| D—–Devonian rocks undivided — Includes Percha Shale, Oñate, and Sly Gap Formations. |
| IPlc—–Lead Camp Formation — In San Andres and Organ Mountains. |
| IPm—–Madera Group — In Manzano Mountains includes Wild Cow Formation and Los Moyos Limestone; in Lucero Mesa includes Red Tanks, Atrasado, Gray Mesa Formations; in Sacramento Mountains includes the non-Madera Holder, Beeman, and Gobbler Formations. May include strata lumped as Magdalena Group in a few areas. |
| IPps—–Panther Seep Formation — In Organ, Franklin, and San Andres Mountains. |
| IPs—–Sandia Formation — Predominantly clastic unit (commonly arkosic) with minor black shales, and limestone in lower part; map unit locally includes Morrowan Osha Canyon Formation in Sierra Nacimiento. |
| IP—–Pennsylvanian rocks, undivided — 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. |
| Je—–Entrada Sandstone — Entrada Sandstone. |
| Jmsu—–Morrison Formation and upper San Rafael Group — Morrison Formation and upper San Rafael Group. |
| Jm—–Morrison Formation — Upper Jurassic nonmarine rocks. |
| Jsr—–San Rafael Group — Consists of Entrada Sandstone, Todilto and Summerville Formations, Bluff Sandstone, and locally Zuni Sandstone (or only Acoma Tongue of Zuni). |
| Jze—–Zuni and Entrada Sandstones, undivided — Zuni and Entrada Sandstones, undivided. |
| Jz—–Zuni Sandstone — Consists of undivided equivalents of the Summerville Formation and Bluff Sandstone; restricted to Zuni Basin area. |
| J—–Upper and Middle Jurassic rocks, undivided — In southwest includes the basalt-bearing Broken Jug Formation. |
| Kcc—–Crevasse Canyon Formation — Coal-bearing units are Dilco and Gibson Coal Members; other members are Bartlett Barren, Dalton Sandstone, and Borrego Pass Sandstone (or Lentil). |
| Kch—–Cliff House Sandstone — Transgressive marine sandstone. |
| Kc—–Carlile Shale — Limited to northeastern area. |
| Kdg—–Upper and Lower Cretaceous rocks of east-central and northeast New Mexico — 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. |
| Kdr—–Dakota Sandstone (Cenomanian) and Rio Salado Tongue of the Mancos Shale — In northwest Socorro County locally includes overlying Tres Hermanos Formation. |
| Kd—–Dakota Sandstone — Includes Oak Canyon, Cubero, and Paguate Tongues; includes Clay Mesa Tongue of Mancos Shale. |
| Kgc—–Greenhorn Formation and Carlile Shale, undivided — Locally includes Graneros Shale. |
| Kgg—–Greenhorn Formation and Graneros Shale — Limited to northeastern area. |
| Kgh—–Greenhorn Formation — Limited to northeastern area; the upper member (Bridge Creek Limestone Member) can be traced into western area where it is commonly shown as a bed-rank unit in Mancos Shale on detailed maps. |
| Kgm—–Gallup Sandstone and underlying D-Cross Tongue of the Mancos Shale — Gallup Sandstone and underlying D-Cross Tongue of the Mancos Shale. |
| Kgr—–Graneros Shale — Limited to northeastern area. |
| Kg—–Gallup Sandstone — Generally regressive marine sandstone. |
| Kkf—–Kirtland and Fruitland Formations — Coal-bearing, primarily in the Fruitland. |
| Kls—–Lewis Shale — Marine shale and mudstone. |
| Klv—–La Ventana Tongue of the Cliff House Sandstone — La Ventana Tongue of the Cliff House Sandstone (Turonian). |
| Kl—–Lower Cretaceous, undivided — In northern Lea and Roosevelt Counties includes equivalents of Tucumcari Shale; in Cornudas Mountains includes Campagrande and Cox Formations and Washita Group; at Cerro de Cristo Rey includes several formations of the Fredericksburg and Washita Groups, and the Boquillas Formation (Cenomanian); in the southwest, includes Mojado, U-Bar (Aptian), and Hell-to-Finish Formations, which are equivalent to Bisbee Group of Arizona. |
