Where is schist found in the united states

Walloomsac Formation - phyllite, schist, metagraywacke. Consists of amphibolite, micaceous quartzite, quartz schist, and recrystallized manganiferous chert. Includes structurally complex amphibole schist and quartz-rich hornblende gneiss of unknown age exposed at and near Chetco Peak west of Cave Junction Smith and others, Consists of a variety of schistose rocks characterized by different proportions of muscovite, quartz, graphite, chlorite, actinolite, and epidote, rare thin layers of metachert, and clinozoisite-actinolite-albite-garnet metagabbro.

Potassium-argon age on muscovite from unit is about Ma Lanphere and others, and on a whole rock sample is about Ma Suppe and Armstrong, , indicating a Late Jurassic metamorphic age. Protolith is probably Triassic and Paleozoic in age. Layered amphibolite, schist, gneiss, and quartzite. Protolith considered to be of Paleozoic age. Highly sheared graywacke, mudstone, siltstone, and shale with lenses and pods of sheared greenstone, limestone, chert, blueschist, and serpentine.

Identified as melange by some investigators. Sandstone, conglomerate, graywacke, rhythmically banded chert lenses. Blake, Jr.

Jayko unpublished data, in Curry and southern Coos Counties. Poorly bedded argillite, chert, phyllite, phyllitic quartzite, calc-phyllite, impure limestone, and marble. In places rocks are strongly foliated. Sparse fossils Fusilina, corals, and crinoids indicate that the unit includes rocks of Leonardian, Ochoan, and Late Triassic age OR In Baker County includes "sedimentary and volcanic rocks" MzPza of Brooks and others OR and metamorphosed sedimentary and minor volcaniclastic rocks containing mineral assemblages indicative of quartz-albite-muscovite-chlorite subfacies and quartz-albite-epidote-biotite subfacies of the greenschist facies.

Antietam Formation - gray, buff-weathering quartzite. Harpers Formation - Dark-greenish-gray phyllite and schist containing thin quartzite layers; includes Montalto Member CAhm - gray quartztite. Antietam Formation - Gray, buff-weathering quartzite and quartz schist. Chickies Formation - Light-gray, hard, massive, Scolithus-bearing quartzite and quartz schist; thin, interbedded dark slate at top; conglomerate Hellam Member at base. Greenstone schist - Fine to medium grained, light to medium green; includes probable metavolcanic rocks.

Harpers Formation - Dark-greenish-gray phyllite and schist containing thin quartzite layers. Harpers Formation - Dark-greenish-gray phyllite and schist containing thin quartzite layers; includes Montalto Member CAhm. Lower Middle? Octoraro Formation - Includes albite-chlorite schist, phyllite, some hornblende gneiss, and granitized members.

Peters Creek Schist - Chlorite-sericite schist containing interbedded quartzite. Setters Quartzite - Includes white feldspathic quartzite, gray mica gneiss, and mica schist.

Rhode Island. Harmony Group - Absalona Formation - Gray, medium- to coarse-grained biotite granite gneiss characterized by alkali feldspar porphyroblasts. Consists of biotite, hornblende, quartz, microcline, microperthite, albite, epidote, garnet, and chlorite. Subordinate amounts of quartz-biotite schist, amphibolite, and quartzite occur as layers and isolated bodies. Narragansett Bay Group - Rhode Island Formation - In northern Rhode Island, consists of gray to black, fine- to coarse-grained quartz arenite, litharenite, shale, and conglomerate, with minor beds of anthracite and meta-anthracite.

In southern Rhode Island, consists of meta-sandstone, meta-conglomerate, schist, carbonaceous schist, and graphite. Plant fossils are common. South Carolina. Amphibolite and interlayered biotite gneiss, hornblende gneiss and minor mica schist Cambrian or Neoproterozoic Amphibolite and interlayered gneiss, hornblende gneiss and minor mica schist. Biotite gneiss having interlayered marble, calc-silicate rock, sillimanite-muscovite schist, and garnet-quartz rock.

