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Mineral Resources > Online Spatial Data > Geology > by state > New Hampshire Geology

Geologic units in Carroll county, New Hampshire

Quartz syenite (Jurassic) at surface, covers < 0.1 % of this area

Quartz syenite - Commonly porphyritic and mesoperthitic; contains biotite and, locally, fayalite, hastingsite, hornblende, or ferrohedenbergite.

Lithology: quartz syenite

Two-mica granite of the Sebago batholith and Effingham pluton of eastern New Hampshire (Mississippian - Pennsylvanian) at surface, covers 20 % of this area

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

Lithology: granite

Concord Granite (Late Devonian ) at surface, covers < 0.1 % of this area

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

Lithology: granite; tonalite

Rhyolite and fine-grained granite (Cretaceous) at surface, covers 2 % of this area

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.

Lithology: rhyolite; granite; ignimbrite; porphyry

Rangeley Formation, Ribbon-banded calc-silicate of eastern New Hampshire (Lower Silurian (Llandoverian)) at surface, covers 1 % of this area

Rangeley Formation, Ribbon-banded calc-silicate of eastern New Hampshire - Probably equivalent to Patch Mountain Member of the Sangerville Formation (Llandoverian and Wenlockian) of central Maine.

Lithology: calc-silicate rock

Trondhjemite and abundant pegmatite (Devonian - Mississippian) at surface, covers 1 % of this area

Trondhjemite and abundant pegmatite - Gray and fine-grained; possibly belonging to the Sebago batholith.

Lithology: trondhjemite; pegmatite

Augite-hornblende-biotite gabbro (Cretaceous) at surface, covers < 0.1 % of this area

Augite-hornblende-biotite gabbro - Fine- to coarse-grained.

Lithology: gabbro

Kinsman Granodiorite (Early Devonian ) at surface, covers 3 % of this area

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.

Lithology: granite; granodiorite; tonalite; quartz diorite

Winnipesaukee Tonalite (Early Devonian) at surface, covers 17 % of this area

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.

Lithology: tonalite; quartz diorite; granodiorite; granite

Mesoperthitic biotite granite (Early Cretaceous) at surface, covers 4 % of this area

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

Lithology: granite

Madrid Formation (Upper Silurian? ) at surface, covers 1.0 % of this area

Madrid Formation - Massive to weakly foliated, purple biotite-feldspar granofels, layered calc-silicate, and dark pelitic-sulfidic schist containing calc-silicate pods in upper member; an eastern facies equivalent to the upper part of the Fitch Formation. Locally mapped as the Warner Formation of Nielson (1981) in southern New Hampshire.

Lithology: granofels; calc-silicate schist; pelitic schist

Hornblende (or alkalic amphibole) syenite (Jurassic) at surface, covers 0.2 % of this area

Hornblende (or alkalic amphibole) syenite.

Lithology: syenite

Nepheline-sodalite-hastingsite syenite (Jurassic) at surface, covers 0.3 % of this area

Nepheline-sodalite-hastingsite syenite - Found at Red Hill in Mt. Chocorua quadrangle (see index accompanying "Sources of Map Data").

Lithology: syenite

Devonian - Silurian Rindgemere Formation upper member (Devonian - Silurian) at surface, covers < 0.1 % of this area

Devonian - Silurian Rindgemere Formation upper member

Lithology: mudstone; sandstone

Medium-grained mesoperthitic granite containing riebeckite and (or) hastingsite (Cretaceous) at surface, covers < 0.1 % of this area

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

Lithology: granite

Porphyritic syenite (Jurassic) at surface, covers 0.5 % of this area

Porphyritic syenite - Hastingsite or hornblende and (or) hedenbergite are present.

Lithology: syenite

Migmatitic rocks (Devonian - Silurian) at surface, covers 2 % of this area

Migmatitic rocks - Formations unidentifiable owing to obliteration of original sedimentary or volcanic characteristics by anatexis or by numerous intrusions.

Lithology: migmatite

Upper part of Rangeley Formation (Lower Silurian (Llandoverian)) at surface, covers 0.7 % of this area

Upper part of Rangeley Formation - Rusty-weathering, pelitic schist, metasandstone, and local coarse-grained metasandstone lentils; calc-silicate pods common; minor coticule. Probably equivalent to member C of Rangeley Formation of Maine.

Lithology: pelitic schist; metasedimentary rock; calc-silicate rock

Jurassic granite (Jurassic) at surface, covers < 0.1 % of this area

Jurassic granite - Jurassic biotite granite undivided

Lithology: granite

Mount Osceola Granite, Granite containing hornblende and, locally, hastingsite, ferrohedenbergite, or fayalite (Early - Middle Jurassic) at surface, covers 8 % of this area

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

Lithology: granite

Devonian - Silurian undifferentiated sedimentary rocks in areas of extreme migmatization (Devonian - Silurian) at surface, covers < 0.1 % of this area

Devonian - Silurian undifferentiated sedimentary rocks in areas of extreme migmatization

Lithology: migmatite

Conway Granite (Middle - Late? Jurassic) at surface, covers 11 % of this area

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

Lithology: granite

Perry Mountain Formation, undivided (Lower? - Middle? Silurian) at surface, covers 0.9 % of this area

Perry Mountain Formation, undivided - Sharply interbedded quartzites, light-gray nongraphitic metapelite, and "fast-graded" meta-turbidites. Coticule layers common.