| Kma—–Moreno Hill Formation and Atarque Sandstone — In Salt Lake coal field and extreme southern Zuni Basin. |
| Kmb—–Mancos Shale (Cenomanian) and Beartooth and Sarten Formations (Albian) — Mancos includes what was formerly referred to as Colorado Shale, which in turn may include equivalents of Tres Hermanos Formation. |
| Kmc—–McRae Formation — Engle Basin–Cutter sag area. |
| Kmd—–Intertongued Mancos Shale and Dakota Sandstone of west-central New Mexico — Includes the Whitewater Arroyo Tongue of Mancos Shale and the Twowells Tongue of the Dakota. |
| Kmf—–Menefee Formation — Mudstone, shale, and sandstone; coal-bearing. |
| Kml—–Mancos Shale, lower part — Mancos Shale, lower part. |
| Kmm—–Mulatto Tongue of Mancos Shale — Mulatto Tongue of Mancos Shale. |
| Kmr—–Rio Salado Tongue of the Mancos Shale — 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. |
| Kms—–Satan Tongue of Mancos Shale — Satan Tongue of Mancos Shale. |
| Kmu—–Mancos Shale, upper part — Mancos Shale, upper part. |
| Kmv—–Mesaverde Group — Includes Cliff House Sandstone, Menefee Formation and Point Lookout Sandstone. |
| Km—–Mancos Shale — Divided into upper and lower parts by Gallup Sandstone. |
| Knf—–Fort Hays Limestone Member of Niobrara Formation — Fort Hays Limestone Member of Niobrara Formation. |
| Kpc—–Pictured Cliffs Sandstone — Prominent, cliff-forming marine sandstone. |
| Kpg—–Pescado Tongue of the Mancos Shale and Gallup Sandstone — In Zuni Basin only; Pescado is chronostratigraphic equivalent of Juana Lopez Member of Mancos Shale. |
| Kph—–Hosta Tongue of Point Lookout Sandstone — Transgressive Sandstone. |
| Kpl—–Point Lookout Sandstone — 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. |
| Kpn—–Pierre Shale and Niobrara Formation — Pierre Shale and Niobrara Formation. |
| Kth—–Tres Hermanos Formation — Formerly designated as lower Gallup Sandstone in the Zuni Basin. |
|
| Ku—–Upper Cretaceous rocks of southwestern New Mexico, undivided — Includes Virden Formation in northern Hidalgo County, Ringbone Formation in Hidalgo, Luna, and Grant Counties, Beartooth and Sarten Formations in Luna and Grant Counties, Mancos Shale in Silver City area. |
| Kvt—–Vermejo Formation and Trinidad Sandstone — Vermejo Formation and Trinidad Sandstone. |
| K—–Cretaceous rocks, undivided — Cretaceous rocks, undivided. |
| MC—–Mississippian through Cambrian rocks, undivided — Includes Lake Valley Limestone (Mississippian); Devonian rocks, undivided; El Paso Formation and Montoya Group or Formation (Ordovician); and Bliss Sandstone (Ordovician and Cambrian). |
| MD—–Mississippian and Devonian rocks, undivided — Includes Helms, Rancheria, Las Cruces, Lake Valley, and Caballero Formations and Escabrosa Group (Mississippian); Percha Shale, Contadero, Sly Gap, and Oñate Formations of south-central New Mexico, and Canutillo Formation of northern Franklin Mountains and Bishops Cap area (Devonian). |
| M—–Mississippian rocks, undivided — Arroyo Peñasco Group in Sangre de Cristo Mountains, Sierra Nacimiento, San Pedro Mountains, and Sandia Mountains; Lake Valley Limestone in south-central New Mexico. |
| OCp—–Ordovician and Cambrian plutonic rocks of Florida Mountains — Ordovician and Cambrian plutonic rocks of Florida Mountains. |
| OC—–Ordovician and Cambrian rocks, undivided — Includes Montoya Formation (or Group), El Paso Formation, and Bliss Sandstone. |
| PIPsc—–Sangre de Cristo Formation — In Sangre de Cristo Mountains. |
