1881.] 505 [Stevenson. 



made and a closer examination would doubtless lead to a moderate change 

 in the thickness of several of the intervals. 



The only coal beds which have been opened are ISTos. 8, 12 and 18, but 

 none of these was in shape for measurement at the time of examination. 

 No. 13 is exposed in the bed of the run, and its thickness is said to be 

 nearly 3 feet. The coal is clean, free from pyrites and slates, is soft and 

 should yield a good coke. No. 18 was mined for local use at the junction 

 of the forks of Camp creek. Its thickness is said to be 4 feet 2 inches. 

 The coal is soft, clean and is admirably fitted for blacksmiths' use. No. 

 24 was once exposed near the creek at half a mile below Reed's mill. The 

 thickness is said to be 3 feet. 



The following section of the Lower Carboniferous rocks was obtained 

 in passing from Little Bluestone to Mountain creek : 



1. Conglomerate 20' 



2. Imperfectly exposed 110' 



3. Yellow shaly sandstone 45' 



4. Concealed 25' 



5. Gray to yellow shaly sandstone 80' 



6. Imperfectly exposed >..... 85' 



7. Conglomerate 10' 



8. Concealed 225' 



9. Limestone 3' 



10. Imperfectly exposed 370' 



973' 

 Exposures of dark red shales occur frequently in the intervals 2, 6 and 

 10, and No. 10 is made up almost wholly of such shales. This section 

 brings one to the sandstone which forms the river bluflfs in the vicinity of 

 Hinton. 



Notes on the Goal-fleld near Canon City, Colorado. By JoJm J. Stevenson, 

 Prof, of Geology in the University of New York. 



{Bead before the American Philosophical Society, October 7, ISSl.) 



A small area of Laramie rocks lying along the easterly foot of the 

 Greenhorn mountains has escaped erosion. Its shape is irregular and its 

 breadth varies from two to five miles, being greatest at little more than 

 midway north and south. The total area is not far from 70 square miles. 



This little field, which has attained much economical importance, owing 

 to the excellence of the coal from one of the beds, is deeply trenched by 

 several streams which flow across it in canons with walls from 200 to 500 

 feet high. The more important of these, beginning at the north, are 

 Alkali gap. Chandler creek, Oak creek, Coal creek and Newland creek. 

 Examinations more or less detailed were made in all except that of New- 

 land creek. 



