Silurian Spragueville Formation

Silurian Spragueville Formation
State Maine
Name Silurian Spragueville Formation
Geologic age Silurian
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 > Mudstone (Bed)W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite; Protolith R - Interbedded pelite and limestone and/or dolostone
Comments Consists of well-bedded metasandstone, thinly laminated metasiltstone, and metashale. Thin medial unit of metalimestone. Thought to be fine-grained facies of Sangerville Formation and is assigned as a member (after usage of Pankiwskyj, 1979). About 1,000 m thick. Gradationally overlies Patch Mountain Member of Sangerville Formation. (ME041). Anasagunticook Member reassigned from Sangerville Formation to Waterville Formation following usage of Osberg (1988). Not shown separately on this map to simplify nomenclature. Rocks previously mapped as Anasagunticook Member of Sangerville Formation in the Bryant Pond, Buckfield, Dixfield, and Farmington 15-min quads are here shown as Waterville Formation (queried). Anasagunticook correlated with Waterville by Osberg (1988) on the basis of lithologic similarity. (ME004) Unit description from USGS GEOLEX website (ME078). GS - Greenschist facies; E - Epidote-amphibolite facies; AA - Low rank amphibolite facies; AB - Medium rank amphibolite facies; AC - High rank amphibolite facies; Protolith Q - Interbedded pelite and sandstone
References
NGMDB product
Counties Aroostook