Geologic units in Lake of the Woods county, Minnesota

Foliated to gneissic tonalite, granodiorite, and diorite (Neoarchean) at surface, covers 38 % of this area

Foliated to gneissic tonalite, granodiorite, and diorite. Includes the Lookout Mountain tonalite (~2,718 Ma) of the Giants Range batholith and other intrusions within batholithic complexes defined by a low-to-moderate gravity signature with magnetic foliation apparent from aeromagnetic maps.

Mafic metavolcanic rocks (Neoarchean) at surface, covers 23 % of this area

Mafic metavolcanic rocks. Includes minor volcaniclastic and hypabyssal intrusive rocks metamorphosed to lower greenschist to lower amphibolite facies; includes the Ely Greenstone (~2,722 Ma).

Granitic intrusion (Neoarchean) at surface, covers 12 % of this area

Granitic intrusion. Includes the Sacred Heart (~2592, 2,603 Ma) and Ortonville granites, the Shannon Lake Granite (~2,674), and other intrusions having low gravity and magnetic signatures.

Volcaniclastic rocks of felsic to intermediate composition (Neoarchean) at surface, covers 11 % of this area

Volcaniclastic rocks of felsic to intermediate composition.

Granite to granodiorite (Neoarchean) at surface, covers 9 % of this area

Granite to granodiorite. Variably magnetic.

Gabbro, peridotite, pyroxenite, lamprophyre, and metamorphic equivalents (Neoarchean) at surface, covers 3 % of this area

Gabbro, peridotite, pyroxenite, lamprophyre, and metamorphic equivalents. Includes the Oaks intrusion (~2,671 Ma) in the Wabigoon subprovince, and a ~2,639 Ma lamprophyre in the western Wawa subprovince; locally defined by variably high gravity and magnetic signatures.

Biotite schist of graywacke protolith, and schist-rich migmatite (Neoarchean) at surface, covers 3 % of this area

Biotite schist of graywacke protolith, and schist-rich migmatite.

Schist of sedimentary protolith (Neoarchean) at surface, covers 0.4 % of this area

Schist of sedimentary protolith. Metamorphosed to upper greenschist to amphibolite facies.

Syenite, monzodiorite, granodiorite, and diorite (Neoarchean) at surface, covers < 0.1 % of this area

Syenite, monzodiorite, granodiorite, and diorite. Commonly hornblende- or pyroxene-bearing; Includes the Coon Lake, Side Lake, and Linden (~2,666 Ma) plutons of north-central Minnesota.

Granitoid intrusion (Neoarchean) at surface, covers < 0.1 % of this area

Granitoid intrusion. Constrained solely by low gravity and magnetic signatures.

Mafic to ultramafic hypabyssal intrusive complexes composed of gabbro, pyroxenite, diorite, and anorthosite (Neoarchean) at surface, covers < 0.1 % of this area

Mafic to ultramafic hypabyssal intrusive complexes composed of gabbro, pyroxenite, diorite, and anorthosite. Includes the Mentor and Deer Lake complexes, intrusions of the Newton Lake Formation, all within the Wawa subprovince; and the UBD intrusion (~2,685 to 2,695 Ma) in the Wabigoon subprovince.