Silurian - Ordovician Vassalboro Formation

Silurian - Ordovician Vassalboro formation
State Maine
Name Silurian - Ordovician Vassalboro Formation
Geologic age Silurian - Ordovician
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Calcareous)GS - Greenschist facies; E - Epidote-amphibolite facies; AA - Low rank amphibolite facies; AB - Medium rank amphibolite facies; AC - High rank amphibolite facies; Protolith M - Calcareous sandstone; interbedded sandstone and impure limestone
Minor
Sedimentary > Carbonate > Limestone (Calcareous)GS - Greenschist facies; E - Epidote-amphibolite facies; AA - Low rank amphibolite facies; AB - Medium rank amphibolite facies; AC - High rank amphibolite facies; Protolith M - Calcareous sandstone; interbedded sandstone and impure limestone
Incidental
Metamorphic > Schist (Greenschist, Amphibolite)GS - Greenschist facies; E - Epidote-amphibolite facies; AA - Low rank amphibolite facies; AB - Medium rank amphibolite facies; AC - High rank amphibolite facies; Protolith M - Calcareous sandstone; interbedded sandstone and impure limestone.
Metamorphic > Metasedimentary > Metaclastic > Quartzite (Greenschist, Amphibolite)GS - Greenschist facies; E - Epidote-amphibolite facies; AA - Low rank amphibolite facies; AB - Medium rank amphibolite facies; AC - High rank amphibolite facies; Protolith M - Calcareous sandstone; interbedded sandstone and impure limestone
Comments W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith Q - Interbedded pelite and sandstone
Stratigraphic units includes: 57 - Saco pluton.
References

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.

Pankiwskyj, K.A., Ludman, A., Griffin, J.R., and Berry, W.B.N., 1976, Stratigraphic relationships on the southeast limb of the Merrimack synclinorium in central and eastern Maine: Geol. Soc. Amer., Memoir 146, p. 263-280.

Fisher, L.W., 1941, Structure and metamorphism of Lewiston, Maine, region: Geological Society of America Bulletin, v. 52, no. 1, p. 107-160.

US Geological Survey, 2005, National Geologic Map Database, Geologic Names Lexicon "GEOLEX", http://ngmdb.usgs.gov/Geolex/.

NGMDB product
Counties Androscoggin - Cumberland - Hancock - Kennebec - Lincoln - Penobscot - Sagadahoc - Somerset - Waldo - Washington - York