GOLD. 103 



tortuous course of the Alatna. Our knowledge concerning the geography of this 

 region is not definite, but the distance across country in a straight line from 

 Bergman to the Koyukuk can hardly exceed 100 miles, and it is probably less. 



The discovery seems to have been made by a party of prospectors and miners 

 who visited the region by sled during the winter of 1903-3, and in company with 

 others continued to prospect there during the summer of 1903. At present a score 

 or more men are reported to be interested in the holdings. 



The country rock is described as quartzite, slate, and schist, and is inferred by 

 the writer to be in all probability a westward extension of the Fickett series (Car- 

 boniferous) which is prominently developed on John River, 60 miles distant, and in 

 which, as indicated on the map (PI. Ill) and on page 106, a mineralized zone in the slate 

 and quartzite was observed by the writer in 1901. Without here affirming that the 

 mineral deposits of these two regions are connected, it should be noted that the newly 

 discovered Alatna deposits seem to lie directly in the trend of the John River 

 deposits and have the same strike. This suggests that the deposits of the two regions 

 may represent the same mineral belt. 



The Alatna ore deposits are reported to consist of six or more veins, or ledges, 

 known as the Copper King, Copper Queen, Lucky Six, Mammoth, Iowa, Gray Eagle, 

 Silver King, and Ground Hog. They are on an average about 1 mile apart, and are 

 accordingly included in a belt about 6 or 7 miles in width. They lie nearly 

 parallel and trend in a northeast-southwesterly direction, and, so far as prospected, 

 are in general nearly vertical, or dip about 75° NW. 



About half of the veins are reported to have a width of approximate^ 75 feet, 

 while the minimum width of the smallest is given as 10 feet. Some of the veins 

 have been traced by croppings for distances varying from several thousand feet to 2 

 miles. 



Through the courtesy of Mr. Prindle the writer has received for study six of 

 these Alatna ore specimens, brought out by the miners in the fall of 1903. In 

 these specimens the ore consists essentially of iron pj^rites and quartz, with also 

 chalcopyrite (copper pyrites) which is conspicuous in two specimens. With the 

 chalcopyrite is associated a little bornite and a trace of malachite. Another specimen 

 is composed essentially of stibuite or sulphide of antimony and epidote. One speci- 

 men contains feldspar as a gangue mineral in addition to quartz, and is locally stained 

 reddish brown by hematite or iron oxide, which is seemingly an alteration product 

 of the pyrites. 



The quartz is largely of the finely granular sugary type, and often remains 

 as a porous honeycombed or coralline-like mass where the metallic contents of the 

 ore have been leached out of the more exposed croppings. This "skeletonized" 

 mass is occasionally traversed by small discontinuous stringers of firmer, greasy - 

 lustered, and evidently younger quartz, producing a semibanded appearance, which, 



