Spheroidal Weathering in Salt River Canyon, Arizona
May 21, 2014
Photographer: Stan Celestian; Stan's Web site
Summary Authors: Stan Celestian; Jackie Phillips
The diabase rocks in the Salt River Canyon of Arizona received their rounded shape through a chemical weathering process known as spheroidal weathering. The process begins as cracks in the rock guide the carbonic acid contained in percolating groundwater around corners and edges, slowly dissolving them away. The corners and edges of the original rock fragments become more rounded and spherical resulting in a rock that looks very much like it was shaped through stream transport. Over time the rock may become exposed at the surface through other various forms of erosion. Photo taken on April 20, 2014.
Photo details: Camera Maker: NIKON; Camera Model: E950; Focal Length: 20.4mm; Aperture: f/6.8; Exposure Time: 0.0082 s (1/122); Software: Adobe Photoshop CS5.1 Windows.