|Name||Metavolcanic member [of Collins Hill Formation]|
|Geologic age||Upper? and Middle Ordovician|
Metamorphic > SchistRanges from mafic to felsic, from dark layered amphibolite and hornblende schist, locally with garnet or epidote.
Metamorphic > AmphiboliteRanges from mafic to felsic, from dark layered amphibolite and hornblende schist, locally with garnet or epidote.
Metamorphic > Gneisslight-gray (in places purplish), laminated gneiss, composed of quartz, oligoclase, and biotite, in which some layers contain garnet (generally manganiferous) and hornblende or cummingtonite
|Comments||Part of Eastern Uplands; Iapetus (Oceanic) Terrane - Bronson Hill Anticlinorium; Brimfield Schist and equivalent formations (includes Collins Hill Formation) (Upper? and Middle Ordovician).|
Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000.
|Counties||Hartford - Middlesex - New Haven|