| State | Connecticut |
|---|---|
| Name | Joshua Rock Member [of New London Gneiss] |
| Geologic age | Proterozoic Z? |
| Lithologic constituents | Major
Metamorphic > GneissMedium-gray (weathers with red spots of hematite), medium-grained, foliated gneiss composed of microperthite, quartz, albite, aegerine-augite, and magnetite; rare riebeckite.
|
| Comments | Part of Eastern Uplands; Avalonian (Continental) Terrane; Avalonian Anticlinorium |
| References | Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000. |
| NGMDB product | |
| Counties | Middlesex - New London |