Sunday, May 6, 2012

Salt Valley Anticline Graben

On our way to Arches National Park for our awesome field studies spring 2012 course, we stopped at a little pagoda to learn about the Salt Valley Anticline just before the turnoff on Rte 163 towards Moab.  The most exciting feature of this anticline is the huge graben that has formed over time.  First, it started out with the formation of the anticline: in the Paradox formation, salt well below the earth's surface began to rise as it flowed upward.  As it rises, it pushes the rock and sediment on top up with it, forming an n-shaped hill or a dome.  This deformation is what created the anticline.  Because of this uplift, the rock starts to form cracks called joints that allow water to pass through all the way down to the salt, where it begins to dissolve.  Where the salt is dissolved, there is weak rock or gaps that, with the help of gravity, cause the rock layers to collapse and form this spectacular graben. (Picture above: The collapsed Salt Valley anticline in the center of Arches National Park)

And our field trip only got better from here!  We got to see lots of arches, fins, toured Fiery Furnace, saw amazing faults, huge large-scale cross beds, hogbacks, dinosaur tracks, petroglyphs, balancing rocks, tons of fossils, poured acid on plenty of calcite, and ended it off chillin at Dead Horse Point. We saw the coolest stuff!

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