Tuesday, June 29, 2010

Sandrock Factory

Every rock lover knows the names. Cocconino, Wingate, Cedar Mesa, colossal Navajo - just a few. The river man, the uranium canyoneer, the roadbuilder, even the curs├Ęd RV tourist can't help but hear insinuations about the history of sandstone. We're always told, and the evidence shows, that these sweeping curved carved beds of tilted cemented grains were once part of giant sand ergs stuck to the side of the continent, petrified now in the middle of ours. In the slabs, we see the bottoms of huge dunes, the damp footprints of dinosaurs and the occasional lens of seabourne shell-hashed lime. But How? What possible mechanism could get such an enormous goggling volume of sand to stretch across hundreds of miles and stay there? The Navajo is 5000 feet thick. What does making that even look like? (!)

Don't point me to the Sahara. Sure, great sand dunes, but I need to see preservation. There's nothing more convincing to a uniformitarian than a dramatic Modern Analog. George Steinmetz and his paraglider provide that with his story in July's National Geographic Magazine. For the first time, we can really see the depositional raw material of the most dramatic and recognizable stone freakshows in the American West, right at the moment of creation. Thanks.

2 comments:

  1. and...that just inspired me to renew my NG subscription.

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  2. always good to score a non-geriatric subscriber. But I'm not waiting for a commission. maybe even try these nerds too: http://www.newyorker.com/online/blogs/newsdesk/2010/04/video-george-steinmetz-aerial-photographer.html

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