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Geologic units containing orthogneiss

Alabama

Elkahatchee Quartz Diorite Gneiss (Precambrian to Paleozoic)

Elkahatchee Quartz Diorite Gneiss - mesocratic to melanocratic, fine to coarse-grained, massive to strongly foliated, locally sheared quartz diorite gneiss.

Connecticut

Brookfield Gneiss (Middle? Ordovician)

Brookfield (dioritic and granodioritic) Gneiss (including Newtown Gneiss of Crowley, 1968) - Dark and light, commonly speckled or banded, medium- to coarse-grained, massive to poorly foliated gneiss, composed of plagioclase, biotite, and hornblende, generally with quartz and K-feldspar, the latter commonly as megacrysts 1 to 3 cm across (also plagioclase megacrysts in darker rocks), locally associated with amphibolite or hornblende schist.

Idaho

Felsic augen gneiss after porphyritic granite; Middle Proterozoic; southern Belt province (Middle Proterozoic)

Augen gneiss, amphibolite and other metamorphosed igneous rocks; possibly Precambrian.

Felsic gneiss, mafic gneiss, orthogneiss, and calc-silicate rock; Early Proterozoic metamorphic rocks; central Idaho; Pioneer Mountains metamorphic core complex (Early Proterozoic)

Precambrian, high-grade metamorphic rock; metasediment subdivisions are (PC3, PC2, PC1).

Garnet-mica schist, gneiss, and quartzite; Proterozoic high-grade metasedimentary rocks; trans-Idaho metamorphic province (Late to Early Proterozoic)

Precambrian high-grade metamorphic rock; metasediment; Kyanite-sillimanite-garnet-mica schist and gneiss; minor quartzite

Metamorphosed granitoid plutonic rocks and metasedimentary rocks, undivided; Cretaceous orthogneiss in Middle Proterozoic metasedimentary host rocks; west-central Idaho (Cretaceous to Middle Proterozoic)

Highly metamorphosed rock of central Idaho; age and origin of rock questionable.

Metamorphosed granodiorite, quartz monzonitek tonalite, quartz diorite; mostly Cretaceous orthogneiss and migmatite; northern and Atlanta batholith; margins of Bitterroot and Atlanta batholiths (Cretaceous)

Metamorphosed granitic intrusive rock; associated with pluton margins and stress areas.

Migmatitic paragneiss, quartzite, orthogneiss, and amphibolite; Early Proterozoic to Late Archean metamorphic rocks; northern Belt province; Settlement antiform in Priest River metamorphic core complex (Early Proterozoic to Late Archean)

Precambrian, high-grade metamorphic rock; metasediment; kyanite-sillimanite garnet-mica coarse-grained schist and gneiss; minor quartzite

Orthogneiss, mica schist, and amphibolite; Early Proterozoic to Late Archean metamorphic rocks; south-central Idaho; Albion Range metamorphic core complex (Early Proterozoic to Late Archean)

Precambrian, high-grade metamorphic rock; metasediment subdivisions are (PC3, PC2, PC1).

Peraluminous monzogranite, granodiorite, pegmatite, aplite, and migmatite; mostly Cretaceous intrusions of the Kaniksu batholithic assemblage, but with minor Eocene intrusions, undivided; northern Idaho (Cretaceous to Eocene)

Cretaceous plutons; felsic; as granite or quartz monzonite; probably includes unmapped older and younger crystalline bodies.

Quartz diorite, tonalite, granodiorite, orthogneiss, migmatite; Cretaceous to Jurassic quartz dioritic plutons; western Idaho, Blue Mountains island-arc complex (Early Cretaceous to Late Jurassic)

Lower Cretaceous to Upper Jurassic intrusions in west-central Idaho.

North Carolina

Biotite Granitic Gneiss (Middle Proterozoic)

Biotite Granitic Gneiss (950-1250 my) - unconformity; contains paragneiss and granitic to quartz monzonitic orthogneiss; locally schistose and mylonitic. Locally includes tectonic slices, infolded remnants, or recrystallized equivalents of the Grandfather Mountain Formation. Equivalent to the Wilson Creek Gneiss.

New Jersey

Syenite Gneiss (Middle Proterozoic)

Syenite Gneiss - Light-pinkish-white- to buff-white-weathering, greenish-gray, medium-grained, moderately foliated rock consisting of two distinct phases: hornblende syenite gneiss containing microcline microperthite, oligoclase, hornblende, and opaque minerals; and pyroxene syenite gneiss containing microcline microperthite, oligoclase, clinopyroxene, accessory amounts of titanite, and opaque minerals. Despite the co-mingling of these two phases, they appear to belong respectively to the Byram and Lake Hopatcong Intrusive Suites. In Hamburg Mountain area.

Pennsylvania

Felsic to mafic gneiss (Precambrian)

Felsic to mafic gneiss - Light, medium grained; predominantly quartz and feldspar of igneous origin.

Virginia

Two-Mica Granite (Proterozoic Y)

Two-mica granite.

Washington

Lower Paleozoic rocks, undivided (Paleozoic; likely Ordovician)

Predominantly gneiss and schist in northern Ferry County. Quartzite, partly interbedded with dolomitic and calcitic marble, lime-silicate gneiss, and amphibolite; including in places forsterite marblean diopside marble, quartz-biotite-sillimanite schist and sillimanite-orthoclase gneiss in northeastern Ferry County. Quartzite with overlying limestone in southeastern Stevens County. Some upper Paleozoic and Precambrian rocks may be included.

Mesozoic granitic rocks, undivided (Mostly Cretaceous-Jurassic)

Granite, quartz monzonite, quartz diorite, granodiorite, and trondhjemite. Includes diorite in southeastern Washington; diorite and gabbro near Concunully in Okanogan County; gneiss, schist, and migmatites in areas of Chelan, Colville, and Okanogan batholiths. Includes high-grade metamorphic rocks of Precambrian age in Spokane area.

Pre-Upper Jurassic gneiss (Mostly Cretaceous)

Biotite, quartz diorite, trondhjemite, and hornblende gneisses, many of which are migmatitic; includes small granitic bodies locally. Small areas of mica schist, marble, amphibolite, and lime-silicate rocks in Entiat Mountains area of Chelan County.

Tertiary-Cretaceous granitic intrusive rocks (Early Tertiary-Late Cretaceous)

Granite, granodiorite, trondhjemite, and quartz diorite. Late Cretaceous and/or early Tertiary.

Upper Paleozoic rocks, undivided (Ordovician)

Mostly graywacke, interbedded quartzite and phyllite, greenstone and serpentine, and black shale with minor limestone. Some quartz-mica schist in Bald Knob area of Ferry County. Schist, gneiss, and amphibolite in other parts of Ferry County. Some rocks of lower Paleozoic age, possibly Precambrian, and Mesozoic may be included.