Organ Mountains National MonumentThese beautiful peaks now form the backbone of what was declared, o
Organ Mountains National MonumentThese beautiful peaks now form the backbone of what was declared, on May 21, to be the United States’ newest National Monument; the Organ Mountains.These sharp peaks are the backbone of three ranges that make up the monument; the nearby Desert Peaks contribute to its full name (Organ Mountains-Desert Peaks National Monument) and the nearby Potrillo Mountains are included as well.The Organ Mountains are held up at their heart by an ancient volcanic system. The sharp peaks rise to over 2700 meters (nearly 9000 feet) and are made of a combination of granitic and rhyolitic rocks – the rhyolites are finer grained and represent the product of volcanic eruptions while the granite is the magma that stayed in the magma chamber below.The magmas were produced in the Oligocene, about 30 million years ago, as the area began to pull apart. This portion of New Mexico sits within the Rio Grande Rift which has been stretched out by tectonic forces over that time. As this area pulled apart, the continental crust thinned, bringing hot mantle rocks and magmas into the crust where they fed the growth of this magma chamber. The nearby mountain ranges are made up of other volcanic rocks and sedimentary rocks that were heated and metamorphosed when these magmas intruded.One location I found described this range as being what Yellowstone might look like if you gave it 30 million years to erode. The rocks are similar; big, granitic magma chambers that feed massive eruptions. The name derives from the erosional style; early settlers compared the main peaks, also known as the Pinnacles, to the pipes used in large organs.As of now, this range has federal protections and its picturesque nature will be preserved for future generations (see here for a discussion of the Antiquities Act:https://www.facebook.com/TheEarthStory/posts/666032223457825).-JBBImage credit: BLMhttps://www.flickr.com/photos/mypubliclands/9469551899Read more:http://www.blm.gov/nm/st/en/prog/blm_special_areas/national_monuments/omdp_national_monument.htmlhttps://nmgs.nmt.edu/publications/guidebooks/downloads/26/26_p0157_p0161.pdfhttp://www.desertusa.com/desert-new-mexico/organ-mountains.htmlhttp://geology.isu.edu/idahorocks/research/OtherResearch/OrganMts/OrganMtsR.html -- source link
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