Volcanism of Long Valley, California: The Bishop Tuff Eruption Essay

Volcanism of Long Valley, California The Bishop Tuff Eruption The west strand of North the States has been tectonically and volcanically active for billions of years. The Sierra Nevada Mountains in east California were born of volcanoes, and magma has been erupting in the Long Valley to the east of the mountains for everyplace three million years (Bailey, et. al., 1989). However, the climactic thrill of the region occurred comparatively recently in the regions geologic history. Ab off 760,000 years ago, a colossal explosion of magma warped the Eastern Sierra into the landscape that exists today. The eruption broken a massive magma chamber below the earths surface so that the chapiter of the chamber imploded, forming what is instanter known as the Long Valley caldera. The caldera is at the eastern base of the Sierra Nevada Mountains, about 50 km northwestward of the town of Bishop, and 30 km south of Mono Lake (Bailey, 1976).The ejecta from the eruption travel over land and through the air the ash that fired out of the volcano was blown as far east as northeast in a huge, dark cloud of plinian ash. A nuee ardente billowed over the strand of the volcano and spread lava to the south, east and north, forming a volcanic outcrop now called the Bishop Tuff. Today, an expanding resurgent dome in the center of the depression indicates current magmatic employment beneath the caldera, and earthquake swarms in the last 25 years could also be linked to subsurface magma movement. Clearly, the Long Valley caldera is not dormant, so understanding the eruption that formed the caldera and surrounding features is essential to assessing the regions current and, more(prenominal) importantly, possible future activity.Volcanic activity existed prior to the Bishop Tuf... ...A. and David P. Hill. Magmatic Unrest at Long Valley Caldera, California, 1980-1990. The Long Valley Caldera, Mammoth Lakes, and Owens Valley component Mono County, California. Joan Baldwi n, et. al, editors. South Coast Geological Society. Annual Field offset Guide Book. No 27. Sept 1999. Francis, Peter. Volcanoes A Planetary Perspective. Clarendon Press, New York. 1992. pg. 292-4.Hildreth, Wes and Gail A. Mahood. Ring-fracture eruption of the Bishop Tuff. Geological Society of America Bulletin. v. 97. p. 396-403. April 1986.Lipshie, Stephen R. Geologic Guidebook to the Long Valley-Mono Craters locality of Eastern California. Second Edition. South Coast Geological Society. Santa Ana. 2001.Sheridan, Michael F. Fuarmolic Mounds and Ridges of the Bishop Tuff, California.Geological Society of America Bulletin. v. 81. March 1970. pg 851-868