Devonian Tomhegan Formation Kineo Rhyolite member, tuffs and volcaniclastic rocks

Devonian Tomhegan Formation Kineo Rhyolite member tuffs and volcaniclastic rocks
State Maine
Name Devonian Tomhegan Formation Kineo Rhyolite member, tuffs and volcaniclastic rocks
Geologic age Devonian
Lithologic constituents
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
NGMDB product
Counties Somerset