Lithology: quartzite; meta-argillite; metasedimentary rock

Devonian granite (Devonian) at surface, covers < 0.1 % of this area

Devonian granite

Lithology: granite

Basalt (Cretaceous ) at surface, covers 0.8 % of this area

Basalt - Black, chiefly massive to porphyritic. Includes minor rhyolitic ignimbrite and andesitic tuff. Part of Ossipee Mountain Complex of Kingsley (1931)

Lithology: basalt; ignimbrite; tuff

Porphyritic granite (Jurassic) at surface, covers < 0.1 % of this area

Porphyritic granite.

Lithology: granite

Granite porphyry (Early Jurassic) at surface, covers 0.6 % of this area

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).

Lithology: granite

Madrid and Smalls Falls Formations, undivided (Silurian) at surface, covers 1 % of this area

Madrid and Smalls Falls Formations, undivided.

Lithology: granofels; schist; calc-silicate schist; pelitic schist

Lower part of Rangeley Formation (Lower Silurian (Llandoverian)) at surface, covers 3 % of this area

Lower part of Rangeley Formation - Gray, thinly laminated (5-25 mm) metapelite with local lentils of turbidites and thin quartz conglomerates in western New Hampshire. Sparse calc-silicate pods and coticule. Probably equivalent to member B of Rangeley Formation of Maine.

Lithology: meta-argillite; meta-conglomerate; calc-silicate rock

Biotite-hornblende granodiorite (Cretaceous) at surface, covers < 0.1 % of this area

Biotite-hornblende granodiorite.

Lithology: granodiorite

Hornblende or alkalic amphibole quartz syenite (Jurassic) at surface, covers 1 % of this area

Hornblende or alkalic amphibole quartz syenite.

Lithology: quartz syenite

Rangeley Formation, undivided (Lower Silurian (Llandoverian)) at surface, covers 2 % of this area

Rangeley Formation, undivided.

Lithology: metasedimentary rock; calc-silicate rock; meta-argillite; quartzite; pelitic schist; granofels; felsic metavolcanic rock

Smalls Falls Formation, undivided (Upper to Middle Silurian (Ludlovian and Wenlockian)) at surface, covers 1 % of this area

Smalls Falls Formation, undivided -Very rusty weathering, thinly bedded sulfidic-graphitic schist and pyrrhotitic calc-silicate granofels. Eastern facies equivalent to lower part of the Fitch Formation. Locally mapped as Francestown Formation of Nielson (1981) in southern New Hampshire.

Lithology: schist; granofels

Mesoperthitic granite (Jurassic) at surface, covers 0.2 % of this area

Mesoperthitic granite - Contains riebeckite and (or) hastingsite.

Lithology: granite

Mount Osceola Granite, Green biotite mesoperthitic granite (Early - Middle Jurassic) at surface, covers 0.8 % of this area

Mount Osceola Granite, Green biotite mesoperthitic granite.

Lithology: granite

Porphyritic biotite granite (Cretaceous) at surface, covers < 0.1 % of this area

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

Lithology: granite

Littleton Formation, undivided (Lower Devonian; Siegenian) at surface, covers 9 % of this area

Littleton Formation undivided - Gray metapelite and metawacke and subordinate metavolcanic rocks; generally, but not everywhere, conformable with underlying Fitch or Madrid Formations. Fossiliferous in western New Hampshire.

Lithology: metasedimentary rock; metavolcanic rock

Large mesoperthitic phenocrysts in a pink to gray quartz syenite porphyry of "Albany type" (Cretaceous) at surface, covers 0.9 % of this area

Large mesoperthitic phenocrysts in a pink to gray quartz syenite porphyry of "Albany type" - Alkalic amphibole or fayalite may be present. Part of Ossipee Mountain Complex of Kingsley (1931).

Lithology: quartz syenite

Carboniferous alkali feldspar granite (muscovite accessory mineral) (Carboniferous) at surface, covers < 0.1 % of this area

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

Lithology: granite

Perry Mountain and Rangeley Formations, undivided (Silurian) at surface, covers 4 % of this area

Perry Mountain and Rangeley Formations, undivided.

Lithology: quartzite; calc-silicate rock; felsic metavolcanic rock; meta-argillite; granofels; metasedimentary rock; conglomerate; pelitic schist

Porphyritic hornblende or alkalic amphibole quartz syenite (Jurassic) at surface, covers 2 % of this area

Porphyritic hornblende or alkalic amphibole quartz syenite.

Lithology: quartz syenite

Hastingsite granite (Jurassic) at surface, covers < 0.1 % of this area

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

Lithology: granite

Two-mica granite of northern and southeastern New Hampshire (Early - Late Devonian) at surface, covers 0.2 % of this area

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

Lithology: granite

Moat Volcanics (Middle Jurassic?) at surface, covers 1 % of this area

Moat Volcanics - Bedded and ignimbritic tuffs, flows, and breccias; also porphyritic rhyolite and minor trachyte.

Lithology: ignimbrite; ash-flow tuff; volcanic breccia (agglomerate); rhyolite; trachyte

Devonian granodiorite (Devonian) at surface, covers < 0.1 % of this area

Devonian granodiorite - biotite granodiorite

Lithology: granodiorite