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

Geologic units in Park county, Colorado

[Additional scientific data in this geographic area]

Bouldery gravel on old erosion surfaces in Front Range and Never Summer Mountains (Phanerozoic | Cenozoic | Tertiary) at surface, covers 0.3 % of this area

Lithology: gravel

Modern alluvium (Phanerozoic | Cenozoic | Quaternary) at surface, covers 0.8 % of this area

Includes Piney Creek Alluvium and younger deposits

Lithology: alluvium

Older glacial drift (Phanerozoic | Cenozoic | Quaternary) at surface, covers 0.3 % of this area

Lithology: glacial drift

Oligocene sedimentary rocks (Phanerozoic | Cenozoic | Tertiary) at surface, covers 4 % of this area

Northwest: includes Duchesne River Fm (sandstone and shale; includes some rocks of Eocene age) and Bishop Conglomerate near Utah border. South-central: includes Florissant Lake Beds (tuffaceous shale and tuff) and Antero Fm (lime

Lithology: sandstone; shale; conglomerate

Laramide intrusive rocks (Phanerozoic | Mesozoic Cenozoic | Cretaceous Tertiary) at surface, covers 2 % of this area

Mainly intermediate to felsic compositions; some mafic

Lithology: granitoid

Biotitic gneiss, schist, and migmatite (Proterozoic | Paleoproterozoic) at surface, covers 18 % of this area

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

Lithology: biotite gneiss; schist; migmatite; quartzite; marble

Granitic rocks of 1700-m.y. age group (Proterozoic | Paleoproterozoic) at surface, covers 8 % 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

Eocene prevolcanic sedimentary rocks (Phanerozoic | Cenozoic | Tertiary) at surface, covers 0.1 % of this area

South-central: Arkosic sand and bouldery gravel of Echo Park Alluvium. Southwest: includes Telluride Conglomerate and Blanco Basin Fm (arkosic mudstone, sandstone, and conglomerate)

Lithology: sandstone; conglomerate; mudstone

Mesozoic rocks (Lower Phanerozoic | Mesozoic | Cretaceous-Triassic) at surface, covers < 0.1 % of this area

Mainly Lower Cretaceous, Jurassic, and Triassic Fms

Lithology: clastic

Laramie Fm and Fox Hills Sandstone (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 0.2 % of this area

Lithology: sandstone; mudstone; coal

Rocks of Pikes Peak Batholith (1000-m.y. age group) (Proterozoic | Mesoproterozoic) at surface, covers 7 % of this area

Includes Pikes Peak, Mount Rosa, Windy Point, and Redskin Granites and unnamed rocks

Lithology: granite; granodiorite; quartz monzonite

Older gravels and alluviums (Phanerozoic | Cenozoic | Quaternary) at surface, covers 2 % of this area

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

Lithology: gravel; alluvium

Dry Union Fm (Phanerozoic | Cenozoic | Tertiary) at surface, covers 2 % of this area

Siltstone, sandstone, and conglomerate. Includes Wagontongue Fm (Miocene) in South Park

Lithology: siltstone; sandstone; conglomerate; tuff

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 0.7 % of this area

Lithology: sandstone; mudstone; limestone

Landslide deposits (Phanerozoic | Cenozoic | Quaternary) at surface, covers 0.1 % of this area

Locally includes talus, rock-glacier, and thick colluvial deposits

Lithology: landslide; talus; colluvium

South Park Fm (Phanerozoic | Cenozoic | Tertiary) at surface, covers 4 % of this area

Arkosic sandstone and shale, volcaniclastic conglomerate, and andesite flows and breccia

Lithology: sandstone; shale; conglomerate; andesite; volcanic breccia (agglo

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

Leadville Limestone, Williams Canyon Limestone , Manitou Limestone, and Sawatch Quartzite (Phanerozoic | Paleozoic | Cambrian Ordovician(?) Silurian(?) Devonian(?) Carboniferous) at surface, covers 2 % of this area

Lithology: limestone; quartzite

Felsic and hornblendic gneisses, either separate or interlayered (Proterozoic | Paleoproterozoic) at surface, covers 3 % of this area

