Cyclic zone

Gabbro to troctolite (~1,099 Ma).
State Minnesota
Name Cyclic zone
Geologic age Mesoproterozoic
Lithologic constituents
Major
Igneous > Plutonic > Gabbroic > Gabbro > Troctolitegabbro to troctolite
Igneous > Plutonic > Gabbroic > GabbroGabbro to troctolite
Comments Part of the Duluth Complex - layered series. Part of the Keweenawan Supergroup and Midcontinent Rift Intrusive Supersuite.
References

Jirsa, Mark A., Boerboom, Terrence J., Chandler, Val W., Mossler, John H., Runkel, Anthony C., and Setterholm, Dale R., 2011, S-21 Geologic Map of Minnesota-Bedrock Geology; Minnesota Geological Survey, State Map Series S-21. Scale 1:500,000.

NGMDB product
Counties Saint Louis