak Series mixed supracrustal rocks in Burro Mountains.

Paleoproterozoic pelitic schist (Paleoproterozoic) at surface, covers 0.9 % of this area

Includes Rinconada Formation in northern New Mexico and Blue Springs Schist in Manzano Mountains.

Upper Tertiary sedimentary units (Pliocene to upper Oligocene) at surface, covers 0.9 % 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.

Pennsylvanian rocks, undivided (Pennsylvanian) at surface, covers 0.7 % of this area

In Sangre de Cristo Mountains may include Sandia, Madera, La Pasada, Alamitos, and Flechado Formations; elsewhere may include Bar-B, Nakaye, Red House, Oswaldo, and Syrena Formations.

Glacial deposits (Upper to middle Pleistocene) at surface, covers 0.6 % of this area

Glacial deposits; till and outwash.

Upper middle Tertiary volcanic rocks (Lower Miocene to upper Oligocene (younger than 30 Ma)) at surface, covers 0.5 % of this area

Mostly a combination of basaltic andesite lavas and rhyolitic ash-flow tuffs of the Mogollon Group (Tuau+Tual+Turp). Includes locally erupted lavas and tuffs in some calderas.

Los Pinos Formation of Lower Santa Fe Group (Miocene and upper Oligocene) at surface, covers 0.4 % of this area

Includes Carson Conglomerate (Dane and Bachman, 1965) in Tusas Mountains-San Luis Basin area.

Upper middle Tertiary basaltic andesites and andesites of the Mogollon Group (Lower Miocene and uppermost Oligocene (22-26 Ma)) at surface, covers 0.3 % of this area

Includes Bearwallow Mountain Andesite and basaltic andesite of Mangas Mountain; also near vent basaltic lavas and shallow intrusions in the Chuska Mountains.

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

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

Paleoproterozoic rhyolite and felsic volcanic schist (Paleoproterozoic) at surface, covers 0.2 % of this area

Includes 1.70 Ga Vadito Group in northern New Mexico and 1.68 Ga Sevilleta Metarhyolite in central New Mexico.

Middle Tertiary volcaniclastic sedimentary units (Oligocene to upper Eocene) at surface, covers 0.2 % of this area

Mostly syneruptive volcaniclastic sedimentary aprons. Lower units dominantly derived from volcanic highlands of andesitic to dacitic composition. Locally includes minor lavas and tuffs. Younger units (above and intertongued with Mogollon Group tuffs, Turp) include upper Bell Top Formation, South Crosby Peak Formation, and upper Spears Group units near Quemado. Older units (below and intertongued with Datil Group tuffs, Tlrp) include Palm Park, lower Bell Top, Espinaso and Pueblo Creek Formatios and lower Spears Group formations such as Rincon Windmill, Chavez Canyon, and Dog Springs.

Paleogene sedimentary units (Paleogene) at surface, covers 0.1 % of this area

Includes Baca, Galisteo, El Rito, Blanco Basin, Hart Mine, Love Ranch, Lobo, Sanders Canyon, Skunk Ranch, Timberlake, and Cub Mountain Formations.

Paleozoic rocks, undivided (Paleozoic) at surface, covers 0.1 % of this area

Paleozoic rocks, undivided

Mississippian rocks, undivided (Mississippian) at surface, covers < 0.1 % of this area

Arroyo Penasco Group in Sangre de Cristo Mountains, Sierra Nacimiento, San Pedro Mountain, and Sandia Mountains; Lake Valley Limestone in south-central New Mexico.

Basalt flows and associated tuff, breccia, and conglomerate of late-volcanic bimodal suite (Tertiary) at surface, covers < 0.1 % of this area

Includes basalts of Hinsdale Fm in San Juan Mountains - Servilleta Fm in San Luis Valley and many other occurrences

Poison Canyon Formation (Paleocene and upper Cretaceous) at surface, covers < 0.1 % of this area

Proximal conglomerates and sandstones in western Raton Basin; generally lacking coal beds. Cretaceous beds mostly restricted to subsurface.

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

Mainly 1.45 - 1.35 Ga megacrystic granites, generally weakly foliated except locally at their margins.

