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Geologic units containing granite

Alabama

Hatchet Creek Group; Pinchoulee Gneiss (Precambrian to Paleozoic)

Pinchoulee Gneiss - medium to fine-grained migmatitic, locally garnetiferous biotite-feldspar gneiss, commonly saturated with granitic pods.

Hissop Granite (Precambrian to Paleozoic)

Hissop Granite - mesocratic to leucocratic, strongly lineated granite to granodiorite.

Opelika Complex; Bottle Granite (Precambrian to Paleozoic)

Bottle Granite - leucocratic, fine to medium-grained, well-foliated quartz monzonite to granite; locally porphyritic.

Rockford Granite (Precambrian to Paleozoic)

Rockford Granite - leucocratic granite, granodiorite, and trondhjemite; locally well foliated, numerous pegmatites. Includes unnamed granitoids in Chilton County.

Uchee Complex; Phenix City Gneiss (Precambrian to Paleozoic)

Phenix City Gneiss - biotite-epidote quartz diorite gneiss and biotite-hornblende gneiss; locally includes migmatitic amphibolite; cut by numerous granitic veins.

Zana Granite (Precambrian to Paleozoic)

Zana Granite - quartz monzonite to granite with strong gneissic texture, cut by small pegmatites and aplite dikes, generally elongate; semiconcordant to foliation of country rock.

Arizona

Early Proterozoic granitic rocks (Early Proterozoic)

Wide variety of granitic rocks, including granite, granodiorite, tonalite, quartz diorite, diorite, and gabbro. These rocks commonly are characterized by steep, northeast-striking foliation. (1600-1800 Ma)

Early Proterozoic metamorphic rocks (Early Proterozoic)

Undivided metasedimentary, metavolcanic, and gneissic rocks. (1600-1800 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)

Early Tertiary to Late Cretaceous granitic rocks (Late Cretaceous to Early Tertiary)

Porphyritic to equigranular granite to diorite emplaced during the Laramide orogeny. Larger plutons are characteristically medium-grained, biotite +/- hornblende granodiorite to granite. Smaller, shallow-level intrusions are typically porphyritic. Most of the large copper deposits in Arizona are associated with porphyritic granitic rocks of this unit, and are thus named 'porphyry copper deposits'. (50-82 Ma)

Early Tertiary to Late Cretaceous muscovite-bearing granitic rocks (Late Cretaceous to Early Tertiary)

Light-colored peraluminous muscovite granite with or without garnet; commonly forms sills and is associated with abundant pegmatite dikes and sills. This unit includes granites in the Harcuvar and Harquahala Mountains of western Arizona and in the Santa Catalina, Rincon, Tortolita, Picacho, and Coyote Mountains of south-central Arizona. These granites typically represent the youngest phase of voluminous magmatism during the Laramide orogeny in Arizona. This unit also includes several muscovite-bearing granites in southern Arizona that are associated with calc-alkaline granites of unit TKg, and a batholith in the Cabeza Prieta area of southwestern Arizona. (50-80 Ma)

Jurassic granitic rocks (Jurassic)

Granite to diorite, locally foliated and locally alkalic; includes Triassic(?) granitoids in the Trigo Mountains. This unit includes two dominant assemblages of igneous rocks. The Kitt Peak-Trigo Peaks superunit includes, from oldest to youngest: dark, foliated or gneissic diorite, medium-grained equigranular to porphyritic granodiorite, and small, irregular intrusions of light-colored, fine-grained granite. The Ko Vaya superunit, limited to south-central Arizona, includes texturally heterogeneous K-feldspar-rich granitic rocks. (150-180 Ma)

Jurassic volcanic rocks (Jurassic)

Massive quartz-feldspar porphyry, generally interpreted as thick, welded rhyolitic tuffs, with locally abundant lava, and sandstone and conglomerate derived from volcanic rocks. Rare eolian quartzite units are interbedded in southern Arizona. Includes Ali Molina Formation, Mount Wrightson Formation, part of the Canelo Hills Volcanics, Cobre Ridge tuff, Black Rock volcanics, Planet Volcanics, and equivalent rocks. (160-200 Ma)

Middle Miocene to Oligocene granitic rocks (Oligocene to Middle Miocene)

Granite to diorite representing solidified magma chambers that were the likely source of overlying and nearby volcanic rocks of map unit Tv. The granitic rocks are typically equigranular and fine- to medium-grained. (14-26 Ma)

Middle Miocene to Oligocene volcanic rocks (Oligocene to Middle Miocene)

Lava, tuff, fine-grained intrusive rock, and diverse pyroclastic rocks. These compositionally variable volcanic rocks include basalt, andesite, dacite, and rhyolite. Thick felsic volcanic sequences form prominent cliffs and range fronts in the Black (Mohave County), Superstition, Kofa, Eagletail, Galiuro, and Chiricahua Mountains. This unit includes regionally extensive ash-flow tuffs, such as the Peach Springs tuff of northwestern Arizona and the Apache Leap tuff east of Phoenix. Most volcanic rocks are 20-30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona, but this unit includes some late Eocene rocks near the New Mexico border in east-central Arizona. (11-38 Ma)

Middle Proterozoic granitic rocks (Middle Proterozoic)

Mostly porphyritic biotite granite with large microcline phenocrysts, with local fine-grained border phases and aplite. Associated pegmatite and quartz veins are rare. This unit forms large plutons, including the Oracle Granite, Ruin Granite, granite in the Pinnacle Peak - Carefree area northeast of Phoenix, and several bodies west of Prescott. (1400-1450 Ma)

Proterozoic granitic rocks (Proterozoic)

Undivided Early and Middle Proterozoic granitic rocks (units Xg and Yg). (1400-1800 Ma)

Tertiary to Early Proterozoic gneissic rocks (Early Proterozoic to Tertiary)

Gneissic rocks with complex histories, typically with well developed, light-colored granitoid layers and dark-colored biotite- and amphibole-rich layers. Protoliths are of Tertiary to Proterozoic age. This unit includes variably mylonitic gneisses in metamorphic core complexes that have been exhumed from middle crustal levels by large-displacement middle Tertiary normal faults, and gneiss exposed at scattered locations near the Colorado River in southwestern Arizona. These rocks are interpreted to record Proterozoic, Mesozoic, and Tertiary metamorphism and deformation. (15-1800 Ma)

California

Cenozoic (Tertiary) granitic rocks, unit 1 (Death Valley) (middle to late Miocene)

Cenozoic (Tertiary) granitic rocks--quartz monzonite, quartz latite, and minor monzonite, granodiorite, and granite; found in the Kingston, Panamint, Amargosa, and Greenwater Ranges in southeastern California.

Mesozoic granitic rocks, unit 1 (Salinian Block) (Early to Late Cretaceous)

Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite

Mesozoic granitic rocks , unit 2 (Peninsular Ranges) (Middle Jurassic to Late Cretaceous)

Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite

Mesozoic granitic rocks, unit 3 (Sierra Nevada, Death Valley area, Northern Mojave Desert and Transverse Ranges) (Permian to Tertiary; most Mesozoic)

Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite

Mesozoic granitic rocks, unit 4 (Klamath Mountains and Northern Sierra Nevada) (Devonian)

Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite

Mesozoic granitic rocks, unit 5 (Klamath Mountains) (Jurassic to early Cretaceous)

Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite

Paleozoic and Permo-Triassic granitic rocks, unit 1 (Eastern Klamath Mountains) (Permian)

Paleozoic and Permo-Triassic granitic rocks in the San Gabriel and Klamath Mountains

Precambrian granitic rocks, unit 1 (Eastern Mojave Desert) (Early Proterozoic to Miocene)

Precambrian granite, syenite, anorthosite, and gabbroic rocks in the San Gabriel Mountains; also various Precambrian plutonic rocks elsewhere in southeastern California

Precambrian granitic rocks, unit 3, (San Gabriel Mountains Granite) (Late Triassic)

Precambrian granite, syenite, anorthosite, and gabbroic rocks in the San Gabriel Mountains; also various Precambrian plutonic rocks elsewhere in southeastern California

Precambrian rocks, undivided, unit 2 (Mojave Desert and Transverse Ranges) (Early Proterozoic to Miocene)

Conglomerate, shale, sandstone, limestone, dolomite, marble, gneiss, hornfels, and quartzite; may be Paleozoic in part

Colorado

Granitic rocks of 1400-m.y. age group (Proterozoic | Mesoproterozoic)

Includes Silver Plume, Sherman, Cripple Creek, St. Kevin, Vernal Mesa, Curecanti, Eolus, and Trimble Granites or Quartz Monzonites; also, San Isabel Granite of Boyer (1962) and unnamed granitic rocks

Granitic rocks of 1700-m.y. age group (Proterozoic | Paleoproterozoic)

Includes Boulder Creek -M.Y. AGE GROUP (AGE 1650-1730 M.Y.)--Includes Boulder Creek, Cross Creek, Denny Creek, Kroenke, Browns Pass, Powderhorn, Pitts Meadow, Bakers Bridge, and Tenmile Granites, Quartz Monzonites, or Granodiorites;

Rocks of Pikes Peak Batholith (1000-m.y. age group) (Proterozoic | Mesoproterozoic)

Includes Pikes Peak, Mount Rosa, Windy Point, and Redskin Granites and unnamed rocks

Connecticut

Mafic phase [of Narragansett Pier Granite] (Permian)

Mafic phase [of Narragansett Pier Granite] - Gray to reddish, medium-grained, generally massive granite, like Pn but with more biotite and locally hornblende.

Narragansett Pier Granite (Permian)

Narragansett Pier Granite - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite. Considerable associated pegmatite.

Nonewaug Granite (Devonian)

Nonewaug Granite - White to pink, fine- to very coarse-grained (commonly pegmatitic), massive to layered granite composed of albite, microcline, quartz, and muscovite, with minor biotite and garnet. Microcline commonly graphic; quartz and muscovite commonly in plumose aggregates.

Plainfield Formation plus Potter Hill Granite Gneiss plus Narragansett Pier Granite (Proterozoic Z? and Permian)

Plainfield Formation plus Potter Hill Granite Gneiss plus Narragansett Pier Granite - Plainfield Formation - Interlayered light-gray, thin-bedded quartzite, in places with feldspar, mica, graphite, or pyrite, light- to medium-gray gneiss composed of quartz, oligoclase, and biotite (rarely microcline), medium- to dark-gray schist composed of quartz, oligoclase, biotite, sillimanite, and garnet, dark-gray or green gneiss composed of plagioclase, quartz, biotite, and hornblende (commonly with diopside), amphibolite, diopsite-bearing quartzite, and calc-silicate rock. In places contains quartz-sillimanite nodules. Potter Hill Granite Gneiss - Light-pink to gray, tan-weathering, fine- to medium-grained, rarely porphyritic, well-foliated (not lineated) granitic gneiss, composed of microcline, quartz, oligoclase (or albite), biotite, and magnetite, minor muscovite, and local garnet. Narragansett Pier Granite - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite. Considerable associated pegmatite.

