Silurian - Ordovician Lobster Lake Formation

Silurian - Ordovician Lobster Lake Formation
State Maine
Name Silurian - Ordovician Lobster Lake Formation
Geologic age Silurian - Ordovician
Lithologic constituents
Major
Sedimentary > Clastic > ConglomerateW - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith H - Lithic sandstone and conglomerate
Sedimentary > Clastic > SandstoneW - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith H - Lithic sandstone and conglomerate
Sedimentary > Clastic > SiltstoneW - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith H - Lithic sandstone and conglomerate
Minor
Metamorphic > Metasedimentary > Metaclastic > Quartzite (Zeolitic (prehnite-pumpellyite))W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith H - Lithic sandstone and conglomerate
Metamorphic > Metasedimentary > Metaclastic > Slate (Zeolitic (prehnite-pumpellyite))W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith H - Lithic sandstone and conglomerate
Sedimentary > Clastic > Mudstone > ShaleW - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith H - Lithic sandstone and 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 R - Interbedded pelite and limestone and/or dolostone.
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.

https://pubs.er.usgs.gov/publication/b1111E

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

NGMDB product
Counties Piscataquis