Kring published this guidebook in 2017 and is now available on-line. He indicated in the Introduction that science does not always move forward in a straight line and rarely at a constant cadence. The study of Barringer Meteorite Crater (a k a Meteor Crater) is a classic example. Although an immense collection of meteorites of undisputable extraterrestrial origin was gathered at northern Arizona’s crater (Foote, 1891), the association was considered coincidental by many (e.g., Gilbert, 1896) and nearly fifteen years passed before a serious case linking the meteorites to the impact origin of the crater was presented (Barringer 1905; Tilghman 1905). That latter effort was part of an intense mining operation at the crater to recover the suspected projectile. The works were extensive, including a reservoir in the distant Canyon Diablo, a pipeline to the crater, and camps on both the crater rim and crater floor. Sadly for investors, economically viable deposits of metal were never recovered. Sadly for science, decades passed before the implications
of Barringer’s work were appreciated.
There are many ways to trace the path of this story, but perhaps the best place to begin is with the mineralogist A. E. Foote, who published the first scientific report about the crater and meteorites found there. Foote’s interest was piqued by a railroad executive who sent him a sample of native iron and
requested an analysis. Foote deduced the sample was a fragment of a meteorite and, having been told more material existed in northern Arizona (“185 miles due north from Tucson”), promptly traveled to the site from Philadelphia. Foote and his team collected several large masses (201, 154, and 40 lbs), 131 smaller masses (ranging from 1/16 oz to 6 lbs 10 oz), and 200 lbs of oxidized meteorite fragments.
After returning to Philadelphia, he received three additional large masses (632, 506, and 145 lbs). Several of the larger samples were perforated with cavities similar to the one in the spectacular Tucson ring meteorite (“Signet Iron”). The iron meteorites also contained troilite, daubréelite, carbon, and diamonds (up to 1/8 inch diameter), the latter of which were described as being mostly black and of little commercial value.
The purpose of Foote’s paper was to describe the diamond-bearing iron meteorites, but he was clearly impressed with the “Crater Mountain,” where the samples were found and provided the scientific community with its first geologic description. He noted an uplifted rim of sandstone and limestone dipping 35 to 40° that stood 432 ft above the surrounding plain. The crater floor appeared to be 50 to 100 ft below the surrounding plain. He further noted that he could not locate any “lava, obsidian or other volcanic products,” and, thus, concluded that he was “unable to explain the cause of this remarkable
geological phenomenon.” He did not recognize any genetic association between the crater and meteorite irons. Nor did he add any remarks about the unusual quantity of iron meteorites.
With regard to the iron oxide fragments, however, he concluded that a large iron meteorite of 500 to 600 pounds “had become oxidized while passing through the atmosphere and was so weakened in its internal structure that it had burst into pieces not long before reaching the earth.”
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