Baraga Group; Tyler Formation

Light- to dark-gray, feldspathic, fine-grained sandstone, argillaceous siltstone, and argillite. Near base, ferruginous argillite contains beds of cherty sideritic and pyritic iron-formation
State Wisconsin
Name Baraga Group; Tyler Formation
Geologic age Early Proterozoic
Lithologic constituents
Major
Sedimentary > Clastic > Siltstone (Bed)Light- to dark-gray, feldspathic, fine-grained sandstone, argillaceous siltstone, and argillite. Near base, ferruginous argillite contains beds of cherty sideritic and pyritic iron-formation
Sedimentary > Clastic > Sandstone (Bed)Light- to dark-gray, feldspathic, fine-grained sandstone, argillaceous siltstone, and argillite. Near base, ferruginous argillite contains beds of cherty sideritic and pyritic iron-formation
Minor
Sedimentary > Chemical > Banded-iron-formation (Bed)Light- to dark-gray, feldspathic, fine-grained sandstone, argillaceous siltstone, and argillite. Near base, ferruginous argillite contains beds of cherty sideritic and pyritic iron-formation
Comments Continental margin assemblage (north of Niagara Fault)
References
NGMDB product
Counties Ashland - Bayfield - Iron