Plainfield Formation plus Stony Creek Granite Gneiss plus Narragansett Pier Granite (Proterozoic Z? and Permian)

Plainfield Formation - Interlayered light-gray, thin-bedded quartzite, in places with feldspar, mica, graphite, or pyrite, light- to medium-gray gneiss composed of quartz, oligoclase, and biotite (rarely microcline), medium- to dark-gray schist composed of quartz, oligoclase, biotite, sillimanite, and garnet, dark-grey or green gneiss composed of plagioclase, quartz, biotite, and hornblende (commonly with diopside), amphibolite, diopside-bearing quartzite, and calc-silicate rock. In places contains quartz-sillimanite nodules. Stony Creek Granite Gneiss - Red to pink, unevenly medium to very coarse grained, variably foliated granite or granite gneiss, composed of oligoclase, K-feldspar, and quartz with minor biotite and magnetite, sporatic garnet (in foliated varieties), and local muscovite. Commonly contains granite and pegmatite of Narragansett Pier type (and probably age). In much of area both granites occur as innumerable veins penetrating other units or as larger bodies full of inclusions of those units, which can be mapped through the bodies of granite. Narragansett Pier Granite (Permian) - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite. Considerable associated pegmatite.

Potter Hill Granite Gneiss plus Narragansett Pier Granite (Proterozoic Z? and Permian)

Potter Hill Granite Gneiss plus Narragansett Pier Granite - Potter Hill Granite Gneiss - Light-pink to gray, tan-weathering, fine- to medium-grained, rarely porphyritic, well-foliated (not lineated) granitic gneiss, composed of microcline, quartz, oligoclase (or albite), biotite, and magnetite, minor muscovite, and local garnet. Narragansett Pier Granite (Permian) - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite. Considerable associated pegmatite.

Quartzite unit [in Plainfield Formation] plus Stony Creek Granite Gneiss plus Narragansett Pier Granite (Proterozoic Z? and Permian)

Quartzite unit [in Plainfield Formation] plus Stony Creek Granite Gneiss plus Narragansett Pier Granite - Quartzite unit [in Plainfield Formation] - light-gray, glassy, generally thin bedded quartzite, also feldspathic and micaceous quartzite containing quartz-sillimanite nodules. Stony Creek Granite Gneiss - Red to pink, unevenly medium to very coarse grained, variably foliated granite or granite gneiss, composed of oligoclase, K-feldspar, and quartz with minor biotite and magnetite, sporatic garnet (in foliated varieties), and local muscovite. Commonly contains granite and pegmatite of Narragansett Pier type (and probably age). In much of area both granites occur as innumerable veins penetrating other units or as larger bodies full of inclusions of those units, which can be mapped through the bodies of granite. Narragansett Pier Granite (Permian) - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite. Considerable associated pegmatite.

Stony Creek Granite Gneiss plus Narragansett Pier Granite (Proterozoic Z? and Permian)

Stony Creek Granite Gneiss plus Narragansett Pier Granite - Stony Creek Granite Gneiss - Red to pink, unevenly medium to very coarse grained, variably foliated granite or granite gneiss, composed of oligoclase, K-feldspar, and quartz with minor biotite and magnetite, sporatic garnet (in foliated varieties), and local muscovite. Commonly contains granite and pegmatite of Narragansett Pier type (and probably age). In much of area both granites occur as innumerable veins penetrating other units or as larger bodies full of inclusions of those units, which can be mapped through the bodies of granite. Narragansett Pier Granite (Permian) - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite. Considerable associated pegmatite.

Waterford Group plus Stony Creek Granite Gneiss plus Narragansett Pier Granite (Proterozoic Z? and Permian)

Waterford Group plus Stony Creek Granite Gneiss plus Narragansett Pier Granite - Waterford Group (may be equivalent in part to Monson Gneiss) - Interlayered part (but layers locally distinct) of Waterford Group, light to dark, generally medium grained gneiss, composed of plagioclase, quartz, and biotite, with hornblende in some layers and microcline in others. Some layers of amphibolite. Stony Creek Granite Gneiss - Red to pink, unevenly medium to very coarse grained, variably foliated granite or granite gneiss, composed of oligoclase, K-feldspar, and quartz with minor biotite and magnetite, sporatic garnet (in foliated varieties), and local muscovite. Commonly contains granite and pegmatite of Narragansett Pier type (and probably age). In much of area both granites occur as innumerable veins penetrating other units or as larger bodies full of inclusions of those units, which can be mapped through the bodies of granite. Narragansett Pier Granite (Permian) - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite. Considerable associated pegmatite.

Westerly Granite (Permian)

Westerly Granite - Light-gray, pink-weathering, fine-grained, massive, aplitic granite, composed of oligoclase or albite, quartz, and K-feldspar, with minor biotite and accessory muscovite, magnetite, allanite, and sphene.

Delaware

Arden Granite (Paleozoic)

Arden Granite - granite

Georgia

Epidote Quartzite/ Amphibolite/ Sericite Schist/ Biotite Granite Gneiss (Precambrian-Paleozoic)

Epidote Quartzite/ Amphibolite/ Sericite Schist/ Biotite Granite Gneiss

Granite/ biotite granite/ amphibolite (Precambrian-Paleozoic)

Granite/ biotite granite/ amphibolite

Granite Gneiss/ Granite (Precambrian-Paleozoic)

Granite Gneiss/ Granite

Granite/ gneissic biotite granite (Precambrian-Paleozoic)

Granite/ gneissic biotite granite

Granite/ granite gneiss (Precambrian-Paleozoic)

Granite/ granite gneiss

Granite undifferentiated (Precambrian-Paleozoic)

Granite undifferentiated

Granitic Gneiss / Gneissic Granite (augen or porphyritic) (Precambrian-Paleozoic)

Granitic Gneiss / Gneissic Granite (augen or porphyritic)

Non-porphyritic granite (Precambrian-Paleozoic)

Non-porphyritic granite

Porphyritic granite (Precambrian-Paleozoic)

Porphyritic granite

Iowa

Crystalline Rock (Proterozoic | Mesoproterozoic)

Includes, granite, gneiss, and gneissoid granite; Rb-Sr dates 1130-1440 M.Y.

Idaho

Diorite, gabbro, and granite; Jurassic to Triassic plutons; western Idaho, Blue Mountains island-arc complex (Jurassic to Triassic)

Lower Mesozoic intrusions; localized near the Snake Canyon of western Idaho.

Granodiorite, quartz monzonite, granite, alaskite, quartz monzodioirte, diorite; Tertiary to Cretaceous, intrusions, undivided; northern, west-central, and southwestern Idaho (Eocene to Cretaceous)

Eocene intrusions; Cretaceous plutons, intermediate, Cretaceous plutons, felsic; metamorphosed granitic intrusive rock

Intrusive rocks: mostly Late Cretaceous granodioritic to granitic plutons of the Idaho batholithic assemblage, but including some Eocene intrusions; northern Idaho and Atlanta batholith (Cretaceous to Eocene)

Cretaceous plutons; probably includes unmapped older and younger crystalline bodies.

Monzogranite, granodiorite, syenite, monzodiorite, monzonite, and diorite; Eocene phaneritic to porphyro-aphanitic intrusions (subunits are Teif and Teii); northern Idaho to central Idaho (Eocene)

Eocene intrusions including large granitic plutons and dike swarms of central Idaho

Monzogranite, syenogranite, and syenite; Eocene phaneritic to porphro-aphanitic intrusions of the pink monzogranite suite; Challis magmatic belt (Eocene)

Eocene intrusions of predominantly felsic (pink granite) composition

Syenite, granite, quartz syenite, and gabbro; Ordovician to Cambrian plutons; east-central Idaho (Ordovician to Cambrian)

Intrusive rock of eastern Idaho; appears older than Cretaceous; possibly Precambrian

Indiana

Precambrian rocks (Precambrian)

Precambrian rocks - Dominantly granite; includes some metasedimentary and basaltic rocks

Massachusetts

Andover Granite (Silurian or Ordovician)

Andover Granite - Light- to medium-gray, foliated, medium-to coarse-grained -muscovite-biotite granite; pegmatite masses common. Includes Acton Granite (Silurian or Ordovician). Intrudes OZn.

Ayer Granite (Lower Silurian)

Ayer Granite - Granite to tonalite, partly porphyritic; locally gneissic, locally muscovitic; may include rocks older than Silurian; intrudes Sb and So. Ayer Granite is divided into the Clinton facies and the Devens-Long Pond facies (Gore, 1976). In addition, there are some masses not assigned to either facies that intrude Berwick Formation west and northwest of Lawrence, and that intrude Paxton and Oakdale Formations south of Worcester and west of probable southern continuation of Wekepeke fault. Radiometric ages obtained for facies of Ayer pose problems in assigning ages to unfossiliferous sedimentary rocks they intrude. Clinton facies has a well-defined U-Pb zircon age of 433 +/-5 Ma (Zartman and Naylor, 1984) that authors cite as Early Silurian; Devens-Long Pond facies has a similar age. This age greatly compresses the time available for deposition, burial, deformation, and metamorphism of Berwick and Paxton if these units are truly Silurian. Some of the Ayer not assigned to a facies may have been more properly correlated with Early Devonian Chelmsford Granite and muscovite-biotite granite at Millstone Hill. Bodies south of Worcester may be more properly correlated with Canterbury Gneiss of CT, which lies on strike with Ayer and has Early Devonian age of 329 +/-9 Ma (Zartman and Naylor, 1984). Zartman and Naylor (1984) believe Ayer Granite has same age range as Newburyport Complex. It is quite possible, based on textural and mineralogical differences that the two facies should be separate units, representing different magmatic events (Wones and Goldsmith, 1991).

Ayer Granite (Lower Silurian and Upper Ordovician?)

Ayer Granite - Devens-Long Pond facies. Equigranular to porphyritic gneissic biotite granite and granodiorite. Ayer Granite is divided into the Clinton facies and the Devens-Long Pond facies (Gore, 1976). In addition, there are some masses not assigned to either facies that intrude Berwick Formation west and northwest of Lawrence, and that intrude Paxton and Oakdale Formations south of Worcester and west of probable southern continuation of Wekepeke fault. Radiometric ages obtained for facies of Ayer pose problems in assigning ages to unfossiliferous sedimentary rocks they intrude. Clinton facies has a well-defined U-Pb zircon age of 433 +/-5 Ma (Zartman and Naylor, 1984) that authors cite as Early Silurian; Devens-Long Pond facies has a similar age. This age greatly compresses the time available for deposition, burial, deformation, and metamorphism of Berwick and Paxton if these units are truly Silurian. Some of the Ayer not assigned to a facies may have been more properly correlated with Early Devonian Chelmsford Granite and muscovite-biotite granite at Millstone Hill. Bodies south of Worcester may be more properly correlated with Canterbury Gneiss of CT, which lies on strike with Ayer and has Early Devonian age of 329 +/-9 Ma (Zartman and Naylor, 1984). Zartman and Naylor (1984) believe Ayer Granite has same age range as Newburyport Complex. It is quite possible, based on textural and mineralogical differences that the two facies should be separate units, representing different magmatic events (Wones and Goldsmith, 1991).

Ayer Granite, Clinton facies (Lower Silurian)

Ayer Granite - Clinton facies. Porphyritic biotite granite with a non-porphyritic border phase; intrudes Sb. Ayer Granite is divided into the Clinton facies and the Devens-Long Pond facies (Gore, 1976). In addition, there are some masses not assigned to either facies that intrude Berwick Formation west and northwest of Lawrence, and that intrude Paxton and Oakdale Formations south of Worcester and west of probable southern continuation of Wekepeke fault. Radiometric ages obtained for facies of Ayer pose problems in assigning ages to unfossiliferous sedimentary rocks they intrude. Clinton facies has a well-defined U-Pb zircon age of 433 +/-5 Ma (Zartman and Naylor, 1984) that authors cite as Early Silurian; Devens-Long Pond facies has a similar age. This age greatly compresses the time available for deposition, burial, deformation, and metamorphism of Berwick and Paxton if these units are truly Silurian. Some of the Ayer not assigned to a facies may have been more properly correlated with Early Devonian Chelmsford Granite and muscovite-biotite granite at Millstone Hill. Bodies south of Worcester may be more properly correlated with Canterbury Gneiss of CT, which lies on strike with Ayer and has Early Devonian age of 329 +/-9 Ma (Zartman and Naylor, 1984). Zartman and Naylor (1984) believe Ayer Granite has same age range as Newburyport Complex. It is quite possible, based on textural and mineralogical differences that the two facies should be separate units, representing different magmatic events (Wones and Goldsmith, 1991).

