Silurian - Ordovician Mars Hill Conglomerate

Silurian - Ordovician Mars Hill Conglomerate
State Maine
Name Silurian - Ordovician Mars Hill Conglomerate
Geologic age Silurian - Ordovician
Lithologic constituents
Major
Sedimentary > Clastic > ConglomerateW - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith I - Conglomerate
Comments Named as a formation in Meduxneag Group (rank raised). Named for community of Carys Mills, Aroostook Co., northeast ME. Formerly called ribbon rock member of Meduxnekeag Formation. Consists of gray-blue limestone and calcareous siltstone interbedded with buff-weathered ankeritic limestone and with gray and green slate. Slate and slate with graywacke lenses present at different stratigraphic levels in Bridgewater quad. Thickness about 12,000 ft in Bridgewater quad. Conformably underlies and grades into Smyrna Mills Formation. (ME052) Unit description from USGS GEOLEX website (ME078). W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith A - Pelite
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.

Neuman, R.B., pers. communication, 1983.

Genes, A.N., Newman, W.A. and Brewer, T.B., 1981, Late Wisconsinan glaciation models of northern Maine and adjacent Canada: Quaternary Research, v. 16, no. 1, p. 48-65.

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

NGMDB product
Counties Aroostook