Geologic units in Teller county, Colorado

Rocks of Pikes Peak Batholith (1000-m.y. age group) (Middle Proterozoic) at surface, covers 61 % of this area

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

Granitic rocks of 1700-m.y. age group (Early Proterozoic) at surface, covers 13 % 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; also, unnamed granitic rocks

Granitic rocks of 1400-m.y. age group (Middle Proterozoic) at surface, covers 9 % 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

Fountain Fm (Permian-Pennsylvanian) at surface, covers 3 % of this area

Arkosic sandstone and conglomerate

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

Loose to well-cemented sand and gravel

Pre-ash-flow andesitic lavas, breccias, tuffs, and conglomerates (Tertiary) at surface, covers 2 % of this area

Includes several named units

Intra-ash flow quartz latitic lavas (Tertiary) at surface, covers 2 % of this area

Intra-ash flow quartz latitic lavas

Oligocene sedimentary rocks (Tertiary) at surface, covers 2 % 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 (limestone tuff, tuffaceous sandstone, and conglomerate). Southwest: includes Creede Fm (tuffaceous siltstone, sandstone, conglomerate) and gravels interbedded with volcanic rocks northeast and southeast of Gunnison

Biotitic gneiss, schist, and migmatite (Early Proterozoic) at surface, covers 1 % of this area

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

Glacial drift (Quaternary) at surface, covers 0.9 % of this area

Includes some unclassified glacial deposits

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

Early ash-flow tuff of Sawatch Range provenance

Manitou Limestone and Sawatch Quartzite in Southern Front Range and Wet Mountains. One or more Ordovician Fms (Fremont Limestone, Harding Sandstone, and Manitou Dolomite), Dotsero Fm, Peerless Fm, and Sawatch Quartzite in west-central and south-central (Ordovician-Cambrian) at surface, covers 0.4 % of this area

Dotsero Fm: Dolomite, in White River plateau only. Peerless Fm: sandstone and dolomite.

Older gravels and alluviums (Quaternary) at surface, covers 0.4 % of this area

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

One or more Ordovician fms (Ordovician) at surface, covers 0.2 % of this area

Fremont Limestone, Harding Sandstone, and Manitou Limestone

Gravels and alluviums (Quaternary) at surface, covers 0.2 % of this area

Includes Broadway and Louviers Alluviums

Leadville Limestone, Williams Canyon Limestone , Manitou Limestone, and Sawatch Quartzite (Mississippian-Cambrian) at surface, covers 0.2 % of this area

Leadville Limestone, Williams Canyon Limestone , Manitou Limestone, and Sawatch Quartzite

Middle Tertiary intrusive rocks (Tertiary) at surface, covers 0.2 % of this area

Intermediate to felsic compositions

Morrison Fm (Jurassic) at surface, covers < 0.1 % of this area

Variegated claystone, mudstone, sandstone, and local beds of limestone

Eocene prevolcanic sedimentary rocks (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)