Geologic units in Grant county, Arkansas

Alluvium (Holocene) at surface, covers 30 % of this area

Alluvial deposits of present streams

Jackson Group (Late Eocene) at surface, covers 21 % of this area

Jackson Group

Terrace deposits (Late Pleistocene) at surface, covers 20 % of this area

Alluvial deposits on one or more terrace levels

Claibourne Group (Middle Eocene) at surface, covers 14 % of this area

Claibourne Group

Wilcox Group (Early Eocene) at surface, covers 13 % of this area

Wilcox Group