Biotite-plagioclase-quartz gneiss and biotite-muscovite schist: variably interlayered, containing subordinate layers of amphibolite and sillimanite-mica schist. Biotite quartz-plagioclase gneiss: biotite quartz-plagioclase gneiss with minor interlayers of amphibolite gneiss and mica schist.

Blacksburg Formation: metamorphosed sedimentary sequence of interlayered sericite schist and phyllite, sericite quartzite, marble, amphibolite and calc-silicate rock. Hammett Grove Meta-igneous Suite - ultramafic rocks: metamorphosed ultramafic rocks: hornblendite, pyroxenite, serpentinite and talc schist. Little River Sequence, metasedimentary rocks: white-mica schist and phyllite, metatuff, quartz-muscovite schist, and minor quartzite.

Migmatite paragneiss and schist of Kiokee belt: migmatitic hornblende-biotite paragneiss having interlayered sillimanite schist and amphibolite.

Quartz-sericite phyllite and schist. Sillimanite schist and sillimanite-mica schist: sillimanite-rich aluminous schist composed mainly of sillimanite, biotite, muscovite, and minor quartz. Tallulah Falls Formation, gneiss and schist: biotite-quartz-plagioclase gneiss interpreted to be metagraywacke, and interlayered biotite-muscovite schist, garnet-mica schist and amphibolite. South Dakota.

Iron-Formation Proterozoic Paleoproterozoic Banded, dark-green, reddish-brown, and white iron-formation, ferruginous chert, and minor mica schist. Includes three or more ages of oxide-, carbonate-, silicate-, and sulifide-facies iron-formation and interbedded tuffaceous rocks. Thickness ft m. Light- to dark-gray, medium- to thick-bedded, quartz-mica schist containing calc-silicate lenses and ellipsoidal masses. Thickness up to 7, ft 2, m. Dark-green amphibolite and amphibolite schist.

Thickness of individual flows ft m. Dark-green amphibolite, actinolite schist, and greenstone. Interflow units consists of graphitic schist, chert, and carbonate- and silicate-facies iron-formation. Thickness of individual flows ft , m. Tan to light-gray, conglomeratic siliceous schist, feldspathic schist, and minor marble. Thickness locally over 6, ft 1, m. Light-gray to gray, conglomeratic and feldspathic schist, biotite schist, taconite, and phyllite.

Individual conglomerate and fanglomerate tongues from ft m thick. Total thickness over 10, ft 3, m. Dark-green sills of amphibolite, actinolite schist, greenstone, and serpentine. Thickness of sills variable, up to 1, ft m. Light- to dark-gray, silceous mica schist and impure quartzite.

Differentiated where possible into three primary tongues or lenses. Xgw1, Xgw2, and Xgw3 Thickness from 1, ft to over 5, ft , m.

Gray, siliceous mica schist and impure quartzite. Thickness undetermined. Lower Xgw- Light- to dark-gray, silceous mica schist and impure quartzite. Middle Xgw- Light- to dark-gray, silceous mica schist and impure quartzite. Upper Xgw- Light- to dark-gray, silceous mica schist and impure quartzite. Dark-gray biotite schist, biotite-muscovite schist, pyritic biotite schist, and local massive chert beds.

Thickness approximately ft , m. Dark-gray to gray, siliceous biotite phyllite, calcareous biotite phyllite, and schist. Minimum thickness 1, ft m.

Dark-gray to gray, siliceous biotite phyllite and schist. Thickness greater than 2, ft m. Gray to grayish-brown, conglomeratic biotite phyllite, siliceous biotite phyllite, mica schist, quartzite, and iron-formation.

Thickness up to 2, ft m. Gray to dark-gray phylite, slate, and mica schist. Estimated thickness at least 5, ft 1, m. Medium-gray to dark-greenish-gray phyllite, slate, and biotite schist containing minor chert and amphibolite. Locally intruded by thin metagabbro sills. Thickness 1,, ft m. Light-gray to light-tan, muscovite schist and muscovite phylite. Thickness approximately 1,, ft m. Light-tan quartzite, siliceous schist, and minor chert. Thickness , ft , m. Gray phyillite, mica schist, and biotite-plagioclase schist.

