DESCRIPTION OF VARIOUS MINES IN COLORADO. 



47 



Year. 



1872 



1873 

 1874 



187S 

 1876 

 1877 

 1878 

 1879 





30.093 



3°- OI 5 

 30.010 

 29.967 

 29.986 

 30.003 

 29.856 

 3°-°53 



& 5 



deg's. 

 37 08 

 42. 10 

 40.00 

 37.60 

 35.i6 

 38.40 

 50.90 

 46.42 



rt 5 



per c't. 

 67-35 



70.40 

 60.20 

 72.60 

 69.80 

 62.00 

 55-52 



pi 



inches. 

 i-95 



i-75 

 3-°5 

 2.50 



5-78 

 4-39 

 2 -35 

 0.32 



Average of Years. 29.990 40.18 67.06 3. 11 73.7 12. 1 30.547 29.359 



s 



deg's. 

 70 



73 

 69 



78 

 68 



78 

 80 



3 



a 



a; 



deg's. 

 16 



5 

 18 



9 

 2 



7 

 28 



pq 



30.760 

 30.670 

 30.656 

 30.427 

 30.605 

 3°-453 

 3°- 2 57 

 30.603 



* s 



o o 

 pq 



29.250 

 29.470 

 29.290 



29-354 

 29.421 

 29.388 

 29-339 



29-573 



Samuel W. Rhode, 



Signal Corps, U. S. A. 



MINING AND OTHER INDUSTRIES. 



DESCRIPTION OF VARIOUS MINES IN COLORADO. 



BY JOHN K. HALLOWELL. 



As Messrs. Hayden and Raymond, in their reports have not given us a 

 nomenclature of the rocks and minerals of this locality, I have thought best to 

 merely use the names for the different rocks as known locally, although satisfied 

 that scientifically they are not, as a general thing correct. 



From the divide near the head of Hardscrabble Canon and following a 

 south of west course, is quite a valley with a general gentle inclination down to the 

 foot-hills bordering the Wet Mountain Valley. On the south side of this and 

 among these foot hills, Round Mountain and Silver Cliff are situated, and about 

 six miles west of the Franklin and Maine Mines, the elevations on the south side 

 with their foot-hills are Porphyry; those elevations to the north, Granite; the 

 deepest denudation of the valley following the line of contact, with spurs of 

 Trachyte appearing between the granite hills to the northward. 



The Porphyry formation is easily distinguished by the largest axis of the hills 

 following the general course- of the valley, viz : East and west. Their rounded 

 tops on the south side bare of trees, covered instead with grass and verdure, no 

 massive out-crops of rock like the granite hills, and having the steepest slope on 



