West Rock Dolerite (uncertain) (CTJwr1;0)

West Rock Dolerite (uncertain) - Dark-gray to greenish-gray (weathers bright orange to brown), medium- to fine-grained, grading from basalt near contacts to fine-grained gabbro in the interior, generally massive with well-developed columnar jointing, composed of plagioclase and pyroxene with accessory opaques and locally devitrified glass, quartz, or olivine.

State	Connecticut
Name	West Rock Dolerite (uncertain)
Geologic age	Lower Jurassic
Original map label	Jwr?
Comments	Part of Central Lowlands; Newark Terrane - Hartford and Pomperaug Mesozoic Basins; Same as Jwr
Primary rock type	basalt
Secondary rock type	gabbro
Other rock types
Lithologic constituents	Major Igneous > Volcanic > Mafic-volcanic > Basalt (Diabase)Dark-gray to greenish-gray (weathers bright orange to brown), medium- to fine-grained, grading from basalt near contacts to fine-grained gabbro in the interior, generally massive with well-developed columnar jointing, composed of plagioclase and pyroxene with accessory opaques and locally devitrified glass, quartz, or olivine.
Map references	Connecticut Geological and Natural History Survey, DEP, in cooperation with the U.S. Geological Survey, 2000, Bedrock Geology of Connecticut, data format: shapefile, file name: bedrock, downloaded from: http://magic.lib.uconn.edu/cgi-bin/MAGIC_DBsearch2.pl?Geography=37800&Loc=0000 on 9/18/2003, scale 1:50,000. [http://magic.lib.uconn.edu/connecticut_data.html#environmental] [http://magic.lib.uconn.edu/cgi-bin/MAGIC_DBsearch2.pl?Geography=37800&Loc=0000]
Unit references	Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 125,000.
Geographic coverage	New Haven