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I mentioned in yesterday’s post entitled Gold Cobblestone that I spent a few days in the Big Bend National Park with some of my photography friends. We spent quite a bit of time photographing and admiring the many natural rock formations found in the park. The BBNP is an amazing geological wonderland. The image below was taken during a hike up the Grapevine Hills Trail. This rock formation is very common in this area and the pattern is a result of Spheroidal Weathering.

Spheroidal weathering is a form of chemical weathering that results in the formation of concentric or spherical layers of highly decayed rock. When these rocks are exposed by physical erosion, these concentric layers peel off as concentric shells much like the layers of a peeled onion. Spheroidal weathering often creates rounded boulders, known as corestones, of relatively unweathered rock. Spheroidal weathering is also called onion skin weathering, concentric weathering, spherical weathering, or woolsack weathering.


BBNP – Rock Formation

This image was taken with my iPhone 6 Plus with the aperture set at f/2.2, shutter speed at 1/120 and the ISO set at ISO 50.

This image is best when viewed large. Click on the image to enlarge it. Please use the section below to post your comments, questions or suggestions.

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© 2015 T. Kahler Photography

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