- Upheaval Dome
Upheaval Dome is a crater-like geological structure in
Canyonlands National Park , near the town Moab (Utah ,United States ).It is 10 km in
diameter and the crater is estimated to be less than 170 million years old (Jurassic or younger). The crater is clearly visible on the surface as bright brown and black coloured concentric rings.There are two well-known theories as to the origin of the upheaval. One theory is the upheaval is a
salt dome . The other theory is it is an impact crater, much like the one near Winslow, Arizona.A salt dome is a phenomenon that occurs when salt extrudes upwards through a heavier layer of rock.
In the 1990s, a team of geologists and seismologists from
NASA and the University of Nevada at Reno performed a detailed study that includedseismic refraction and rock mapping. The results of this study favored themeteorite theory. In 2008, it was announced thatshocked quartz was discovered, adding evidence to the meteor impact theory.Nevertheless, the underlying cause of the structure is still unknown, and a matter of scientific debate.
External links
* [http://www.nps.gov/cany/naturescience/upheavaldome.htm U.S. Dept. of the Interior, National Park Service "Upheaval Dome"]
* [http://www.meteorite.com/impact/upheaval.htm The Controversy Over Utah's Upheaval Dome]
* [http://maps.google.com/maps?t=k&hl=en&ie=UTF8&ll=38.434363,-109.933491&spn=0.179915,0.196724&z=12&om=1 Satellite image of the region] (from Google Maps)
* [http://www.unb.ca/passc/ImpactDatabase/images/upheaval-dome.htm Earth Impact Database]
* [http://dsc.discovery.com/news/2008/03/11/upheaval-dome-utah-print.html Shocked Quartz discovery]
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