Biotite granite (Proterozoic Z)

Biotite granite - Light-gray to grayish-pink, biotite granite, locally foliated. Mafic minerals less prominent than in Milford Granite but granular quartz common. Includes mafic-poor granite similar to Zhg. Intrudes Zdi, Agb, and Zv.

Biotite-muscovite granite (Devonian)

Biotite-muscovite granite - Slightly foliated.

Chelmsford Granite (Lower Devonian)

Chelmsford Granite - Light-gray, even and medium-grained, muscovite-bearing granite; locally foliated; intrudes Sb.

Cooleyville Granitic Gneiss (Devonian)

Cooleyville Granitic Gneiss - Biotite tonalite to granite in composition, strongly foliated and lineated; contains inclusions of Dpgb; intrudes Dl.

Dedham Granite (Proterozoic Z)

Dedham Granite - Light grayish-pink to greenish-gray, equigranular to slightly porphyritic, variably altered, granite south and west of Boston. Includes dioritic rock near Scituate and Cohasset and Barefoot Hills Quartz Monzonite of Lyons (1969) and Lyons and Wolfe (1971). Intrudes Zdi, Zgb, Zb, Zv. Extensive calc-alkaline plutons separated by Boston basin have long been mapped as Dedham. Those to the north of Boston and studied in this report, are referred to as Dedham North. Crystallization ages for the Dedham North suite (based on titanites and zircons) have been determined at 607+/-4 Ma, while ages for the Lynn are slightly younger at 596+/-3 Ma. Both are clearly part of the Late Proterozoic magmatic event. Dates on two samples from Sheffield Heights indicate that the diorite and granite are part of the Dedham North suite. The Dedham south and west of Boston has been dated at 630+/15 Ma (Zartman and Naylor, 1984). Dedham North Granite has a compositionally highly variable suite ranging from leucogranites to granodiorites, tonalites, and quartz diorite. The granites originated by partial melting of a sedimentary protolith, while the intermediate members show a mixing of granitic magma and mafic magma (Hepburn and others, 1993).

Dedham Granite (Proterozoic Z)

Dedham Granite - Gray granite to granodiorite more mafic than Zdgr north of Boston. Intrudes Zw, Zv. Extensive calc-alkaline plutons separated by Boston basin have long been mapped as Dedham. Those to the north of Boston and studied in this report, are referred to as Dedham North. Crystallization ages for the Dedham North suite (based on titanites and zircons) have been determined at 607+/-4 Ma, while ages for the Lynn are slightly younger at 596+/-3 Ma. Both are clearly part of the Late Proterozoic magmatic event. Dates on two samples from Sheffield Heights indicate that the diorite and granite are part of the Dedham North suite. The Dedham south and west of Boston has been dated at 630+/15 Ma (Zartman and Naylor, 1984). Dedham North Granite has a compositionally highly variable suite ranging from leucogranites to granodiorites, tonalites, and quartz diorite. The granites originated by partial melting of a sedimentary protolith, while the intermediate members show a mixing of granitic magma and mafic magma (Hepburn and others, 1993).

Diorite and gabbro (Proterozoic Z)

Diorite and gabbro - Complex of diorite and gabbro, subordinate metavolcanic rocks and intrusive granite and granodiorite.

Esmond Granite (Proterozoic Z)

Esmond Granite - Light-gray to pink biotite granite, generally slightly altered, locally foliated. Gradational with Zgmgd. Intrudes Zsg. Esmond Granite occupies nearly 100 sq km in RI and forms an elongate pluton southeast of Woonsocket, RI, of which only the northern part is in MA. Occurs in Dedham batholith. Consists of mottled red and green, mainly massive granite. Coarse-grained facies intrudes Blackstone Group rocks and a related tonalite; fine-grained facies intrudes the tonalite and coarse-grained facies (Hermes and Zartman, 1985). Contact relations with Milford Granite not known, although phases of Milford resemble Esmond. Age of 621 +/-8 Ma (U/Pb methods on zircon by Hermes and Zartman, 1985) is close to age of Milford (Wones and Goldsmith, 1991).

Fine-grained granite and granite porphyry (Precambrian to Phanerozoic)

Fine-grained granite and granite porphyry.

Fitchburg Complex (Lower Devonian or younger)

Fitchburg Complex - Light-gray to white, medium-grained, weakly foliated muscovite-biotite granite; commonly contains white pegmatite bearing muscovite and tourmaline; may include some granite of late Paleozoic age; locally intrudes Dfgrg, Dfgd, and Dl.

Granite (Precambrian to Paleozoic)

Granite - Mostly nonfoliated.

Granite, gneiss, and schist, undivided (Proterozoic Z)

Granite, gneiss, and schist, undivided - Plutonic and metamorphic rocks of probable Proterozoic Z age. May include plutonic and volcanic rocks of Paleozoic or younger age.

Granite of Rattlesnake Hill pluton (Devonian)

Granite of Rattlesnake Hill pluton - Coarse-grained biotite-granite and fine-grained riebeckite granite. Intrudes Zdgr.

Granite of the Fall River pluton (Proterozoic Z)

Granite of the Fall River pluton - Light-gray, medium-grained, biotite granite, in part mafic-poor. Gneissic in New Bedford area. Includes Bulgarmarsh Granite (Proterozoic Z). Intrudes Zgs. Fall River pluton of the MA State map (Zen and others, 1983) is here referred to as the Fall River Granite. According to the authors, the change in name is meant to indicate the heterogeneous nature of the granite and the fact that it may consist of more than a single pluton. Included in this unit is the Bulgarmarsh Granite of Fall River and a mass of alaskitic gneiss shown on the State map south of Fall River. No type section is designated. Geologic map shows the Fall River present in the New Bedford area of MA and RI and bounded on the west by the Narragansett Bay Group. The Fall River was dated by Zartman and Naylor (1984) at about 600 Ma (U-Th-Pb zircon) (Murray and others, 1990).

Light-gray muscovite granite (Precambrian to Silurian)

Light-gray muscovite granite.

Massive to weakly foliated, pink and gray, fine- to medium-grained biotite granite (Pennsylvanian)

Massive to weakly foliated, pink and gray, fine- to medium-grained biotite granite - In the Townsend area; commonly contains pink magnetite-bearing pegmatite identical to granite of Milford, New Hampshire; intrudes OZma and Sp.

Middlefield Granite (Devonian)

Middlefield Granite - Moderately foliated, biotite-muscovite granite with microcline megacrysts. Intrudes OCAr and Om.

Milford granite (Proterozoic Z)

Milford Granite - Mafic phase. Gray, seriate to sub-porphyritic granite to granodiorite, mafic minerals tend to be in clots; locally gneissic. Intrudes Zb. Occupies an area of about 100 sq km. Central mass near Milford is elliptical and is divided into and mapped as a light-colored phase and a dark-colored phase; dark-colored phase defines an irregular border for largest of light-colored plutons. Intrudes Blackstone Group rocks and Ponaganset Gneiss, but was deformed with them at some later unknown time. Isotopic age of 630 +/-15 Ma was determined using U-Pb methods on zircon by Zartman and Naylor (1984). Characterized by salmon-pink color, bluish quartz on weathered surfaces, and lineations defined by lenticular mosaics of quartz and oriented patches of biotite; texture contrast strongly with that of Dedham Granite (Wones and Goldsmith, 1991).

Milford granite (Proterozoic Z)

Milford Granite - Light-gray to pale orange-pink biotite granite; biotite tends to be in clots or short streaks, quartz granular; locally gneissic. Intrudes Zb. Occupies an area of about 100 sq km. Central mass near Milford is elliptical and is divided into and mapped as a light-colored phase and a dark-colored phase; dark-colored phase defines an irregular border for largest of light-colored plutons. Intrudes Blackstone Group rocks and Ponaganset Gneiss, but was deformed with them at some later unknown time. Isotopic age of 630 +/-15 Ma was determined using U-Pb methods on zircon by Zartman and Naylor (1984). Characterized by salmon-pink color, bluish quartz on weathered surfaces, and lineations defined by lenticular mosaics of quartz and oriented patches of biotite; texture contrast strongly with that of Dedham Granite (Wones and Goldsmith, 1991).

Muscovite-bearing granite (Lower Devonian)

Muscovite-bearing granite - At Millstone Hill; intrudes So.

Newburyport Complex (Silurian)

Newburyport Complex - Gray, medium-grained porphyritic granite with microcline phenocrysts; intrudes SOk. Newburyport Complex was divided into two facies, tonalitic granodiorite and granite, by Shride (1971). Tonalitic facies was originally termed Newburyport Quartz Diorite and included dioritic rocks north of Clinton-Newbury fault zone that are now called Sharpners Pond Diorite in Nashoba zone, and Topsfield Granodiorite in Milford-Dedham zone. These correlations are no longer tenable due to differences in age and composition. Therefore, Newburyport Complex is restricted to the two facies present in Newburyport area. Rocks formerly mapped as Newburyport Quartz Diorite and Salem Gabbro-Diorite, except for gabbros at Salem Neck, MA, are included in undifferentiated diorite and gabbro unit (Zdigb) on MA State Geologic Map (Zen and others, 1983), largely because they could not be mapped separately at 1:250,000 scale. Unit Zdigb also includes mafic dikes and sills that are probably younger or contemporaneous. Most of the dioritic rocks northeast of Boston previously assigned to Newburyport Quartz Diorite are now assigned to an undifferentiated diorite unit (Zdi) on MA State Geologic Map. Newburyport Complex forms a large mass near Newburyport and a small one to its west, both truncated by Clinton-Newbury fault. Tonalite and granodiorite facies occupies core of Newburyport Complex at Newburyport and is intruded to the north by granite facies; described as medium to dark gray in fresh rock, weathering to both green and red, fine to medium grained, and highly variable in mineralogy. A U-Pb zircon age of 455 +/-15 Ma was determined by Zartman and Naylor (1984) for the tonalite. Granite facies intrudes both the Kittery Formation and the tonalite and granodiorite facies and covers an area of about 45 sq km. Described as light gray to dark gray, buff weathering, and porphyritic. No radiometric ages available for granite facies, but it is conceivable that the two facies are different in age. [Papers presented as chapters in U.S. Geological Survey Professional Paper 1366 are intended as explanations and (or) revisions to MA State bedrock geologic map of Zen and others (1983) at scale of 1:250,000.] (Wones and Goldsmith, 1991).

Orange-pink, rusty-weathering, medium- to coarse-grained biotite granite to granodiorite (Silurian)

Orange-pink, rusty-weathering, medium- to coarse-grained biotite granite to granodiorite - Locally porphyritic. Intrudes Ssqd.

