Ordovician - Cambrian Megunticook Formation (MEOCAme;0)

State	Maine
Name	Ordovician - Cambrian Megunticook Formation
Geologic age	Ordovician - Cambrian
Original map label	OCAme
Comments	Secondary unit description from USGS Geologic Names Lexicon (ref. ME078): Simplified stratigraphic column for the Islesboro-Rockport belt in eastern ME shows (ascending) Precambrian rocks of Gilkey Harbor, Islesboro Formation, Coombs Limestone, Cambrian Rockport Quartzite and Megunticook(?) Formation. Some question as to whether unit is correctly identified in this area and correlates with the type Megunticook in the St. Croix belt where unit consists of gray quartz-muscovite-biotite-andalusite-garnet schist and sparse beds of quartz-plagioclase-biotite granulite. Battie Quartzite forms a distinctive lens within the Megunticook. These rocks do not correlate with the Kendall Mountain and Woodland Formations in the Calais area, as previously thought. In St. Croix belt, underlies Penobscot Formation and unconformably overlies lower part of Jam Brook Formation AA - Low rank amphibolite facies AB - Medium rank amphibolite facies AC - High rank amphibolite facies GS - Greenschist facies Protolith A - Pelite
Primary rock type	schist
Secondary rock type	granulite
Other rock types	quartzite
Lithologic constituents	Major Metamorphic > GranuliteProtolith A - Pelite AA - Low rank amphibolite facies AB - Medium rank amphibolite facies AC - High rank amphibolite facies GS - Greenschist facies Metamorphic > SchistProtolith A - Pelite AA - Low rank amphibolite facies AB - Medium rank amphibolite facies AC - High rank amphibolite facies GS - Greenschist facies Minor Metamorphic > Metasedimentary > Metaclastic > QuartziteProtolith A - Pelite AA - Low rank amphibolite facies AB - Medium rank amphibolite facies AC - High rank amphibolite facies GS - Greenschist facies
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. [http://apollo.ogis.state.me.us/catalog/catalog.asp?state=2&extent=cover#bedrock]
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. USGS Geologic Names Lexicon (GEOLEX) [http://ngmdb.usgs.gov/Geolex/]
Geographic coverage	Knox - Waldo