|Name||Shelton Member [of Trap Falls Formation]|
|Geologic age||Middle or Lower Ordovician|
Metamorphic > GneissWhite, light-gray, or buff, fine- to medium-grained, generally well foliated granitic gneiss, composed of sodic plagioclase, quartz, microcline, muscovite, and garnet (in tiny almost ubiquitous grains), also commonly minor biotite. Generally interlayered with biotite gneiss.
Metamorphic > Schist > Mica-schistgenerally interlayered with mica schist
Metamorphic > Metasedimentary > Calc-silicate-rockgenerally interlayered with calc-silicate rock
|Comments||Part of Central Lowlands; Iapetus (Oceanic) Terrane - Connecticut Valley Synclinorium; Hartland Belt. Part of Hawley Formation and equivalent formations (includes Trap Falls and Cobble Mountain Formations) (Middle Ordovician). 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.