| PIP—–Permian and Pennsylvanian rocks, undivided — Includes Concha, Scherrer, Colina, Epitaph, and Earp Formations (Permian) and Horquilla Limestone. |
| PZ—–Paleozoic rocks, undivided — Paleozoic rocks, undivided. |
| Pal—–Lower part of Abo Formation — Lower part of Abo Formation. |
| Pat—–Artesia Group — Shelf facies forming broad south-southeast trending outcrop from Glorieta to Artesia area; includes Tansill, Yates, Seven Rivers, Queen and Grayburg Formations (Guadalupian). May locally include Moenkopi Formation (Triassic) at top. |
| Pau—–Upper part of Abo Formation — Upper part of Abo Formation. |
| Pa—–Abo Formation — Red beds, arkosic at base, finer and more mature above; 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. |
| Pbc—–Bell Canyon Formation — Basin facies—sandstone, limestone, and shale. |
| Pb—–Bursum Formation — Shale, arkose, and limestone. |
| Pcc—–Cherry Canyon Formation — Basin facies—sandstone, limestone, and shale. |
| Pco—–Cutoff Shale — In Brokeoff Mountains only. |
| Pcp—–Capitan Formation — Limestone (reef facies). |
| Pct—–Cutler Formation — Used in northern areas and Chama embayment only. |
| Pc—–Castile Formation — Dominantly anhydrite sequence. |
| Pg—–Glorieta Sandstone — Texturally and mineralogically mature, high-silica quartz sandstone. |
| Ph—–Hueco Formation or Group — Limestone unit restricted to south-central area. Pendejo Tongue of Hueco Formation divides Abo Formation into upper and lower parts in Sacramento Mountains. |
| Pqg—–Queen and Grayburg Formations — Sandstone, gypsum, anhydrite, dolomite, and red mudstone. |
| Pqm—–Quartermaster Formation — Red sandstone and siltstone. |
| Pqr—–Quartermaster and Rustler Formations — Quartermaster and Rustler Formations. |
| Pr—–Rustler Formation — Siltstone, gypsum, sandstone, and dolomite. |
| Psa—–San Andres Formation — Limestone and dolomite with minor shale. |
| Psg—–San Andres Limestone and Glorieta Sandstone — San Andres Limestone and Glorieta Sandstone. |
| Psl—–Salado Formation — Evaporite sequence, dominantly halite. |
| Psr—–Seven Rivers Formation — Gypsum, anhydrite, salt, dolomite, and siltstone. |
| Psy—–San Andres, Glorieta, and Yeso Formations, undivided — San Andres, Glorieta, and Yeso Formations, undivided. |
| Pty—–Tansill and Yates Formations — Sandstone, siltstone, limestone, dolomite, and anhydrite. |
| Pvp—–Victorio Peak Limestone — In Brokeoff Mountains only. |
| Pya—–Yeso and Abo Formations, undivided — Yeso and Abo Formations, undivided. |
| Py—–Yeso Formation — Sandstones, siltstones, anhydrite, gypsum, halite, and dolomite. |
| P—–Permian rocks, undivided — Permian rocks, undivided. |
| QTb—Basaltic to andesitic lava flows (late Pleistocene to early Pliocene)—Includes minor vent deposits. |
| QTg—–Gila Group, Formation, or Conglomerate — Includes Mimbres Formation and several informal units in southwestern basins. |
| QTp—–Older piedmont alluvial deposits and shallow basin fill — Includes Quemado Formation and in northeast, high-level pediment gravels. |
| QTsf—–Santa Fe Group, undivided — Basin fill of the Rio Grande rift. Locally represents upper Miocene formations of the middle Santa Fe Group in the northern Albuquerque Basin. |
| QTs—–Upper Santa Fe Group — Includes Camp Rice, Fort Hancock, Palomas, Sierra Ladrones, Arroyo Ojito, Ancha, Puye, and Alamosa Formations. |
| QTt—–Travertine — Includes some pedogenic carbonate south of Sierra Ladrones. |
| Qa—–Alluvium — Alluvium |
| Qbo—–Basaltic to andesitic lava flows — Includes vent deposits. |
| Qbt—Bandelier Tuff (early Pleistocene)—Includes large blocks of older andesite in caldera-collapse breccia facies locally exposed on resurgent dome of the Valles caldera. |