Total thickness unknown; approximately ft m exposed. Light- to dark-gray, quartz-mica-feldspar schist, quartz-mica schist, staurolite and garnet-rich schist, metaconglomerate, calc-silicate gneiss, and cummingtonite-quartz schist. Thickness up to 14, ft 4, m. Cranberry Granite Precambrian Cranberry Granite - Complex of intertonguing rock types including migmatite, granitic gneisses, monzonite, quartz diorite, greenstone, mica and hornblende schists, abundant granitic pegmatite.

Mount Rogers Group - Metavolcanics, typically purplish and reddish; massive lavas and tuffs, altered rhyolites and quartz latites; strongly foliated; interbedded arkose, shale, and conglomerate.

Thickness 1, to 3, feet; Includes Bakersville Gabbro - Metagabbro, dark, porphyritic; contains diorite, basalt, anorthosite, and diabase; occurs as thin to massive dikes and lenticular masses; Beech Granite - Granite, porphyritic, light-gray to reddish; coarse potash feldspar crystals and clustered interstitial mafics chloritized biotite and hornblende give spotted appearance; includes Max Patch Granite; Cranberry Granite - Complex of intertonguing rock types including migmatite, granitic gneisses, monzonite, quartz diorite, greenstone, mica and hornblende schists, abundant granitic pegmatite; and Roan Gneiss - Layered hornblende and garnet gneiss and granitic migmatite with zones of mica schist and amphibolite, foliation commonly contorted; contains numerous granitic and gabbroic dikes.

Roan Gneiss - Layered hornblende and garnet gneiss and granitic migmatite with zones of mica schist and amphibolite, foliation commonly contorted; contains numerous granitic and gabbroic dikes. Cambrian quartzite in northwestern Utah Cambrian? Alligator Back Formation - Banded marble. Alligator Back Formation - Meta-argillite is feldspathic metagraywacke; graphitic mica schist, and quartzite. Amphibolite, amphibole gneiss, and schist.

Amphibolite and amphibole-bearing gneiss and schist. Arvonia Formation - Kyanite quartzite and schist. Arvonia Formation - Slate and porphyroblastic schist. Buffards Formation - Micaceous conglomerate, schist, and phyllite. Hyco Formation - Lithic and crystal metatuff. Interlayered Mafic and Felsic Metavolcanic Rocks - Amphibolite, hornblende-biotite gneiss, and schist. Metagraywacke, Quartzose Schist, and Melange - Meta-argillite is metagraywacke; quartzose schist.

Piney Branch Complex - Metamorphosed mafic and ultramafic rocks. Quantico Formation - Micaceous quartzite. Quantico Formation - Slate and porphyroblastic schist. Schist as exotic blocks within melange units. Swift Run Formation - Phyllite, metasandstone, and metaconglomerate.

Ta River Metamorphic Suite - Amphibolite gneiss. Albee Formation Ordovician Albee Formation - Massive, gray, white-weathered quartzite and feldspathic quartzite interbedded with greenish-gray slate, phyllite, feldspthic phyllite and quartzose argillaceous phyllite.

Micaceous quartzite, quartz-mica schist, mica schist and hornfels contining porphyroblasts of biotite, garnet, staurolite and sillimanite in the vicinity of granitic plutons. Soda-rhyolite tuff occurs locally. Micaceous quartzite characterized by thin, schistose "pinstripe" partings is common in many areas. Cavendish Formation, Readsboro Member - Quartz-muscovite schist containing biotite or chlorite and characterized by conspicuous porphyroblasts of sodic plagioclase; less commonly quartz-muscovite-paragonite schist containing chlorite, garnet, or chloritoid, or, in Chester dome, quartz-muscovite-paragonite schist containing garnet, staurolite, and locally kyanite Gassetts schist.

Usage follows Thompson , but is extended to include some rocks on Star Hill, including inner and outer cover rocks assigned by Downie to Hoosac and Pinney Hollow Formations. Formation is divided into four map units: calc-silicate rock and gneiss, marble, feldspathic schist or granofels, and the Gassetts Schist Member.

