872 PROCEEDINGS OF THE ACADEMY OF [DeC, 



certainly from the upper portion of the Red Beds already referred 

 to. 



This brings me to describe more particularly the rim itself. On first 

 examination it would seem that the fragmentary material and silica are 

 almost equally distributed on all sides of the crater. Upon closer 

 examination, however, it is found that there is vastly more of it to the 

 southwest, south and southeast than to the northeast, north and north- 

 west. It also will be observed that the fragmentary material is much 

 more comminuted to the southwest, south and southeast than it is on 

 the opposite sides of the crater. It will also be observed that the 

 limestone cliffs on the interior of the crater are much more shattered to 

 the southwest and south than anywhere else, and the limestone bed 

 itself is raised higher, and to the southeast is to be found the great 

 wedge-shaped piece of the material forming the cliffs and rim, which 

 was turned over and seems to have been near to going out bodily. It 

 will also be observed that the lowest point on the crater is on the north 

 rim, somewhat to the west of a north-and-south line passing through it; 

 and finally the ejected fragments, of ten tons or more in weight, are 

 found distributed over the plain at a greater distance south and south- 

 east of the crater than anj^where else. From all of these facts, the infer- 

 ence is unavoidable that the cause which produced the crater acted 

 with somewhat more violence in a southwest, south and southeast 

 direction than in the opposite direction. 



It would be possible to extend this description of the crater to a 

 much greater length ; but I hope that in the above I have stated most 

 of the salient facts which would impress the careful observer. Now, 

 there are only three conceivable causes for such a tremendous disturb- 

 ance of the horizontal strata at this point, and I will take them up 

 separately. 



I. An extremely violently acting volcano. This can be set aside as 

 being impossible inasmuch — 



First: No lava is to be found, or any other volcanic rock, for many 

 miles in any direction. Nor is there to be seen any sulphur, which is 

 found in most volcanic craters of recent origin. 



Second : I assume that huge fragments of rock, weighing perhaps 

 upwards of fifty tons, could not have been expelled from the crater 

 and deposited a mile or more distant from its center by volcanic action, 

 in the absence of other numerous and indisputable facts to show that 

 a volcano existed at this place. Moreover, any stone which has been 

 hurled from a volcanic crater through the agency of steam is usually of 

 igneous origin. 



Third : We know absolutely the series of rocks at this point, and this 



