Grand Teton, Mount Owen, and Uplifted Cambrian Shoreline
May 19, 2011
The above photo shows Mount Owen (left) and Grand Teton the two highest peaks in Grand Teton National Park, Wyoming. The Cambrian Flathead sandstone, shown here as the nearly flat-lying rock of the middle ground, reflects encroachment of the ocean onto continental North America at the beginning of the Paleozoic Era about 540 million years ago. This sandstone crops out throughout the western United States, and includes the Tapeats Sandstone of the Grand Canyon. Beneath the sandstone lies much older rock, which in the Tetons is Archean gneiss and Proterozoic granite. The gneiss appears in the cliffs below the sandstone and in Mount Owen; the Proterozoic granite makes up most of the Grand Teton. The older rock of the peaks appears higher than the Cambrian Sandstone because of slip on the Buck Mountain fault zone during the late Mesozoic. Photo taken July 23, 2006. [Revised December 2017]
Photo Details: Camera Maker: Canon; Camera Model: Canon EOS 30D; Focal Length: 90.0mm; Aperture: f/10.0; Exposure Time: 0.0031 s (1/320); ISO equiv: 100.