| Qb—–Basaltic to andesitic lava flows — Flows south of Grants and west of Carrizozo are Holocene. Includes minor vent deposits. |
| Qd—–Glacial deposits; till and outwash — Glacial deposits; till and outwash. |
| Qeg—–Gypsiferous eolian deposits — Gypsiferous eolian deposits. |
| Qep—–Eolian and piedmont deposits — Interlayed eolian sands and piedmont-slope deposits along the eastern flank of the Pecos River valley, primarily between Roswell and Carlsbad. Typically capped by thin eolian deposits. |
| Qe—–Eolian deposits — Eolian deposits. |
| Ql—–Landslide deposits and colluvium — Landslide deposits on western flanks of Socorro Mountains not shown for clarity. |
| Qoa—–Older alluvial deposits of upland plains and piedmont areas, and calcic soils and eolian cover sediments of High Plains region — Includes scattered lacustrine, playa, and alluvial deposits of the Tahoka, Double Tanks, Tule, Blackwater Draw, and Gatuña Formations, the latter of which may be Pliocene at base; outcrops, however, are basically of Quaternary deposits. |
| Qpl—–Lacustrine and playa deposits — Includes associated alluvial and eolian deposits of major lake basins. |
| Qp—–Piedmont alluvial deposits — 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. |
| Qr—–Older rhyolite lavas and early volcaniclastic sedimentary fill deposits of the Valles caldera — Units are associated with resurgent doming or predate doming of the caldera core. Includes minor middle Pleistocene tuffs of the upper Valles Rhyolite on north side of caldera. |
| Qvr—–Ring-fracture rhyolite lava domes of the Valles caldera — Upper members of the Valles Rhyolite in Jemez Mountains. Includes 60-ka Banco Bonito and El Cajete Members on south margin of caldera. |
| Qv—–Basaltic tephra and lavas near vents — Tuff rings, maars, cinder cones, and minor proximal lavas. Includes maars at Kilbourne Hole and Zuni Salt Lake. |
| SOC—–Silurian through Cambrian rocks, undivided — Silurian through Cambrian rocks, undivided. |
| SO—–Silurian and Ordovician rocks, undivided — Silurian and Ordovician rocks, undivided. |
| TKav—–Tertiary–Cretaceous andesitic to dacitic lavas and pyroclastic breccias — Includes many remnants of eruptive centers in Grant and Hidalgo Counties and Upper Cretaceous andesitic lavas in Sierra County. |
| TKa—–Animas Formation — Volcaniclastic sedimentary rocks of intermediate composition in northern San Juan Basin. |
| TKi—–Tertiary–Cretaceous intrusive rocks — Includes granodiorite to quartz monzonite stocks and plutons at Hanover, Fierro, Tyrone, Lordsburg, and the 73-Ma quartz monzonite porphyry stock at Copper Flats in Sierra County. Also includes many northeast-trending monzonite porphyry dikes in the Silver City region. |
| TKpc—–Poison Canyon Formation — Proximal conglomerates and sandstones in western Raton Basin; generally lacking coal beds. Cretaceous beds mostly restricted to subsurface. |
| TKpr—–Poison Canyon and Raton Formations — Broadly intertonguing conglomeratic sandstones, sandstones and mudstones; minor coal beds. |
| TKr—–Raton Formation — Distal sandstones, mudstones, and coal beds in eastern Raton Basin. Middle barren zone laterally equivalent to Poison Canyon Formation. K/T boundary discontinuously exposed about 100 m above basal conglomerate in area southwest of Raton. |
| TRb—–Bull Canyon Formation — Bull Canyon Formation. |
| TRcu—–Upper Chinle Group, Garita Creek through Redonda Formations, undivided — Upper Chinle Group, Garita Creek through Redonda Formations, undivided. |
