Porphyritic biotite granodiorite in northern Jefferson dome in Milan quadrangle (NHOo2bx;0)

State	New Hampshire
Name	Porphyritic biotite granodiorite in northern Jefferson dome in Milan quadrangle
Geologic age	Late Ordovician
Original map label	Oo2bx
Comments	Part of the Oliverian Plutonic Suite (Late Ordovician) - Pink, weakly to moderately foliated, locally porphyritic biotite granitoids found in mantled gneiss domes. Mafic varieties contain hornblends. Variably metamorphosed up to amphibolite facies.
Primary rock type	granodiorite
Secondary rock type
Other rock types
Lithologic constituents	Major Igneous > Plutonic > Granitic > Granodiorite (Pluton)porphyritic biotite granodiorite
Map references	Bennett, D. S, , Wittkop, C.A., and Dicken, C.L., 2006 , Bedrock Geologic Map of New Hampshire - A Digital Representation of the Lyons and others 1997 map and ancillary files: U.S. Geological Survey Data Series 215, scale 1:250,000, CD-ROM. [http://pubs.er.usgs.gov/publication/ds215]
Unit references	Lyons, J.B., Bothner, W.A., Moench, R.H., and Thompson, J.B., Jr., 1997, Bedrock Geologic Map of New Hampshire: Reston, VA, U.S. Geological Survey Special Map, 1:250,000, 2 sheets.
Geographic coverage	Coos