Silurian - Ordovician Carys Mills Formation (MESOcm;0)

State	Maine
Name	Silurian - Ordovician Carys Mills Formation
Geologic age	Silurian - Ordovician
Original map label	SOcm
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
Primary rock type	limestone
Secondary rock type	siltstone
Other rock types	slate; graywacke
Lithologic constituents	Major Sedimentary > Carbonate > Limestone (Bed)W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith R - Interbedded pelite and limestone and/or dolostone Sedimentary > Clastic > Siltstone (Calcareous)W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith R - Interbedded pelite and limestone and/or dolostone Minor Metamorphic > Metasedimentary > Metaclastic > Slate (Bed)W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith R - Interbedded pelite and limestone and/or dolostone Incidental Sedimentary > Clastic > Sandstone > Graywacke (Bed)W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith R - Interbedded pelite and limestone and/or dolostone
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. Pavlides, Louis and Berry, W.B.N., 1966, Graptolite-bearing Silurian rocks of the Houlton-Smyrna Mills area, Aroostook County, Maine, IN Geological Survey research 1966: U.S. Geological Survey Professional Paper, 550-B, p. B51-B61. [http://pubs.er.usgs.gov/publication/pp550B] Pavlides, L., 1966, Meduxnekeag Group and Spraugueville Formation of Aroostook County, northeast Maine, in Cohee, G.V., and West, W.S., Changes in stratigraphic nomenclature in the U.S. Geological Survey - 1965: U.S. Geological Survey Bull. 1244-A, p. 52-60. [http://pubs.er.usgs.gov/publication/b1244A] Pavlides, L., 1968, Stratigraphic and facies relationships of the Carys Mills Formation of Ordovician and Silurian age, northeast Maine: U.S. Geological Survey Bull. 1264, p. 44. [http://pubs.er.usgs.gov/publication/b1264] Rickards, R. B., and Riva, J., 1981, Glyptograptus? persculptus (Salter), its tectonic deformation, and its stratigraphic significance for the Carys Mills Formation of NE Maine, U.S.A.: Geol. Jour., v. 16, p. 219-235. USGS Geologic Names Lexicon (GEOLEX) [http://ngmdb.usgs.gov/Geolex/]
Geographic coverage	Aroostook