692 IDAHO MINING DISTRICTS. 



in connection with dike rocks (p. 682). The vein is of very irregular 

 width, from a few inches up to 6 feet, and has a great tendency to 

 throw out stringers in the porphyry in the hanging wall; these when 

 followed were found to be rich, but soon gave out. The ore consists 

 of free gold and sulphurets, the latter chiefly iron pyrite, also some 

 antimonite, which is said to be intimately associated with gold. Small 

 traces of tellurium are also reported. About 50 per cent of the value 

 is in free gold, and this proportion is likely to remain stable as depth 

 is attained. _ The sulphurets are reported to be of high grade. The 

 old workings of Gold Hill extend up on the steep hill northeast of 

 Quartzburg. 



The Pioneer claim adjoins the Gold Hill on the south. A vertical 

 shaft 400 feet deep is sunk on it. It is located on a fissured zone in 

 the same porphyry dike which forms the hanging wall of Gold Hill, 

 and which contains a great number of small seams with very rich ore, 

 the whole forming a large body of low-grade ore. The porphyry is 

 yellowish and decomposed, filled with pyrite, sericite, and some cal- 

 cite. The sulphurets of the Pioneer are of much lower grade than 

 those of Gold Hill. 



A short distance below the Pioneer there are several claims on a 

 vein crossing the creek, the principal one being called Mountain Girl. 

 The ore consists chiefly of sulphides without any free gold, but some- 

 times contains much silver, being similar to the Centennial, which 

 lies in a similar position in front of the Mountain Chief vein. 



Immediately adjoining the Gold Hill on the northwest is a flat vein 

 called the Lone Star, from which, in early days, much gold was 

 obtained by surface sluicing. 



The Iowa vein. This vein lies a short distance north of the Gold 

 Hill, and was opened in 1896 by an 800-foot tunnel starting from the 

 10-stamp mill one-eighth of a mile north of Quartzburg. The tunnel 

 is driven through granite, which near the vein is much decomposed. 

 The vein is a narrow seam in granite filled with a soft clay gouge and 

 containing streaks extremely rich in gold. There is also some pyrite. 



In the extension of the Iowa lie the Yellow Jacket and other claims 

 which have been less developed. 



The Carroll veins. A group of five claims lies at the head of Cali- 

 fornia Gulch, 1 miles northeast of Quartzburg. The surface in this 

 vicinity was extremely rich and has been extensively washed. It 

 can not be said that the direction and extent of the veins have been 

 definitely established, but that rich veins exist in this ground is not 

 to be doubted. On the Ivanhoe claim some work was done in 1896, 

 the vein being opened up by means of a tunnel several hundred feet 

 long and exposing a good ore shoot. In this tunnel the vein dips south 

 at a steep angle, and lies entirely in soft, decomposed granite. Outside 

 of the ore shoot the vein is indicated only by a black-clay seam. The 

 character of the ore in the shoot is illustrated in fig. 64, showing the 



