Ratlum Mountain Schist (CTOr;0)

State	Connecticut
Name	Ratlum Mountain Schist
Geologic age	Lower? Ordovician
Lithologic constituents	Major Metamorphic > Granoblastic > GranofelsGray, medium-grained, interlayered schist and granofels, composed of quartz, oligoclase, biotite, and garnet. 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. 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; Hartland Belt. Equivalents of Savoy Schist of Massachusetts (Emerson, 1898, 1917) (CT009, CT010) and of Moretown Formation of Vermont and Massachusetts (Bedrock Geologic Map of Massachusetts, Zen and others, 1983) (CT011) (includes Golden Hill and Ratlum Mountain Schists) (Lower? Ordovician).
References	Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000. Emerson, B.K., 1898, Geology of old Hampshire County, Massachusetts, comprising Franklin, Hampshire, and Hampden Counties: U.S. Geological Survey Mon. 29, 790 p. https://pubs.er.usgs.gov/publication/m29 Emerson, B.K., 1917, Geology of Massachusetts and Rhode Island: U.S. Geological Survey Bulletin 597, 289 p. https://pubs.er.usgs.gov/publication/b597 Zen, E-an (editor), Goldsmith, Richard (compiler), Ratcliffe, N.M. (compiler), Robinson, Peter (compiler), Stanley, R.S. (compiler), Hatch, N.L., Jr., Shride, A.F., Weed, E.G.A. and Wones, D.R., 1983, Bedrock geologic map of Massachusetts: U.S. Geological Survey Special Map, 3 sheets, scale 1:250,000. https://pubs.er.usgs.gov/publication/70046713
NGMDB product	NGMDB product page for 54245
Counties	Fairfield - Hartford - Litchfield - New Haven

State

Name

Ratlum Mountain Schist

Geologic age

Lower? Ordovician

Lithologic constituents

Major

Metamorphic > Granoblastic > GranofelsGray, medium-grained, interlayered schist and granofels, composed of quartz, oligoclase, biotite, and garnet.

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.

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; Hartland Belt. Equivalents of Savoy Schist of Massachusetts (Emerson, 1898, 1917) (CT009, CT010) and of Moretown Formation of Vermont and Massachusetts (Bedrock Geologic Map of Massachusetts, Zen and others, 1983) (CT011) (includes Golden Hill and Ratlum Mountain Schists) (Lower? Ordovician).

References

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

Emerson, B.K., 1898, Geology of old Hampshire County, Massachusetts, comprising Franklin, Hampshire, and Hampden Counties: U.S. Geological Survey Mon. 29, 790 p.

https://pubs.er.usgs.gov/publication/m29

Emerson, B.K., 1917, Geology of Massachusetts and Rhode Island: U.S. Geological Survey Bulletin 597, 289 p.

https://pubs.er.usgs.gov/publication/b597

Zen, E-an (editor), Goldsmith, Richard (compiler), Ratcliffe, N.M. (compiler), Robinson, Peter (compiler), Stanley, R.S. (compiler), Hatch, N.L., Jr., Shride, A.F., Weed, E.G.A. and Wones, D.R., 1983, Bedrock geologic map of Massachusetts: U.S. Geological Survey Special Map, 3 sheets, scale 1:250,000.

https://pubs.er.usgs.gov/publication/70046713

NGMDB product

NGMDB product page for 54245

Counties

Fairfield - Hartford - Litchfield - New Haven