Clough Formation - Quartzite, quartz-conglomerate, and mica schist; lenses of fossiliferous calcareous quartzite in upper part. Southeastern Vermont. Fitch Formation - Quartz-plagioclase-biotite granulite; actinolite-diopside granulite; impure limestone and dolomite; mica schist; the carbonate-rich beds are typically an inch or two thick and segmented so as to give the weathered outcrop a characteristic pitted appearance.

Gile Mountain Formation, Hall Stream Member - Highly feldspathic grit, probably volcanic; feldspathic chlorite-ankerite schist and amphibolite; all northeast of Nulhegan River. Hoosac Formation, Plymouth Member - Quartzite, schistose quartzite, dolomitic quartzite; carbonaceous phyllite; buff to dark gray dolomite with partings locally of carbonaceous phyllite; quartz-sericite-chlorite-albite schist; carbonaceous albite schist.

Southern and Central Vermont. Consists of a series of feldspathic and dolomitic quartzites, dolostones and black phyllites that overlie probable Middle Proterozoic gneisses. The Plymouth Formation can be divided into several informal members. The lower contact of the formation is below a sequence of dolomitic quartzites or thin bedded quartzite.

Dark laminated silty phyllites laterally replace the more feldspathic quartzites and dark-gray schistose quartzites, massive vitreous quartzites, and dolomitic quartzites pass upward to the east into well bedded cream-weathered light-gray dolostone breccia; these lithologies make up the dolostone member of the Plymouth Formation.

The upper member of the Plymouth Formation is a black graphitic and siliceous phyllite that contains 1 to 3 cm thick layers of dark-gray ferruginous quartzite, dolomitic quartzite, and ribbony beds of dolostone. The upper contact of the Plymouth Formation is placed at the first occurrence of light-silvery-green magnetite-muscovite-quartz knotted phyllites of the Pinney Hollow Formation Ratcliffe, West of Guildhall are lustrous, light to dark gray biotite-garnet phyllite and schist, some slate, and subordinate quartzite and impure quartzite.

South of Bellows Falls gray phyllite passes eastward into gray mica schist containing porphyroblasts of biotite, garnet, and staurolite. Schist and phyllite commonly contain biotite and garnet porphyroblasts in southern Vermont. Missisquoi Formation, Whetstone Hill Member - Carbonaceous black to light gray phyllite and schist containing porphyroblasts of biotite and garnet; beds of gray micaceous quartzite, fine-grained biotite gneiss and amphibolite.

Mount Holly Complex - Mainly fine- to medium-grained biotitic gneiss, locally muscovitic, and in western areas chloritic; massive and granitoid in some localities, fine-grained or schistose and compositionally layered in others; also abundant amphibolite and hornblende gneiss, and minor beds of mica schist, quartzite, and calc-silicate granulite; includes numerous small bodies of pegmatite and gneissoid granitic rock.

Includes a suite of metatonalites, metatrondhjemite, and possible metadacite with chemical characteristics of a calc-alkaline volcanic-plutonic suite. Mappable units are College Hill Granite Gneiss and 10 unnamed subdivisions including several varieties of gneiss as well as schist, amphibolite, and quartzite.

U-Pb zircon upper intercept ages of 1. Dust collected by abrasion of zircons, thought to represent migmatitic overgrowth, has a Pb-Pb age of approx Ma. College Hill is discordant to contacts and folds in paragneiss units of Mount Holly Complex. They are interbedded with thick succession of rusty-weathering, quartz-pebble gneisses, calc-silicate rocks and garnet-sillimanite schist similar to, but much thicker than, the rusty-weathering gneiss and schist unit of Mount Holly Complex exposed in Green Mountains of VT.

It is possible that the metadacitic and metatrondhjemitic suite of VT constitutes a lateral, south-to-north facies of the Washington Gneiss of MA Ratcliffe, in press. Northfield Formation - Dark gray to black quartz-sericite slate or phyllite with fairly widely-spaced interbeds a few inches thick of siltstone and silty crystalline limestone like that of the Waits River Formation; calcareous slate north of Lamoille River; phyllite passes into gray quartz-sericite schist containing abundant porphyroblasts of biotite and garnet in southern Vermont.

