Volcanic rocks (Jurassic) (ORJv;0)

Lava flows, flow breccia, and agglomerate dominantly of plagioclase, pyroxene, and hornblende porphyritic and aphyric andesite. Includes flow rocks that range in composition from basalt to rhyolite as well as some interlayered tuff and tuffaceous sedimentary rocks. Commonly metamorphosed to greenschist facies; locally foliated, schistose or gneissic. Includes the Rogue Formation and volcanic rocks commonly assigned to the Galice Formation (Wells and Walker, 1953; Wells and Peck, 1961). Considered to be accreted island-arc terrane

State	Oregon
Name	Volcanic rocks (Jurassic)
Geologic age	Late Jurassic
Original map label	Jv
Primary rock type	andesite
Secondary rock type	basalt
Other rock types	felsic volcanic rock; mudstone; chert
Lithologic constituents	Major Igneous > Volcanic > Mafic-volcanic > Andesite (Flow) Minor Igneous > Volcanic > Mafic-volcanic > Andesite (Volcaniclastic, volcanic breccia) Igneous > Volcanic > Felsic-volcanic (Flow) Igneous > Volcanic > Mafic-volcanic > Basalt (Flow) Incidental Sedimentary > Chemical > Chert (Bed) Sedimentary > Clastic > Mudstone (Bed) Igneous > Volcanic > Felsic-volcanic (Pyroclastic)
Map references	Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Unit references	Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000. Irwin, W.P., 1994, Geologic map of the Klamath Mountains, California and Oregon: U.S. Geological Survey Miscellaneous Investigations Series Map I-2148, scale 1:500,000. [http://pubs.er.usgs.gov/publication/i2148] Wells, F.G. and Peck, D.L., 1961, Geologic map of Oregon west of the 121st meridian: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-325, scale 1:500,000. [http://pubs.er.usgs.gov/publication/i325] Wells, F.G., and Walker, G.W., 1953, Geology of the Galice quadrangle, Oregon: U.S. Geological Survey Geologic Quadrangle Series GQ-25, scale 1:62,500. [http://pubs.er.usgs.gov/publication/gq25]
Geographic coverage	Coos - Curry - Douglas - Jackson - Josephine