ArtThis image is another of the winners from the 2014 annual Smithsonian photography contest. Taken
ArtThis image is another of the winners from the 2014 annual Smithsonian photography contest. Taken by Willie Huang of California, it shows a sunrise over a portion of California known as Owens Valley.Owens Valley is the valley that sits between the Sierra Nevada mountain range in the west and the White/Inyo mountain ranges to the east. It formed over the past few million years due to extension throughout the western United States. The North American continent is being slowly pulled apart and extended, leading to the formation of normal faults and long, linear valleys like Owens Valley.This location is particularly interesting geologically. This photo was taken looking west, towards the Sierras, but if you look closely in the foreground in front of the high peaks you can kind of see that a portion of the mountain range is shrinking and disappears into the valley floor from left to right.This location is northeast of the town of Bishop and sits close to the edge of a geological feature known as the Long Valley Caldera. 760,000 years ago, a massive volcanic eruption, comparable in size to the most recent major eruption at Yellowstone caldera, tore through this valley. The eruption emptied a giant magma chamber, wider than the valley itself, and the rocks of the Eastern Sierra that sat above the magma chamber collapsed downwards as the ground sank and the caldera formed.Normally, Owens Valley is a pretty dry place. It sits in the rain shadow of the mighty Sierra Nevada, so most of the moisture from the Pacific is rung out before it can rain in this valley. However, right in this spot, the range has been torn in half by the Long Valley Caldera eruption, creating a gap. That gap allows some extra moisture to flow through, creating a more livable area and probably explaining why this particular location hosts these ancient drawings. People could actually live in this area thanks to a giant volcanic eruption long before they ever arrived.The drawings are estimated to be about 8000 years old. The rocks drawn on are volcanic tuffs; erupted during the Long Valley explosions. There are several locations within the Sierras with these drawings and more details about them can be found linked below.-JBBImage credit: Smithsonina Maghttp://www.smithsonianmag.com/photocontest/photo-contest-finalists-11th-annual-180950372/?src=socialtrends&no-ist(Fair use as defined here: http://www.si.edu/termsofuse)Sierran drawings:http://www.thesierraweb.com/generalinfo/petroglyphs.cfmhttp://renmarphoto.com/2011/11/06/petroglyph-paradise-–-the-volcanic-tablelands-of-bishop-california/ -- source link
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