540 



MINING INDUSTEY. 



yields very good ore. The American Flag, still further north, not far above the 

 bed of the stream, has also been worked to a depth of several hundred feet and 

 gives indications of much value. 



Flack. — A more minute description of the Flack mine, on the Flack lode, 

 and of the claim until lately known as the Stalker and Stanley, on the California 

 lode, will suffice to represent the general character of this group of veins. The 

 Flack was one of the early discoveries of the district and was worked in 1862. 

 The top quartz is said to have yielded a good deal of money, but detailed 

 records of the product are not in the possession of the writer. At a depth of 

 60 feet the crevice was small and poor and continued so for 100 or 125 feet 

 further, when a good pay-seam was found. Difficulties among the owners led 

 to a subsequent suspension of work, which was only resumed again in June of 

 1868. Two shafts are being carried down for permanent work, with the inten- 

 tion of opening ground by successive levels and stoping overhand. One of 

 these had reached a depth of 400 feet in 1869. Drifting and stoping were 

 in progress in the neighborhood of both shafts. The vein is shown by these 

 developments to be narrow, varying from three or four inches to two feet. 

 The walls are of gneiss, sometimes passing into granite, and, where broken, 

 frequently show lines of bedding or structure dipping eastward. The walls 

 are generally very well defined and smooth and show evidences of movement 

 in the beautifully polished and striated surfaces that are formed on the ore- 

 seam where in contact with one or the other wall. Sometimes there is a dis- 

 tinctly marked selvage of clay between the wall and the harder filling of the 

 vein. The vein-matter is chiefly quartz; where associated with pay it is of a 

 softened or sometimes friable character, mixed with some feldspar; where 

 poor, it is harder, sometimes forming a granulitic mixture of quartz and feld- 

 spar. This is generally, not only in this but in other veins of the district, the 

 character of the "cap" or barren ground of the lode. The "cap," a term 

 usually employed to express the impoverished condition of the vein, may be 

 due either to the pinching together of the walls of the fissure, or, where the 

 latter maintain their regular distance apart from each other, to the filling of 

 the vein with barren rock, usually resembling granulite or the granite of the 

 country. Thus in the east shaft of the Flack, which passes through a hun- 

 dred feet or more of "cap," the walls were observed to be two feet or more 