Orfordville Formation, Post Pond Volcanics - Greenstone, green chloritic schist interbedded with schistose felsite, quartz-feldspar-sericite schist; fine-grained chloritic, biotitic gneiss, all west of Ammonoosuc fault; mainly amphibolite east of the Ammonoosuc fault. Orfordville Formation, Sunday Mountain Volcanics - Greenstone, chloritic schist, felsite, and quartz-feldspar-sericite schist. Ottauquechee Formation - Black carbonaceous phyllite or schist containing interbeds of massive quartzite commonly criss-crossed by veins of white quartz; quartzite is dark gray and carbonaceous, light gray, or white; also includes light green quartz-sericite-chlorite phyllite or schist and sercitic quartzite; beds of phyllitic graywacke and feldspar granule conglomerate are north of Lamoille River.

Schist contains abundant porphyroblasts of garnet and biotite from Ludlow south. The black phyllite contains a previously unreported sub-unit of gray carbonate schist. The Thatcher Brook Member named in an abstract by Armstrong and others, is a carbonaceous albitic schist with greenstones and ultramafics.

These rocks have previously been included in the Ottauquechee but have never been differentiated from the black phyllite. Member is in fault contact with the silvery green schist of the Pinney Hollow Formation to the west. Age is Cambrian Ratcliff, in press. Pinnacle Formation - Schistose graywacke, gray to buff, commonly striped, quartz-albite-sericite-biotite-chlorite rock predominates; quartz-cobble and boulder conglomerate is common, chiefly near base.

Northern and Central Vermont. Pinney Hollow Formation - Pale green quartz-sericite muscovite-paragonite -chlorite phyllite and schist with abundant magnetite, chloritoid phyllite and schist, quartz-sericite-albite-chlorite schist, and rare beds of carbonaceous and schistose quartzite; garnet porphyroblasts common south of Ottauquechee River. Schist can originate as a sedimentary rock or igneous rock. It can contain different miners. Interesting Schist Rock Facts: Schist and slate are very similar in that they are made from the same rock types except schist is subjected to more heat and pressure.

Schist is often referred to as schistosity because of its large mica flakes. Large crystals cause schist rocks to reflect lots of light which gives it a very shiny appearance. Time to turn back the clocks…to million years ago! Catalina Island was formed from geological events back in the Mesozoic era when dinosaurs still roamed the Earth. The beautiful flora and fauna of Catalina Island sit on two main types of rock: igneous and metamorphic.

Igneous rock is the younger of the two because it is produced from direct volcanic activity. Three plates in the crust—North American, Farallon, and Pacific—were responsible for many of the geological features in the Channel Islands and United States west coast. Because the Farallon Plate was a heavy oceanic plate it sank underneath the lighter continental North American Plate, creating a subduction zone. Heat and pressure resulted from the two plates grinding against each other for millions of years and subsequently created different kinds of metamorphic rocks.

Geologic activity that produces mountainous regions is called regional metamorphism, and the Channel Islands are an excellent showcase of this process. There are three subtypes of Catalina Schist: garnet amphibolite , greenschist , and blueschist. During the Farallon subduction, some parts of the crust experienced more heat than others, resulting in different kinds of schist. The Great Pillars, seen here, are among the largest examples of schist in the canyon.

The main difference between schist and gneiss is the thickness of their internal layers, known as lamellae pronounced "la MEL lee". Gneiss has thick lamellae and schist have very thin, fine layers. There are two kinds of schists found in the canyon, either a mica-rich schist, that has a lot of biotite and muscovite mica, or a schist rich in hornblende, a type of mineral called amphibole.

Rare minerals such as garnets, sillimanite, staurolite or andalusite can be common in places. Plagioclase Plagioclase is a whole family of minerals that make up what is called a solid solution series. That means there are two ends of a scale with "pure" members at each end, with blended members of the family in between. If you mix a few other elements in you find white, reddish-gray or black colors as well, making this hard mineral an important part of most metamorphic and igneous rocks, and is one of the most common rock-forming minerals you will find.