302 GEOLOGICAL SURVEY OF THE TERRITORIES. 



yield being from $5 to $6 per day. There are four men working, at from 

 $2.50 to $3 per day. 



Little French, or upper claim, has two men working on it. 



JSTear Hamilton there are two claims, worked by Hawkshurst & Foote. 

 There are five men working, at $2.58 and board per day. The average 

 yield is about $100,4)er week. While I was there they cleaned up $75 

 for five days' work. In 186O-'05 there was in Hamilton a population of 

 about 5,000 inhabitants ; to-day there are not more than about half a 

 dozen families. 



■ SILVER HEELS MOUNTAIN. 



The following are some of the lodes that have been opened on the 

 mountain : 



Uncle Sam lode. — The crevice is 8 feet in width and dips to the north- 

 west. It was discovered in 1868 by Sargent & Greene, who are still its 

 owners. But little work has been done. The gold and silver are found 

 associated with pyrites in a quartz-gangue. The walls of the lode are 

 gneissic. The ore is said to assay from $10 to $45 to the ton. 



Black Eagle lode. — Four-foot crevice discovered by Hawkshurst & 

 Foote in 1867, who. still hold it. Associated with gold and silver, mag- 

 netic iron and pyrite are found. It is said to assay from $100 to $600 

 to the ton. The lode is in gneiss, and dips to the southeast. Other 

 lodes are the Black Warrior, Eepublic, Slater, and Mineral lode. 

 Yery few, if any, are worked. In the Eepublic, the ore is galena. The 

 general angle of dip of all these lodes is about 30°. 



FAIR PLAY, COLORADO. 



Further notes in regard to the mines in the vicinity of Fair Play than 

 are given below will be found in Dr. Hayden's report. Placer-mining 

 was formerly carried on very extensively on the South Platte River, 

 and on all the streams tributary to it rising in the range that lies be- 

 tween South Park and the Arkansas Eiver. In almost all the gulches 

 we may find the ruins of what were once active and thriving towns. 

 There is still some mining going on on the Platte. The gravel on the 

 river opposite Fair Play is about 70 to 100 feet in thickness. There are 

 several claims being j)rofitably worked here. The principal mining 

 interest, however, centers in the silver-bearing limestones of Mount 

 Bross, Mount Lincoln, and Horseshoe Mountain. The following section 

 of Mount Bross was made by Mr. Stevens, of Fair Play, and shows the 

 geological position of the argentiferous belt. The section corresponds 

 with the illustration shown in Plate XY, (map). 



1. Gneiss. 



2. Yellow quartzite and sandstone, about 400 feet. 



3. Blue limestone ^ 



4. Light-colored limestone, 100 feet > 350 feet. 



5. Blue limestone j 



6. Quartzite - 10 to 20 feet. 



7 100 feet. 



8. Black quartzite slates ) nn f^^f 



9. Sandstone I '^ ^^^^• 



10 200 feet. 



11. Limestone 20 to 30 feet. 



12. Sandstone 150 feet. 



13 500 to 600 feet. 



