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

Geologic units in Herkimer county, New York

Clinton Group (Silurian) at surface, covers 1 % of this area

Clinton Group - Herkimer Sandstone including Joslin Hill and Jordanville Members; Kirkland Hematite; Willowvale Shale; Westmoreland Hematite; Sauquoit Formation-sandstone, shale; Otsquago Sandstone; Oneida Conglomerate.

Lithology: shale; sandstone; chemical; conglomerate

Marcellus Formation (Middle Devonian) at surface, covers 0.7 % of this area

Marcellus Formation - Pecksport, Solsville, Otsego, and Chittenango shale and sandstone Members, Cherry Valley Limestone, and Union Springs Shale Members.

Lithology: black shale; limestone; shale; sandstone

Helderberg Group (Lower Devonian) at surface, covers 4 % of this area

Helderberg Group - West of Albany: Alsen, Becraft, New Scotland, Kalkberg, Coeymans, and Manlius Limestones; Rondout Dolostone. South of Albany: Port Ewen, Alsen thru Manlius Limestones; Rondout Dolostone.

Lithology: limestone; dolostone (dolomite)

Glacial and Alluvial Deposits (Quaternary) at surface, covers 7 % of this area

Glacial and Alluvial Deposits - underlying bedrock geology unknown.

Lithology: alluvium; glacial drift

Quartz-feldspar gneiss (Middle Proterozoic) at surface, covers 0.8 % of this area

Quartz-feldspar gneiss - with variable amounts of garnet, sillimanite, biotite.

Lithology: felsic gneiss

Charnockite, granitic and quartz syenite gneiss (Middle Proterozoic) at surface, covers 4 % of this area

Charnockite, granitic and quartz syenite gneiss - variably leucocratic, containing varying amounts of hornblende, pyroxenes, biotite; may contain interlayered amphibolite, metasedimentary gneiss, migmatite. Overprint signifies inequigranular texture or phacoidal structure.

Lithology: granulite; felsic gneiss; granitic gneiss; amphibolite; migmatite

Leucogranitic (alaskitic) gneiss (Middle Proterozoic) at surface, covers 0.1 % of this area

Leucogranitic (alaskitic) gneiss - sodic plagioclase ranges from generally subordinate to locally dominant; locally with biotite, hornblende, pyroxene, garnet, sillimanite, disseminated magnetite; commonly contains metasedimentary layers, amphibolite, migmatite; plagioclase-rich variety is host to magnetite ore bodies in eastern Adirondacks.

Lithology: granitic gneiss; metasedimentary rock; amphibolite; migmatite

Onondaga Limestone (Lower to Middle Devonian) at surface, covers 3 % of this area

Onondaga Limestone - Schoharie Formation-shale, limestone; Carlisle Center Siltstone; Esopus Shale.

Lithology: shale; limestone; siltstone

Ilion Shale (Upper Silurian) at surface, covers 0.2 % of this area

Ilion Shale

Lithology: black shale

Biotite-quartz-plagioclase paragneiss (Middle Proterozoic) at surface, covers 2 % of this area

Biotite-quartz-plagioclase paragneiss - commonly very low in biotite content, with interbedded feldspathic and biotitic quartzite and amphibolite; sillimanite and garnet common, graphite sporadic.

Lithology: paragneiss; quartzite; amphibolite

Trenton Group (Middle Ordovician) at surface, covers 2 % of this area

Trenton Group - In Black River Valley: Cobourg Formation-Hillier shale and limestone Member, Hallowell limestone Member; Denley, Sugar River, Kings Falls, and Rockland Limestones. In Champlain Valley: Glens Falls Formation-Montreal shale and limestone Member, Larrabee limestone Member.

Lithology: limestone; shale

Beekmantown Group (in part) (Lower Ordovician) at surface, covers 0.2 % of this area

Beekmantown Group (in part) - In St. Lawrence Valley: Ogdensburg Dolostone (Beauharnois Dolostone in Canada); In Champlain Valley: Providence Island Dolostone; Fort Cassin Formation-limestone, dolostone; Fort Ann Formation (Spellman of Clinton and Essex Counties)-limestone, dolostone; Cutting Formation-dolostone (locally cherty), limestone, siltstone. In Vermont: includes Bridport, Bascom, Cutting, and Shelburne carbonates.

Lithology: dolostone (dolomite); limestone; chert; siltstone

Biotite and/or hornblende granite gneiss (Middle Proterozoic) at surface, covers 22 % of this area

Biotite and/or hornblende granite gneiss - locally pyroxenic; commonly with subordinate leucogranitic gneiss, biotite-quartz-plagioclase gneiss, other metasedimentary rocks, amphibolite, migmatite. Amphibolite with porphyroblasts of K-feldspar locally prominent in northwest Adirondacks. Overprint signifies inequigranular texture or phacoidal structure. In northwest Adirondacks, grades into Yphg.

