Porphyritic quartzofeldspathic dikes

Porphyritic quartzofeldspathic dikes. Typically hypabyssal intrusions associated with felsic volcanic sequences.
State Minnesota
Name Porphyritic quartzofeldspathic dikes
Geologic age Neoarchean
Lithologic constituents
Igneous > Hypabyssal > Felsic-hypabyssal (Dike or sill)porphyritic quartzofeldspathic dikes
Comments Intrusions in all subprovinces of the Superior Province. Part of generally discrete, unfoliated to weakly magmatically foliated or lineated plutons.

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 Cook - Lake - Saint Louis