Stevenson.] ^-»-t> [Oct. 7, 



but there seems to be no doubt that it exists and that the coal is tliere. 

 The upper member of the Dakota shows the usual features, but the lowest 

 member is a coarse conglomerate, 10 or 15 feet thick, which is made up of 

 fragments of the coarse gneissoid granite on which it rests. These frag- 

 ments have suffered little from water, and the conglomerate can be distin- 

 guished only with difficulty from the underlying granite. 



No exposures occur on the mesa between Oak creek and South Oak 

 creek, aside from fragmentary exhibitions of sandstones, which barely 

 suffice to indicate the dip, and give no information respecting the succes- 

 sion of the beds. 



Goal Greek. — Coal creek is followed by a branch of the Denver and Rio 

 Grande railroad, leading to the mines of the Colorado Coal and Iron Com- 

 pany. One branch of the stream flows northward along the eastern edge 

 of the field, while several tributaries flow to it from the west, each of 

 which has eroded a canon, exposing a large part of the section. Examina- 

 tions were made along several of the streams. 



At the mines of the Colorado Coal and Iron Company, on Coal creek, 

 the following exposure was found : 



1. GoalUdC 0' 8" 



2. Shale and sandstone 50' 



3. Coal bedB 0' 10" 



4. Shale 30' 



5. Coal bed A 6' 2" 



And the dip is N. 30° W. mag. 



Goal bed C, the same with that mined in shaft No. 2 of the Canon City 

 'Coal Company, on Oak creek, is represented here only by a little carbona- 

 ceous shale. Coal bed B is well shown on the face of the bluff, and de- 

 scends with the road from the top of the hill. Coal bed A is mined exten- 

 sively and yields a superior coal, which is used in the railroad engines and 

 is shipped largely to be used as fuel at Denver and other cities of Colorado. 

 The bed shows the following structure at the mouth of the slope : 



Coal V 



Clay 1" 



Coal 4' 7" 



At half a mile further up this branch of Coal creek, the same bed is 

 mined by the Grand Canon Coal Company. The bed was not measured 

 here, but the thickness is reported by the President to be 3 feet 6 inches, 

 and the quality is regarded as equal to that of coal from the other mine. 

 Only the lower division of the bed is present in the slope. The upper 

 division is merely a "rider" coal, and the interval between it and the 

 main body varies from zero to 11 feet ; the latter interval being seen at 

 the Cassidy slope, while the two divisions are in contact at many places 

 in the Colorado Company's mine. The rider is distinctly shown in the 

 gulch at the Cassidy slope. 



