THE REGION ABOUT GOLDEN. 103 



dip, while their continuance t" the easl of the axis is at a <li]i of but the 

 slightesl amount. This curve may a1 times be complete within a distance 

 of 50 feet. A faull is therefore unnecessary to explain the abrupt change 

 from the vertical to the horizontal position. Moreover, observations show 

 that the 1 >enver and Arapahoe beds actually take pari in this fold at a point 

 directly opposite South Table Mountain. The complicated geology of the 

 region would verj naturally lead one to mistaken conclusions unless a 

 thorough knowledge were possessed not only of tin- area of disturbance 

 here considered, hut also of the general structure of tin- region far beyond. 

 The fourth point in the quoted remarks of Professor Ward relates to the 

 manner in which he accounts foi the fossil Mactra found, according to prior 

 statements, "over" the coal. As a matter of fact, the fossil docs not occur 

 over the coal, hut beneath it, in its usual position in the Pierre hod. its 

 apparent position being due to its lying within a locally faulted area, the 

 hods of which have been tin-own to the eastward of the general trend of 

 the coal in the unaffected area to the south ami north. 



The views of others. — In addition to the views of the above writers, others 

 have from time to time been expressed, implying belief in a faull in 

 the vicinity of Grolden to account for the peculiarities of structure there 

 displayed. In reply to this it need only he stated that no fault can be 

 conceived which will at once account for the several features in the geology 



of this region as exposed over the present surface of tin- area and set forth 



in the preceding pages. 



SPECIAL IRREGULARITIES I.N" nil') GOLDEN REGION. 



The Raiston faults. — These occur in the vicinity of the Ralston dike, mid- 

 way between North Table .Mountain and Ralston Creek. They entered 



only into the later development of the region in a manner incidental to 

 rather than as a primary factor in the events that transpired. 



There are three fractures, and their peculiar features are due chiefly 



to exceptional local conditions connected with the neighboring eruptive 



phenomena. The fractures 1 ad the western, northern, and southern sides 



of a rectangular bloct of strata of indefinite hut not greal thickness, beneath 



which there is probably a large mass of eruptive rock, a part of that which 



