Includes dune sand and silt and Peoria Loess
Arkosic sandstone, shale, mudstone, conglomerate, and local coal beds
Pierre Shale--Upper unit
Shale, claystone, sandstone, and major coal beds
Arkosic sandstone, conglomerate, and shale. Includes Green Mountain Conglomerate south of Golden
Includes Piney Creek Alluvium and younger deposits
Fox Hills Sandstone
Includes Broadway and Louviers Alluviums
East: Ashy claystone and sandstone. Includes Castle Rock Conglomerate in region southeast of Denver. Northwest: Ashy claystone in North Park
Includes Slocum, Verdos, Rocky Flats, and Nussbaum Alluviums in east, and Florida, Bridgetimber, and Bayfield Gravels in southwest
Sandstone, mudstone, claystone, and conglomerate; Denver is characterized by andesitic materials