310 ANNUAL REPORT SMITHSONIAN INSTITUTION, 193 3 



Besides diamond, the Canon Diablo meteoric iron contains T.33 

 percent of nickel and small amounts of the precious metals platinum 

 and iridium. One assay gave platinum 3.65 and iridium 14.95 grams 

 per metric ton. It therefore seemed to offer a promising mining 

 venture, the supposition being that the main mass of the large mete- 

 orite, perhaps 600 feet across ° and weighing over 14 million tons, 

 that formed the crater would be found buried inside. Mining claims 

 were taken out by the Standard Iron Co, in 1903 and many trial 

 shafts (6) and bore holes (23) were put down at considerable ex- 

 pense, but nothing of value was found. After passing through 

 crushed and metamorphosed sandstone and abundant rock flour, un- 

 disturbed sandstone was met at a depth of 620 feet. The meta- 

 morphosed sandstone shows a partial fusion of the grains of quartz 

 and grades into a friable and porous silica glass." 



Another company, the Meteor Crater Exploration & Mining Co., 

 was formed in 1927, and a new drill hole was put down through the 

 southern wall of the crater (under the supposition that the meteorite 

 had entered at a slanting angle). After passing through 30 feet of 

 iron shale cementing fragments of metamorphosed sandstone, the 

 drill stuck at a depth of 1,376 feet, presumably against some hard 

 object, which was believed to be the main mass of the meteorite. 

 An attempt was then made to sink a shaft outside the crater to a 

 depth of 1,500 feet from which the mass could be reached by a cross 

 cut, but at a depth of 640 feet a heavy flow of water was encountered 

 and the work had to be abandoned after the expenditure of $293,000. 

 Attempts are now being made to raise funds for further exploration. 



All this work, which has added much valuable detail to a knowledge 

 of the crater, was carried out by the late Daniel Moreau Barringer, 

 of Philadelphia, who was an enthusiastic supporter of the meteorite 

 theory; and it is now being continued by his son, D. M. Barringer, 

 Jr. Under the guidance of Mr. Barringer the crater was examined 

 in detail by the late Dr. George P. Merrill, of the United States 

 National Museum, and eventually he became an adherent of the 

 meteorite theory. Previously this theory had been rejected by G. K. 

 Gilbert, of the United States Geological Survey, in favor of the 

 theory that the crater had been formed by a volcanic steam or gas 

 explosion without the extrusion of any lava. Although there are no 

 volcanic materials in the immediate neighborhood of the crater, yet 

 there are extensive basaltic flows at a distance of 10 miles, and the 

 extinct volcanoes of the San Francisco Mountains are only 30 miles 



6 A small asteroid of 1,500 feet diameter has also been suggested. This, composed of 

 meteoric Iron, would have a mass of 378 million tons. 



8 Rogers, A. F., A unique occurrence of lechatelierite or silica glass. Amer. Journ. Sci., 

 ser. 5, vol. 19, 195-202, 9 figs., 1930. This silica glass is more like a sintered sandstone: 

 it does not show the effects of complete fusion, as at Wabar. 



