Image: Kurt A. Fisher 9/23/2008.
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Image: Kurt A. Fisher 9/23/2008. |
In March 2008, Thomas Kenkmann, a geologist with Humboldt University in Berlin (after six years of research), and Elmar Buchner of the University of Stugggart, provided conclusive evidence that the Upheaval Dome, an impact-shaped feature in Canyonlands National Park, Utah, was caused by a meteor strike. Buchner and Kenkmann located planar deformation features (PDFs) in quartz crystals embedded in the outer sandstone ring of this two ring crater. PDFs are microscopic fractures in quartz crystals that correlate with the intensity of a shock impact experienced by the cyrstal. These PDFs evidence a shock wave greater than 10 gigapascals travelled through Upheaval's sandstone outer ring, unambigously showing a shock generated wave of non-terresterial origin. The feature that we see today is not the original 170 million year old impact crater. The original crater was around 8 kilometers in diameter and extended between 1 and 2 kilometers above the south rim view area shown here. 155 million years ago, Upheaval Dome probably looked something like the 4 kilometer diameter Steinheim Basin in Bavaria, or the 2.5 kilometer blown-sand filled Roter Kamm Crater in Nambia. Subsequent uplift and erosion removed this overburden, leaving this unique 3 kilometer diameter dissection of what the geologic layers might look like at or beneath the surface of an analogous lunar complex crater such as Triesnecker. Several traces of the impact are seen in rock from the south rim view area: a fractured Kayenta layer, radial faults in the inner ring wall, 30 meter tall displaced blocks, verge or circular faulting in the central uplift and melted sandstone dikes near the impact center.
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