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Geologic units containing intermediate metavolcanic rock

Arizona

Cretaceous to Late Jurassic sedimentary rocks with minor volcanic rocks (Late Jurassic to Cretaceous)

Sandstone and conglomerate, rarely forms prominent outcrops; massive conglomerate is typical near base of unit and locally in upper part. These deposits are nonmarine except in southeastern Arizona, where prominent gray marine limestone (Mural Limestone) forms the middle of the Bisbee Group. Sandstones are typically medium-bedded, drab brown, lithic-feldspathic arenites. Includes Bisbee Group (largely Early Cretaceous) and related rocks, Temporal, Bathtub, and Sand Wells formations, rocks of Gu Achi, McCoy Mountains Formation, and Upper Cretaceous Fort Crittenden Formation and equivalent rocks. (80-160 Ma)

Early Proterozoic metavolcanic rocks (Early Proterozoic)

Weakly to strongly metamorphosed volcanic rocks. Protoliths include basalt, andesite, dacite, and rhyolite deposited as lava or tuff, related sedimentary rock, and shallow intrusive rock. These rocks, widely exposed in several belts in central Arizona, include metavolcanic rocks in the Yavapai and Tonto Basin supergroups. (1650 to 1800 Ma)

Jurassic sedimentary and volcanic rocks (Jurassic)

Sandstone and conglomerate derived from volcanic rocks with associated intermediate-composition lava flows, breccias, and tuffs. In southern Arizona this unit includes rocks of the Artesa sequence, Pitoikam Formation, Mulberry Wash volcanics, Rudolfo Red Beds, Recreation Red Beds, and Gardner Canyon Formation. In western Arizona it includes the Harquar Formation, rocks of Slumgullion, and related(?) unnamed units in the Kofa and Middle Mountains. This unit is characterized by maroon, brown, and purplish-gray volcanic-lithic sandstone and siltstone, with subordinate to abundant conglomerate, quartz-rich sandstone and sparse limestone. (150-170 Ma)

Idaho

Metasedimentary and metavolcanic rocks; Permian greenschist-facies rocks; western Idaho, Blue Mountains island-arc complex (Late Permian)

Upper Permian submarine volcanic complex in the Snake Canyon of western Idaho.

Shale, arenite, conglomerate, intermediate and felsic volcanic rocks; Late Proterozoic rifted continental margin; southeastern Idaho (Late Proterozoic)

Younger Precambrian volcanic and diamictic units of central and southeastern Idaho.

North Carolina

Cid Formation; Felsic Metavolcanic Rock (Cambrian/Late Proterozoic)

(southwest of Asheboro); Felsic Metavolcanic Rock - metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; interbedded with mafic and intermediate metavolcanic rock, meta-argillite, and metamudstone.

Cid Formation; Mafic Metavolcanic Rock (Cambrian/Late Proterozoic)

(Southwest of Asheboro); Mafic Metavolcanic Rock - metamorphosed basaltic flows and tuffs, dark green to black; interbedded with felsic and intermediate metavolcanic rock and metamudstone.

Felsic Metavolcanic Rock (Cambrian/Late Proterozoic)

Felsic Metavolcanic Rock - metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; minor mafic and intermediate metavolcanic rock.

Felsic Metavolcanic Rock (Cambrian/Late Proterozoic)

Felsic Metavolcanic Rock - metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; interbedded with mafic and intermediate metavolcanic rock, meta-argillite, and metamudstone.

Felsic Metavolcanic Rock (Cambrian/Late Proterozoic)

Felsic Metavolcanic Rock - metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; interbedded with mafic and intermediate metavolcanic rock, meta-argillite, and metamudstone.

Intermediate Metavolcanic Rock (Cambrian/Late Proterozoic)

Intermediate Metavolcanic Rock - metamorphosed andesitic tuffs and flows, medium to dark grayish green; minor felsic and mafic metavolcanic rock.

Intermediate Metavolcanic Rock (Cambrian/Late Proterozoic)

Intermediate Metavolcanic Rock - metamorphosed andesitic tuffs and flows, medium to dark grayish green; minor felsic and mafic metavolcanic rock.

Mafic Metavolcanic Rock (Cambrian/Late Proterozoic)

Mafic Metavolcanic Rock - metamorphosed basaltic flows and tuffs, dark green to black; interbedded with felsic and intermediate metavolcanic rock and metamudstone.

Mafic Metavolcanic Rock (Cambrian/Late Proterozoic)

Mafic Metavolcanic Rock - metamorphosed basaltic flows and tuffs, dark green to black; interbedded with felsic and intermediate metavolcanic rock and metamudstone.

Metavolcanic Rock (Cambrian/Late Proterozoic)

Metavolcanic Rock - interbedded felsic to mafic tuffs and flowrock.

Uwharrie Formation; Felsic Metavolcanic Rock (Cambrian/Late Proterozoic)

(at Asheboro and to south); Felsic Metavolcanic Rock - metamorphosed dacitic to rhyolitic flows and tuffs, light gray to greenish gray; interbedded with mafic and intermediate metavolcanic rock, meta-argillite, and metamudstone.

Yadkin Formation (Cambrian/Late Proterozoic)

Yadkin Formation - metamorphosed graywacke, volcanic sandstone, and siltstone; interbedded with mafic and intermediate metavolcanic flows and tuffs.

Oregon

Sedimentary and volcanic rocks, partly metamorphosed (Paleozoic) (Paleozoic)

Undifferentiated sedimentary and volcanic rocks some of which are highly deformed and locally metamorphosed to amphibolite and schist. Occurs mostly in Strawberry and Aldrich Mountains of the Blue Mountains province. Includes undivided Paleozoic rocks and Paleozoic volcanic rocks of Brown and Thayer (1966) and Dixie Butte Meta-andesite of Brooks and others (1984)

Volcanic rocks (Triassic and Permian) (Permian to Triassic)

Massive flows of porphyritic meta-andesite, metabasalt, spilite, and keratophyre, volcanic breccia, and subordinate amounts of fine-grained volcaniclastic rocks. In eastern Oregon probably mostly Late Triassic in age, but includes some Permian rocks (OR084). Includes Clover Creek Greenstone (OR035), Gold Creek greenstone (informal name; OR029), and greenstone of Ashley (OR081)

Virginia

Chopawamsic Formation - Mafic to intermediate metavolcanic rocks (Cambrian)

Chopawamsic Formation - Mafic to intermediate metavolcanic rocks