by Dr. David Kring
In 1926, during the exploration phase of the Barringer Meteorite Crater, D. Moreau Barringer Jr. had an opportunity to explore another crater-like structure near the west Texas town of Odessa. Within a few hours, he found iron meteorites and shale balls and concluded that the structure was an impact crater with at least one satellite impact crater. He telegraphed the news to his father immediately. In private correspondence, Daniel Moreau Barringer wondered if his crater and the Odessa crater could have been produced at the same time by a pair of asteroids traveling together.
The possibility was further explored by Brandon Barringer in a paper presented to The Meteoritical Society in 1965 and published in 1967. Several hints seemed to link the two impact events. (1) Both were produced by similar types of iron asteroids. (2) Although the ages of the craters were imprecisely known, they were approximately similar. Estimated ages for Barringer Meteorite Crater and Odessa Crater were 20,000 and 25,000 years, respectively at the time of Brandon Barringer’s report. (3) There were hints that both craters were produced by objects with roughly north to south trajectories.
Additional research and newer technology shed light on the hypothesis. The chemical compositions of the iron asteroids that produced the craters have been analyzed in greater detail and the ages of the two craters have been better determined.
John Wasson and his colleagues examined the trace element compositions of the iron meteorites at the Barringer Meteorite Crater and those at Odessa. Although both groups of meteorites are part of the same chemical class (called type IAB), there are subtle differences between the meteorites that led Wasson and his colleagues to suggest they formed from two unrelated iron asteroids.
The second set of studies began in 1985, when Steve Sutton examined the crystalline damage caused by naturally occurring radioactive isotopes in crater rocks. Using the isotopes as a clock, he estimated the Barringer Meteorite Crater was produced approximately 49,000 years ago. In the early 1990's, Kuni Nishiizumi and his colleagues, plus Fred Phillips and his colleagues, used different types of isotopic clocks in crater rocks. They too estimated the Barringer Meteorite Crater formed approximately 49,000 years ago.
More recently (2005), techniques similar to those of Sutton were applied by Vance Holliday and his colleagues at the Odessa impact site. They estimated the Odessa craters were produced approximately 63,000 years ago. Although the ages of Barringer and Odessa craters are still not precisely known, these approximate ages suggest Odessa formed earlier. Thus, the two impact events may not be directly related.
On the other hand, binary impact events have occurred elsewhere. Clearwater East and Clearwater West craters in Canada are a pair of craters produced at the same time. Steinheim and Ries craters in Germany are another pair of craters produced at the same time. Although existing data suggest the Odessa and Barringer craters were produced by slightly different asteroids and separated in time by several thousand years, more research about their origin is still needed. Additional studies will continue to refine details of the impact events, including their timing.
Stay tuned .................
Hand Built for maximum Impact by The Cyrus Company. 1998.