Devonian Tomhegan Formation Kineo Rhyolite member, tuffs and volcaniclastic rocks (MEDtokc;0)

State	Maine
Name	Devonian Tomhegan Formation Kineo Rhyolite member, tuffs and volcaniclastic rocks
Geologic age	Devonian
Lithologic constituents	Major Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic-tuff)W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; GS - Greenschist facies; Protolith T - Rhyolitic volcanic rocks
Comments	Named as a member of Tarratine formation (new) after McKenney Ponds, Upper Enchanted Township, Pierce Pond 15-min quad. Type section is at northeast end of ponds. Occurs in a small area in northern Somerset Co., ME, just northwest of Enchanted Pond. Consists of white-weathering, coarse-grained limestone exhibiting rounded solution surfaces and composed largely of pelmatozoan debris with some quartz and feldspar grains. Also consists of subordinate slate and dark sandstone resembling that of Tarratine formation near contacts with main body. Base of member northeast of McKenney Ponds is arkosic, containing angular, unweathered, cream-colored feldspar fragments and well-rounded frosted quartz grains, and much calcareous cement. Northwest of McKenney Ponds, contains shell debris and quartz, feldspar, granitic, and felsite pebbles. Grades laterally into main part of Tarratine. Base of member rests on granitic rocks of basement complex or on undifferentiated Silurian or Ordovician volcanic rocks. Contacts hard to distinguish. Report includes geologic map and correlation chart. (ME003) Unit description from USGS GEOLEX website (ME078). GS - Greenschist facies; Protolith S - Interbedded pelite, sandstone, and limestone and/or dolostone.
Stratigraphic units	Moose River Group
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 Moench, R.H., Boone, G.M., Bothner, W.A., Boudette, E.L., Hatch, N.L., Jr., Hussey, A.M., III, Marvinney, R.G. and Aleinikoff, J.N., 1995, Geologic map of the Sherbrooke-Lewiston area, Maine, New Hampshire, and Vermont, United States, and Quebec, Canada: U.S. Geological Survey Miscellaneous Investigations Series Map, I-1898-D, 56 p., 2 sheets, scale 1:250,000, Prepared in cooperation with the Maine Geological Survey and the New Hampshire Geological Survey. https://pubs.er.usgs.gov/publication/i1898D Boucot, A.J., 1969, Geology of the Moose River and Roach River synclinoria, northwestern Maine: Maine Geol. Surv., Bull. 21, 123 p. US Geological Survey, 2005, National Geologic Map Database, Geologic Names Lexicon "GEOLEX", http://ngmdb.usgs.gov/Geolex/.
NGMDB product	NGMDB product page for 16547
Counties	Somerset

State

Name

Devonian Tomhegan Formation Kineo Rhyolite member, tuffs and volcaniclastic rocks

Geologic age

Devonian

Lithologic constituents

Major

Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic-tuff)W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; GS - Greenschist facies; Protolith T - Rhyolitic volcanic rocks

Comments

Named as a member of Tarratine formation (new) after McKenney Ponds, Upper Enchanted Township, Pierce Pond 15-min quad. Type section is at northeast end of ponds. Occurs in a small area in northern Somerset Co., ME, just northwest of Enchanted Pond. Consists of white-weathering, coarse-grained limestone exhibiting rounded solution surfaces and composed largely of pelmatozoan debris with some quartz and feldspar grains. Also consists of subordinate slate and dark sandstone resembling that of Tarratine formation near contacts with main body. Base of member northeast of McKenney Ponds is arkosic, containing angular, unweathered, cream-colored feldspar fragments and well-rounded frosted quartz grains, and much calcareous cement. Northwest of McKenney Ponds, contains shell debris and quartz, feldspar, granitic, and felsite pebbles. Grades laterally into main part of Tarratine. Base of member rests on granitic rocks of basement complex or on undifferentiated Silurian or Ordovician volcanic rocks. Contacts hard to distinguish. Report includes geologic map and correlation chart. (ME003) Unit description from USGS GEOLEX website (ME078). GS - Greenschist facies; Protolith S - Interbedded pelite, sandstone, and limestone and/or dolostone.

Stratigraphic units

Moose River Group

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

Moench, R.H., Boone, G.M., Bothner, W.A., Boudette, E.L., Hatch, N.L., Jr., Hussey, A.M., III, Marvinney, R.G. and Aleinikoff, J.N., 1995, Geologic map of the Sherbrooke-Lewiston area, Maine, New Hampshire, and Vermont, United States, and Quebec, Canada: U.S. Geological Survey Miscellaneous Investigations Series Map, I-1898-D, 56 p., 2 sheets, scale 1:250,000, Prepared in cooperation with the Maine Geological Survey and the New Hampshire Geological Survey.

https://pubs.er.usgs.gov/publication/i1898D

Boucot, A.J., 1969, Geology of the Moose River and Roach River synclinoria, northwestern Maine: Maine Geol. Surv., Bull. 21, 123 p.

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

NGMDB product

NGMDB product page for 16547

Counties

Somerset