Ponaganset Gneiss (Proterozoic Z)

Ponaganset Gneiss - Gneissic biotite granite containing megacrysts of microcline; biotite in coarse streaks and patches. Equivalent to part of former Northbridge Granite Gneiss (usage now abandoned). Sterling Plutonic Suite is here restricted to the Hope Valley terrane. (The Hope Valley together with the Esmond-Dedham terrane make up the Avalon superterrane of this report.) The Ponaganset Gneiss and the Ten Rod Granite Gneiss lie within the Esmond-Dedham terrane and are therefore removed from the Sterling. Ponaganset lies east of the Hope Valley shear zone and extends from RI into MA. [Apparently does not occur in CT.] Predominantly granite, ranges to tonalite. Gray to light gray, some pink, generally medium- to coarse-grained, but ranges from fine-grained to porphyritic. Alkali K-feldspar, plagioclase, quartz, and biotite are major minerals. The Ponaganset is interpreted as an intensely deformed phase of the Esmond Plutonic Suite. Strong lineation is defined by elongate aggregates of quartz and feldspar and trains of biotite and hornblende. Age is Late Proterozoic based on correlation with Northbridge Gneiss (MA), which has been dated at 557+/-4 Ma by Zartman and Naylor (1984) (Skehan and Rast, 1990).

Porphyritic granite (Proterozoic Z)

Porphyritic granite - Gray to gray-green, seriate to porphyritic biotite granite containing clots and streaks of biotite, epidote, and sphene. Mafic inclusions common. Gneissic in New Bedford area. Intrudes Zgs.

Scituate Granite Gneiss (Proterozoic Z)

Scituate Granite Gneiss - Gneissic granite containing biotite in small clots. Equivalent to part of former Northbridge Granite Gneiss (usage now abandoned). Gradational with Zhg.

Westwood Granite (Proterozoic Z)

Westwood Granite - Light-gray to pinkish-gray, fine- to medium-grained granite. Intrudes Zdgr. Proterozoic Z Westwood Granite forms small lenses of light-colored granite intruding Proterozoic Z Dedham Granite and older rocks. Occurs within Dedham batholith. Some rocks resembling Westwood, such as those exposed in Plymouth quarries near Weymouth, have been mapped as part of Dedham Granite on MA State Geologic Map (Zen and others, 1983). Extensive intrusion breccias occur at contacts of Westwood with older mafic rocks. Contacts with Dedham are commonly abrupt; dikes of Westwood cut Dedham and rare inclusions of Dedham are found within Westwood (Chute, 1966). No reports of cobbles of Westwood within Roxbury Conglomerate; therefore, it is possible that Westwood is intrusive equivalent of Mattapan Complex that underlies Roxbury and that Westwood was not exposed to erosion at time of deposition of Roxbury. Also may be an intrusive equivalent of Lynn Volcanic Complex. A somewhat questionable Rb/Sr whole-rock age of 579 +/-28 Ma (Fairbairn and others, 1967) obtained from Westwood indicates it may be younger than Dedham and may be about same age as Mattapan (Wones and Goldsmith, 1991).

White to gray and black-spotted muscovite-biotite granite and granodiorite (Ordovician)

White to gray and black-spotted muscovite-biotite granite and granodiorite - Intruded near or along thrust faults. Intrudes CAZh and Proterozoic Y gneisses.

Maryland

Relay Quartz Diorite (Early Paleozoic - Late Precambrian (?))

Relay Quartz Diorite - Intensely foliated, fine-grained, light colored; ranges from quartz diorite to albite granite; age 550 +/- 50 m.y. * by radiogenic dating.

Maine

Carboniferous alkali feldspar granite (muscovite accessory, abundant sedimentary inclusions) (Carboniferous)

Carboniferous alkali feldspar granite (muscovite accessory, abundant sedimentary inclusions) - muscovite-biotite granite

Carboniferous alkali feldspar granite (muscovite accessory mineral) (Carboniferous)

Carboniferous alkali feldspar granite (muscovite accessory mineral) - muscovite-biotite granite

Carboniferous granite (muscovite accessory mineral) (Carboniferous)

Carboniferous granite (muscovite accessory mineral) - muscovite-biotite granite undivided

Carboniferous granite undivided (Carboniferous)

Carboniferous granite undivided - biotite granite

Cretaceous granite (Cretaceous)

Cretaceous granite - Cretaceous biotite granite

Devonian alkali feldspar granite (Devonian)

Devonian alkali feldspar granite; alkali feldspar-biotite granite

Devonian granite (Devonian)

Devonian granite - biotite granite

Devonian granite (Devonian)

Devonian granite

Devonian granite-granodiorite (hornblende accessory mineral) (Devonian)

Devonian granite-granodiorite (hornblende accessory mineral)

Devonian granite (granophyric texture) (Devonian)

Devonian granite (granophyric texture)

Devonian granite (hornblende accessory mineral) (Devonian)

Devonian granite (hornblende accessory mineral); hornblende-biotite granite

Devonian granite (hornblende accessory mineral) (Devonian)

Devonian granite (hornblende accessory mineral) - hornblende-biotite granite undivided

Devonian granite (intrusive breccia texture) (Devonian)

Devonian granite (intrusive breccia texture)

Devonian granite (muscovite accessory mineral) (Devonian)

Devonian granite (muscovite accessory mineral); muscovite-biotite granite

Devonian granite (muscovite accessory mineral) (Devonian)

Devonian granite (muscovite accessory mineral) - muscovite-biotite granite undivided

Devonian granite (muscovite accessory mineral), tonalite (Devonian)

Devonian granite (muscovite accessory mineral), tonalite

Devonian granite (porphyritic texture) (Devonian)

Devonian granite (porphyritic texture) - biotite granite undivided

Devonian granite (pyroxene plus hornblende accessory mineral) (Devonian)

Devonian granite (pyroxene plus hornblende accessory mineral) - pyroxene-hornblende-biotite granite undivided

Devonian granite-quartz diorite (Devonian)

Devonian granite-quartz diorite: biotite granite, biotite granodiorite, biotite tonalite, biotite quartz syenite, biotite quartz monzodiorite, and biotite quartz diorite.

Devonian granite-quartz monzonite (hornblende accessory mineral) (Devonian)

Devonian granite-quartz monzonite (hornblende accessory mineral) Devonian hornblende-biotite granite to quartz monzonite- hornblende-biotite granite, hornblende-biotite granodiorite, hornblende-biotite tonalite, hornblende-biotite alkali feldspar quartz syenite, hornblende-biotite quartz syenite, and hornblende-biotite quartz monzonite.

Jurassic granite (Jurassic)

Jurassic granite - Jurassic biotite granite undivided

Mesozoic granite (hornblende accessory mineral) (Mesozoic)

Mesozoic granite (hornblende accessory mineral) - Mesozoic hornblende-biotite granite undivided

Ordovician granite (Ordovician)

Ordovician granite - Ordovician biotite granite

Ordovician granite (Ordovician)

Ordovician granite - Ordovician biotite granite undivided

Ordovician granite, granodiorite ()

Ordovician biotite granite and granodiorite

Silurian granite (Silurian)

Silurian granite

Michigan

Athelstane Quartz Monzonite (1836 +/- 15 Ma) (Early Proterozoic)

Athelstane Quartz Monzonite (1836 +/- 15 Ma) - Pink, coarse-grained granite to granodiorite containing nearly equal amounts of microcline microperthite, plagioclase, and quartz and 5-10 percent biotite and (or) hornblende. Mafic minerals are interstitial and give a clotty appearance.

Gabbroic rocks of Keweenawan affinity (Middle Proterozoic)

Gabbroic rocks of Keweenawan affinity - gabbro, anorthosite, granite, peridotite

Granitic rocks (Early Proterozoic)

Granitic rocks - Gray to pinkish-gray, mottled, medium-grained syenite, granite, and granodiorite. Moderately strong propylitic alteration and weak cataclasis. Forms small bodies south of Crystal Falls, MI (James and others, 1968). A body near Tobin Location has a U-Pb concordia intercept age of 1840 +/-5 Ma (Z.E. Peterman, written communication, 1988). Includes porphyritic red granite that intrudes Lake Archean Dickinson Group - Red mylonitic gneissic granite (about 1970 Ma).

Mellen Intrusive Complex; Granite (about 1000 Ma) (Middle Proterozoic)

Mellen Intrusive Complex; Granite (about 1000 Ma)

Peavy Pond complex (Early Proterozoic)

Peavy Pond complex - Chiefly hornblende metagabbro, but includes metanorite, metatonalite, granodiorite, and granite (Bayley, 1959).

Puritan Quartz Monzonite (Late Archean) (Late Archean)

Puritan Quartz Monzonite (Late Archean) - Pink to pinkish-gray, medium- to coarse-grained, equigranular to inequigranular granite to granodiorite in Puritan batholith south of Gogebic Range. Age 2710 +/- 140 Ma (Sims and others, 1977)

Minnesota

Duluth Complex; Felsic series (Middle Proterozoic)

Duluth Complex; Felsic series - Granophyric granite and related felsic rocks

Late-tectonic intrusions of the Penokean orogen (Early Proterozoic)

Late-tectonic intrusions of the Penokean orogen - Includes the St. Cloud and Rockville Granites and Reformatory granodiorite of east-central Minnesota, the Section 28 granite, the Cedar Mountain Complex, and other unnamed intrusions exposed along the Minnesota River Valley in southwestern Minnesota

Migmatitic gneiss, amphibolite, and granite (Middle to Early Archean)

Migmatitic gneiss, amphibolite, and granite - Montevideo and Morton Gneisses (3600-3000 m.y.) in the Minnesota River Valley, southwestern Minnesota; McGrath Gneiss (2750 m.y.) east of Mille Lacs Lake; components of Hillman Migmatite southwest of Mille Lacs Lake; and Sartell Gneiss in Stearns County. Inferred to include various younger rocks, including granitoid intrusions in the Hillman Migmatite and pillowed basalt in poorly exposed areas of southwestern Minnesota.

Subvolcanic mafic rocks, undivided; Selected granophyric and leuco-granitic phases of troctolitic-gabbroic intrusions in the Beaver Bay Complex (Middle Proterozoic)

Subvolcanic mafic rocks, undivided; Selected granophyric and leuco-granitic phases of troctolitic-gabbroic intrusions in the Beaver Bay Complex

Syntectonic intrusions of the Penokean orogen (Early Proterozoic)

Syntectonic intrusions of the Penokean orogen - Includes the Pierz Granite, the Freedhem and Bradbury Creek Granodiorites, and several unnamed intrusions of granite, granodiorite, tonalite, and gabbro in east-central Minnesota

Syntectonic to pretectonic granitoid rocks (Late Archean)

Syntectonic to pretectonic granitoid rocks - Granite and granodiorite of the Vermilion Granitic Complex, the Giants Range and Bemidji batholiths, as well as smaller intrusions of tonalite and monzonite of the Algoman orogen in northern Minnesota. Also includes the Odessa, Sacred Heart, and Fort Ridgely Granites exposed along the Minnesota River Valley in southwestern Minnesota.

Missouri

ST. FRANCOIS MOUNTAINS INTRUSIVE SUITE (SUBVOLCANIC, ALKALI GRANITIC RING COMPLEXES) (Precambrian [Y])

ST. FRANCOIS MOUNTAINS INTRUSIVE SUITE (SUBVOLCANIC, ALKALI GRANITIC RING COMPLEXES)

North Carolina

Amphibolite and Biotite Gneiss (Cambrian/Late Proterozoic)

Amphibolite and Biotite Gneiss - interlayered; minor layers and lenses of hornblende gneiss, metagabbro, mica schist, and granitic rock.

Banded Gneiss (Cambrian/Late Proterozoic)

Banded Gneiss - interlayered with calc-silicate rock, metaconglomerate, amphibolite, sillimanite-mica schist, and granitic rock.

