Juniper Pine and Rock Weathering
October 11, 2012
Photographer: Ken DePue; Ken's Web site
Summary Authors: Ken DePue; Jim Foster
The juniper pine featured above has managed to take root in a small crevasse of this chunk of limestone. Over the years it's slowly split it apart, pushing the two pieces ever further away as it continues to grow. This is a classic example of mechanical or physical weathering -- the rock’s size and shape has changed but its chemical composition remains the same. The process of erosion has likely been aided by freeze/thaw cycles, where ice formation in small cracks and subsequent melt acts to gradually break down the rock. Photo taken in eastern Wyoming on August 28, 2012.
Photo details: Camera Maker: NIKON CORPORATION; Camera Model: NIKON D7000; Lens: VR 18-105mm lens (f/3.5-5.6); Focal Length: 30.0mm (35mm equivalent: 45mm); Aperture: f/8.0; Exposure Time: 0.011 s (1/90); ISO equiv: 100; Exposure Bias: none; Metering Mode: Matrix; Exposure: aperture priority (semi-auto); White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: Capture NX 2.3.1 W.