| State | Connecticut |
|---|---|
| Name | Preston Gabbro |
| Geologic age | Middle Ordovician or older |
| Lithologic constituents | Major
Igneous > Plutonic > Gabbroic > GabbroDark, medium- to coarse-grained, mainly massive gabbro, composed of labradorite, augite, and opaques, generally with hornblende, locally hypersthene, or olivine or both.
|
| Comments | Part of Eastern Uplands; Iapetus (Oceanic) Terrane - Merrimack Synclinorium |
| 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 | New London - Windham |