Lithology: paragneiss; metasedimentary rock; amphibolite; migmatite

Gabbroic or noritic metanorthosite (Middle Proterozoic) at surface, covers < 0.1 % of this area

Gabbroic or noritic metanorthosite - dark mineral content in excess of 10 percent (part of unit Ya).

Lithology: metavolcanic rock

Frankfort Formation (Upper Ordovician) at surface, covers 4 % of this area

Frankfort Formation - shale, siltstone.

Lithology: shale; siltstone

Cobleskill Limestone (Upper Silurian) at surface, covers 2 % of this area

Cobleskill Limestone; Bertie, Camillus, and Syracuse Formations - shale, dolostone; Brayman Shale.

Lithology: limestone; shale; dolostone (dolomite)

Black River Group (Middle Ordovician) at surface, covers 0.1 % of this area

Black River Group - In Black River Valley: Chaumont Limestone-locally cherty; Lowville Limestone; Pamelia Formation-dolostone, shale, arkose. In Champlain Valley: Amsterdam, Isle La Motte, and Lowville Limestones: Pamelia Dolostone.

Lithology: limestone; dolostone (dolomite); shale; arkose; chert

Trenton and Black River Groups, undivided (Middle Ordovician) at surface, covers 4 % of this area

Trenton and Black River Groups, undivided - Glens Falls and Orwell Limestones. In Canada: Lindsay, Verulam, Bodcaygeon, Gull River Limestones; Shadow Lake Dolostone.

Lithology: limestone

Amphibolite (Middle Proterozoic) at surface, covers < 0.1 % of this area

Amphibolite - commonly biotitic; garnetiferous, pyroxenic, in and adjacent to Adirondack Highlands.

Lithology: amphibolite

Calcitic and dolomitic marble (Middle Proterozoic) at surface, covers 0.2 % of this area

Calcitic and dolomitic marble - predominantly; variably siliceous; in part with calcsilicate rock and amphibolite.

Lithology: marble; calc-silicate rock; amphibolite

Undifferentiated Hamilton Group (Middle Devonian) at surface, covers < 0.1 % of this area

Undifferentiated Hamilton Group - shale, siltstone. In eastern Orange County: Skunnemunk Formation-sandstone, conglomerate; Bellvale Formation-shale, sandstone; Cornwall Shale.

Lithology: shale; siltstone; sandstone; conglomerate

Vernon Shale (Upper Silurian) at surface, covers 0.6 % of this area

Vernon Shale

Lithology: shale; black shale

Pulaski and Whetstone Gulf Formations (Upper Ordovician) at surface, covers < 0.1 % of this area

Pulaski and Whetstone Gulf Formations - siltstone, shale.

Lithology: siltstone; shale

Undivided metasedimentary rock and related migmatite (Middle Proterozoic) at surface, covers 7 % of this area

Undivided metasedimentary rock and related migmatite.

Lithology: metasedimentary rock; migmatite

Utica Shale (Middle Ordovician) at surface, covers 12 % of this area

Utica Shale

Lithology: black shale

Biotite and/or hornblende granite gneiss (Middle Proterozoic) at surface, covers 2 % of this area

Biotite and/or hornblende granite gneiss - locally pyroxenic; commonly with subordinate leucogranitic gneiss, biotite-quartz-plagioclase gneiss, other metasedimentary rocks, amphibolite, migmatite. Amphibolite with porphyroblasts of K-feldspar locally prominent in northwest Adirondacks. Overprint signifies inequigranular texture or phacoidal structure. In northwest Adirondacks, grades into Yphg.

Lithology: granitic gneiss; metasedimentary rock; amphibolite; migmatite

Pyroxene-hornblende-quartz-plagioclase gneiss (Middle Proterozoic) at surface, covers 0.6 % of this area

Pyroxene-hornblende-quartz-plagioclase gneiss.

Lithology: mafic gneiss

Interlayered metasedimentary rock and granitic, charnockitic, mangeritic, or syenitic gneiss (Middle Proterozoic) at surface, covers 14 % of this area

Interlayered metasedimentary rock and granitic, charnockitic, mangeritic, or syenitic gneiss.

Lithology: metasedimentary rock; gneiss

Charnockite, mangerite, pyroxene-quartz syenite gneiss (Middle Proterozoic) at surface, covers 5 % of this area

Charnockite, mangerite, pyroxene-quartz syenite gneiss - overprint signifies inequigranular texture.

Lithology: granulite; monzonite; gneiss

Beekmantown Group (in part) (Cambrian) at surface, covers 1 % of this area

Beekmantown Group (in part) - In Champlain Valley: Whitehall Formation-dolostone, limestone (with Cryptozoon reefs); Ticonderoga Formation-dolostone (locally cherty), sandstone. In Vermont: Clarendon Springs Dolostone; Danby Formation-sandstone, quartzite, dolostone.

Lithology: dolostone (dolomite); limestone; sandstone; quartzite