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Mineral Resources > Online Spatial Data > Geology > by state > Colorado Geology

Geologic units in Las Animas county, Colorado

[Additional scientific data in this geographic area]

Morrison Formation (Phanerozoic | Mesozoic | Jurassic) at surface, covers < 0.1 % of this area

Morrison Formation; Upper Jurassic nonmarine rocks present only in northern one-third of state

Lithology: fine-grained mixed clastic; limestone

basalt and andesite flows, Neogene (Phanerozoic | Cenozoic | Tertiary) at surface, covers < 0.1 % of this area

Basalt and andesite flows; Neogene. Includes flows interbedded with Santa Fe and Gila Groups

Lithology: basalt; andesite

Sangre de Cristo Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian) at surface, covers 1 % of this area

Arkosic conglomerate, sandstone, and siltstone

Lithology: conglomerate; sandstone; siltstone

Granitic rocks of 1700-m.y. age group (Proterozoic | Paleoproterozoic) at surface, covers < 0.1 % of this area

Includes Boulder Creek -M.Y. AGE GROUP (AGE 1650-1730 M.Y.)--Includes Boulder Creek, Cross Creek, Denny Creek, Kroenke, Browns Pass, Powderhorn, Pitts Meadow, Bakers Bridge, and Tenmile Granites, Quartz Monzonites, or Granodiorites;

Lithology: granite; granodiorite; quartz monzonite

middle and upper Jurassic rocks, unidivided (Phanerozoic | Mesozoic | Jurassic) at surface, covers < 0.1 % of this area

Jurassic rocks, Middle and Upper, undivided

Lithology: clastic; sedimentary rock

Niobrara Fm (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 13 % of this area

Calcareous shale and limestone

Lithology: shale; limestone

Morrison, Ralston Creek, and Entrada (or Exeter) Fms (Phanerozoic | Mesozoic | Jurassic) at surface, covers 5 % of this area

Lithology: mudstone; sandstone

Older gravels and alluviums (Phanerozoic | Cenozoic | Quaternary) at surface, covers < 0.1 % of this area

Includes Slocum, Verdos, Rocky Flats, and Nussbaum Alluviums in east, and Florida, Bridgetimber, and Bayfield Gravels in southwest

Lithology: gravel; alluvium

Dakota, Purgatoire, Morrison, Ralston Creek, and Entrada Fms in southeast. Dakota, Morrison, and Entrada Fms in central mountains. Dakota, Burro Canyon, Morrison, Wanakah, and Entrada Fms in Gunnison River area. Dakota, Morriso (Phanerozoic | Mesozoic | Jurassic Cretaceous) at surface, covers 0.3 % of this area

Lithology: sandstone; mudstone; limestone

Raton Fm (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary) at surface, covers 9 % of this area

Arkosic sandstone, siltstone, and shale; contains major coal deposits in Raton Basin

Lithology: sandstone; mudstone; coal

Upper Permian rocks, undivided (Phanerozoic | Paleozoic | Permian) at surface, covers 0.3 % of this area

Siltstone, dolomite, and sandstone; in southeast

Lithology: siltstone; dolostone (dolomite); sandstone

Poison Canyon Fm (Phanerozoic | Cenozoic | Tertiary) at surface, covers 7 % of this area

Arkosic conglomerate, sandstone, and shale

Lithology: sandstone; conglomerate; shale

Minturn Fm in west-central and south-central and other units (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian) at surface, covers 0.2 % of this area

Arkosic sandstone, conglomerate, shale, and limestone. Includes Madera Fm and Sharpsdale Fm of Chronic (1958) in Sangre de Cristo Range and Gothic Fm of Langenheim (1952) in Elk Mountains. Other units of Middle Pennsylvanian age.

Lithology: sandstone; conglomerate; shale; limestone

Vermejo Fm and Trinidad Sandstone (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 1 % of this area

Shale, sandstone, and major coal beds; sandstone

Lithology: sandstone; shale; coal

Belden Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian) at surface, covers < 0.1 % of this area

Shale, limestone, and sandstone. Includes Kerber Fm in south-central

Lithology: shale; limestone; sandstone

Cuchara Fm (Phanerozoic | Cenozoic | Tertiary) at surface, covers 0.7 % of this area

Sandstone and shale

Lithology: sandstone; shale

Chinle Group (Phanerozoic | Mesozoic | Triassic) at surface, covers < 0.1 % of this area

Chinle Group; Upper Triassic; includes Moenkopi Formation (Middle Triassic) at base in many areas; in eastern part of state the following five formations are mapped:

