1905.] NATURAL SCIENCES OF PHILADELPHIA. 867 



material, but roughly guess it to be in the neighborhood of 200,000,000 

 tons; perhaps rather less than more. An additional reason for the 

 existence of the elevation known as Coon Butte or Coon Mountain is 

 to be found in the fact that the uppermost strata exposed in the walls 

 of the interior crater dip quaquaversally, or generally speaking in every 

 direction from the exact center of the crater, at an angle usually vary- 

 ing from ten to forty degrees, and in one case from sixty to seventy de- 

 grees. It should be stated, however, that in this case it is evident that a 

 great, presumably wedge-shaped, piece of the material of the cliffs which 

 form the sides of the crater and the rim, has nearly been turned out 

 bodily by the force which produced this enormous hole in the earth's 

 surface. The effect of this would be, of course, to turn the strata 

 nearly on edge at this place. Naturally, this wedge-shaped piece — an 

 expression which is used for want of a better one — lies between two 

 faults, on the other side of each of which the strata dip at a much lower 

 angle, not to exceed perhaps twenty degrees in the one case, that is to 

 the north, and not to exceed five or ten degrees in the other, that is to 

 the southwest. On the west side of the crater the strata are upturned 

 so that they dip at about forty-five degrees west. It is an interesting 

 fact that many large fragments of limestone, which have been hurled 

 -out of the crater, are to be found at least a mile from it ; and if I am 

 not mistaken there are several large fragments, weighing perhaps 

 fifty tons each, which are more than a mile distant from the center of 

 the crater. These fragments, great and small, are distributed con- 

 centrically around the crater, being more abundant near the rim than 

 distant from it. It is worthy of note, however, that the greater 

 number of the larger fragments of the limestone stratum, some of 

 them weighing probably over 5,000 tons, are to be found on the 

 slopes of the mountain outside of the crater, on an east-and-west line 

 passing through the center of the crater. That is to say, there are two 

 places on the rim where these large fragments are most abundant; one 

 almost directly east of the center and the other almost directly west of 

 the center. It is also interesting to see how shattered and cracked 

 many of the exposed limestone fragments are, showing probably that 

 they have been subjected to the concussion from a great blow. These 

 great and small angular blocks of limestone lie in every conceivable 

 position on the slopes of the mountain, many of them standing on end 

 so to speak, that is with the lines of stratification showing a vertical or 

 nearly vertical dip. 



I have made more than ten trips to this locality and have examined 

 almost every foot of the ground around it most carefully, and have 



