Geologic units containing meta-rhyolite

Metarhyolite

A low-grade, felsic metavolcanic rock with preserved evidence of its original rhyolitic character

This category is also used for meta-rhyolite.

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Arizona

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

Metavolcanic and metasedimentary rocks; Jurassic greenschist-facies metamorphic rocks; western Idaho, Blue Mountains island-arc complex (Jurassic): Jurassic mixed marine detrital and volcanic rocks 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.

Maryland

Metarhyolite and Aasociated Pyroclastic Sediments (Late Precambrian): Metarhyolite and Assoicated Pyroclastic Sediments - Metarhyolite - Dense, blue, cryptocrystalline, with white feldspar phenocrysts and glassy quartz; red porphyritic metarhyolite at contact with Catoctin Metabasalt; and Pyroclastic sediments - tuff breccia, blue slaty tuff, white tuffaceous sericitic schist, and banded green slate.

North Carolina

Mount Rogers Formation; Metagraywacke (Late Proterozoic): Metagraywacke - interlayered with metaconglomerate, laminated metasiltstone, and slate; minor calcareous metasandstone, greenstone, and metarhyolite.

New Hampshire

Ironbound Mountain Formation, Metarhyolite and microgranite intrusions (Lower Devonian): Ironbound Mountain Formation, Metarhyolite and microgranite intrusions.

New Jersey

Chestnut Hill Formation (Late Proterozoic): Chestnut Hill Formation (Drake, 1984) - Interbedded arkose, ferruginous quartzite, quartzite conglomerate, metarhyolite, and metasaprolite. Confined to a few small areas north and east of Phillipsburg, on the western side of Bowling Green Mountain, northwest of High Bridge, and a few areas too small to show at this map scale.

Pennsylvania

Metarhyolite (Precambrian): Metarhyolite - Light gray, green, and purple; commonly schistose, containing quartz augen and veins.

Wisconsin

Felsic metavolcanic rocks of 1835- to 1845-Ma age group (Early Proterozoic): Felsic metavolcanic rocks of 1835- to 1845-Ma age group - Rhyolite to dacite and, locally, andesite tuff, breccia, and minor sedimentary rocks, including conglomerate. Exposed in central Wisconsin.