Mineral Resources On-Line Spatial Data
Mineral Resources > Online Spatial Data > Geology > by state > Indiana Geology
Geologic units in Allen county, Indiana
- Muscatatuck Group (Devonian) at surface, covers 73 % of this area
Muscatatuck Group - Limestone and dolomite
- Detroit River Group (Devonian) at surface, covers < 0.1 % of this area
Detroit River Group - Dolomite; brown to gray; medium to thick bedded; laminated; nodules or interbeds of anhydrite and/or gypsum; basal part becomes sandy dolomite or fine-grained sandstone; as much as 170 feet thick.
- Antrim Shale (Devonian) at surface, covers 11 % of this area
Antrim Shale - Black shale; gray shale and limestone in lower part
- Salina Group (Silurian) at surface, covers < 0.1 % of this area
Salina Group - Dolomite, gray, yellow-gray to olive-gray, laminated to thin bedded; occasional thin bed and laminae of dark gray shale and anhydrite and/or gypsum; brecciated zones in part.
- Wabash Formation (Silurian) at surface, covers 16 % of this area
Wabash Formation - Limestone, dolomite, and argillaceous dolomite