22 LAKES OF NORTH AMERICA. 



description of a model of the locality published in the American 

 Geologist.^ 



This " crater *" in what is known as Coon butte, is three-fourths of a 

 mile in diameter and its bottom is depressed from 500 to 600 feet below 

 the encircling rim, which rises 150 to 200 feet above the surrounding 

 plains. The surface limestone of the region, elsewhere horizontal, is 

 steeply inclined quaquaversally in the cliffs around the crater ; and 

 masses of the same stratum and of an underlying sandstone, are strewn 

 in irregular profusion outward from the crater to the base of the butte, 

 which has a diameter of about two miles. In less amount, the same 

 debris reaches outward on all sides over a nearly circular area to a 

 distance of about four miles. No lava, bombs, lapilli, or other vol- 

 canic products, were seen. The formation of this irregular crater-like 

 depression is referred by Gilbert, perhaps provisionally, to a steam 

 explosion. 



The occurrence in the vicinity of Coon butte of hundreds of frag- 

 ments of meteoric iron, up to about a pound in weight, and of several 

 pieces weighing from 20 to 600 pounds, led at first to the thought 

 that possibly a meteorite of great size might have struck this spot, buried 

 itself out of sight and thrown up a crater-like rim. This hypothesis, 

 upon l^eing tested, was aljandoned, however, because the volume of the 

 raised rim and of the rock fragments scattered about, was found to corre- 

 spond very closely with that of the depression below the level of the 

 plain : and for the second reason, that a magnetic survey failed to 

 indicate the existence of any large mass of meteoric iron competent to 

 make such a crater, within at least a depth of many miles. This second 

 objection, however, is now considered of but little weight, since the 

 meteoric fragments found about the crater, although now magnetic, 

 have undergone alterations of a character which seem to indicate that 

 when they first reached the earth they might not have had any or but 

 slight magnetic properties. The changes produced in the surface frag- 

 ments are due to atmospheric influences, which would not reach a deeply 

 buried body. 



The orater-like depression in the summit of Coon butte is without 

 water, for the reason that it is situated in an arid region, but under 

 humid skies would no doubt be transformed into a lake. 



The only counterpart of Coon butte as yet discovered, is situated in 

 the central part of the Peninsula of India, some 200 miles northeast of 



1 Vol. 13, 1894, p. 115. 



