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

Geologic units in Dutchess county, New York

Manhattan Formation, undivided (Ordovician?) at surface, covers 3 % of this area

Manhattan Formation, undivided - pelitic schists, amphibolite; Units ?Omb, ?Omc, and ?Omd may be Cambrian eugeosynclinal rocks thrust upon Oma; ?Omd - sillimanite-garnet-muscovite-biotite-plagioclase-quartz gneiss; ?Omc - sillimanite-garnet-muscovite-biotite-quartz-plagioclase schistose gneiss, sillimanite nodules, local quartz-rich layers; ?Omb - discontinous unit of amphibolite and ?Omc-type schist.

Lithology: pelitic schist; gneiss; amphibolite

Glacial and Alluvial Deposits (Quaternary) at surface, covers 0.4 % of this area

Glacial and Alluvial Deposits - underlying bedrock geology unknown.

Lithology: alluvium; glacial drift

Stuyvesant Falls Formation (Ordovician) at surface, covers 2 % of this area

Stuyvesant Falls Formation - south of Troy; shale, siltstone.

Lithology: shale; siltstone

Cambrian thru Middle Ordovician carbonate rock (Cambrian - Middle Ordovician) at surface, covers < 0.1 % of this area

Cambrian thru Middle Ordovician (Barneveld) carbonate rock - occuring as slivers caught along thrusts of later allochthones, or carbonate blocks in Taconic Melange.

Lithology: carbonate; melange

Biotite granite gneiss (Middle Proterozoic) at surface, covers 3 % of this area

Biotite granite gneiss - overprint signifies inequigranular texture.

Lithology: granitic gneiss

Germantown Formation (Cambrian) at surface, covers 2 % of this area

Germantown Formation - south of Troy; shale, conglomerate, limestone.

Lithology: shale; conglomerate; limestone

Austin Glen Formation (Pawlet in Vermont) (Middle Ordovician) at surface, covers 18 % of this area

Austin Glen Formation (Pawlet in Vermont) - graywacke, shale.

Lithology: graywacke; shale

Stissing Formation (Cambrian) at surface, covers 0.2 % of this area

Stissing Formation - dolostone, shale.

Lithology: dolostone (dolomite); shale

Stockbridge Formation (Cambrian - Lower Ordovician) at surface, covers 8 % of this area

Stockbridge Formation - calcitic and dolomitic marble.

Lithology: marble

Elizaville Formation (Cambrian - Ordovician) at surface, covers 3 % of this area

Elizaville Formation - shale, argillite, quartzite.

Lithology: shale; argillite; quartzite

Biotite-quartz-plagioclase gneiss (Middle Proterozoic) at surface, covers 0.8 % of this area

Biotite-quartz-plagioclase gneiss - with subordinate biotite granitic gneiss, amphibolite, calcsilicate rock.

Lithology: gneiss; granitic gneiss; amphibolite; calc-silicate rock

Poughquag Quartzite (Cambrian) at surface, covers 1 % of this area

Poughquag Quartzite - (includes local Dalton Formation at base)-locally conglomeratic.

Lithology: quartzite; conglomerate

Walloomsac Formation (Middle Ordovician) at surface, covers 19 % of this area

Walloomsac Formation - slate, phyllite, schist, metagraywacke.

Lithology: slate; phyllite; schist; metasedimentary rock

Hornblende granite and granite gneiss (Middle Proterozoic) at surface, covers 1 % of this area

Hornblende granite and granite gneiss - with subordinate leucogranite.

Lithology: granite; granitic gneiss

Copake and Halcyon Lake Formations, Rochdale Limestone (Lower Ordovician) at surface, covers 1 % of this area

Copake and Halcyon Lake Formations, Rochdale Limestone - Columbia County: Copake Formation-limestone, dolostone; Halcyon Lake Formation-chert, calc-dolostone.

Lithology: limestone; dolostone (dolomite); chert

Garnet-bearing gneiss and interlayered quartzite (Middle Proterozoic) at surface, covers 0.2 % of this area

Garnet-bearing gneiss and interlayered quartzite - contains varying amounts of biotite, garnet, sillimanite; minor marble, amphibolite, rusty paragneiss.

Lithology: gneiss; quartzite; marble; amphibolite; paragneiss

Nassau Formation (Cambrian ?) at surface, covers 3 % of this area

Nassau Formation - south of 43 degrees; slate, shale, thin quartzite, includes Stuyvesant Conglomerate, Diamond Rock Quartzite, Curtis Mountain Quartzite, and Bomoseen Graywacke Members.

Lithology: shale; quartzite; slate; conglomerate; graywacke

Amphibolite (Middle Proterozoic) at surface, covers 0.2 % of this area

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

Lithology: amphibolite

Mount Merino and Indian River Formations (Ordovician) at surface, covers 2 % of this area

Mount Merino and Indian River Formations - shale, slate, cherts.

Lithology: shale; slate; chert

Wappinger Group (Cambrian - Lower Ordovician) at surface, covers 8 % of this area

Wappinger Group - (including Fishkill limestone and dolostone): Copake Formation ?-limestone, dolostone; Rochdale Formation-limestone, dolostone; Halcyon Lake Dolostone-locally cherty; Briarcliff Dolostone; Pine Plains Formation-dolostone, shale, oolite; Stissing Formation-dolostone, shale.

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

Garnet-biotite-quartz-feldspar gneiss (Middle Proterozoic) at surface, covers 0.2 % of this area

Garnet-biotite-quartz-feldspar gneiss - quartzite, quartz-feldspar gneiss, calcsilicate rock.

Lithology: gneiss; quartzite; calc-silicate rock

Balmville Limestone (Middle Ordovician) at surface, covers 0.3 % of this area

Balmville Limestone - Vermont: Whipple Limestone.

Lithology: limestone

Stockbridge Formation (Lower Cambrian) at surface, covers < 0.1 % of this area

Stockbridge Formation - Massive to finely laminated steel-gray calcitic dolomite marble containing a prominent zone of white quartz nodules near top.

Lithology: marble

Taconic Melange (Middle Ordovician) at surface, covers 1.0 % of this area

Taconic Melange - chaotic mixture of Early Cambrian thru Middle Ordovician pebble to block-size clasts in a pelitic matrix of Middle Ordovician (Barneveld) age. Rims and floors earlier submarine gravity slides of Taconian Orogeny.

Lithology: melange

Normanskill Shale (Middle Ordovician) at surface, covers 8 % of this area

Normanskill Shale - minor mudstone, sandstone.

Lithology: shale; mudstone; sandstone

Everett Schist (Cambrian?) at surface, covers 8 % of this area

Everett Schist - minor meta-graywacke lenses. Includes Greylock Schist in Massachusetts.

Lithology: schist; metasedimentary rock

Interlayered metasedimentary rock and granitic, charnockitic, mangeritic, or syenitic gneiss (Middle Proterozoic) at surface, covers 1 % of this area

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

Lithology: metasedimentary rock; gneiss

Briarcliff Dolostone and Pine Plains Formation (Cambrian) at surface, covers 2 % of this area

Briarcliff Dolostone and Pine Plains Formation - Columbia County: Pine Plains-dolostone, oolite, shale.

Lithology: dolostone (dolomite); shale

Pyroxene-hornblende-quartz-plagioclase gneiss (Middle Proterozoic) at surface, covers 0.2 % of this area

Pyroxene-hornblende-quartz-plagioclase gneiss.

Lithology: mafic gneiss