Biotite Gneiss and Schist (Cambrian/Late Proterozoic)

Biotite Gneiss and Schist - (Located in the Lilesville granite aureole) inequigranular, locally abundant potassic feldspar and garnet; interlayered and gradational with calc-silicate rock, sillimanite-mica schist, mica schist, and amphibolite. Contains small masses of granitic rock.

Biotite Gneiss and Schist (Cambrian/Late Proterozoic)

Biotite Gneiss and Schist - inequigranular and megacrystic; in places contains garnet; interlayered and gradational with mica schist and amphibolite; includes small masses of granitic rock.

Biotite Gneiss and Schist (Cambrian/Late Proterozoic)

Biotite Gneiss and Schist - inequigranular and megacrystic; abundant potassic feldspar and garnet; interlayered and gradational with calc-silicate rock, sillimanite-mica schist, mica schist, and amphibolite. Contains small masses of granitic rock.

Biotite Gneiss and Schist (Cambrian/Late Proterozoic)

Biotite Gneiss and Schist - inequigranular, locally abundant potassic feldspar and garnet; interlayered and gradational with calc-silicate rock, sillimanite-mica schist, mica schist, and amphibolite. Contains small masses of granitic rock.

Cherryville Granite (Mississippian)

Cherryville Granite (351 my) - massive to weakly foliated; contains pegmatites, lithium-bearing on east side.

Cherryville Granite (Mississippian)

Cherryville Granite (351 my) - massive to weakly foliated; contains pegmatites.

Foliated to Massive Granitic Rock (Permian/Pennsylvanian)

Foliated to Massive Granitic Rock (270-320my) - megacrystic to equigranular. Butterwood Creek intrusive and Rocky Mount intrusive suite.

Foliated to Massive Granitic Rock (Permian/Pennsylvanian)

Foliated to Massive Granitic Rock (270-320 my) - megacrystic to equigranular. High Shoals Granite.

Foliated to Massive Granitic Rock (Permian/Pennsylvanian)

Foliated to Massive Granitic Rock (270-320my) - megacrystic to equigranular. Rolesville suite, Wise and Lemon Springs (?) intrusives.

Granite of Salisbury Plutonic Suite (Devonian/Silurian)

Granite of Salisbury Plutonic Suite (385-415 my) - pink, massive to weakly foliated. Gold Hill, Kannapolis, Salisbury, Southmont, and Yadkin intrusives.

Granitic Rock (Permian/Pennsylvanian)

Granitic Rock (265-325 my) - megacrystic to equigranular. Castalia and Wilton intrusives.

Granitic Rock (Devonian/Ordovician)

Granitic Rock - locally pinkish gray, massive to weakly foliated; contains hornblende.

Granitic Rock (Permian/Pennsylvanian)

Granitic Rock (265-325 my) - megacrystic to equigranular. Castalia, Lillington, Medoc Mountain, Sims, Contentnea Creek (?), and Elm City (?) intrusives.

Granitic Rock (Permian/Pennsylvanian)

Granitic Rock (265-325 my) - megacrystic to equigranular. Churchland Plutonic Suite (Western group) - Churchland, Landis, and Mooresville intrusives.

Granitic Rock (Permian/Pennsylvanian)

Granitic Rock (265-325 my) - megacrystic to equigranular. Lilesville granite.

Injected Gneiss (Cambrian/Late Proterozoic)

Injected Gneiss - biotite gneiss and schist intruded by numerous sills and dikes of granite, pegmatite, and aplite; minor hornblende gneiss.

Max Patch Granite (Late Proterozoic)

Max Patch Granite - mottled pink and light green, coarse grained to porphyritic, massive; contains biotite.

Metagraywacke, Amphibolite, and Kyanite Schist (Cambrian/Late Proterozoic)

Metagraywacke, Amphibolite, and Kyanite Schist - metagraywacke (biotite gneiss) interlayered and gradational with amphibolite and kyanite schist; minor ultramafic and granitic rock.

Metagraywacke and Muscovite-Biotite Schist (Cambrian/Late Proterozoic)

Metagraywacke and Muscovite-Biotite Schist - metagraywacke (biotite gneiss) interlayered and gradational with muscovite-biotite schist; minor marble and granitic rock.

Metamorphosed Granitic Rock (Cambrian/Late Proterozoic)

Metamorphosed Granitic Rock (520-650 my) - megacrystic, well foliated, locally contains hornblende; Vance County suite and Buckhorn granite.

New Hampshire

Ayer Granodiorite (Early Silurian)

Ayer Granodiorite - Gneissic granite to tonalite, locally coarsely porphyritic and muscovitic, southeastern New Hampshire.

Bethlehem Granodiorite (Early Devonian)

Bethlehem Granodiorite (Bethlehem Gneiss of Billings, 1955) - Gray, strongly foliated biotite-muscovite granodiorite and associated tonalite and granite.

Biotite granite (Late Ordovician)

Biotite granite - Pink, moderately to weakly foliated.

Biotite granite (Middle Ordovician)

Biotite granite - Contains minor muscovite. Makes up Cambridge Black pluton.

Biotite granite stock and dikes (Early - Late Silurian)

Biotite granite stock and dikes - Northernmost New Hampshire.

Concord Granite (Late Devonian )

Concord Granite - Gray two-mica granite, locally grading to tonalite.

Conway Granite (Middle - Late? Jurassic)

Conway Granite - Typically pink, coarse-grained mesoperthitic biotite (amphibole-free) granite; locally fine-grained or porphyritic.

Exeter Diorite (Early Devonian)

Exeter Diorite - Includes associated intrusive rocks of southeastern New Hampshire; pyroxene and pyroxene-hornblende diorite and gabbro, along with minor granodiorite and granite.

Fine-grained granite (Jurassic)

Fine-grained granite - Commonly contains alkalic amphibole and mesoperthite.

Granite, granodiorite, and tonalite (Late Ordovician)

Granite, granodiorite, and tonalite.

Granite, granodiorite, and trondhjemite (Late Ordovician)

Granite, granodiorite, and trondhjemite.

Granite porphyry (Early Jurassic)

Granite porphyry - Granite containing phenocrysts of smoky quartz and microperthite; alkalic amphibole, hornblende, and hedenbergite or fayalite may be present. "Mount Lafayette" type granite porphyry of Billings (1955).

Gray biotite granite (Permian)

Gray biotite granite - Contains minor muscovite. Found in Milford quadrangle.

Hastingsite granite (Jurassic)

Hastingsite granite - Leucocratic, pink or light-brown, and mesoperthitic.

Hornblende-biotite granite (Late Ordovician)

Hornblende-biotite granite.

Hornblende granite to granodiorite (Late Ordovician)

Hornblende granite to granodiorite - Part of Lost Nation pluton of northwestern New Hampshire.

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

Ironbound Mountain Formation, Metarhyolite and microgranite intrusions.

Kinsman Granodiorite (Early Devonian )

Kinsman Granodiorite - (Kinsman Quartz Monzonite of Billings, 1955) - Foliated granite, granodiorite, tonalite, and minor quartz diorite; large megacrysts of potassium feldspar characteristic; garnet locally abundant.

Leucocratic granite to quartz syenite (Jurassic)

Leucocratic granite to quartz syenite.

Massabesic Gneiss Complex (Late Proterozoic)

Massabesic Gneiss Complex - Quartzose-feldspathic gneiss and biotite schists (locally rusty), granofels, and cal-silicate rocks closely intruded by, and grading into, a pink gneissic granite (623 Ma) that produced a migmatite.

Massabesic Gneiss Complex (Late Proterozoic)

Massabesic Gneiss Complex - Migmatite consisting of pink, foliated biotite granite intruding gneissic and granulose metasedimentary and metavolcanic rocks in southeastern New Hampshire.

Medium-grained mesoperthitic granite containing riebeckite and (or) hastingsite (Cretaceous)

Medium-grained mesoperthitic granite containing riebeckite and (or) hastingsite.

Mesoperthitic biotite granite (Early Cretaceous)

Mesoperthitic biotite granite - Pink Conway-type granite of Kingsley (1931).

Mesoperthitic granite (Jurassic)

Mesoperthitic granite - Contains riebeckite and (or) hastingsite.

Mount Osceola Granite, Granite containing hornblende and, locally, hastingsite, ferrohedenbergite, or fayalite (Early - Middle Jurassic)

Mount Osceola Granite, Granite containing hornblende and, locally, hastingsite, ferrohedenbergite, or fayalite.

Mount Osceola Granite, Green biotite mesoperthitic granite (Early - Middle Jurassic)

Mount Osceola Granite, Green biotite mesoperthitic granite.

Newburyport Complex (Late Silurian)

Newburyport Complex - Medium-grained porphyritic granite.

Pink equigranular biotite granite (Late Devonian)

Pink equigranular biotite granite - Found in Woodsville and Whitefield quadrangles and in small intrusive units in northern and southeastern New Hampshire.

Porphyritic (alkalic feldspar) biotite granite (Late Ordovician)

Porphyritic (alkalic feldspar) biotite granite.

Porphyritic biotite granite (Cretaceous)

Porphyritic biotite granite - Pink to gray; hastingsite or riebeckite in some varieties.

Porphyritic granite (Jurassic)

Porphyritic granite.

Rhyolite and fine-grained granite (Cretaceous)

Rhyolite and fine-grained granite - Includes some ignimbritic caldera-fill and minor intrusive rocks (part of Ossipee Mountain Complex of Kingsley, 1931); also some aphanitic gray, black, or tan quartz-feldspar porphyry.

Rye Complex (Ordovician? - Late Proterozoic?)

Rye Complex - Migmatite of gray, foliated, sheared or mylonitized two-mica granite and pegmatite, minor hornblende-biotite diorite, intruding metapelites and metavolcanic rocks in southeastern New Hampshire.

Spaulding Tonalite (Early Devonian)

Spaulding Tonalite (Spaulding Quartz Diorite of Fowler-Billings, 1949) - Weakly foliated to nonfoliated, spotted biotite quartz diorite, tonalite, granodiorite, and granite; garnet and muscovite may or may not be present.

Tonalite, diorite, granodiorite, and granite (Late Ordovician )

Tonalite, diorite, granodiorite, and granite - More mafic rocks have hornblende; part of Lost Nation pluton.

Two-mica granite (Devonian - Mississippian)

Two-mica granite - Found in northern New Hampshire.

Two-mica granite of northern and southeastern New Hampshire (Early - Late Devonian)

Two-mica granite of northern and southeastern New Hampshire - Similar to Concord Granite.

Two-mica granite of the Sebago batholith and Effingham pluton of eastern New Hampshire (Mississippian - Pennsylvanian)

Two-mica granite of the Sebago batholith and Effingham pluton of eastern New Hampshire.

Winnipesaukee Tonalite (Early Devonian)

Winnipesaukee Tonalite (Winnipesaukee Quartz Diorite of Billings, 1955) - Gray, massive to foliated tonalite and minor quartz diorite, granodiorite, and granite. Probably coeval with Spaulding Tonalite.

New Jersey

Albite-Oligoclase Granite (Middle Proterozoic)

Albite-Oligoclase Granite - White-weathering, light-greenish-gray, medium- to coarse-grained granite composed of albite or oligoclase, quartz, and sparse amounts of hornblende or clinopyroxene. Petrogenetically related to quartz-oligoclase gneiss (Ylo) but Yla has a more granulitic texture. Includes small bodies of pegmatite not shown on map.

