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

Geologic units in Randolph county, Arkansas

[Additional scientific data in this geographic area]

Terrace deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Late) at surface, covers 5 % of this area

Terrace deposits - Alluvial deposits on one or more terrace levels

Lithology: alluvial terrace

Sand and clay (Phanerozoic | Mesozoic | Cretaceous) at surface, covers 6 % of this area

Sand and clay

Lithology: sand; clay or mud

Dune sand (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Late) at surface, covers 9 % of this area

Dune sand - Deposited mostly on terrace deposits of the second level. Younger than some terrace deposits, older than others

Lithology: dune sand

Alluvium and terrace deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene Holocene) at surface, covers 3 % of this area

Alluvium and terrace deposits - Alluvial deposits of present streams and on one or more terrace levels

Lithology: alluvium; alluvial terrace

SMITHVILLE DOLOMITE, POWELL DOLOMITE, COTTER DOLOMITE, JEFFERSON CITY DOLOMITE (Phanerozoic | Paleozoic | Ordovician-Early [Ibexian]) at surface, covers < 0.1 % of this area

SMITHVILLE DOLOMITE, POWELL DOLOMITE, COTTER DOLOMITE, JEFFERSON CITY DOLOMITE - fine crystalline, silty, cherty dolomite, and oolitic chert with local sandstone beds

Lithology: dolostone (dolomite); sandstone; shale; conglomerate; chert

Alluvium - Alluvial deposits in major stream channels or in mappable meanders of major streams (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 2 % of this area

Alluvial deposits in major stream channels or in mappable meanders of major streams - Includes alluvial deposits in natural levees in some areas.

Lithology: alluvium

Gravel (Phanerozoic | Cenozoic | Tertiary) at surface, covers 0.2 % of this area

Gravel - Gravel on isolated hills within 40 miles (64km) of the Mississippi Embayment. Many small deposits to the west not shown

Lithology: gravel

Cotter and Jefferson City Dolomites (Phanerozoic | Paleozoic | Ordovician-Early) at surface, covers 61 % of this area

Cotter and Jefferson City Dolomites

Lithology: dolostone (dolomite); chert; sandstone; shale

Alluvium - Alluvial deposits of local streams or of overbank flow of major streams (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 11 % of this area

Alluvial deposits of local streams or of overbank flow of major streams - In some areas includes deposits in abandoned meanders of major streams

Lithology: alluvium

Powell Dolomite (Phanerozoic | Paleozoic | Ordovician-Early) at surface, covers 2 % of this area

Powell Dolomite

Lithology: dolostone (dolomite); shale; sandstone; conglomerate