Massive to finely laminated steel-gray calcitic dolomite marble containing a prominent zone of white quartz nodules near top.
Rusty-weathering, muscovite-biotite-sillimanite and/or kyanite-garnet schist; blue-quartz ribbed conglomerate, interlayered garnet-plagioclase-quartz metadacite.
Dark-gray, graphitic quartz phyllite and schist containing minor lenses of limestone.
Containing beds of amphibolite, aluminous schist, quartzite, and calc-silicate gneiss.
Light pinkish-gray ferrohastingsite-biotite, quartz-rodded granodioritic to quartz monzonitic gneiss, coarsely porphyritic, locally having fine-grained aplitic border. Intrudes all Berkshire Proterozoic Y units.
White to blue-gray and white layered calcite marble.
Beige, tan, and dark-gray weathering quartzose dolomite marble containing interbeds of black, green and maroon phyllite and punky weathering blue quartz pebble quartzite.
Light-green and greenish-gray chlorite-muscovite-albite or chloritoid-rich phyllite. Predominantly dark-gray chloritoid-rich schist in Lenox Mountain.
Tan weathering, muscovite-microcline quartzite and feldspathic quartzite rich in black tourmaline, locally includes thin beds of other rock types listed below.
Undifferentiated Hoosac Formation.
Lustrous, soft green, yellowish-green and purple laminated chloritoid-chlorite phyllite (Mettawee Member).
Well-layered, rusty-tan weathering muscovite-biotite plagioclase-microcline-quartz granofels containing layers of rusty sulfidic calc-silicate rocks.
White to light-powdery-blue-gray dolostone with disseminated grains of quartz and prominent sprays of tremolite in higher-grade areas.
White, massive vitreous quartzite.
Biotite ferrohastingsite granodioritic and granitic gneiss with large schlieren of biotite, locally contains garnet and muscovite.
Gray to dark-greenish-gray, siliceous phyllite with abundant beds of quartzite, olive-gray metasiltstone and subgraywacke (includes Bomoseen Graywacke Member and Zion Hill quartzite Member).
Light-green to light-bluish-gray schist having thin granular quartz lenses and lamellae. Kyanite and staurolite typical at higher grades.
Probably metamorphosed rhyolite.
Light-greenish-gray to buff, fine-grained, pinstriped granofels and schist.
Blue and gray mottled limestone and calcite marble and beds of beige dolostone.
Soft, lustrous green phyllite with minor beds of green quartzite and well laminated gray dolomitic phyllite; resembles Hoosac (CAZhg) and Nassau (CAZnp).
Lustrous greenish-gray schist characterized by 1-1.5 cm garnets; resembles Gassetts Schist of Vermont.
Hornblende-spotted plagioclase-hornblende-quartz gneiss and granofels and well-layered biotite-hornblende-plagioclase-quartz gneiss containing knots of diopside or epidote.
Including calcitic or dolomitic chondrodite-diopside marble, coarse hornblende-plagioclase-diopside and diopside rock, locally containing beds of lustrous muscovite-kyanite sillimanite-garnet schist.
Orangish-gray, gray, and light-greenish-gray muscovite-quartz schist and interlayered feldspathic quartzite and quartz conglomerate; minor beds of rusty albitic schist.
Green to gray-green chlorite-sericite-quartz phyllite; interbeds of chloritoid- or albite-rich schist and minor quartzite, locally rich in garnet and kyanite.
Tan to orangish-tan quartz and gneiss cobble and pebble conglomerate, rusty feldspathic schist, and lustrous greenish-gray muscovite quartz schist.
Black to dark-gray carbonaceous quartz schist.
Greenish chlorite-albite-magnetite-sericite-quartz schist and granofels.
White to yellowish-gray weathering, flaggy quartzite interbedded in feldspathic quartzite.
Gray to black, fine-grained , slightly rusty, moderately carbonaceous schist; minor fine- to medium-grained dark-gray to white quartzite. Minor lenses of rock identical to OCAr.
Light-green to gray, white albite-spotted phyllite and interbedded blue-quartz metagraywacke, salmon-pink dolostone, and blue-quartz conglomerate. Minor interbeds of black and white albite-spotted phyllite resembles Hoosac (CAZhga).
Contains irregular pods of diopside or cummingtonite-talc rock or amphibole calc-silicate, epidote-layered quartz-plagioclase gneiss near Hinsdale.
Orange-brown weathering, graphite-albite-biotite calcitic marble and schistose marble and interbedded black phyllite.