| TRc—–Chinle Group — Map unit includes Moenkopi Formation (Middle Triassic) at base in many areas; in eastern part of state the following five formations are mapped. |
| TRg—–Garita Creek Formation — Garita Creek Formation. |
| TRm—–Moenkopi Formation — Moenkopi Formation. |
| TRrp—–Rock Point Formation of Chinle Group — May locally include Wingate Sandstone (Triassic). |
| TRr—–Redonda Formation — Redonda Formation. |
| TRs—–Santa Rosa Formation — Includes Moenkopi Formation (Middle Triassic) at base in most areas. |
| TRt—–Trujillo Formation — Trujillo Formation. |
| TR—–Triassic rocks, undivided — Continental red beds. |
| Tc—–Chuska Sandstone — Restricted to Chuska Mountains. |
| Tfl—–Fence Lake Formation — Conglomerate and conglomeratic sandstone, coarse fluvial volcaniclastic sediments, minor eolian facies, and pedogenic carbonates of the southern Colorado Plateau region. |
| Thb—–Hinsdale Basalt — Northern Taos and eastern Rio Arriba Counties; basalt flows interbedded with Los Pinos Formation. |
| Tim—–Tertiary mafic intrusive rocks — 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. |
| Ti—–Tertiary intrusive rocks of intermediate to silicic composition — 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. |
| Tla—–Lower middle Tertiary andesitic to dacitic lavas and pyroclastic flow breccias — 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 Madera Limestone, as much as one mile long, occur within Rubio Peak lavas in the central Black Range, west of Winston. |
| Tlp—–Los Pinos Formation of lower Santa Fe Group — Includes Carson Conglomerate (Dane and Bachman, 1965) in Tusas Mountains–San Luis Basin area. |
| Tlrf—–Lower middle Tertiary rhyolitic lavas and local tuffs — Includes Mimbres Peak Formation, rhyolite of Cedar Hills, and other units in the Bootheel region. |
| Tlrp—–Lower middle Tertiary rhyolitic to dacitic pyroclastic rocks of the Datil Group, ash-flow tuffs — Regional ash-flow tuffs include Hells Mesa, Kneeling Nun, Caballo Blanco, Datil Well, Lebya 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 intracaldera units; includes minor volcaniclastic sedimentary units and lavas between thin outflow sheets. |
| Tlv—–Lower middle Tertiary volcanic rocks — Mostly intermediate lavas of the lower Datil Group and intermediate volcaniclastic sediments of the lower Spears Group (Tla + Tvs). Locally includes ash-flow tuffs of the upper Datil Group (Tlrp). Includes intermediate volcaniclastic sedimentary rocks of the Conejos Formation in northern New Mexico. |
| Tmb—Basaltic to andesitic lava flows (Miocene)—Includes minor vent deposits. Flows are commonly interbedded in the Santa Fe and Gila Groups. |
| Tnb—Basaltic to andesitic lava flows (Neogene)—Includes minor vent deposits. Flows are commonly interbedded in the Santa Fe and Gila Groups. |
| Tnr—Silicic to intermediate volcanic rocks (Neogene, mostly Miocene)—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. |
| Tnv—Intermediate to silicic volcanic rocks (Neogene)—Mostly andesitic to dacitic stratovolcanoes. Includes rhyolite lavas and tuffs in the Jemez Mountains. Volcanoes in Jemez Mountains and eastern Colfax County are late Miocene. Mount Taylor and composite volcanoes in the Taos Plateau volcanic field are Pliocene. |
| Tn—–Nacimiento Formation — San Juan Basin. |
| Toa—–Ojo Alamo Formation — San Juan Basin. |
| To—Ogallala Formation (early Pliocene to middle Miocene)—Alluvial and eolian deposits, and petrocalcic soils of the southern High Plains. Locally includes Qoa. |
| Tpb—Basaltic to andesitic lava flows (Pliocene)—Includes minor vent deposits and small shield volcanoes. Flows are commonly interbedded in the Santa Fe and Gila Groups. |
