Geologic units in Denver county, Colorado

Additional scientific data in this geographic area

Eolian deposits (Quaternary) at surface, covers 45 % of this area

Includes dune sand and silt and Peoria Loess

Denver Fm or lower part of Dawson Arkose (Tertiary-Cretaceous) at surface, covers 20 % of this area

Arkosic sandstone, shale, mudstone, conglomerate, and local coal beds

Modern alluvium (Quaternary) at surface, covers 15 % of this area

Includes Piney Creek Alluvium and younger deposits

Denver and Arapahoe Fms (Tertiary-Cretaceous) at surface, covers 13 % of this area

Sandstone, mudstone, claystone, and conglomerate; Denver is characterized by andesitic materials

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

Includes Broadway and Louviers Alluviums

Older gravels and alluviums (Quaternary) at surface, covers 3 % of this area

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