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

Geologic units in Washington county, New York

Calcitic and dolomitic marble (Middle Proterozoic) at surface, covers 0.6 % of this area

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

Lithology: marble; calc-silicate rock; amphibolite

Hortonville Formation (Ordovician) at surface, covers < 0.1 % of this area

Hortonville Formation - Black, carbonaceous and pyritic slate and phyllite, locally sandy; brown weathered limy beds are common near base. Occurs east of Highgate Springs, Champlain, and Orwell thrusts.

Lithology: slate; phyllite

St. Catherine Formation (Cambrian) at surface, covers < 0.1 % of this area

St. Catherine Formation - Purple, gray-green, and variegated slate and phyllite containing minor interbeds of white to green quartzite; locally albitic. Purple and green chloritoid-bearing slate and phyllite is within dashed line in northern Taconic Range, but not separated farther south.

Lithology: slate; phyllite; quartzite

Potsdam Sandstone (Cambrian) at surface, covers 2 % of this area

Potsdam Sandstone (Covey Hill in Quebec)

Lithology: sandstone

Undifferentiated Middle Ordovician thru Lower Cambrian allochthonous rocks (Cambrian - Ordovician) at surface, covers 19 % of this area

Undifferentiated Middle Ordovician thru Lower Cambrian allochthonous rocks - principally pelite; lesser quartzite, limestone, conglomerate, graywacke.

Lithology: mudstone; quartzite; limestone; conglomerate; graywacke

Shelburne, Whitehall, and Strites Pond Formations (Ordovician) at surface, covers < 0.1 % of this area

Shelburne, Whitehall, and Strites Pond Formations - The Shelburne is chiefly a white marble or gray limestone characterized by raised reticulate lines of gray dolomite on the weathered surface; includes Sutherland Falls marble, intermediate dolomite and Columbian marble of the marble quarries. Interbedded massive dolomite increases westward and predominates in the Whitehall formation, west of Champlain and Orwell thrusts. The Strites Pond, which is identical to the Shelburne, is east of Philipsburg thrust.

Lithology: marble; limestone; dolostone (dolomite)

Valcour, Crown Point, and Day Point Limestones (Middle Ordovician) at surface, covers < 0.1 % of this area

Valcour, Crown Point, and Day Point Limestones - locally reefy, Ste. Therese Siltstone at base; Middlebury Limestone in Vermont; St. Martin and Rockcliffe Limestones in St. Lawrence Valley. Includes some Otbr and Obk adjacent to Champlain Thrust in Vermont.

Lithology: limestone; siltstone

Biotite-quartz-plagioclase paragneiss, amphibolite, and related migmatite (Middle Proterozoic) at surface, covers 4 % of this area

Biotite-quartz-plagioclase paragneiss, amphibolite, and related migmatite - locally sillimanitic; commonly garnetiferous in and adjacent to Adirondack Highlands.

Lithology: paragneiss; amphibolite; migmatite

Pulaski and Whetstone Gulf Formations (Upper Ordovician) at surface, covers 0.6 % of this area

Pulaski and Whetstone Gulf Formations - siltstone, shale.

Lithology: siltstone; shale

Bascom Formation, and undifferentiated Luke Hill, Naylor Ledge and Hastings Creek Limestones (Ordovician) at surface, covers < 0.1 % of this area

Bascom Formation, and undifferentiated Luke Hill, Naylor Ledge and Hastings Creek Limestones - Interbedded dolomite, limestone or marble, calcareous sandstone, quartzite and limestone breccia; irregular dolomitic layers, thin sandy laminae, and slaty or phyllitic partings characterize limestone and marble of lower, middle, and upper parts of the Bascom, respectively; south of West Rutland it includes some of the Chipman formation. The combined Luke Hill, Naylor Ledge, and Hastings Creek, east of Philipsburg thrust, are stratigraphically equivalent to the Bascom.

