Geologic units in Izard county, Arkansas

Additional scientific data in this geographic area

St. Peter Sanstone and Everton Formation (Middle Ordovician) (Middle Ordovician) at surface, covers 66 % of this area

St. Peter Sanstone and Everton Formation (Middle Ordovician)

Powell Dolomite (Early Ordovician) at surface, covers 18 % of this area

Powell Dolomite

Cason Shale and Fernvale Limestone (Upper Ordovician) and Kimmswick Limestone, Plattin Limestone, and Joachim Dolomite (Middle Ordovician) (Late Ordovician to Middle Ordovician) at surface, covers 8 % of this area

Cason Shale and Fernvale Limestone (Upper Ordovician) and Kimmswick Limestone, Plattin Limestone, and Joachim Dolomite (Middle Ordovician)

Cotter and Jefferson City Dolomites (Early Ordovician) at surface, covers 5 % of this area

Cotter and Jefferson City Dolomites

Boone Formation (Early Mississippian- Meramecian to Osagean) at surface, covers 2 % of this area

Boone Formation

Lafferty, St. Clair and Brassfield Limestones (Late Silurian to Early Silurian) at surface, covers 0.6 % of this area

Lafferty, St. Clair and Brassfield Limestones

Chattanooga Shale (Lower Mississippian and Upper Devonian), Clifty Limestone (Middle Devonian), and Penters Chert (Lower Devonian) (Early Mississippian to Early Devonian) at surface, covers < 0.1 % of this area

Chattanooga Shale (Lower Mississippian and Upper Devonian), Clifty Limestone (Middle Devonian), and Penters Chert (Lower Devonian)