Geologic units in Pope county, Arkansas

Atoka Formation, undivided (Middle Pennsylvanian- Atokan) at surface, covers 47 % of this area

Atoka Formation, undivided

Bloyd Shale, and Prairie Grove Member of the Hale Formation (Middle Pennsylvanian- Morrowan) at surface, covers 24 % of this area

Bloyd Shale, and Prairie Grove Member of the Hale Formation

Atoka Formation - Upper part (Middle Pennsylvanian- Atokan) at surface, covers 9 % of this area

Atoka Formation - Upper part

Harthshorne Sandstone (Middle Pennsylvanian- Des Moinesian) at surface, covers 8 % of this area

Harthshorne Sandstone

Alluvium (Holocene) at surface, covers 6 % of this area

Alluvial deposits of present streams

Terrace deposits (Late Pleistocene) at surface, covers 3 % of this area

Alluvial deposits on one or more terrace levels

McAlester Formation (Middle Pennsylvanian- Des Moinesian) at surface, covers 2 % of this area

McAlester Formation