140 SILVER-LEAD DEPOSITS OF EUREKA, NEVADA. 



some of these "indications." Ore bodies have sometimes been found after 

 drifting hundreds of feet through the hardest and most unfavorable looking 

 ground. This was the case on the seventh level of the Richmond (see 

 Plate XIV.), where a drift had been run to make a connection. Where the 

 ore was first found there was no indication whatever of its proximity until 

 the ore body itself was encountered. The limestone was of a hard, com- 

 pact nature and grayish color, and was not considered particularly favora- 

 ble for ore. On the eighth and ninth levels some notice of the near ap- 

 proach to ore was given by stained limestone through which the drifts 

 passed before it was reached, and by a fissure. Since the discovery these 

 ore bodies on the different levels have been connected by upraises and 

 winzes, and a well-defined ore channel has been established from the seventh 

 to the ninth levels, even connecting with the west ore body above the sixth. 

 True, the ore was not entirely continuous, but fissures, seams, and stained 

 limestone extended over the whole distance, forming a connection between 

 the ore bodies such that all of the latter would have been discovered if the 

 indications had been followed downward from the large ore body on the 

 fifth level. 



Method of prospecting in the Richmond. Owillg tO the liatlU'e of the Richmond 



ground it is doubtful if the method of following the quartzite and limestone 

 contact adopted in the Eureka and other southeastern mines would have 

 been productive of good results. The ore bodies in the Richmond, with one 

 exception near the compromise line, do not touch the quai'tzite, but are inva- 

 riably connected with some fissure. In the deeper workings of this mine it 

 has been customary to drive straight levels in the limestone, independently of 

 the quartzite, and to follow the fissures which may be encountered in all direc- 

 tions. Drifts are also run where other indications point to a possible ore body, 

 or where it is necessary to cut up a large block of ground, which, though 

 it may not be thought particularly favorable for ore, must not remain un- 

 prospected. This last method is made necessary in this mine by the fact 

 that the ground which lies between the quartzite and the Ruby Hill fault is 

 very extensive and ore bodies might easily exist in it without indicating 

 their presence in any manner. Although ore has not been found near the 

 quartzite in this mine, except in one instance, there is a possibility that it 



