The Cobre Ridge caldera is a large Jurassic volcano in the U.S. state of Arizona. It formed about 170 million years ago when a VEI-8 eruption ejected more than 1,000 km3 (240 cu mi) of crystal-rich rhyodacite ignimbrite.[1]
References
edit- ^ Riggs, Nancy R.; Busby-Spera, Cathy J. (1991). "Facies analysis of an ancient, dismembered, large caldera complex and implications for intra-arc subsidence: Middle Jurassic strata of Cobre Ridge, southern Arizona, USA". Sedimentary Geology. 74 (1–4): 39–68. doi:10.1016/0037-0738(91)90034-B.
External links
edit- "Cobre Ridge". The Collapse Caldera Database.
31°21′47″N 111°07′37″W / 31.363°N 111.127°W
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