Well-layered hornblende-biotite gneiss .
Tan-beige weathering quartzose calcite and dolomite marble; minor cross-laminated quartzite.
Tan to dark-blue-gray laminated quartzite and calcareous quartzite previously mapped as Bellowspipe Quartzite.
White to gray biotite-oligoclase-microcline Rapakivi granite gneiss containing blue quartz. Intrudes Yb, Ybu.
Rusty-weathering, coarse garnet schist and feldspathic schist.
Bluish-gray weathering black sulfidic slate and chert.
Dark-gray to black chloritoid-rich phyllite.
Austerlitz Phyllite - minor quartzite
Coarse- to medium-grained hornblende-garnet amphibolite, hornblende-plagioclase gneiss and phlogopite-hornblende-plagioclase amphibolite (metabasalt).
Green to dark-green greenstone or amphibolite.
Rusty-brown to dark-gray, albite-spotted muscovite-biotite schist or gneiss, with interlayered black garnet-biotite-albite-quartz schist near base; interfingers with Dalton Formation.
Slate, phyllite, schist, metagraywacke.
Intruded near or along thrust faults. Intrudes CAZh and Proterozoic Y gneisses.
Rusty-weathering diopside and sulfidic -rich calcite marble and calc-silicate rock.
Consisting of completely mixed phyllites of Walloomsac Formation Taconic allochthon.
Minor meta-graywacke lenses. Includes Greylock Schist in Massachusetts.
Light-gray to tan, albite-muscovite-calcite spangled schist.
Zones of mixed inclusions of Stockbridge Formation, Walloomsac Formation, and phyllites of the Taconic allochthon.
Associated with blastomylonite along thrust slices. Intrudes Proterozoic Y gneisses.
Gray conglomerate containing pebbles of albite and blue quartz, and boulders of gneiss.
Greenish-gray albitic phyllite.
Olive-gray to green, blue-quartz pebble metagraywacke and quartzite.
Greenish-gray, plagioclase-rich, blue quartz pebble metagraywacke and minor gneiss-cobble conglomerate.
Calcitic and dolomitic marble.
Fine- to medium-grained, well-layered and foliated amphibolite; epidote-rich layers locally abundant. Includes its typical Chester Amphibolite Member at Chester, Massachusetts.
Dark-green to greenish brown, massive to well foliated stilpnomelane-chlorite-oligoclase-epidote metabasalt and basaltic tuff.
Locally with relict subophitic texture. Intrudes Yw and Ygg.
Grayish to greenish (some rusty-weathering), fine- to medium-grained, foliated but poorly layered schist or phyllite, composed of quartz, albite or oligoclase, muscovite, garnet, staurolite or chloritoid, and generally chlorite. Local layers are dark-gray to silvery schist or phyllite.
Interpreted as tectonic slivers.
Gray, generally massive dolomite marble, commonly contains quartz grains, locally beds of sandstone; may be calcitic near top.
Predominantly greenish-gray to pale-lustrous-green chlorite-muscovite-quartz phyllite; and green and purple, bedded and mottled phyllite. Locally contains boudins and thin beds of limestone and pods of pinkish-gray to cream-white dolostone, and minor quartzite. Unit interfingers with the West Castleton Formation above and laterally grades into the Bomoseen Graywacke Member. Also shown as CZnm (Mettawee Member of the Nassau Formation of Potter, 1972). Rocks of the Giddings Brook, Sunset Lake, and Bird Mountain slices. Part of the Taconic Allochthon.
Intrudes Yw and Ygg.
Black to dark-or silvery-gray, rarely layered schist or phyllite, composed of quartz, albite, and commonly garnet and staurolite or sillimanite (locally strongly retrograded to chlorite and muscovite). Locally feldspathic or calcareous near the base.
Diorite at Goff Ledges (Ogd) and similar diorite (Od) in the Windsor quadrangle. Very coarse-grained to pegmatitic, slightly foliated hornblende-plagioclase diorite, minor hornblende pyroxenite. Ogd intrudes CAZh and CAZhk. Od intrudes the Rowe Schist of the Rowe-Hawley zone.
Occuring as slivers caught along thrusts of later allochthones, or carbonate blocks in Taconic Melange. Also mapped as horses along normal faults.
White, pink, cream, and light-gray, generally well bedded dolomitic marble interlayered with phyllite and schist and with siltstone, sandstone, or quartzite, commonly dolomitic.
White to gray massive calcite marble, commonly mottled with dolomite and locally interlayered with dolomite marble and calcareous siltstone and sandstone.