Gneiss of Highlands massifs (including Fordham Gneiss)

Mixture of rock types described below, where not separately mapped.
State Connecticut
Name Gneiss of Highlands massifs (including Fordham Gneiss)
Geologic age Proterozoic Y; may contain some older rocks
Lithologic constituents
Metamorphic > Gneisspossibly contains: granitic, augen, layered, and mafic gneiss (mixture of Ygr, Yga, Ygn, Ygh, and Ygs).
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).

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