Upper member [of Middletown Formation] (CTOmu;0)

Upper member [of Middletown Formation]

Light-gray, generally rusty weathering, well-layered gneiss and granofels, composed of oligoclase, quartz, biotite, and amphibole (cummingtonite, anthophyllite, gedrite, or hornblende, or several of these), also garnet and chlorite. Many layers of amphibolite and biotite gneiss throughout.

State	Connecticut
Name	Upper member [of Middletown Formation]
Geologic age	Middle Ordovician
Lithologic constituents	Major Metamorphic > Granoblastic > GranofelsLight-gray, generally rusty weathering, well-layered gneiss and granofels, composed of oligoclase, quartz, biotite, and amphibole (cummingtonite, anthophyllite, gedrite, or hornblende, or several of these), also garnet and chlorite. Metamorphic > GneissLight-gray, generally rusty weathering, well-layered gneiss and granofels, composed of oligoclase, quartz, biotite, and amphibole (cummingtonite, anthophyllite, gedrite, or hornblende, or several of these), also garnet and chlorite; also biotite gneiss. Minor Metamorphic > Amphibolite
Comments	Part of Eastern Uplands; Iapetus (Oceanic) Terrane - Bronson Hill Anticlinorium
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	NGMDB product page for 54245
Counties	Middlesex

Upper member [of Middletown Formation]

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