|Name||West Rock Dolerite (uncertain)|
|Geologic age||Lower Jurassic|
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.
|Comments||Part of Central Lowlands; Newark Terrane - Hartford and Pomperaug Mesozoic Basins; Same as Jwr|
Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000.