|Name||Beardsley Member [of Harrison (Prospect) Gneiss]|
|Geologic age||Middle? Ordovician|
Metamorphic > GneissMedium- to dark-gray, medium-grained, well-layered and lineated gneiss, composed of plagioclase, quartz, microcline, hornblende, biotite, and epidote. Microcline may occur as megacrysts 1 to 3 cm across.
Metamorphic > SchistMinor layers of garnetiferous schist.
Metamorphic > Metasedimentary > Calc-silicate-rockrarely calc-silicate rock
Metamorphic > Metasedimentary > Metacarbonate > Marblerarely marble
|Comments||Part of Central Lowlands; Iapetus (Oceanic) Terrane - Connecticut Valley Synclinorium; Hartland Belt. Secondary unit description per CT007.|
Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000.
Sevigny, J.H. and Hanson, G.N., 1993, Orogenic evolution of the New England Appalachians of southwestern Connecticut: Geological Society of America Bulletin, v. 105, no. 12, p. 1591-1605.
|Counties||Fairfield - Hartford - New Haven|