Volcanic rocks (ORTRPv1;0)

Volcanic rocks

Massive flows of porphyritic meta-andesite, metabasalt, spilite, and keratophyre, volcanic breccia, and subordinate amounts of fine-grained volcaniclastic rocks. In southwest Oregon includes hornblende, pyroxene, and plagioclase porphyritic andesite flows, breccia, agglomerate, tuff, and locally, some basalt flows and dacitic tuffs of the Applegate Group

State	Oregon
Name	Volcanic rocks
Geologic age	Triassic and (or) Jurassic
Lithologic constituents	Major Metamorphic > Metaigneous > Metavolcanic > Metaandesite Metamorphic > Hydrothermally-altered > Spilite Metamorphic > Metaigneous > Metavolcanic > Metabasalt Minor Igneous > Volcanic > Mafic-volcanic > Andesite (Flow, Pyroclastic)Includes pyroxene and hornblende andesites Incidental Igneous > Volcanic > Mafic-volcanic > Basalt (Flow) Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic-tuff)
Comments	Unit is considered possibly correlative with the Hayfork Terrane by Irwin (1994)
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. https://pubs.er.usgs.gov/publication/i2148
NGMDB product	NGMDB product page for 16259
Counties	Jackson - Josephine

Volcanic rocks

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.