Geologic units in Otero county, Colorado

Additional scientific data in this geographic area

Niobrara Fm (Cretaceous) at surface, covers 26 % of this area

Calcareous shale and limestone

Older gravels and alluviums (Quaternary) at surface, covers 20 % of this area

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

Carlile Shale, Greenhorn Limestone, and Graneros Shale (Cretaceous) at surface, covers 17 % of this area

Carlile Shale, Greenhorn Limestone, and Graneros Shale

Eolian deposits (Quaternary) at surface, covers 14 % of this area

Includes dune sand and silt and Peoria Loess

Modern alluvium (Quaternary) at surface, covers 7 % of this area

Includes Piney Creek Alluvium and younger deposits

Dakota Sandstone and Purgatoire Fm (Cretaceous) at surface, covers 6 % of this area

Sandstone and shale

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

Includes Broadway and Louviers Alluviums

Morrison, Ralston Creek, and Entrada (or Exeter) Fms (Jurassic) at surface, covers 3 % of this area

Morrison, Ralston Creek, and Entrada (or Exeter) Fms

Pierre Shale--Lower unit (Cretaceous) at surface, covers 0.3 % of this area

Sharon Springs Member (organic-rich shale and numerous bentonite beds) in lower part