Biotite Granite (Middle Proterozoic)

Biotite Granite - Pink- to buff-weathering, light-pinkish-gray, medium-grained, massive, moderately foliated granite composed of microcline microperthite, quartz, oligoclase, and biotite.

Hornblende Granite (Middle Proterozoic)

Hornblende Granite - Pinkish-gray- to medium-buff-weathering, pinkish-white or light-pinkish-gray, medium- to coarse-grained, gneissoid to indistinctly foliated granite and sparse granite gneiss composed principally of microcline microperthite, quartz, oligoclase, and hornblende. Some phases are quartz syenite or quartz monzonite. Includes small bodies of pegmatite and amphibolite not shown on map. U-Pb age approximately 1,090 Ma (Drake and others, 1991b).

Microantiperthite Alaskite (Middle Proterozoic)

Microantiperthite Alaskite - White-weathering, locally rusty, light-greenish-gray medium- to coarse-grained, gneissic granite and alaskite containing microantiperthite, quartz, oligoclase, and sparse amounts of hornblende, clinopyroxene, biotite, and magnetite.

Microperthite Alaskite (Middle Proterozoic)

Microperthite Alaskite - Pink- to buff-weathering, light-pinkish-gray or pinkish-white, medium- to coarse-grained, gneissoid to indistinctly foliated granite composed principally of microcline microperthite, quartz and oligoclase. Includes small bodies of amphibolite not shown on map.

Mount Eve Granite (Middle Proterozoic)

Mount Eve Granite (Drake and others, 1991a) - Light-pinkish-gray or grayish-tan-weathering, light-gray to pinkish-gray, medium- to coarse-grained granite containing microcline microperthite, quartz, oligoclase, and biotite. Common accessory minerals include hornblende, biotite, magnetite, and allanite. Most of the rock is a syenogranite. Upper intercept U-Pb age of 1,020 +/- 4 Ma (Drake and others, 1991a). Occurs in Pochuck Mountain area along New York boundary.

Pyroxene Alaskite (Middle Proterozoic)

Pyroxene Alaskite - Light-gray- or tan-weathering, greenish-buff to light-pinkish-gray, medium- to coarse-grained, massive, moderately foliated granite composed of mesoperthite to microantiperthite, oligoclase, and quartz. Common accessory minerals are clinopyroxene, titanite and magnetite. Locally includes small bodies of amphibolite not shown on map.

Pyroxene Granite (Middle Proterozoic)

Pyroxene Granite - Gray- to buff- or white-weathering, greenish-gray, medium- to coarse-grained, massive, gneissoid to indistinctly foliated granite containing mesoperthite to microantiperthite, quartz, oligoclase, and clinopyroxene. Common accessory minerals include titanite, magnetite, apatite, and trace amounts of pyrite. Some phases are monzonite, quartz monzodiorite, or granodiorite. Locally includes small bodies of amphibolite not shown on map.

Nevada

Diorite (Jurassic to Cretaceous)

Granitic rocks (Middle Proterozoic)

GRANITIC ROCKS-Porphyritic rapakivi granite.

Granitic rocks (Middle Triassic to Early Jurassic)

GRANITIC ROCKS-Quartz monzonite in northern Esmeralda County

Granitic rocks (Paleocene to Late Miocene)

GRANITIC ROCKS-Mostly quartz monzonite and granodiorite

Granitic rocks (Jurassic)

GRANITIC ROCKS-Mostly quartz monzonite and granodiorite

Granitic rocks (Cretaceous)

GRANITIC ROCKS-Mostly quartz monzonite and granodiorite

Granitic rocks, central and eastern Nevada (Jurassic to Miocene)

GRANITIC ROCKS, CENTRAL AND EASTERN NEVADA-Mostly quartz monzonite and granodiorite. Inconclusively dated or not dated radiometrically

Granitic rocks, western Nevada (Jurassic to Cretaceous)

GRANITIC ROCKS, WESTERN NEVADA (Mesozoic)-Mostly quartz monzonite and granodiorite. Inconclusively dated or not dated radiometrically

Igneous and metamorphic complex (Paleozoic sedimentary rocks with Mesozoic intrusive rocks)

IGNEOUS AND METAMORPHIC COMPLEX-Pegmatitic granite and other granitic rocks complexly intermixed with metasedimentary rocks. Considered to be Mesozoic igneous complex intruding lower Paleozoic and possibly Precambrian Z sedimentary rocks. Grades into units shown on map as lower Paleozoic. Ruby Mountains and East Humboldt Range, Elko County

Intrusive rocks (Late Cretaceous to Middle Miocene)

INTRUSIVE ROCKS-Aphanitic, porphyritic, and coarsely granular rocks ranging in composition from diorite to granite. Clark County

Leucogranite and rhyolite porphyry (Mississippian to Triassic)

LEUCOGRANITE AND RHYOLITE PORPHYRY

Metamorphic rocks (Early Proterozoic)

METAMORPHIC ROCKS-Gneiss and schist and lesser amounts of gneissic granite, pyroxenite, hornblendite, migmatite, pegmatite, and marble.

New York

Biotite-hornblende granite and granite gneiss (Middle Proterozoic)

Biotite-hornblende granite and granite gneiss.

Ferrohedenbergite-fayalite granite and granite gneiss (Middle Proterozoic)

Ferrohedenbergite-fayalite granite and granite gneiss.

Hornblende granite and granite gneiss (Middle Proterozoic)

Hornblende granite and granite gneiss - with subordinate leucogranite.

Muscovite-biotite granite (Upper Devonian)

Muscovite-biotite granite - of Peekskill Pluton.

Oklahoma

Spavinaw Granite (Phanerozoic | Paleozoic | Cambrian-Middle)

TULSA- no description given

Tishomingo and Troy Granites (Phanerozoic | Paleozoic | Cambrian-Middle)

ARDMORE-SHERMAN- Granite, pink, with much microcline and biotite; "Troy" is fine grained; "Tishomingo" is coarse grained. Estimated thickness, 10 miles. (1.3 billion years old) Occurs in the ARBUCKLE MTNS

Wichita Granite Group (Phanerozoic | Paleozoic | Cambrian-Middle)

CLINTON- Pink, medium-grained granite; three outliers have been mapped in the southern part of quadrangle. LAWTON- Granites of various textures; thickness, 600 to 15,000 feet (180 to 4,570 m).

Oregon

Granite and diorite (Jurassic and Triassic) (Triassic to Jurassic)

Felsic to intermediate, granitoid intrusive rocks. Includes Jurassic muscovite granodiorite, hornblende gabbro, tonalite, and quartz diorite of southwest Oregon (Smith and others, 1982)

Pennsylvania

Granitic gneiss and granite (Probably lower Paleozoic)

Granitic gneiss and granite - Includes Springfield Granodiorite (granitized Wissahickon) in Philadelphia area.

Rhode Island

Dedham Granite (Late Proterozoic)

Dedham Granite - Pale-colored grayish-pink to greenish-gray, equigranular to slightly porphyritic, variably altered granite, consisting mainly of plagioclase, alkali-feldspar, and quartz, with secondary development of epidote and chlorite.

Esmond Igneous Suite - fine-grained granite (Late Proterozoic)

Esmond Igneous Suite - fine-grained granite - Gray to pale-pink, fine-grained, equigranular rock, containing microcline, perthite, plagioclase, quartz, and accessory biotite, epidote, sphene, zircon, monazite, apatite, and opaque minerals. Secondary muscovite, chlorite, and calcite. Mainly massive. Includes rock mapped formerly as fine-grained Esmond Granite.

Esmond Igneous Suite - granite (Late Proterozoic)

Esmond Igneous Suite - granite - Gray, tan, greenish, or pale-pink, medium- to coarse-grained, mainly equigranular rock. Contains microcline, perthite, plagioclase, quartz, and accessory biotite, epidote, zircon, allanite, monazite, apatite, sphene, and opaque minerals; secondary muscovite, chlorite, and calcite. Mainly massive, but locally foliated and lineated. Includes rock mapped formerly as Esmond Granite.

Granites of southeastern Rhode Island - granite (Late Proterozoic)

Granites of southeastern Rhode Island - granite - Pink to gray, coarse-grained, equigranular rock composed of microcline, perthite, plagioclase, quartz, and accessory biotite, sphene, zircon, and opaque minerals; secondary chlorite and muscovite. Generally massive, but locally foliated and lineated. Includes some rock mapped formerly as Bulgarmarsh Granite and Metacom Granite Gneiss.

Granites of southeastern Rhode Island - porphyritic granite (Late Proterozoic)

Granites of southeastern Rhode Island - porphyritic granite - Gray, pink, or greenish, generally massive, coarse-grained, porphyritic (microcline phenocrysts) granite. Contains microcline, perthite, plagioclase, quartz, and accessory biotite, hornblende, apatite, sphene, and opaque minerals; secondary chlorite, epidote, and sericite. Includes some rock mapped formerly as Bulgarmarsh Granite and Newport Granite Porphyry.

Narragansett Pier Plutonic Suite - fine-grained granite (Permian)

Narragansett Pier Plutonic Suite - fine-grained granite - Gray to pink, fine-grained equigranular, massive to faintly foliated granite composed of microcline, oligoclase, quartz, biotite, magnetite, zircon, monazite, allanite, and apatite; secondary chlorite, muscovite, calcite. Occurs mainly as elongate (up to 2.5 km) dikes, up to 80 m wide. Mapped formerly as Westerly Granite.

Narragansett Pier Plutonic Suite - granite (Permian)

Narragansett Pier Plutonic Suite - granite - Dark-pink to pale-gray, medium-grained equigranular granite, with lesser granodiorite and quartz monzonite. Composed of microcline, oligoclase, quartz, and accessory biotite, magnetite, ilmenite, apatite, sphene, zircon, monazite, apatite, and allanite; muscovite and garnet locally present; secondary chlorite and calcite. Mainly massive, but locally exhibits faint flow foliation. Cut locally by abundant pegmatite, aplite, and composite aplite-pegmatite of mineralogy similar to the host granite. Unit is a 5 km by 40 km batholith that underlies the southern coast of RI. Intrusion during the latter part of Alleghanian deformation of the Narragansett Basin is indicated by its Permian age, rapid cooling, and field relations. The age of the Narragansett Pier is well constrained by several factors. Brown and others (1978) report a Pennsylvanian fossil contained in an inclusion in the pluton. Radiometric ages of 276 Ma by Kocis and others (1978), 272+/-4 Ma by Hermes and others (1981), and 273+/-2 Ma by Zartman and Hermes (1987) are consistently Early Permian. Structural studies by Mosher (1983) and Reck and Mosther (1988) indicate that intrusion began during the third period of deformation in the Narragansett Basin. Argon release patterns (Dallmeyer, 1982) indicate that the granite and intruded sediments had cooled below argon retention temperatures of hornblende by the Late Permian and of biotite by the Early Triassic. Intruded by the Westerly Granite, which has been radiometrically dated at 276+/-7 Ma. The two granites are probably genetically related based on similarities in age, mineralogy, and geochemistry (Hozik, 1992).

