Weathering
Due to the nature of Morrison's location, the rocks endure heavy ice and snow during the winter, and plenty of sunlight and heat in the summer. This fluctuation between hot and cold can cause physical weathering of the rocks in certain areas. Water expands within the crevices of the rocks as it freezes, and therefore splits the rock in the process. This is called frost weathering. Another form of weathering is called pressure release. In this case, the sandstone rocks in Morrison formed under a great deal of pressure, which eventually allowed it to break apart into large slabs.
(Image courtesy of denver.com/red-rocks)
At the very top of both Ship Rock and Creation Rock (pictured above) you can see large cracks where frost weathering has taken place. If you look at the bottom right corner of this photo, you can also see signs of pressure release, where large, flat slabs of rocks seem to have detached. Pictured below is a more detailed example of pressure release found on the top of these rocks.
(Image courtesy of 1957timecapsule.wordpress.com/2011/07)
Here is another form of weathering called basal weathering. Just as the name sounds, these rocks were weathered down at the base, giving them their rather awkward shape.
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| (Image courtesy of modmidmod.com/category/red-rocks) |
Mass Wasting
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| (Image courtesy of modmidmod.com/category/red-rocks |
Mass wasting, or basically "rock fall" in this case, can be seen all around the vicinity of Red Rocks. To the left you can see large piles of sedimentary boulders that have toppled over each other from the top of the cliff.
I think you did a great job explaining the process of physical weathering and weathering thru pressure release. The evidence you provided for both process makes perfect sense . I can see by the image you provided that slabs could have easily been once connected and then later detached because of pressure release. The Structures located at Red Rocks seemed to me as if they have always existed in that form, but your blog gave me a whole new prospective on the power of mother nature.
ReplyDeleteYour explanation of the weathering process was very thorough. The process of weathering due to hot and cold conditions in Morrison really made it clear how the rocks came to look as they do. After visiting red rocks and observing this phenomena, your explanation and blog become incredibly useful!
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