Metamorphic rocks (NVXm;0)

State	Nevada
Name	Metamorphic rocks
Geologic age	Early Proterozoic
Original map label	Xm
Comments	Includes outcrops n Nye County: the Bullfrog Hills have quartz-muscovite-feldspar gneiss and quartz-muscovite-biotite schist intruded by irregular bodies of gneissic pegmatitic granite and the Trappman Hills have gneissic quartz monzonite and biotite-amphibolite schist, all of which may be younger or unrelated to the X and Y (see NVYgr) rocks in Clark and Lincoln Counties (Stewart, 1980).
Primary rock type	gneiss
Secondary rock type	schist
Other rock types	marble; granite; pyroxenite; hornblendite; migmatite; pegmatite; amphibolite
Lithologic constituents	Major Metamorphic > Schist (Amphibolite)Includes quartz-mica schist and green chlorite schist (Longwell and others, 1965). Metamorphic > Gneiss (Amphibolite)Includes banded gneiss (modification of biotite schist by lit-par-lit intrusion of granitic material) and quartzose gneiss (Longwell and others, 1965). Minor Igneous > Plutonic > Granitic > Granite (Pluton) Incidental Metamorphic > Amphibolite (Amphibolite)Locally in Virgin Canyon (Longwell and others, 1965). Metamorphic > Migmatite (Amphibolite) Metamorphic > Marble (Amphibolite) Igneous > Plutonic > Ultramafic > Hornblendite (Dike or sill) Igneous > Plutonic > Ultramafic > Pyroxenite (Dike or sill)
Map references	Stewart, J.H., and Carlson, J.E., 1978, Geologic Map of Nevada: U.S. Geological Survey and Nevada Bureau of Mines and Geology, 1:500,000 (not part of any formal series, printed and distributed by the U.S. Geological Survey, G75163, reprinted, 1981, G81386).
Unit references	Stewart, J.H., and Carlson, J.E., 1978, Geologic Map of Nevada: U.S. Geological Survey and Nevada Bureau of Mines and Geology, 1:500,000 (not part of any formal series, printed and distributed by the U.S. Geological Survey, G75163, reprinted, 1981, G81386). Stewart, J. H., 1980, Geology of Nevada: A discussion to accompany the Geologic Map of Nevada: Nevada Bureau of Mines and Geology Special Publication 4. Longwell, C.R., Pampeyaan, E.H., Bowyer, B., and Roberts, R.J., 1965, Geology and Mineral Deposits of Clark County, Nevada: Nevada Bureau of Mines and Geology Bulletin 62, 218 p., 16 pl.
Geographic coverage	Clark - Lincoln - Nye