Ordovician Benner Hill formation (MEObh;0)

State	Maine
Name	Ordovician Benner Hill formation
Geologic age	Ordovician
Original map label	Obh
Comments	AA - Low rank amphibolite facies AB - Medium rank amphibolite facies E - Epidote-amphibolite facies Protolith Q - Interbedded pelite and sandstone
Primary rock type	gneiss
Secondary rock type	sandstone
Other rock types	mudstone
Lithologic constituents	Major Metamorphic > Gneiss (Amphibolite)felsic gneiss; lithology is assigned based on interpretation of rock unit derived from metamorphic isograds laid over the protolith map (done by M.P. Foose and Julie Mueller, USGS). Minor Sedimentary > Clastic > SandstoneAA - Low rank amphibolite facies AB - Medium rank amphibolite facies E - Epidote-amphibolite facies Protolith Q - Interbedded pelite and sandstone Sedimentary > Clastic > MudstoneAA - Low rank amphibolite facies AB - Medium rank amphibolite facies E - Epidote-amphibolite facies Protolith Q - Interbedded pelite and sandstone
Map references	Digital bedrock data downloaded from Maine Office of GIS in September 2005 from http://apollo.ogis.state.me.us/catalog/catalog.asp?state=2&extent=cover#bedrock Bedrock units table (publication date 11/15/2002) downloaded from same site. Permission to redistribute these data granted by Dr. Robert Marvinney, State Geologist of Maine, in September 2006. [http://apollo.ogis.state.me.us/catalog/catalog.asp?state=2&extent=cover#bedrock]
Unit 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. Boucot, A.J., 1961, Stratigraphy of the Moose River synclinorium, IN Contributions to general geology, 1959: U.S. Geological Survey Bulletin, 1111-E, p. E153-E188. [http://pubs.er.usgs.gov/publication/b1111E]
Geographic coverage	Knox