1905.] NATURAL SCIENCES OF PHILADELPHIA. 887 



COON BUTTE, ARIZONA. 

 BY BENJAMIN CHEW TILGHMAN. 



In Central Arizona, situated at approximately longitude 111° 1' west 

 and latitude 36° 2' north, about five miles almost due south of Sun- 

 shine Station on the line of the Atchison, Topeka & Santa ¥6 Railroad, 

 is situated the very remarkable eminence known locally by the names 

 of Coon Butte, Coon Mountain and Crater Mountain. 



This so-called mountain consists of a circular ridge from 130 to 160 

 feet in height, surrounding an almost circular cup-shaped depression 

 in the earth about 400 feet deep and varying from 3,600 to 3,800 feet 

 in diameter. Viewed from the inside, the crest of the ridge is elevated 

 from 530 to 560 feet above the level of the flat interior plain. 



The strata penetrated by this hole are, first, from twenty to forty feet 

 of red sandstone; second, about 250 to 350 feet of a yellowish silicious 

 limestone, or possibly more correctly a very calcareous sandstone; 

 third, an unknown depth of a whitish or light gray sandstone, consisting 

 of rather small water-worn grains but weakly attached to each other; 

 fourth, about 80 to 100 feet of brownish sandstone in which it ter- 

 minates. The contact between these latter strata is some 880 feet 

 below the floor of the crater, but there is some reason to think it may 

 not be in place but below its original position. These strata are of 

 late Carboniferous formation, and in the surrounding plain lie perfectly 

 level and conformably with each other. The uppermost, the red sand- 

 stone, being almost removed by erosion and only showing in spots upon 

 the plain in the form of more or less scattered flat-topped red buttes, 

 although it seems to have been nearly or quite continuous over the 

 area now occupied by the interior edge of the crater. 



These same level strata cover the plain in all directions for many 

 miles. They are cut through by Cafion Diablo to a depth of some 

 sixty to seventy feet about two miles to the westward of the crater, 

 and near this gorge are two large earth cracks penetrating the strata to 

 an unknown depth. 



Immediately around the crater the strata dip outward in all directions 

 from the center of the crater at an angle of about thirty degrees, and 

 are raised from 140 to 180 feet above the normal position. This is the 

 locality in which the Cafion Diablo meteoric iron has been found to the 



