Geologic units in Nevada county, Arkansas

Wilcox Group (Early Eocene) at surface, covers 35 % of this area

Wilcox Group

Alluvium (Holocene) at surface, covers 19 % of this area

Alluvial deposits of present streams

Claibourne Group (Middle Eocene) at surface, covers 19 % of this area

Claibourne Group

Midway Group (Paleocene) at surface, covers 16 % of this area

Midway Group

Terrace deposits (Late Pleistocene) at surface, covers 5 % of this area

Alluvial deposits on one or more terrace levels

Arkadelphia Marl (Late Cretaceous) at surface, covers 3 % of this area

Arkadelphia Marl

Nacatoch Sand (Late Cretaceous) at surface, covers 3 % of this area

Nacatoch Sand