SANDSTONE DIKES OF UTE PASS. 125 



up. Thus, on the high, steep and smooth hill (14) 

 directly south of the Denver and Rio Grande Depot 

 I found that a broad sandstone dike crosses the lower 

 northern slope of the hill ; all the upper and main part of 

 the hill, including the crest, is granite; the col leading 

 from this hill to the higher summit on the southwest 

 shows two sandstone dikes, probably fifteen to twenty 

 feet wide and separated by twenty to thirty feet of 

 granite, the more southern dike, especially, showing a 

 strong southerly hade; and, finally, several hundred feet 

 farther southwest up the ridge is a small dike (10 feet?). 

 Below the sandstone dikes and the fault-line the Foun- 

 tain beds form as usual a gently sloping plain or terrace 

 and exhibit near the mountains low east to southeast dips 

 (5° to 10°). But farther down the slope toward the 

 railroad, in the numerous excellent outcrops and monu- 

 ments, the beds dip due south 20° to 25°, seeming thus to 

 show in the diminished dips toward the fault-line the 

 lifting eflfect or upward drag of this great displacement. 

 In the long deep cut on the railroad, however, the dip is 

 east-southeast as usual and not exceeding 10° or possibly 

 15°. The Ute fault is clearly, in all this part of its 

 course, a thrust fault ; and hence this pronounced roll 

 of the Fountain beds, and the general disturbance of 

 the stratification, may be regarded as normal features. 

 Returning toward the mountains by the spur or mesa that 

 slopes up in a southwest direction from the limekiln 

 (15) east of Manitou, and leaving the gulch containing 

 the little cemetery on the west, the following dips were 

 observed. Near the railroad the Fountain beds dip E. 

 by S. about 10°. Farther south this changes to S. or S. 

 by E. about 20°. Quite clearly a low anticline runs 

 about southeast and pitches in that direction one-third to 

 one-half mile from the fault and the base of the moun- 



ESSEX INST. BULLETIN, VOL. XXVII 12* 



