CARBONATE HILL. 427 



exploration of the gi-ouncl many others might be found, especially if the 

 search were not confined to the contact surface alone, but were also ex- 

 tended where indications of mineralized jointing planes seem to warrant it, 

 into the body of the limestone below. 



Area on top of hill. — In the area to the east of the claims of the southern 

 group, on the top of Carbonate Hill, several prospecting shafts have been 

 sunk in the White Porphyry, notably the Excelsior, William Wallace (300 

 feet), Tip Top (297 feet), Little Nell (440 feet), Thespian (400 feet), and 

 the Modoc (600 feet). Of these, only the Excelsior and Modoc have reached 

 the Blue Limestone. