Waterford Group and Branford Gneiss (CTZw+Zb;0)

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. Some layers of amphibolite. Branford Gneiss - Gray to white but rarely pink., medium-grained, well-foliated granitic gneiss, composed of oligoclase, K-feldspar, quartz, biotite, garnet, magnetite, and muscovite.

State	Connecticut
Name	Waterford Group and Branford Gneiss
Geologic age	Proterozoic Z?
Original map label	Zw+Zb
Comments	Part of Eastern Uplands; Avalonian (Continental) Terrane; Avalonian Anticlinorium; Branford Gneiss only = East Haven granitic body (may be equivalent to Sterling Plutonic-Group) (includes Light House Gneiss, Branford Gneiss, and Stony Creek Granite Gneiss) (Proterozoic Z?). Printed map has unit Zb by itself, digital map combines Zb with Zw.
Primary rock type	gneiss
Secondary rock type	granitic gneiss
Other rock types	amphibolite
Lithologic constituents	Major Metamorphic > GneissWaterford 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. Branford Gneiss - Gray to white but rarely pink., medium-grained, well-foliated granitic gneiss, composed of oligoclase, K-feldspar, quartz, biotite, garnet, magnetite, and muscovite. Minor Metamorphic > AmphiboliteWaterford Group - some layers of amphibolite
Map references	Connecticut Geological and Natural History Survey, DEP, in cooperation with the U.S. Geological Survey, 2000, Bedrock Geology of Connecticut, data format: shapefile, file name: bedrock, downloaded from: http://magic.lib.uconn.edu/cgi-bin/MAGIC_DBsearch2.pl?Geography=37800&Loc=0000 on 9/18/2003, scale 1:50,000. [http://magic.lib.uconn.edu/connecticut_data.html#environmental] [http://magic.lib.uconn.edu/cgi-bin/MAGIC_DBsearch2.pl?Geography=37800&Loc=0000]
Unit references	Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 125,000.
Geographic coverage	New Haven