Narragansett Pier Plutonic Suite - leucocratic granite (Permian)

Narragansett Pier Plutonic Suite - leucocratic granite - White to gray leucocratic granite composed of microcline, oligoclase, and quartz. Up to 10% accessory muscovite and garnet, with lesser apatite, zircon, and monazite. Biotite and opaque minerals notably sparse or absent. Mainly massive, but locally exhibits flow foliation caused by alternating layers of pegmatite, aplite, and medium-grained equigranular granite; pegmatitic and aplitic material of mineralogy similar to the host granite. The granite contains widespread xenolithic inclusions and screens of metasedimentary rock, some of which are PAnbr; bedding and fabric in the screens generally is oriented parallel to that in the host metasedimentary country rock. Unit is a 5 km by 40 km batholith that underlies the southern coast of RI. Intrusion during the latter part of Alleghanian deformation of the Narragansett Basin is indicated by its Permian age, rapid cooling, and field relations. The age of the Narragansett Pier is well constrained by several factors. Brown and others (1978) report a Pennsylvanian fossil contained in an inclusion in the pluton. Radiometric ages of 276 Ma by Kocis and others (1978), 272+/-4 Ma by Hermes and others (1981), and 273+/-2 Ma by Zartman and Hermes (1987) are consistently Early Permian. Structural studies by Mosher (1983) and Reck and Mosther (1988) indicate that intrusion began during the third period of deformation in the Narragansett Basin. Argon release patterns (Dallmeyer, 1982) indicate that the granite and intruded sediments had cooled below argon retention temperatures of hornblende by the Late Permian and of biotite by the Early Triassic. Intruded by the Westerly Granite, which has been radiometrically dated at 276+/-7 Ma. The two granites are probably genetically related based on similarities in age, mineralogy, and geochemistry (Hozik, 1992).

Narragansett Pier Plutonic Suite - porphyritic granite (Permian)

Narragansett Pier Plutonic Suite - porphyritic granite - Similar to Png, except contains phenocrysts of microcline and plagioclase up to 1.5 cm in a medium-grained groundmass. Unit is a 5 km by 40 km batholith that underlies the southern coast of RI. Intrusion during the latter part of Alleghanian deformation of the Narragansett Basin is indicated by its Permian age, rapid cooling, and field relations. The age of the Narragansett Pier is well constrained by several factors. Brown and others (1978) report a Pennsylvanian fossil contained in an inclusion in the pluton. Radiometric ages of 276 Ma by Kocis and others (1978), 272+/-4 Ma by Hermes and others (1981), and 273+/-2 Ma by Zartman and Hermes (1987) are consistently Early Permian. Structural studies by Mosher (1983) and Reck and Mosther (1988) indicate that intrusion began during the third period of deformation in the Narragansett Basin. Argon release patterns (Dallmeyer, 1982) indicate that the granite and intruded sediments had cooled below argon retention temperatures of hornblende by the Late Permian and of biotite by the Early Triassic. Intruded by the Westerly Granite, which has been radiometrically dated at 276+/-7 Ma. The two granites are probably genetically related based on similarities in age, mineralogy, and geochemistry (Hozik, 1992).

Scituate Igneous Suite - fine-grained granite (Devonian)

Scituate Igneous Suite - fine-grained granite - Gray to pink, fine-grained, equigranular to locally porphyritic granite (phenocrysts of perthite and plagioclase). Contains microcline, perthite, plagioclase, quartz, and accessory biotite, zircon, allanite, sphene, monazite, fluorite, and opaque minerals; minor garnet is present in some varieties. Partly massive, but locally lineated and foliated. Includes rock mapped formerly as fine-grained Scituate Granite Gneiss, and some rock mapped as Hope Valley Alaskite Gneiss.

Scituate Igneous Suite - granite (Devonian)

Scituate Igneous Suite - granite - Gray to pink, coarse-grained, porphyritic to subporphyritic subsolvus granite (phenocrysts of perthite, microcline, and plagioclase). Contains microcline, perthite, plagioclase, quartz, and accessory biotite, hornblende, allanite, zircon, apatite, sphene, fluorite, and opaque minerals; minor garnet is present in some varieties; some secondary muscovite, calcite, and epidote. Ovoid clots of mafic and accessory minerals are locally prominent. Some rock is massive, but most is commonly lineated and foliated, especially in the west and south near the Hope Valley shear zone. Includes most rock mapped formerly as Scituate Granite Gneiss, and some rock mapped as Hope Valley Alaskite Gneiss.

South Carolina

Edgemoor metagranite (Cambrian or Neoproterozoic)

Edgemoor metagranite: medium-grained, foliated to non-foliated, metamorphosed metagranite containing biotite +/- muscovite +/- garnet

Equigranular granite of Lowrys pluton (Devonian)

Equigranular granite of Lowrys pluton

Granite (Carboniferous to Permian)

Granite

Granite- Bald Rock pluton (Carboniferous to Permian)

Granite- Bald Rock pluton

Granite- Batesburg (gneissic) pluton (Carboniferous to Permian)

Granite- Batesburg (gneissic) pluton

Granite- Catawba-Roddey pluton (Carboniferous to Permian)

Granite- Catawba-Roddey pluton

Granite- Cherryville pluton (Carboniferous to Permian)

Granite- Cherryville pluton

Granite- Clouds Creek pluton (Carboniferous to Permian)

Granite- Clouds Creek pluton

Granite- Clover pluton (Carboniferous to Permian)

Granite- Clover pluton

Granite- Cold Point pluton (Carboniferous to Permian)

Granite- Cold Point pluton

Granite- Columbia pluton (Carboniferous to Permian)

Granite- Columbia pluton

Granite- Coronaca pluton (Carboniferous to Permian)

Granite- Coronaca pluton

Granite- Cuffytown Creek pluton (Carboniferous to Permian)

Granite- Cuffytown Creek pluton

Granite- Edgefield pluton (Carboniferous to Permian)

Granite- Edgefield pluton

Granite- Graniteville-Vaucluse pluton (Carboniferous to Permian)

Granite- Graniteville-Vaucluse pluton

Granite- Harbison pluton (Carboniferous to Permian)

Granite- Harbison pluton

Granite- Johnson pluton (gneissic sheets) (Carboniferous to Permian)

Granite- Johnson pluton (gneissic sheets)

Granite- Lexington pluton (Carboniferous to Permian)

Granite- Lexington pluton

Granite- Liberty Hill pluton (Carboniferous to Permian)

Granite- Liberty Hill pluton

Granite- Pageland pluton (Carboniferous to Permian)

Granite- Pageland pluton

Granite- Winnsboro pluton (Carboniferous to Permian)

Granite- Winnsboro pluton

Granite- York pluton (Carboniferous to Permian)

Granite- York pluton

Gray Court metagranite (Devonian)

Gray Court metagranite: foliated, medium-grained, equigranular to porphyritic biotite granite

Great Falls metagranite (Cambrian or Neoproterozoic)

Great Falls metagranite: foliated, metamorphosed muscovite-biotite granite having accessory garnet and discordantly intruding surrounding rocks

Longtown Metagranite (Neoproterozoic)

Longtown Metagranite: biotite metagranite

Metamorphosed granite and granodiorite (Cambrian or Neoproterozoic)

Metamorphosed granite and granodiorite

Newberry granite (Silurian)

Newberry granite

Pacolet granite (Devonian)

Pacolet granite

Pleasant Hill metagranite (Cambrian or Neoproterozoic)

Pleasant Hill metagranite: possibly similar to nearby Great Falls metagranite

Porphyritic granite of Lowrys pluton (Devonian)

Porphyritic granite of Lowrys pluton

Santuck granite (Paleozoic)

Santuck granite

Unnamed granite of Eastern Piedmont (Carboniferous to Permian)

Unnamed granite of Eastern Piedmont

Waxhaw metagranite (Ordovician to Cambrian)

Waxhaw metagranite: metamorphosed fine- to medium-grained biotite granite and hypabyssal quartz porphyry, non-foliated except adjacent to Gold Hill and Waxhaw shear zones where it is gneissic to phyllonitic

South Dakota

Granite (Archean )

Pink and gray, strongly foliated, medium- to coarse-crystalline, locally pegmatitic, biotite-muscovite granite and gneissic granite.

Harney Peak Granite (Proterozoic | Paleoproterozoic)

Pink to tan, finely crystalline to pegmaticic, peraluminous, muscovite granite and pegmatite containing accessory biotite, garnet, apatite, and tourmaline. Batholith body is dome-shaped with numerous smaller dikes and sills.

Milbank Granite (Archean )

Pink to dark-red, coarse-crystalline granite composed of orthoclase, quartz, and biotite.

Pegmatite (Archean(?) Proterozoic | Paleoproterozoic)

Light-tan to pink pegmatite

Tennessee

Beech Granite (Precambrian)

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.

Mount Rogers Group including Bakersville Gabbro, Beech Granite, Cranberry Granite, and Roan Gneiss (Precambrian)

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 1,000 to 3,000 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 (Precambrian)

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.

Texas

Granite (preCambrian-Proterozoic [Grenville])

Granite

Red Mountain Gneiss (preCambrian-Proterozoic)

Red Mountain Gneiss

Tertiary intrusive rocks, undivided (Phanerozoic | Cenozoic | Tertiary)

Tertiary intrusive rocks, undivided

Town Mountain Granite (preCambrian-Proterozoic)

Town Mountain Granite

Younger granitic intrusion (preCambrian-Proterozoic)

Younger granitic intrusion

Utah

Jurassic intrusive rocks in western Utah (Jurassic)

Tertiary intrusive rocks in central Utah (Late Eocene to Oligocene)

Tertiary intrusive rocks in Salt Lake City-Coalville-Randolph region (Late Eocene to Oligocene)

Tertiary intrusive rocks in southeastern Utah (Oligocene)

Tertiary intrusive rocks in southwestern Utah (Oligocene to Miocene)

Tertiary intrusive rocks in western Utah (Late Eocene to Early Miocene)

Virginia

Alkali Feldspar Leucogranite (Proterozoic Y)

Alkali feldspar leucogranite

Biotite Granite (Proterozoic)

Biotite granite

Biotite Granite (Proterozoic Y)

Biotite granite

Biotite Granite (Proterozoic)

Biotite granite

Biotite Granodiorite and Biotite Granite (Proterozoic Z)

Biotite granodiorite, biotite granite

Biotite-Muscovite Granite (Proterozoic)

Biotite-muscovite granite

Buffalo Granite (Proterozoic)

Buffalo granite - Granite

Buggs Island Pluton (Mississippian Pennsylvanian)

Buggs Island pluton - Granite

Carysbrook Pluton (Proterozoic)

Carysbrook pluton - Granite.

Columbia pluton (Ordovician)

Columbia pluton - Granite

Crozet Granite (Proterozoic Y)

Crozet granite - Granite

Falls Church Intrusive Suite (Cambrian-Ordovician)

Falls Church Intrusive Suite - Tonalite, granodiorite, monzogranite, and trondhjemite.

Falls Run Granite Gneiss (Silurian)

Falls Run Granite Gneiss - Granite

Falmouth Intrusive Suite (Mississippian - Pennsylvanian)

Falmouth Intrusive Suite - Granite, quartz monzonite, granodiorite, and tonalite

Fine Creek Mills Granite (Proterozoic)

Fine Creek Mills granite - Granite

Flat Rock Granite (Proterozoic)

Flat Rock granite - Granite

Foliated Biotite Granite (Proterozoic)

Foliated biotite granite

Garnetiferous Leucocratic Metagranite (Proterozoic Y)

Garnetiferous leucocratic metagranite

Gneissic Granite and Granodiorite (Proterozoic)

Gneissic granite and granodiorite

Granite (Proterozoic)

Granite

Green Springs Pluton - Quartz diorite and granite. (Proterozoic Z-Pennsylvanian)

Green Springs Pluton - Quartz diorite and granite.

