About 50,000 years ago, a meteorite the size of a small house hit the earth near Winslow. The impact and explosion that followed left a crater 600 feet deep and almost a mile wide. The arid climate has preserved the crater, and geologists from all over the world come to Arizona to study it. Associated with the crater are many specimens of meteorite, melted and brecciated rock, and new high-pressure minerals called coesite and stishovite. David Barringer staked mining claims over the crater in 1903 to mine the meteorite. He was never successful, but the Barringer family still owns the crater today.
A Geological Marvel from the Sky
Meteor Crater is awe-inspiring. Also known as Barringer Crater, this site is one of the most well-preserved and recognizable impact craters on Earth. Created by a meteorite impact approximately 50,000 years ago, Meteor Crater provides a unique window into the Earth’s geological history and the forces that have shaped our planet.
Discovery and Formation
A sheepherder found iron-nickel meteorite fragments in the area in 1886. He did not report the finding until 1891.
Such discoveries led to the suggestion, by some, that the crater had been formed by a giant meteorite. But in 1891, the chief geologist of the United States Geological Survey, G.K. Gilbert, briefly visited the crater. Despite having studied impact craters on the moon, he interpreted Meteor Crater as being of volcanic origin.
In 1902, mining engineer Daniel Barringer became interested in the site as a potential source for mining iron. He visited the crater and was convinced that it had been formed by the impact of a large iron meteorite.
He also assumed that the meteorite was still buried beneath the crater floor. Barringer formed the Standard Iron Company and filed mining claims, obtaining ownership crater. The Barringer family still owns the area. It has been found that the initial meteorite broke up, and only pieces have been found. Some of those pieces have been quite large.
Native American tribes and early pioneers, of course, had known about the crater for centuries.
Approximately 50,000 years ago, a nickel-iron meteor, estimated to be about 150 feet (46 meters) in diameter, hurtled towards Earth at a tremendous speed of around 40,000 to 45,000 miles per hour (64,000 to 72,000 kilometers per hour). The meteor collided with the Earth’s surface, resulting in a cataclysmic event carving out the impressive crater we see today.
Geological Features
Meteor Crater’s main geological features are a testament to the immense energy and forces involved in the impact:
Rim and Ejecta Blanket
The crater has a rim that rises around 150 feet (46 meters) above the surrounding terrain. The ejected material from the impact, known as the ejecta blanket, is spread around the crater’s perimeter.
Central Uplift
At the center of the crater is a raised mound called the central uplift, formed by the rebound of the Earth’s crust after the impact.
Impact Breccia
The crater is filled with impact breccia, a rock formed from the fragmented and shattered material created by the intense impact forces.
Shocked Quartz
The impact generated high-pressure shock waves that caused minerals like quartz to exhibit distinctive shock-induced features, known as shocked quartz.
Scientific Significance
Meteor Crater holds immense scientific value, offering valuable insights into the processes and effects of meteorite impacts on Earth:
Planetary Defense
The study of Meteor Crater helps us understand the potential impact hazard from near-Earth objects and informs strategies for planetary defense.
Impact Processes
The features preserved at Meteor Crater allow scientists to study the geological and structural effects of high-velocity impacts, such as crater formation, shock metamorphism, and ejecta deposition.
Impact Chronology
Meteor Crater serves as a reference point in the geological record, helping scientists date and correlate other impact structures and events worldwide.
Origin of Meteorites
The study of Meteor Crater and the recovered meteorite fragments provides insights into the origins and composition of meteorites.
Ongoing Research
Meteor Crater continues to be a site of active research, with ongoing investigations in various fields:
Impact Modeling
Researchers use advanced computer modeling techniques to simulate the impact event and understand the crater’s formation and subsequent modifications.
Shock Metamorphism
Studies of shocked minerals and impact structures help researchers refine our understanding of shock metamorphism and the energy transfer during impacts.
Astrobiology
Meteor Crater’s extreme environment and subsurface conditions make it a relevant analog for understanding microbial life in impact craters on other planets.
Planetary Geology
Meteor Crater serves as a terrestrial analog for understanding impact craters on other planetary bodies, providing valuable data for planetary geologists.
Preservation and Conservation
Meteor Crater is a designated National Natural Landmark and is under the care of the Barringer family, who has owned the crater’s land for over a century. The preservation and conservation efforts ensure that this geological wonder is protected for future generations to appreciate and study.
Conclusion
Meteor Crater, stands as an enduring testament to the immense forces of nature and the dynamic history of our planet. The result of a meteorite impact that occurred thousands of years ago, this geological marvel continues to captivate researchers and visitors alike. Its significance extends beyond Earth, offering insights into impact processes on other planetary bodies and contributing to our understanding of the early solar system. As we continue to explore and study Meteor Crater, its geological features and scientific value will inspire generations of geologists, mineralogists, and curious minds to come. The impact event that formed this extraordinary site provides a unique opportunity to unravel the mysteries of the cosmos and gain a deeper appreciation for the dynamic and ever-evolving nature of our planet.