|Name||Silurian Sangerville Formation sulfidic pelite member|
|Comments||In central Maine trough, Sangerville Formation is mapped as principal sandstone and shale facies, and subdivided into (ascending) Patch Mountain Limestone Member (name revised from Patch Mountain Member to emphasize lithology), consisting of thinly interbedded impure marble, coarsely crystallized calc-silicate rocks, granofels, and pelitic schist (high metamorphic grade), or thinly interbedded, gray micritic metalimestone, limy metasandstone, metasiltstone, and slate or pelitic schist (low metamorphic grade); a conglomerate member; euxinic shale lenses; Taylor Pond Member of Hussey (1983), consisting of feldspathic biotite- and hornblende-biotite granofels, thinly bedded calc-silicate rocks, and sparse garnet-rich laminations (coticule); an unnamed limestone member similar to Patch Mountain Limestone Member but at a higher stratigraphic level; and Thorncrag Hill Member of Hussey (1983), consisting of migmatitic pelitic gneiss and some calc-silicate rocks. Anasagunticook Member of Pankiwskyj and others (1976) and Moench and Pankiwskyj (1988) is tentatively reassigned to Waterville Formation, following usage of Osberg (1988). (ME004) Unit description from USGS GEOLEX website (ME078). AB - Medium rank amphibolite facies AC - High rank amphibolite facies Protolith C - Sulfidic/carbonaceous pelite|
|Primary rock type||shale|
|Secondary rock type|
|Other rock types|
Sedimentary > Clastic > Mudstone > Shale (Carbonaceous)AB - Medium rank amphibolite facies AC - High rank amphibolite facies Protolith C - Sulfidic/carbonaceous pelite
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.
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.
|Counties||Androscoggin - Kennebec|