Death Valley Dunes and Former Lake Bed

November 21, 2011

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Photographer
: Marli Bryant Miller; Marli's Web site  
Summary Author: Marli Bryant Miller

November 2011 Earth Science Picture of the Day Viewer's ChoiceThe Mesquite Flat dune field, part of which is shown above, is the largest and most accessible of five dune fields in Death Valley National Park. Like all dune fields, it requires three conditions to form: 1) a steady supply of sand, which here is supplied by nearby alluvial fans, 2) plenty of wind to move the sand, and 3) a natural windbreak so the wind will actually deposit the sand. Most of the dune fields of Death Valley lie in windbreaks afforded by irregularities in the adjacent mountain front. The fine-grained, mud-cracked deposits in the foreground underlie many of the interdune areas of the dune field. They're sediments of a former lake, which covered the area when the climate was wetter. The mountains in the background, the Grapevine Mountains, were uplifted relative to the valley floor along an active fault zone. They consist mostly of Paleozoic limestone, dolomite, and sandstone. Photo taken on May 2, 2011.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS 5D Mark II; Lens: EF17-40mm f/4L USM; Focal Length: 19.0mm; Aperture: f/10.0; Exposure Time: 0.020 s (1/50); ISO equiv: 100; Exposure Bias: +1.00 EV; Metering Mode: Spot; Exposure: program (Auto); White Balance: Manual; Flash Fired: No  (enforced); Orientation: Normal; Color Space: Adobe RGB (1998); Software: Adobe Photoshop Lightroom.