Geologic units in Lonoke county, Arkansas

Mineral Resources On-Line Spatial Data

Alluvium - Alluvial deposits of local streams or of overbank flow of major streams (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 44 % 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

Atoka Formation - Middle part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan]) at surface, covers 2 % of this area

Atoka Formation - Middle part

Wilcox Group (Phanerozoic | Cenozoic | Tertiary | Eocene-Early) at surface, covers 5 % of this area

Wilcox Group

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

Lithology: alluvium

Terrace deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene-Late) at surface, covers 34 % of this area

Terrace deposits - Alluvial deposits on one or more terrace levels

Atoka Formation - Upper part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan]) at surface, covers 1 % of this area

Atoka Formation - Upper part

Johns Valley Shale (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Early [Morrowan]) at surface, covers 0.7 % of this area

Johns Valley Shale

Alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 0.7 % of this area

Alluvium - Alluvial deposits of present streams

Lithology: alluvium

Atoka Formation - Lower part (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Atokan]) at surface, covers 2 % of this area

Atoka Formation - Lower part

Midway Group (Phanerozoic | Cenozoic | Tertiary | Paleocene) at surface, covers 2 % of this area

Midway Group