Leatherwood Granite (Cambrian)

Leatherwood Granite - Granite

Leucocharnockite (Proterozoic Y)

Leucocharnockite

Leucocratic Metagranite (Proterozoic Y)

Leucocratic metagranite

Marshall Metagranite (Proterozoic Y)

Marshall Metagranite - Medium-granied biotite metagranite

Marshall Metagranite (Proterozoic Y)

Marshall Metagranite - Coarse-grained metagranite

Megacrystic Charnockite (Proterozoic Y)

Megacrystic charnockite

Melrose Granite (Cambrian)

Melrose Granite - Granite

Mobley Mountain Granite (Proterozoic Z)

Mobley Mountain granite - Granite

North View Granite (Proterozoic)

North View Granite

Occoquan Granite (Cambrian-Ordovician)

Occoquan Granite - Granite

Old Rag Granite (Proterozoic Y)

Old Rag granite - Granite

Petersburg Granite (Mississippian)

Petersburg Granite - Granite

Piney Branch Complex (Proterozoic Z-Cambrian)

Piney Branch Complex - Metamorphosed mafic and ultramafic rocks

Porphyritic Granite (Proterozoic)

Porphyritic granite

Porphyritic Granite (Proterozoic)

Porphyritic granite

Porphyritic Leucocharnockite (Proterozoic Y)

Porphyritic Leucocharnockite - Leucocharnockite

Porphyroblastic Biotite Granite (Proterozoic)

Porphyroblastic biotite granite

Red Oak Pluton (Proterozoic)

Red Oak pluton - Granite

Robertson River Igneous Suite (Proterozoic Z)

Robertson River Igneous Suite - White Oak alkali feldspar granite

Robertson River Igneous Suite - Amissville alkali feldspar granite (Proterozoic Z)

Robertson River Igneous Suite - Amissville alkali feldspar granite

Robertson River Igneous Suite - Arrington Mountain alkali feldspar granite (Proterozoic Z)

Robertson River Igneous Suite - Arrington Mountain alkali feldspar granite

Robertson River Igneous Suite - Battle Mountain granite (Proterozoic Z)

Robertson River Igneous Suite - Battle Mountain granite

Robertson River Igneous Suite - Laurel Mills granite (Proterozoic Z)

Robertson River Igneous Suite - Laurel Mills granite

Robertson River Igneous Suite - Rivanna granite (Proterozoic Z)

Robertson River Igneous Suite - Rivanna granite

Schaeffer Hollow Granite (Proterozoic Y)

Schaeffer Hollow granite - Granite

Shelton Formation (Ordovician)

Shelton Formation - Granite and quartz monzonite gneiss

Striped Rock Granite (Proterozoic Z)

Striped Rock Granite - Biotite granite and syenite.

Ta River Metamorphic Suite (Cambrian)

Ta River Metamorphic Suite - Amphibolite gneiss

Vermont

Granites (Permian-Triassic)

Granites - Biotite and hornblende granites.

Mount Holly Complex (Precambrian)

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 1.35 to 1.30 Ga have been determined and interpreted as age of crystallization (Ratcliffe and others, unpub. data). Cores of abraded zircon obtained from College Hill Granite Gneiss of Mount Holly Complex have a U-Pb upper intercept age of 1245 +/-14 Ma, interpreted as crystallization age for that granite (Aleinikoff and others, 1990). Dust collected by abrasion of zircons, thought to represent migmatitic overgrowth, has a Pb-Pb age of approx 1100 Ma. These data suggest that College Hill Granite Gneiss was intruded at 1245 Ma and migmatized at 1100 Ma. On north and south slopes of College Hill, College Hill Granite Gneiss grades outward into migmatitic biotite granite gneiss of Mount Holly Complex. College Hill is discordant to contacts and folds in paragneiss units of Mount Holly Complex. Dacitic metavolcanics are found within Washington Gneiss of Berkshire massif of MA (Ratcliffe and Zartman, 1968). 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).

Undifferentiated Granitic Rocks (Ordovician)

Undifferentiated granitic rocks.

Waits River Formation, Barton River Member (Devonian)

Waits River Formation, Barton River Member - Interbedded siliceous crystalline limestone and sercite-quartz-chlorite phyllite in northern Vermont; diopsidic limestone and cordierite hornfels at contacts with granitic dikes and sills.

Washington

Mesozoic alkali intrusive rocks (Likely Eocene)

Albite granite as small plugs and sills near Boundary in Stevens County.

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.

Tertiary dikes, sills, and small intrusive bodies (Middle to Late Tertiary)

Dikes are commonly diabase; plugs and sills are generally andesite porphyry and dacite.

Tertiary granitic rocks (Probably mostly Eocene; ranges from Miocene to Paleocene)

Granite, quartz monzonite, quartz diorite, granodiorite, and trondhjemite. Includes dacite porphyry and granite breccia near Bumping Lake, Yakima County.

Wisconsin

Alkali feldspar granite of 1835 Ma age group (Early Proterozoic)

Alkali feldspar granite of 1835 Ma age group - Red to pink, medium-grained leucocratic alkali feldspar granite; contains miarolitic cavities; biotite is altered to opaque oxide minerals; contains fluorite locally. Called red granite previously (Sims, 1990). Exposed in both Pembine-Wausau and Marshfield terranes.

Athelstane Quartz Monzonite (Early Proterozoic)

Athelstane Quartz Monzonite - Pink, coarse-grained granite to granodiorite containing nearly equal amounts of microcline microperthite, plagioclase, and quartz and 5-10 percent biotite and (or) hornblende. Mafic minerals are interstitial and give a clotty appearance. (1836 +/- 15 Ma)

Gabbroic rocks of Keweenawan affinity (Middle Proterozoic)

Gabbroic rocks of Keweenawan affinity - gabbro, anorthosite, granite, peridotite

Gneissic granite (1,871 +/- 5 Ma) (Early Proterozoic)

Gneissic granite (1,871 +/- 5 Ma) - Pale-red, medium- to fine-grained, leucocratic, mylonite gneiss exposed near Neillsville, Wisc.

Granite near Cherokee (1853 +/- 21 Ma) (Early Proterozoic)

Granite near Cherokee (1853 +/- 21 Ma) - Pink, coarse-grained granite consisting of microcline microperthite and oligoclase phenocrysts in a fine-grained matrix of quartz, potassium feldspar, and oligoclase. Hornblende and (or) biotite occur in clots

Granite-tonalite (Early Proterozoic)

Granite-tonalite - Gray to pinkish-gray, medium-grained, generally equigranular granite to tonalite and granitoid gneiss; locally includes diorite. Intrudes older metavolcanic rocks. Zircon ages range from 1852 +/- 15 to 1862 +/- 5 Ma

Granitic rocks of 1760-Ma age group (Early Proterozoic)

Granitic rocks of 1760-Ma age group - In northern Wisconsin, granite to granodiorite of varied texture. In southern Wisconsin (not mapped separately), red to pink alkali-feldspar granophyric granite associated with rhyolites of both peraluminous and metaluminous affinities (unit Xr of Marshfield terrane).

Granitic rocks, undivided (Early Proterozoic)

Granitic rocks, undivided - Gray, weakly foliated to massive granite in poorly exposed areas.

Granophyre (Middle Proterozoic)

Granophyre

Mellen Intrusive Complex; Granite (about 1000 Ma) (Middle Proterozoic)

Mellen Intrusive Complex; Granite (about 1000 Ma)

Migmatitic gneiss and amphibolite (Late to Early Archean) (Archean)

Migmatitic gneiss and amphibolite (Late to Early Archean) - Varied gneisses of mostly unknown age in cores of gneiss domes and fault-bounded uplifts (Archean gneiss terranes). Except for the Watersmeet dome (Late to Early Archean), all dated rocks are Late Archean. Includes granite of Late Archean age that transgresses gneisses and amphibolite.

Porphyritic granite (Early Proterozoic)

Porphyritic granite - Granite containing plagioclase, microcline, and quartz phenocrysts in a fine-grained granophyric matrix. Probably subvolcanic intrusions related to volcanic rocks of 1835- to 1845-Ma age group

Puritan Quartz Monzonite (Late Archean) (Late Archean)

Puritan Quartz Monzonite (Late Archean) - Pink to pinkish-gray, medium- to coarse-grained, equigranular to inequigranular granite to granodiorite in Puritan batholith south of Gogebic Range. Age 2710 +/- 140 Ma (Sims and others, 1977)

Rhyolite (Early Proterozoic)

Rhyolite - Ash-flow tuffs and interbedded volcaniclastic sedimentary rocks and cogenetic granite (unit Xga) exposed as inliers in southern Wisconsin. In central Wisconsin pink, flow-banded rhyolite and chert-cemented breccia inferred to be 1760 Ma.

Spikehorn Granite and Bush Lake Granites, undivided (1835 +/- 6 Ma) (Early Proterozoic)

Spikehorn Granite and Bush Lake Granites, undivided (1835 +/- 6 Ma) - Gray to pinkish-gray, fine- to medium-grained, massive granite containing scattered phenocrysts of potassium feldspar. Exposed in northeastern Wisconsin

Wausau Pluton; Granite near Big Eau Pleine Reservoir (Middle Proterozoic)

Wausau Pluton; Granite near Big Eau Pleine Reservoir - pink to red, medium- to fine-grained granite containing miarolitic cavities

Wausau Pluton; Granite near Nine Mile Swamp (Middle Proterozoic)

Wausau Pluton; Granite near Nine Mile Swamp - Orange to pink, coarse-grained massive granite composed of alkali feldspar sporadically mantled by plagioclase, quartz, and biotite; contains miarolitic cavities

Wolf River batholith (1470 Ma); Hager Formation; Quartz porphyry member (Middle Proterozoic)

Wolf River batholith (1470 Ma); Hager Formation; Quartz porphyry member - Contains 30-45 percent resorbed quartz phenocrysts (3-4 mm) and less abundant alkali feldspar and plagioclase phenocrysts (4-5 mm) in a fine-grained matrix of quartz, two feldspars, biotite, and hornblende

Wolf River batholith (1470 Ma); High Falls Granite (Middle Proterozoic)

Wolf River batholith (1470 Ma); High Falls Granite - Gray to pink, equigranular to porphyritic granite to granodiorite containing microcline microperthite, concentrically zoned plagioclase, quartz, biotite, and hornblende

Wolf River batholith (1470 Ma); Red River Granite (Middle Proterozoic)

Wolf River batholith (1470 Ma); Red River Granite - Contains alkali feldspar phenocrysts (0.5-2 cm), subordinate plagioclase and quartz, and rare clusters of biotite with or without hornblende

Wolf River batholith (1470 Ma); Waupaca Granite (Middle Proterozoic)

Wolf River batholith (1470 Ma); Waupaca Granite - Rapakivi granite (wiborgite) containing 70-80 percent coarse (1.5 -5 cm) ovoid alkali feldspars mantled by plagioclase, coarse anhedral quartz, and interstitial hornblende and biotite

Wolf River batholith (1470 Ma); Wolf River Granite (Middle Proterozoic)

Wolf River batholith (1470 Ma); Wolf River Granite- Red, coarse-grained rapakivi granite consisting of large (1-3 cm) ovoid alkali feldspar sporadically mantled by plagioclase, interstitial plagioclase, quartz, biotite, hornblende, and ilmenite

Wolf River Batholith; Belongia Granite (Middle Proterozoic)

Wolf River Batholith; Belongia Granite- Red to pink granite consisting of both a coarse-grained and a fine-grained facies. Probably an epizonal intrusion

Wyoming

Sherman Granite (Proterozoic | Mesoproterozoic (1415-1435 Ma))

SHERMAN GRANITE (AGE 1,415 TO 1,435 Ma)--In Medicine Bow and Laramie Mountains.