| Tps—–Paleogene sedimentary units — Includes Baca, Galisteo, El Rito, Blanco Basin, Hart Mine, Love Ranch, Lobo, Sanders Canyon, Skunk Ranch, Timberlake, and Cub Mountain Formations. |
| Tsf—–Lower Santa Fe Group — Includes Hayner Ranch, Rincon Valley, Popotosa, Cochiti, Tesuque, Chamita, Abiquiu, Zia, and other formations. |
| Tsj—–San Jose Formation — San Juan Basin. |
| Tual—–Lower-upper middle Tertiary basaltic andesites and andesites of the Mogollon Group — 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. |
| Tuau—–Upper middle Tertiary basaltic andesites and andesites of the Mogollon Group — Includes Bearwallow Mountain Andesite and basaltic andesite of Mangas Mountain; also near-vent basaltic lavas and shallow intrusions in the Chuska Mountains. |
| Turf—–Upper middle Tertiary rhyolitic lavas and local tuffs — 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. |
| Turp—–Upper middle Tertiary rhyolitic pyroclastic rocks of the Mogollon Group, ash-flow tuffs — Regional ash-flow tuffs include the La Jencia, Vicks Peak, Lemitar, South Canyon, Bloodgood Canyon, Shelly Peak, Davis Canyon, Park, Rhyolite Canyon, Apache Spring, and AmaliaTuffs; 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. |
| Tus—–Upper Tertiary sedimentary units — Includes Bidahochi Formation (Pliocene to late 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. |
|
| Tuv—–Upper middle Tertiary volcanic rocks — 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. |
| Tvs—Middle Tertiary volcaniclastic sedimentary units (Oligocene to late Eocene)—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 Formations and lower Spears Group formations such as Rincon Windmill, Chavez Canyon, and Dog Springs. |
|
| Tv—–Middle Tertiary volcanic rocks, undifferentiated — Includes the predominantly andesitic to dacitic stratovolcano complex at Sierra Blanca (Oligocene to late Eocene) and many smaller outliers. |
| Xg—Paleoproterozoic granitic plutonic rocks (Paleoproterozoic)—Variably foliated granites and granitic gneisses; 1.65–1.71 Ga in northern New Mexico; 1.65–1.66 Ga in central and southern New Mexico. |
| Xpc—Paleoproterozoic calc-alkaline plutonic rocks (Paleoproterozoic)—Granodiorite, diorite, and gabbro complexes; 1.71–1.78 Ga; interpreted to be intrusive part of juvenile volcanic arc basement. |
| Xps—–Paleoproterozoic pelitic schist — Includes Rinconada Formation in northern New Mexico and Blue Springs Schist in Manzano Mountains. |
| Xq—Paleoproterozoic quartzite (Paleoproterozoic)—Includes ≈1.70 Ga Ortega Quartzite and equivalents in northern New Mexico and ≈1.67 Ga quartzites in central New Mexico. |
| Xs—–Paleoproterozoic metasedimentary rocks — 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. |
| Xvf—Paleoproterozoic rhyolite and felsic volcanic schist (Paleoproterozoic)—Includes 1.70 Ga Vadito Group in northern New Mexico and ≈1.68 Ga Sevilleta Metarhyolite in central New Mexico. |
| Xvm—–Paleoproterozoic mafic metavolcanic rocks with subordinate felsic metavolcanic rocks — Includes the 1.72–1.78 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. |
| YXp—–Mesoproterozoic and Paleoproterozoic plutonic rocks, undivided — Plutonic rocks, undivided. |
| Yg—Mesoproterozoic granitic plutonic rocks (Mesoproterozoic)—Mainly 1.35–1.45 Ga megacrystic granites, generally weakly foliated except locally at their margins. |
| Ys—Mesoproterozoic sedimentary rocks (Mesoproterozoic)—Exposed in Sacramento Mountains, present in subsurface in southeastern New Mexico as De Baca Group. |
| playa—–playa — playa |
| water—–water — water |
