Wednesday, July 25, 2012
The Abandoned Lands...A Journey Through the Colorado Plateau: Not so much abandoned as obliterated
And then there are those things that come right out of left field, features that are so out of place that they serve only to teach the uncertainty of life on planet Earth. Meteor Crater is one of those places. There's no particular reason that it should be on the Colorado Plateau and not somewhere else. But there it is, out on the plains of Arizona.
But then, there is sort of an interruption in the flatness off to the south of the freeway. We know what is there, but it doesn't really look like much in the distance. We turn off the freeway and drive up the access road.
More than a century ago, this spot was called Franklin's Hole. As obvious as it seems today, the origin of this 550 foot deep hole was not clear at first. Most people figured it was some kind of volcanic feature, even after chunks of iron and nickel were discovered (not to mention a total lack of volcanic material).
It really sparks the imagination. 50,000 or so years ago, a big chunk of rock hit the Earth's atmosphere at 26,000 miles per hour and flared brighter than the sun. It hit the ground creating a massive explosion, leaving behind a crater 4,000 feet wide and 700 feet deep. It is a bit scary to contemplate the effect of such a collision in the present day. Not an extinction-level event, but devastating to anyone unfortunate enough to be anywhere nearby (the meteorite that caused the extinction of the dinosaurs is thought to have been several miles across). The impact actually caused the layers of Kaibab Limestone and Coconino Sandstone to rise and fold over on themselves, so the stratigraphy is inverted along the crater rim.
Look here for an explanation of my "abandonment" theme for this series: http://geotripper.blogspot.com/2012/06/abandoned-landsa-journey-through.html