| State | Connecticut |
|---|---|
| Name | Gneiss of Highlands massifs (including Fordham Gneiss) |
| Geologic age | Proterozoic Y; may contain some older rocks |
| Lithologic constituents |
Major
Metamorphic > Gneisspossibly contains: granitic, augen, layered, and mafic gneiss (mixture of Ygr, Yga, Ygn, Ygh, and Ygs).
Minor
Metamorphic > Amphibolitefrom unit Ygh
Metamorphic > Schistfrom Ygs
|
| Comments | Part of Western Uplands; Proto-North American (Continental) Terrane - Proterozoic Massifs - "Grenville". "Rocks described below" in the description include the following units: Ygr (Pink granitic gneiss), Yga (Augen gneiss), Ygn (Layered gneiss), Ygh (Hornblende gneiss and amphibolite), and Ygs (Rusty mica schist and gneiss). |
| 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 | Fairfield - Litchfield |