Chugwater formation 

 or upper Wyoming-] 

 beds. 



FORMATIONS OF THE FRONT RANGE 423 



Gods and Glen Eyrie, Colorado, was measured a short distance north of 

 the gateway : 



& J Feet 



Morrison .... Clays 



Gypsum. 30 



Red shales, with thin gypsum bed . 30 



Limestone 3 -i 



Ked shales, with thin limestones. 22 j- (Minnekahta) 



Limestone, purple, thin layers. . . 1 ) 



Soft red shale and sandstone ... . 55 



Top of lower VVyo- Massive white sandstone Tensleep sandstone 



ming beds. 



To the south the two series of Red beds preserve the same general 

 features to the overlap at the foot of Cheyenne mountain, but there are 

 local variations. Southwest of Fountain, where the beds are again ex- 

 posed, the upper Wyoming appears to be present for a few miles, and 

 then thins out, giving place to coarse grained red beds of lower Wyo- 

 ming character, directly overlain by Morrison beds. This coarse series, 

 or the entire Red Bed succession of this region, has been designated the 

 Fountain formation by Cross and Gilbert. The typical Fountain de- 

 posits are precisely equivalent to the lower, coarse grained Red beds in 

 the Garden of the Gods region, and, on special investigation of this point 

 in the field. I could find no suggestion but that they both represent the 

 same period of deposition. They are alike in character, representing 

 the same conditions as to origin; they are similarly underlain uncon- 

 formably by remnants of Millsap limestone, and there is not the slightest 

 evidence that one overlaps the other. 



The Fountain formation in the region extending from southwest of 

 Fountain to Canyon City consists mainly of coarse grained, crumbling 

 arkosic sandstone in massive beds, usually cross-bedded. Many con- 

 glomeratic streaks occur, and at various horizons there are layers of 

 finer grained material. The beds are prominently reddish, but some are 

 gray and others are mottled gray and red. The finer grained materials 

 are nearly all of a bright brownish red color. The thickness is estimated 

 at 1,000 feet, but it varies considerably. For the greater part of their 

 course, the deposits to which the name has been applied are separated 

 from the granites and gneiss by limestones of Ordovician age, but in 

 places they overlap the crystalline rocks, and at some localities the under- 

 lying limestones are faulted out. In the vicinity of Canyon City and at 

 a small locality on Cripple creek, at the head of Garden park, the under- 

 lying Millsap limestone appears. 



In the region southwest of Pueblo the thickness of the Fountain for- 

 mation, as measured by Mr Gilbert, is 2,100 feet, which includes prac- 



