U-Haul #97: Iowa
Posted by: 
ODragon
N 41° 34.560 W 093° 37.020
15T E 448563 N 4602885
Did you know?!?
A crater 24 miles in diameter lies hidden by glacial sediment under crop fields centered in Pocahontas County. What effects did the impact of an enormous meteor have on Iowa?
Waymark Code: WM6H1X
Location: Iowa, United States
Date Posted: 06/03/2009
Views: 125
WHAT IS IT?
The Manson Impact Structure is one of the largest known meteorite craters in the continental United States. Measuring more than 24 miles in diameter, the crater is believed to have been created by the impact of a stony meteorite that seared through the Earth’s atmosphere and collided with our planet some 74 million years ago. The meteorite spanned approximately 1.5 miles in diameter, weighed close to 10 billion tons and was traveling at a rate of 45,000 miles per hour when it crashed into the Earth. The crater was named after the small town of Manson, Iowa, which lies near its center.
The unusual geology of the land surrounding the Manson structure was discovered in 1912, when a town water well was drilled. Rock samples were discovered to be unlike other rocks in the region. Instead of the bedrock typically found in north-central Iowa, drillers encountered thick shale directly above granitic rock.
The mysterious geology was originally thought to be a river-channel deposit. In 1953, the Iowa Geological Survey and the U.S. Geological Survey obtained two drill cores from the structure to investigate the site further. They concluded that the crater was a cryptovolcanic structure produced by a giant blast of volcanic gas. It was not until 1959 that evidence was found by Robert Dietz, which proposed the Manson structure to be of meteor-impact origin. In 1966, Nicholas Short confirmed Dietz’s proposal.
Want to know more? Check out the link below.
"Default Image and any additional cited content and/or images from the U-Haul SuperGraphics website are used with permission from U-Haul International."
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Coordinates of Featured Scene: N 40° 40.068 W 111° 59.214
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