Menominee Group; Hemlock Formation

Predominantly mafic to intermediate volcanic flows and pyroclastic rocks with interlayered slate and tuff beds
State Michigan
Name Menominee Group; Hemlock Formation
Geologic age Early Proterozoic
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic (Flow, Pyroclastic)Predominantly mafic to intermediate volcanic flows and pyroclastic rocks with interlayered slate and tuff beds
Incidental
Metamorphic > Metasedimentary > Metaclastic > SlatePredominantly mafic to intermediate volcanic flows and pyroclastic rocks with interlayered slate and tuff beds
Comments Continental margin assemblage (north of Niagara Fault)
References
NGMDB product
Counties Baraga - Dickinson - Iron - Marquette