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Precambrian Z rocks of Islesboro limestone

Precambrian Z rocks of Islesboro limestone
State Maine
Name Precambrian Z rocks of Islesboro limestone
Geologic age Precambrian
Comments Islesboro Formation is of Late Proterozoic age. Consists of interbedded pelite, siltstone and sandstone, limestone and dolomite, conglomerate, rhyolite, and basalt. D.B. Stewart (1990, oral commun.) considers Islesboro to be distal facies of North Haven Greenstone, Ellsworth Schist and schist at Columbia Falls (eastern coastal ME). (ME072) Unit description from USGS GEOLEX website (ME078). GS - Greenschist facies AA - Low rank amphibolite facies Protolith N - Limestone and/or dolostone
Primary rock type limestone
Secondary rock type dolostone (dolomite)
Other rock types
Lithologic constituents
Major
Sedimentary > Carbonate > DolostoneGS - Greenschist facies AA - Low rank amphibolite facies Protolith N - Limestone and/or dolostone
Sedimentary > Carbonate > LimestoneGS - Greenschist facies AA - Low rank amphibolite facies Protolith N - 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.
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.
Rankin, D.W. (editor), Chiarenzelli, J.R., Drake, A.A., Jr., Goldsmith, Richard, Hall, L.M., Hinze, W.J., Isachsen, Y.W., Lidiak, E.G., McLelland, James, Mosher, Sharon, Ratcliffe, N.M., Secor, D.T., Jr. and Whitney, P.R., 1993, Proterozoic rocks east and southeast of the Grenville Front, IN Reed, J.C., Jr., and others, eds., Precambrian; conterminous U.S.: Geological Society of America, The Geology of North America, The Decade of North American Geology (DNAG), v. C-2, p. 335-461.
USGS Geologic Names Lexicon (GEOLEX)
Counties Knox - Waldo