Geologic units in Elkhart county, Indiana

Ellsworth Shale (Devonian-Mississippian) at surface, covers 78 % of this area

Green shale; some black shale in lower part

Coldwater Shale (Mississippian) at surface, covers 15 % of this area

Mostly gray shale

Antrim Shale (Devonian) at surface, covers 6 % of this area

Black shale; gray shale and limestone in lower part

Coldwater Shale (Mississippian) at surface, covers 0.5 % of this area

Coldwater Shale

Ellsworth Shale (Late Devonian) at surface, covers 0.1 % of this area

Ellsworth Shale