Includes metabasalt, metatuff, and interbedded metagraywacke; locally contains interlayered biotite gneiss. Derived principally from volcanic rocks

Lithology: felsic gneiss; mafic gneiss; meta-basalt; meta-graywacke

Granitic rocks of 1400-m.y. age group (Proterozoic | Mesoproterozoic) at surface, covers 8 % 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

Lithology: granite; granodiorite; quartz monzonite

Basalt flows and associated tuff, breccia, and conglomerate of late-volcanic bimodal suite (Phanerozoic | Cenozoic | 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

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

Intra-ash flow andesitic lavas (Phanerozoic | Cenozoic | Tertiary) at surface, covers 2 % of this area

Lithology: andesite

Ash-flow tuff of main volcanic sequence (Phanerozoic | Cenozoic | Tertiary) at surface, covers 0.1 % of this area

Includes many named units

Lithology: ash-flow tuff

Dakota and Morrison Fms (Phanerozoic | Mesozoic | Jurassic Cretaceous) at surface, covers 0.1 % of this area

Lithology: sandstone; mudstone; shale

Maroon Fm (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian) at surface, covers 0.8 % of this area

Arkosic sandstone, siltstone, conglomerate, and local limestone

Lithology: sandstone; siltstone; conglomerate; limestone

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

Lithology: sandstone

Minturn and Belden Fms (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian) at surface, covers 2 % of this area

Lithology: sandstone; shale; limestone; conglomerate

Leadville Limestone, Williams Canyon Limestone, and one or more of: Fremont Limestone, Harding Sandstone, and Manitou Limestone (Phanerozoic | Paleozoic | Ordovician Silurian(?) Devonian(?) Carboniferous Mississippia) at surface, covers 0.3 % of this area

Lithology: limestone; sandstone

Wall Mountain Tuff (Phanerozoic | Cenozoic | Tertiary) at surface, covers 0.8 % of this area

Early ash-flow tuff of Sawatch Range provenance

Lithology: ash-flow tuff

Middle Tertiary intrusive rocks (Phanerozoic | Cenozoic | Tertiary) at surface, covers 1 % of this area

Intermediate to felsic compositions

Lithology: plutonic rock (phanerit

Colorado Group (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 0.6 % of this area

Consists of Niobrara Formation (Kn) and either Benton Shale or Carlile, Greenhorn, and Graneros Fms (Kcg)

Lithology: shale; limestone

Glacial drift (Phanerozoic | Cenozoic | Quaternary) at surface, covers 3 % of this area

Includes some unclassified glacial deposits

Lithology: glacial drift

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

Red siltstone, sandstone, and limestone-pellet conglomerate

Lithology: siltstone; sandstone; conglomerate

Evaporitic facies of Minturn And Belden Fms in South Park and southward (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian) at surface, covers 4 % of this area

Gypsum, siltstone, and shale

Lithology: siltstone; shale; evaporite

Fox Hills Sandstone (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 0.1 % of this area

Lithology: sandstone

Pierre Shale, undivided (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 3 % of this area

Lithology: shale

Pre-ash-flow andesitic lavas, breccias, tuffs, and conglomerates (Phanerozoic | Cenozoic | Tertiary) at surface, covers 11 % of this area

Includes several named units

Lithology: andesite; tuff; volcanic breccia (agglomerate)

Granitic rocks of 1400- and 1700-m.y. age groups, undivided, or, in Taylor River region, rocks with characteristics of Xg but U-Th-Pb zircon ages of Yg (Proterozoic | Paleoproterozoic Mesoproterozoic) at surface, covers 0.8 % of this area

Granitic rocks of 1400- and 1700-m.y. age groups, undivided, or, in Taylor River region, rocks with characteristics of Xg but U-Th-Pb zircon ages of Yg

Lithology: granitoid

Gravels and alluviums (Phanerozoic | Cenozoic | Quaternary) at surface, covers 6 % of this area

Includes Broadway and Louviers Alluviums

Lithology: gravel; alluvium