|Name||Waterford Group plus Stony Creek Granite Gneiss plus Narragansett Pier Granite|
|Geologic age||Proterozoic Z? and Permian|
Metamorphic > GneissStony Creek Granite Gneiss - Red to pink, unevenly medium to very coarse grained, variably foliated granite or granite gneiss, composed of oligoclase, K-feldspar, and quartz with minor biotite and magnetite, sporatic garnet (in foliated varieties), and local muscovite. Waterford Group (may be equivalent in part to Monson Gneiss) - Interlayered part (but layers locally distinct) of Waterford Group, light to dark, generally medium grained gneiss, composed of plagioclase, quartz, and biotite, with hornblende in some layers and microcline in others.
Igneous > Plutonic > Granitic > GraniteNarragansett Pier Granite - Pink to red, medium- to coarse-grained (commonly pegmatitic), generally massive (not gneissic) granite, composed of microcline, oligoclase, quartz, and biotite, and accessory muscovite and magnetite.
Metamorphic > AmphiboliteWaterford Group
Igneous > Plutonic > Granitic > Leucocratic-granitic > PegmatiteNarragansett Pier Granite - Considerable associated pegmatite.
|Comments||Part of Eastern Uplands; Avalonian (Continental) Terrane. Units are described seperately on printed map; combined in digital map.|
Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000.