|Name||Precambrian gneisses of the Chain Lakes Massif|
Metamorphic > Gneiss (Greenschist)GS - Greenschist facies; Protolith Y - Basement
|Comments||Islesboro Formation is of Late Proterozoic age. Consists of interbedded pelite, siltstone and sandstone, limestone and dolomite, conglomerate, rhyolite, and basalt. D.B. Stewart (1990, oral commun.) considers Islesboro to be distal facies of North Haven Greenstone, Ellsworth Schist and schist at Columbia Falls (eastern coastal ME). (ME072) Unit description from USGS GEOLEX website (ME078). GS - Greenschist facies; AA - Low rank amphibolite facies; Protolith Q - Interbedded pelite and sandstone|
Osberg, P.H., Hussey, A.M., and Boone, G.M., 1985, Bedrock geologic map of Maine: Maine Geological Survey, Dept. of Conserv., scale 1:500,000.
|Counties||Franklin - Oxford - Somerset|