|By Morgan Patterson |
Aug 13, 2013
Did a little digging... Southington Mountain Member of The Straits Schist (Devonian or Silurian or both).
Info: Southington Mountain Member [of The Straits Schist] - Gray to silvery, non-rusty, medium-grained, well-layered alternating schist and granofels, composed of quartz, oligoclase, muscovite, biotite, and garnet, commonly with staurolite and kyanite (or sillimanite); schist commonly graphitic. Metamorphosed strata named Southington Mountain Schist by Fritts (1963) is traceable into southern Bristol quad., and is here revised as Southington Mountain Member of The Straits Schist. Consists of alternating bands of quartz-feldspar granulite and of graphitic, muscovite-biotite schist. Unit is characterized by distinct, widespread, graded bedding and locally abundant staurolite. Unit may correlate with the Goshen Formation of the Heath quad, MA-VT, of Middle Silurian to Early Devonian age (Simpson, 1990).
The reason there's all the rock is that it's an old fault line with New Haven Arkose (Upper Triassic; possibly Lower Jurassic at top)which is the valley floor to the East. here's the map:
And here's the link to the Google Earth CT Geology Layer... awesome stuff for u rock hunters out there... What has always surprised me is the amount of Marble in the western part of the state and yet we have little to no known climbing on the Marble. Tons of crap schist though.
CT Geology Layer