Meteor Crater - the Second Largest Hole in Arizona

History of Meteor Crater

50,000 years ago, a small light grew brightly into a 26,000 miles per hour flaming meteor and struck a rocky plain in the northern Arizona desert and exploded with a force greater than 20 million tons of TNT.  The impact generated powerful shock waves that swept across the plain.  Pressures in the ground rose to over 20 million pounds per square inch and iron and rock experienced vaporization and melting.  Due to these violent conditions, a giant bowl-shaped cavity was created, 700 feet deep and over 4,000 feet wide.  Over 175 million tons of sandstone and limestone were ejected into the air and landed all around the crater forming a beautiful blanket and debris. 

Meteor Crater Today

Lots of people bypass the meteor crater in Arizona because why go see the second largest hole in Arizona when the first, the Grand Canyon, is so close?  The crater is privately owned by the Barringer family.  Daniel Barringer was the first man to suggest that the crater had been produced by the impact of a large iron-metallic meteorite.  His company, the Standard Iron Company, received a patent signed by Teddy Roosevelt in 1903 for the 640 acres around the center of the crater.

Barringer's Standard Oil Company conducted lots of research on its origins and it was concluded that the crater had for sure been caused by an extremely violent impact.  Barringer documented evidence with his partner, physicist Benjamin C. Tilghman, and presented papers to the U.S. Geological Survey in 1906 and published his findings in the Proceedings of the Academy of Natural Sciences in Philadelphia

My personal view of Meteor Crater

His arguments were met with skepticism, but he persisted and sought to uncover the remains of the meteorite.  He spent 27 years mining the crater, but no significant deposits of iron were found.  Barringer was unaware at this time that the meteorite had vaporized on impact. 

Barringer's findings were not solidified until 1960 when his hypothesis was confirmed by Eugene Shoemaker.  Shoemaker helped make the key discovery of two key elements at Meteor Crater: coesite and stishovite.  Both of these elements are high-pressure polymorphous forms of silicon dioxide.  They're formed by extremely high pressures equivalent to 300,000 pounds per square inch.  These elemtns had before been produced in laboratories, but were never before been identified in nature.  These two minerals are key criteria of ancient impact crater scars.