Lithology: medium-grained mixed clastic; fine-grained mixed clastic; limestone; chert; evaporite

Huerfano Fm (Phanerozoic | Cenozoic | Tertiary) at surface, covers 0.2 % of this area

Shale and sandstone. Includes Farisita Conglomerate in northwestern Huerfano County

Lithology: shale; sandstone; conglomerate

Eolian deposits (Phanerozoic | Cenozoic | Quaternary) at surface, covers 0.8 % of this area

Includes dune sand and silt and Peoria Loess

Lithology: dune sand; silt; loess

Dakota Sandstone and Purgatoire Fm (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 30 % of this area

Sandstone and shale

Lithology: sandstone; shale

Pierre Shale (Kp), Niobrara (Kn), and Carlile, Greenhorn, and Graneros (Kcg) Fms, undivided (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 0.8 % of this area

Lithology: shale; limestone

Dakota Group (Phanerozoic | Mesozoic | Cretaceous) at surface, covers < 0.1 % of this area

Dakota Group of east-central and northeast New Mexico; in ascending order, Mesa Rica Sandstone, Pajarito Shale, and Romeroville Sandstone; includes the underlying Tucumcari Shale in Tucumcari area and Glencairn Formation in Union County. Encompasses both Upper and Lower Cretaceous rocks

Lithology: sandstone; medium-grained mixed clastic

Carlile Shale, Greenhorn Limestone, and Graneros Shale (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 16 % of this area

Lithology: shale; limestone

Basalt flows and associated tuff, breccia, and conglomerate of late-volcanic bimodal suite (Phanerozoic | Cenozoic | Tertiary) at surface, covers 3 % of this area

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

Lithology: basalt; tuff; volcanic breccia (agglomerate); conglomerate

Morrison Formation and upper San Rafael Group (Phanerozoic | Mesozoic | Jurassic) at surface, covers < 0.1 % of this area

Morrison Formation and upper San Rafael Group

Lithology: fine-grained mixed clastic; sedimentary rock; limestone

Middle Tertiary intrusive rocks (Phanerozoic | Cenozoic | Tertiary) at surface, covers < 0.1 % of this area

Intermediate to felsic compositions

Lithology: plutonic rock (phanerit

Ogallala Formation (Phanerozoic | Cenozoic | Tertiary) at surface, covers < 0.1 % of this area

Ogallala Formation, alluvial and eolian deposits, and petrocalcic soils of the southern High Plains; Lower Pliocene to middle Miocene (locally includes unit Qoa)

Lithology: alluvium; eolian; carbonate

Raton Formation (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary) at surface, covers < 0.1 % of this area

Raton Formation; in Raton Basin; unit contains conformable K/T boundary

Lithology: sandstone; mudstone; coal; conglomerate

Entrada Sandstone (Phanerozoic | Mesozoic | Jurassic) at surface, covers < 0.1 % of this area

Entrada Sandstone, Middle Jurassic; Callovian

Lithology: sandstone

landslide deposits and colluvium (Phanerozoic | Cenozoic | Quaternary) at surface, covers < 0.1 % of this area

Landslide deposits and colluvium

Lithology: landslide; colluvium

Ogallala Fm (Phanerozoic | Cenozoic | Tertiary) at surface, covers 3 % of this area

Loose to well-cemented sand and gravel

Lithology: sandstone; conglomerate

Glacial drift (Phanerozoic | Cenozoic | Quaternary) at surface, covers < 0.1 % of this area

Includes some unclassified glacial deposits

Lithology: glacial drift

Dockum Group (Phanerozoic | Mesozoic | Triassic) at surface, covers 2 % of this area

Red sandstone, siltstone, and local limestone

Lithology: sandstone; siltstone; limestone

Pierre Shale, undivided (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 6 % of this area

Lithology: shale

Basaltic intrusive rocks related to basalt flows (Phanerozoic | Cenozoic | Tertiary) at surface, covers < 0.1 % of this area

In dikes and plugs

Lithology: basalt

Poison Canyon Formation (Phanerozoic | Cenozoic | Tertiary) at surface, covers < 0.1 % of this area

Poison Canyon Formation; Paleocene, Raton Basin

Lithology: sandstone

Graneros Shale and Greenhorn Formation (Phanerozoic | Mesozoic | Cretaceous) at surface, covers < 0.1 % of this area

Graneros Shale and Greenhorn Formation; limited to northeastern area; lower Turonian and Cenomanian

Lithology: shale; limestone