Lithology: dolostone (dolomite); limestone; marble; sandstone; quartzite; sedimentary breccia

Mettawee Slate (Cambrian?) at surface, covers 9 % of this area

Mettawee Slate (Bull in Vermont) - includes Castleton (North Brittain) Conglomerate. Mudd Pond Quartzite, Zion Hill Quartzite, and Bomoseen Graywacke Members.

Lithology: slate; quartzite; conglomerate; graywacke

Undivided metasedimentary rock and related migmatite (Middle Proterozoic) at surface, covers 3 % of this area

Undivided metasedimentary rock and related migmatite.

Lithology: metasedimentary rock; migmatite

Taconic Melange (Middle Ordovician) at surface, covers 2 % 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

Cutting Dolomite, and Undifferentiated Morgan Corner and Wallace Creek Formations (Ordovician) at surface, covers < 0.1 % of this area

Cutting Dolomite, and Undifferentiated Morgan Corner and Wallace Creek Formations - Typical Cutting is a massive, gray weathered, nondescript dolomite with finely laminated calcareous sandstone at base. The combined Morgan Corner and Wallace Creek Formations, east of Philipsburg thrust, are stratigraphically equivalent to the Cutting. Cutting Formation of Cady (1945) is stratigraphically extended to include Division D, member 1 of Brainerd and Seeley, 1890, (now called Smith Basin Member), and is here renamed Cutting Hill Formation. No new type section is designated. Redefined unit includes Winchell Creek Sandstone Member, East Shoreham Member (named), and Smith Basin Member (Washington and Chisick, 1988).

Lithology: dolostone (dolomite); sandstone

Biotite and/or hornblende granite gneiss (Middle Proterozoic) at surface, covers < 0.1 % 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

Poultney Formation ("A" Member) (Cambrian) at surface, covers 7 % of this area

Poultney Formation ("A" Member) - shale, limestone; Hatch Hill Formation-shale, dolostone; West Castleton Formation-shale, limestone, conglomerate.

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

Beekmantown Group (in part) (Cambrian) at surface, covers 3 % 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

gneiss, quartzite, calc-silicate granulite (Precambrian) at surface, covers < 0.1 % of this area

Gneiss, quartzite, calc-silicate granulite.

Lithology: gneiss; quartzite; granulite

Canajoharie Shale (Middle Ordovician) at surface, covers 13 % of this area

Canajoharie Shale - includes Hortonville and Ira Shales in Vermont.

Lithology: black shale

Quartzite, quartz-biotite schist and graphitic schist (Middle Proterozoic) at surface, covers 0.3 % of this area

Quartzite, quartz-biotite schist and graphitic schist - in part feldspathic, micaceous, garnetiferous, sillimanitic.

Lithology: quartzite; schist

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

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

Lithology: felsic gneiss

Glacial and Alluvial Deposits (Quaternary) at surface, covers 4 % of this area

Glacial and Alluvial Deposits - underlying bedrock geology unknown.

Lithology: alluvium; glacial drift

Lamprophyre, trachyte, and rhyolite dikes (Jurassic - Lower Cretaceous) at surface, covers < 0.1 % of this area

Lamprophyre, trachyte, and rhyolite dikes - not shown in Proterozoic terrane.

Lithology: lamprophyre; trachyte; rhyolite

Metagabbro (Middle Proterozoic) at surface, covers 1.0 % of this area

Metagabbro - metagabbro, olivine metagabbro, derived amphibolite.

Lithology: mafic metavolcanic rock; amphibolite

Charnockite, granitic and quartz syenite gneiss (Middle Proterozoic) at surface, covers 5 % 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 0.4 % 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

Cambrian thru Middle Ordovician carbonate rock (Cambrian - Middle Ordovician) at surface, covers 0.2 % 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

Poultney Formation ("B" and "C" Members) (Ordovician) at surface, covers 5 % of this area

Poultney Formation ("B" and "C" Members) - shale, slate, siltstone.

