Selected Studies of Archean Gneisses and Lower Proterozoic Rocks, Southern Canadian Shield, Issues 179-181G. B. Morey, Gilbert N. Hanson |
Contents
Archean rocks of the Granite Falls area southwestern Minnesota | 17 |
Part 1 Lithology | 43 |
Part 2 Geochemistry | 57 |
Copyright | |
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Common terms and phrases
adamellite adamellite gneiss adamellite-1 America Bulletin amphibolite amphibolite enclave analyses aplite aplite dike Archean banded gneiss basaltic basement biotite chem chemical coarse-grained composition deformation diabase emplacement event F₂ Figure folds foliated tonalite foliation geochronology Geological Society gneiss terrane Goldich grains Granite Falls Granite Falls area granite gneiss granitic rocks granoblastic granodiorite granodioritic gneiss gray Himmelberg hornblende intrusion isochron isotopic layered lineated tonalite m.y. ago m.y. old mafic mafic gneisses medium-grained metamorphism microcline migmatite mineral lineations Minnesota Geological Survey Minnesota River Minnesota River Valley mode Montevideo Montevideo Gneiss Morton area Morton Gneiss northern Wisconsin older outcrops pegmatite pegmatitic granite Penokean orogeny Peterman plagioclase plot plutons Precambrian Proterozoic quarry Quartz Monzonite ratios Rb-Sr Rb/Sr rock types Sacred Heart Granite Schmus shearing Sims Society of America southwestern Minnesota Special Paper 182 structure Table tholeiitic tonalitic gneiss tr tr tr U.S. Geological Survey volcanic whole-rock zircon