Jurassic volcanic rocks (AZJv;0)

Jurassic volcanic rocks

Massive quartz-feldspar porphyry, generally interpreted as thick, welded rhyolitic tuffs, with locally abundant lava, and sandstone and conglomerate derived from volcanic rocks. Rare eolian quartzite units are interbedded in southern Arizona. Includes Ali Molina Formation, Mount Wrightson Formation, part of the Canelo Hills Volcanics, Cobre Ridge tuff, Black Rock volcanics, Planet Volcanics, and equivalent rocks. (160-200 Ma)

State	Arizona
Name	Jurassic volcanic rocks
Geologic age	Jurassic
Lithologic constituents	Major Sedimentary > Clastic > Conglomerate Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic-tuff) Sedimentary > Clastic > Sandstone Minor Metamorphic > Metasedimentary > Metaclastic > Quartzite
Comments	The Jurassic quartz porphyry, Ali Molina, Mt Wrightson, Cobre Ridge, Black Rock volcanics, Planet Volcanics.
Stratigraphic units	Ali Molina Formation, Topawa Group, Mount Wrightson Formation, Canelo Hills Volcanics, Cobre Ridge Tuff, Black Rock volcanics, Planet Volcanics
References	Richard, S.M., Reynolds, S.J., Spencer, J.E., and Pearthree, P.A., 2000, Geologic Map of Arizona: Arizona Geological Survey Map 35, 1 sheet, scale 1:1,000,000. Tosdal R.M., Haxel, G.B., and Wright, J.E., 1989, Jurassic geology of the Sonoran Desert region, southern Arizona, southeastern California, and northernmost Sonora: Construction of a continental-margin magmatic arc, in Jenney, J.P., and Rey
NGMDB product	NGMDB product page for 34746
Counties	Cochise - La Paz - Mohave - Pima - Santa Cruz

Jurassic volcanic rocks

Richard, S.M., Reynolds, S.J., Spencer, J.E., and Pearthree, P.A., 2000, Geologic Map of Arizona: Arizona Geological Survey Map 35, 1 sheet, scale 1:1,000,000.

Tosdal R.M., Haxel, G.B., and Wright, J.E., 1989, Jurassic geology of the Sonoran Desert region, southern Arizona, southeastern California, and northernmost Sonora: Construction of a continental-margin magmatic arc, in Jenney, J.P., and Rey