Daniel Barringer (geologist)

From Wikipedia, the free encyclopedia

For other persons named Daniel Barringer, see Daniel Barringer.

Daniel Moreau Barringer (18601929) is best known for being the first person to prove the existence of a meteorite crater on Earth, the Barringer Meteorite Crater, or Meteor Crater, in Arizona.

Daniel Barringer, the son of Daniel Moreau Barringer and nephew of Rufus Barringer, graduated from Princeton University in 1879 at the age of 19, and in 1882 graduated from the University of Pennsylvania's Law School. He later studied geology and mineralogy at Harvard University and the University of Virginia respectively.

In 1892 Barringer, along with his friend Richard A. F. Penrose, Jr. and others, purchased a gold and silver mine near Cochise, Arizona. Later he discovered the Commonwealth Silver Mine in Pearce, Arizona. These mining ventures left him a wealthy man.

In 1902 Barringer learned of the existence of a large (1.5 km in diameter) crater, located 35 miles east of Flagstaff, Arizona. The crater, known as Coon Mountain, had previously been studied by the geologist Grove Karl Gilbert in 1891. Gilbert had hypothesized that the crater must have been the result of either a gas explosion or a meteorite. After performing experiments in the crater, however, Gilbert concluded that the crater could not be the result of an impact, and therefore could only be the result of an explosion. He concluded this despite the clear presence of small meteoritic particles in the vicinity of the crater.

Upon hearing of the existence of the crater and the meteoritic iron, Barringer became convinced that the crater was of meteoritic origin. With both scientific and monetary aims in mind, Barringer created the Standard Iron Company in order to mine the crater for the iron that he assumed must be buried under the surface.

The Standard Iron Company conducted drilling operations in and around the crater between 1903 and 1905, and concluded that the crater had indeed been caused by a violent impact. They were unable to find the meteorite, however.

In 1906 Barringer and his partner, the mathematician and physicist Benjamin C. Tilghman, presented their first papers to the U.S. Geological Survey outlining the evidence in support of the impact theory. The papers were published in the Proceedings of the Academy of Natural Sciences in Philadelphia.

The mining of the crater continued until 1929 without ever finding the ten-million ton meteorite that Barringer assumed must be hidden. At this time the astronomer Forest Ray Moulton performed calculations on the energy expended by the meteorite on impact, and concluded that the meteorite had most likely vaporized when it landed. By this point Barringer had spent over $600,000 in mining the crater, nearly bankrupting him, with no iron profits to show for it.

Barringer died of a heart attack on November 30, 1929, shortly after reading the very persuasive arguments that no iron was to be found.

By the time of his death, Barringer had convinced most of the scientific community that his impact theory was correct. The theory has been further confirmed with new evidence since then, most notably by Eugene Shoemaker in the 1960s.

Barringer had a small crater named after him posthumously on the far side of the Moon. He was survived by his wife, Margaret Bennett, and eight children, who, together with their descendants, formed the Barringer Crater Company, which owns the site to this day.

[edit] See also

[edit] References and external links