Haiciif.r : Tin: IruAssK' Dinosair DErosiis. 33.'J 



and easily recognizable horizons in the entire section and its materials 

 are utilized (iiiite extensively for the manufacture of Portland cement, 

 large mills having been erected for that purpose at Portland a few miles 

 below Florence on the Arkansas River. These limestones are overlaid 

 by several hundred feet of dark colored, friable, arenaceous shales which 

 toward their summit assume a yellowish color and pass gradually into 

 a stratum of rather soft, yellow chalk not unlike in general appearance 

 the softer strata of the chalks of central and western Kansas. The 

 entire series commencing with the twelve feet of shale immediately 

 overlying the brown sandstone at the top of the Benton, including the 

 limestone and superimposed shales and terminating with the chalks just 

 mentioned, constitutes the Niobrara or upper member of the Colorado 

 formation. They are all well shown in the hills to the west of the 

 road which leads from Canyon City to Garden Park about a half mile 

 below the mouth of Oil Creek canon. 



The Pierre Shales. — Conformably overlying the chalks are a series 

 of usually quite soft, fine-grained and finely laminated shales of great 

 thickness and with numerous large concretions and septaria quite simi- 

 lar in form and structure to those found so abundant in the Pierre 

 shales farther north. These shales doubtless belong to the lower 

 member of the Montana formation, and while no direct evidence was 

 found as to their exact age, I have referred them to the Pierre. They 

 are well shown in the abandoned railway cuts on the ]:»rojected and par- 

 tially constructed road from Canyon City to Cripple Creek, where it 

 passes over the low divide between Oil Creek and Canyon City, as 

 also in the bluffs south of the Arkansas River, where they are overlaid 

 by a series of sandstones and shales in which are perhaps represented 

 rocks belonging to both the Fox Hills, Laramie and Denver forma- 

 tions, though of the existence of the former I was not able to satisfy 

 myself. 



The Bone Quarries in the Jurassic at Garden Pari;. — Fossil bones 

 were first discovered in the Jurassic of this locality by the family of 

 Mr. M. P. Felch in 1876. 'Phrough the local and Denver newspapers 

 the attention of Professor Marsh was called to the locality and in the 

 spring of 1877 Mr. S. W. Williston was sent by Professor Marsh to 

 Canyon City to investigate the alleged discoveries. Mr. Williston at 

 once recognized the importance of the locality and nature of the con- 

 tained animal remains and began immediately the unearthing of the 

 dinosaurian fossils. The tpiarry o[)ened by Dr. Williston was worked 