Lithology: shale; slate; siltstone

Austin Glen Formation (Pawlet in Vermont) (Middle Ordovician) at surface, covers 2 % of this area

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

Lithology: graywacke; shale

Clarendon Springs, Ticonderoga, and Rock River Dolomites; Gorge Formation (Cambrian) at surface, covers < 0.1 % of this area

Clarendon Springs, Ticonderoga, and Rock River Dolomite; Gorge Formation - Fairly uniform, massive, smooth weathered gray dolomite characterized by numerous geodes and knots of white quartz; quartz sandstone and irregular masses of chert are near the top. Called the Ticonderoga west of Orwell and Champlain thrusts and the Rock River east of Philipsburg thrust. The Gorge is a partly conglomeratic facies on the west limb of the St. Albans synclinorium..

Lithology: dolostone (dolomite); sandstone; chert; conglomerate

Germantown Formation (Cambrian) at surface, covers 0.4 % of this area

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

Lithology: shale; conglomerate; limestone

Danby and Potsdam Formations (Cambrian) at surface, covers < 0.1 % of this area

Danby and Potsdam Formations - The Danby is comprised of interbedded quartzite and dolomite; white quartzite beds, more than a foot thick, separated by 10 to 12 feet of dolomite in eastern areas, increase westward to continuous sections of white to pink weathered, massively bedded Potsdam quartzite, west of Orwell thrust.

Lithology: quartzite; dolostone (dolomite)

Hatch Hill and West Castleton Formations, Undifferentiated (Cambrian) at surface, covers < 0.1 % of this area

Hatch Hill and West Castleton Formations, Undifferentiated - The Hatch Hill, a relatively thin formation that succeeds the West Castleton, is characterized by rusty and spongy weathered gray calcareous quartzite traversed by numerous white-quartz viens. The West Castleton is a gray to black, siliceous, carbonaceous, and pyritiferous slate containing paper-thin white sandy laminae. Black slates are common to both formations. A blue-gray weathered black limestone is near the base of the West Castleton in a few places.

Lithology: quartzite; slate; limestone

Biotite-quartz-plagioclase paragneiss (Middle Proterozoic) at surface, covers 0.4 % 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

Beekmantown Group (in part) (Lower Ordovician) at surface, covers 5 % 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 0.9 % 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

Walloomsac Formation (Middle Ordovician) at surface, covers 1 % of this area

Walloomsac Formation - slate, phyllite, schist, metagraywacke.

Lithology: slate; phyllite; schist; metasedimentary rock

Chipman, Bridport, and Beldens Formations, Providence Island Dolomite; Bridport Dolomite Member (Ordovician) at surface, covers < 0.1 % of this area

Chipman, Bridport, and Beldens Formation, Providence Island Dolomite; Bridport Dolomite Member - Buff to brown weathered, sharply defined and laterally persistent beds chiefly of medium bedded to massive, scored dolomite; variously designated Bridport Formation and Providence Island Dolomite in northwestern Vermont.

Lithology: dolostone (dolomite)

Hybrid rock: mangeritic to charnockitic gneiss (Middle Proterozoic) at surface, covers 3 % of this area

Hybrid rock: mangeritic to charnockitic gneiss - with xenocrysts of calcic andesine and, locally, xenoliths of anorthosite; with increasing percentage of anorthosite component, passes gradationally into anorthositic rocks.

Lithology: gneiss; anorthosite

Mount Merino and Indian River Formations (Ordovician) at surface, covers 5 % of this area

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

Lithology: shale; slate; chert

Amphibolite (Middle Proterozoic) at surface, covers 1 % of this area

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

Lithology: amphibolite

Trenton and Black River Groups, undivided (Middle Ordovician) at surface, covers 0.7 % 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

Nassau Formation (Cambrian ?) at surface, covers 1 % 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