Oronto Group; Freda Sandstone

Mainly reddish-brown, medium- to fine-grained lithic arkosic sandstone, siltstone, and micaceous silty shale.
State Michigan
Name Oronto Group; Freda Sandstone
Geologic age Middle Proterozoic
Lithologic constituents
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Clastic > Sandstone > Arkose (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
NGMDB product
Counties Gogebic - Houghton - Keweenaw - Ontonagon