Page:The Scientific Monthly vol. 3.djvu/436

 TEE SCIENTIFIC MONTHLY

��Pta. la LiBOEBT Block in tbb Ejvcti oh Btii op Cbatbb Mound, Abicom. A

mRM of llm«itoDe 60 feet Id diameter nelgblng about SO,0O0

tons. Photo b; Q. E. Qllbert.

removed by eroEion, Undoubtedly its bedded condition was caused by a simultaneous outburst of water.

Crater Mound, or Coon Butte aa it was originally named, is so well known that I will not review it in detail and there is nothing new to add to previous descriptions." Some of the ealient features are shown in map end cross section, Fig. 14, and the views in Figs. 13, 15, 1? and 18. Its origin has not been ascertained and it remains one of the greatest enigmas in nature. The idea that it was caused by impact of a meteoric iron 50 to 100 feet in diameter has not jet been sub- stantiated by borings, shaft and the surrey of magnetic declination. It is interesting to compare this crater with the illustrations of explosion craters given above and the close similarity of many features is very suggestive in connection with Gilberi;'s original suggestion that Crater Mound was caused by a steam explosion.

II Qilbert, O. K., "The Origin of Hypotheses IlluBtrated bj the Discuasion of a Topographic Problem," Qeol. Soc. Wash,, Presidential Address, 1S95, &nd Science, N. S., Vol. 3, pp. 1-12, 1896. Barringer, D. M., and Tighlman, B. C, "Coon Mountain and Ita Crater," Phil. Acad. 5d., Froc, 1906, pp. 861-914. Merrill, G. B., "The Meteor Crater of Canyon Diablo, Arizona, Ita History, Origin and Associated Meteoric Irons," Smith. MUcell. Coll., Vol. 50, Pt. i, pp. 461-498, 190S. Barringer, D. M., "Meteor Crater in Northern Central Arisona," Xat. Acad. Sci., Nov. 16, 1909, 24 pp., pis. Darton, N. H., "A Beconnaisnineo of Parts of Northwestern New Meiico and Northern Arizona," U, 8. QeoI. Survey, Bull. 435, 1910.

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