Geologic units in Republic county, Kansas

Loess (Holocene to Pleistocene) at surface, covers 57 % of this area

eolian silts

Greenhorn Limestone and Graneros Shale (Late Cretaceous) at surface, covers 18 % of this area

Greenhorn FM- thin bedded gray, chalky limestone and calcareous shale. Graneros Shale- fissile, noncalcareous, gray shale locally contains sandstone and siltstone beds.

Alluvium (Holocene to Pleistocene) at surface, covers 16 % of this area

unconsolidated sand, silt, clay, and gravel

Dakota Formation (Early Cretaceous) at surface, covers 4 % of this area

White, gray, red, brown and tan kaolinitic claystone, mudstone, shale and siltstone interbedded with grayish to yellowish brown thick lenticular sandstone beds. It also contains lignite and sandstone is commonly well cemented with iron oxide and calcite.

Carlile Shale (Late Cretaceous) at surface, covers 3 % of this area

Chalky shale with bentonite and thick chalk beds, dark gray fissile shale containing septarian concretions, and fine-grained sandstone.

Alluvium (Pleistocene) at surface, covers 2 % of this area

unconsolidated sand, silt, clay, and gravel

Dune Sand (Holocene to Pleistocene) at surface, covers 0.4 % of this area

unconsolidated dune sand

Greenhorn Limestone and Graneros Shale (Late Cretaceous) at surface, covers 0.3 % of this area

Greenhorn Limestone- medium- to light-gray limestone interbedded with argillaceous limestone, marl and calcareous shale; contains Inoceramus fossils. Upper and lower contacts gradational. Approx. max thickness 30 ft. Graneros Shale- medium- to dark-gray, partly calcareous shale. Interbeds of siltstone, sandstone, and carbonaceous shale, and thin bentonite layers in upper part. Approx. max thickness 60 ft.

Carlile Shale (Late Cretaceous) at surface, covers < 0.1 % of this area

Shale, limestone, and sandstone. At top, locally 5 feet of gray to pale-yellowish brown siltstone or very fine grained sandstone. Upper 200 feet of shale is drak gray to medium gray; locally contains ironstone concretions, and interbedded with thin siltstone. Lower 80 feet of shale is medium gray, calcareous, and contains many very thin bedded, fossiliferous, shaly limestone and calcareous shale layers. Approx. max thickness 300 ft.

Dakota Group (Early Cretaceous) at surface, covers < 0.1 % 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.