METEORITE CRATERS — SPENCER 309 



crater itself. It was loiown locally as " Crater Mountain " or " Coon 

 Butte ", and was afterward called " Meteor Crater." The irons are 

 known as the " Canon Diablo meteorite " from the Canon Diablo 

 nearby. The locality is situated in Coconino County in the desert of 

 north central Arizona and clo3e to the Santa Fe railroad. 



The crater is a basin-shaped depression approximately circular in 

 outline with a maximum diameter of 3,950 feet and a minimum 

 diameter of 3,850 feet, or three-quarters of a mile. Its depth is 570 

 feet. The outer slopes rise gently from the surrounding desert 

 plain to a height of 130 to 160 feet at the rim, while the inner slopes 

 are steep and precipitous, and partly covered with talus. The bot- 

 tom is level (410 feet below the plain) with an area of over 300 

 acres, and was once occupied by a lake as shown by the presence of 

 lacustrine deposits up to 88 feet in thickness. In the surrounding 

 country the beds of sandstone and limestone (of Carboniferous age) 

 are horizontal, but in the walls of the crater they dip radially out- 

 ward at angles of 10° to 80°, and in one place are faulted. The 

 outer slopes are covered pell-mell with fragmentary material rang- 

 ing in size from blocks of rock estimated to weigh over 4,000 tons 

 down to the finest " rock flour." Fragments are littered about for 

 a distance of 6 miles from the center, and they were evidently 

 ejected from the crater, the largest blocks being nearest the rim. 

 Indiscriminately mixed with this material, and also buried in it, 

 have been found thousands of pieces of meteoric iron ranging in 

 weight up to 460 kilos (1,014 pounds) and also pieces of laminated 

 iron shale resulting from the weathering of the iron. About 20 

 tons of the iron has been collected, but inside the crater only four 

 small pieces have been found and relatively little of the iron shale. 

 It is obvious that this meteoritic material must have been ejected 

 from the crater at the same time as the blocks of sandstone and 

 limestone. 



Gilbert, G. K., The origin of liypotlieses, illustrated by tho. discussion of a topo- 

 graphical problem. Science, vol. 3, pp. 1-13, 2 pis., 1896; and I'residontinl Addresses, 

 Geol. Soc, pp. 2-24, 18 figs., Washington, 1896. 



Karringcr, D. M., Coon Mountain and its crater. Proc. Acad. Nat. Sci. Philadelphia, 

 \ol. 57 (for 1005), pp. 861-886, 1906. 



Tilghinan, 15. C, Coon Butte, Arizona. Ibid, pp. 887-914. 



Fletcher, L., A search for a buried meteorite. Nature, vol. 74, pp. 490-492, 1906. 



Merrill, G. P., Tlie Meteor Crater of Canyon Diablo, Arizona ; its liistory, origin, and 

 associated meteoric irons. Smithsonian Misc. Coll., vol. 50, pp. 401-408, 15 pis., 1908. 



Barringer, D. M., Meteor Crater (formerly called Coon Mountain or Coon Butte) 

 in northern central Arizona. I'aper road before the National Academy of Sciences, Nov. 

 16, 1900; privately printed, 24 pp., 18 pis. [I'hiladclphia, 1910.] Further notes on 

 Meteor Crater In northern central Ai'lzona. Proc. Acad. Nat. Sci. Pliiladelphia. vol. 66 

 (for 1914), pp. 556-565, 3 pis., 1915; vol. 76 (for 1924), pp. 275-278, 1 pi., 1925. 



For more recent short notes see Nat. Geogr. Mag., vol. 53, pp. 721-7o0, IOL'8. Science, 

 vol. 69, pp. 485-487, 1929; vol. 72, pp. 463-467, lO.'JO; vol. 73, pp. 38-39, 60-07, 1931. 

 Scientific American, .Tuly, August, and September, 1927; June 1932, p. 363. Eng. 

 and Min. Journ., vol. 133, p. 392, 1932. 



