Mineral Resources On-Line Spatial Data
Mineral Resources > Online Spatial Data > Geology > by state > Maine
|Name||Ordovician - Cambrian Dead River formation upper member|
|Geologic age||Ordovician - Cambrian|
|Original map label||OCAdq|
|Comments||Secondary unit description from USGS Geologic Names lexicon (ref. ME078): Dead River Formation of Bronson Hill-Boundary Mountains anticlinorium was previously mapped as Albee Formation in Cupsuptic 15-min quad by Harwood (1973) and in Oquossoc 15-min quad by Guidotti (1977) in ME and in wide areas of northern NH by Billings (1956) and Green (1968). In Cupsuptic quad, consists of a main body of thinly interbedded greenish-gray slate and typically subordinate quartzite or feldspathic quartzite. Unit is also divided into three parts not shown on this map--a main body, a green slate and phyllite member, and a red, maroon, and purplish-gray slate member. A quartzite-rich member is mapped separately in Kennebago Lake 15-min quad, ME, and further east. An unnamed quartzite and phyllite member at Percy, in Percy, NH, 15-min quad, is mapped separately and consists of quartzite and grit interbedded with phyllite; possibly a volcaniclastic facies of Perry Mountain Formation. Dead River Formation is undated, but is assigned a Late Cambrian(?) and Ordovician (Whiterockian) age based on position below Ordovician (Whiterockian and Mohawkian) Ammonoosuc Volcanics and above Cambrian(?) Hurricane Mountain Formation. AA - Low rank amphibolite facies AB - Medium rank amphibolite facies E - Epidote-amphibolite facies GS - Greenschist facies W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite Protolith Q - Interbedded pelite and sandstone|
|Primary rock type||phyllite|
|Secondary rock type||quartzite|
|Other rock types|
Metamorphic > Metasedimentary > Metaclastic > PhylliteProtolith E - Feldspathic sandstone E - Epidote-amphibolite facies GS - Greenschist facies W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite
Metamorphic > Metasedimentary > Metaclastic > QuartziteProtolith E - Feldspathic sandstone E - Epidote-amphibolite facies GS - Greenschist facies W - Weakly metamorphosed; contains local occurrences of prehnite and pumpellyite
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.
|Geographic coverage||Franklin - Oxford - Piscataquis - Somerset|
Show this information as [XML]