Lower middle Tertiary andesitic to dacitic lavas and pyroclastic flow breccias (Upper to middle Eocene (33-43 Ma)) at surface, covers < 0.1 % of this area

Includes Rubio Peak Formation, Orejon Andesite, andesite of Dry Leggett Canyon, andesite of Telephone Canyon, and other units in southwestern, central, and northern New Mexico. Locally includes minor mafic lavas. Ancient landslide blocks of Mader Limestone, as much as one mile long, occur within Rubio Peak lavas in the central Black Range, west of Winston.

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.

Glorieta Sandstone (Leonardian) at surface, covers < 0.1 % of this area

Texturally and mineralogically mature, high-silica quartz sandstone.

Gravels and alluviums (Quaternary) at surface, covers < 0.1 % of this area

Includes Broadway and Louviers Alluviums

Pierre Shale and Niobrara Formation (Campanian to Coniacian) at surface, covers < 0.1 % of this area

Pierre Shale and Niobrara Formation

Santa Fe Fm (Tertiary) at surface, covers < 0.1 % of this area

Siltstone, sandstone, and conglomerate

Lower middle Tertiary rhyolitic to dacitic pyroclastic rocks of the Datil Group, ash-flow tuffs (Lower Oligocene to upper Eocene (31-36 Ma)) at surface, covers < 0.1 % of this area

Regional ash-flow tuffs include Hell's Mesa, Kneeling Nun, Caballo Blanco, Datil Well, Leyba Well, Rock House Canyon, Blue Canyon, Sugarlump, Oak Creek, Bluff Creek, Gillespie, Box Canyon, Cooney and Chiquito Peak Tuffs; the tuffs of Steins Mountain, Black Bill Canyon, Woodhaul Canyon, and Farr Ranch; tuffs of the Organ cauldron; and lower tuffs in the Bell Top Formation. Includes some locally erupted lavas and tuffs within thick intra-caldera units; includes minor volcaniclastic sedimentary units and lavas between thin outflow sheets.

Panther Seep Formation (Virgilian) at surface, covers < 0.1 % of this area

In Organ, Franklin, and San Andres Mountains.

Chinle Group (Upper to middle Triassic) at surface, covers < 0.1 % 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.

Pre-ash-flow andesitic lavas, breccias, tuffs, and conglomerates (Tertiary) at surface, covers < 0.1 % of this area

Includes several named units

Mesoproterozoic and Paleoproterozoic plutonic rocks, undivided (Mesoproterozoic and Paleoproterozoic) at surface, covers < 0.1 % of this area

Mesoproterozoic and Paleoproterozoic plutonic rocks, undivided

Basaltic to andesitic lava flows (Upper Pleistocene to lower Pliocene) at surface, covers < 0.1 % of this area

Includes minor vent deposits.

Granitic rocks of 1400-m.y. age group (Middle Proterozoic) at surface, covers < 0.1 % of this area

Includes Silver Plume, Sherman, Cripple Creek, St. Kevin, Vernal Mesa, Curecanti, Eolus, and Trimble Granites or Quartz Monzonites; also, San Isabel Granite of Boyer (1962) and unnamed granitic rocks

Upper and Middle Jurassic rocks, undivided (Upper and Middle Jurassic) at surface, covers < 0.1 % of this area

In southwest includes the basalt-bearing Broken Jug Formation.

Upper and lower Cretaceous rocks of east-central and northeast New Mexico (Cenomanian and Albian) at surface, covers < 0.1 % of this area

Consists of Dakota Group, which includes Romeroville Sandstone (Cenomanian), Pajarito Shale, and Mesa Rica Sandstone (Albian); the underlying Tucumcari Shale (Albian) in Tucumcari area and Glencairn Formation (Albian) in Union County.

Vermejo Formation and Trinidad Sandstone (Maastrichtian to Campanian) at surface, covers < 0.1 % of this area

Vermejo Formation and Trinidad Sandstone

Greenhorn Formation and Carlile Shale, undivided (Turonian to Cenomanian) at surface, covers < 0.1 % of this area

Locally includes Graneros Shale.

Quartzite, conglomerate, and interlayered mica schist (Early Proterozoic) at surface, covers < 0.1 % of this area

Quartzite, conglomerate, and interlayered mica schist

Biotitic gneiss, schist, and migmatite (Early Proterozoic) at surface, covers < 0.1 % of this area

Locally contains minor hornblende gneiss, calc-silicate rock, quartzite, and marble. Derived principally from sedimentary rocks