Ratlum Mountain Schist

Gray, medium-grained, interlayered schist and granofels, composed of quartz, oligoclase, muscovite (in the schist), biotite, and garnet, also staurolite and kyanite in the schist. Numerous layers and lenses of amphibolite; also some of quartz-spessartine (coticule) and calc-silicate rock.
State Connecticut
Name Ratlum Mountain Schist
Geologic age Lower Ordovician
Lithologic constituents
Major
Metamorphic > SchistGray, medium-grained, interlayered schist and granofels, composed of quartz, oligoclase, muscovite (in the schist), biotite, and garnet, also staurolite and kyanite in the schist.
Metamorphic > Granoblastic > GranofelsGray, medium-grained, interlayered schist and granofels, composed of quartz, oligoclase, biotite, and garnet.
Minor
Metamorphic > Amphibolite
Incidental
Metamorphic > Metasedimentary > Calc-silicate-rocksome of quartz-spessartine (coticule) and calc-silicate rock
Comments Part of Central Lowlands; Iapetus (Oceanic) Terrane - Connecticut Valley Synclinorium; Equivalents of Savoy Schist of Massachusetts (Emerson, 1898, 1917) and of Moretown Formation of Vermont and Massachusetts (Bedrock Geologic Map of Massachusetts, Zen and others, 1983) (includes Golden Hill and Ratlum Mountain Schists) (Lower? Ordovician). Same as Or
References

Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000.

NGMDB product
Counties Fairfield