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

Geologic units in Washington county, Nebraska

Dakota Group (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 72 % of this area

Upper part is white, light-gray, brownish-gray, yellow, redish-brown, and red sandstone and shale. Sandstone is very fine to coarse grained, friable, micaeous, crossbedded, and lenticular; locally contains gravel near base. contains numerous zones of ironstone and siltstone concretions of variable thickness. Middle part is light-gray, yellow, red brown and dark-gray, sandy carbonaceous shale; commonly contains a zone of concretions near top. Lower part is sandstone similar to that in upper except there are zones of siderite concretions and, locally a basal zone of chert pebbles. Approx. max thickness 600 ft.

Lithology: sandstone; shale; gravel

Lansing Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missourian]) at surface, covers 1 % of this area

Limestone and shale. Limestone is dark gray to light gray, very thin bedded to massive, sandy fossiliferous, and cherty. Shale is dark gray to light gray, maroon, black, fossiliferous, and calcareous. Approx. max thickness 75 ft

Lithology: limestone; shale

Kansas City Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missourian]) at surface, covers 19 % of this area

Limestone and shale. Limestone is dark gray to light gray, brownish gray, very thin bedded to massive, argillaceous, fossiliferous; contains very thin layers of chert, pyrite crystals, and small flakes of mica near base. Shale is dark gray to light gray, greenish gray, red, and black; locally slighty sandy, calcareous, carbonaeous, fissile, and fossiliferous. Approx. max thickness 200 ft

Lithology: limestone; shale

Marmaton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Desmoinesian]) at surface, covers 7 % of this area

Shale and limestone. Shale is dark gray to light gray, greenish gray, black, red, silty, sandy carbonaceous, fissile, calcareous; contains scattered limestone nodules. Limestone is medium gray to light gray, red, mottled thin bedded to thick bedded, sandy, shaly, vuggy, fossiliferous. Approx. max thickness 125 ft

Lithology: shale; limestone

Kansas City Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri]) at surface, covers 0.9 % of this area

Cyclic deposits with prominent limestone beds, shale; Bonner Springs Shale at top and Hertha Limestone at base.

Lithology: limestone; shale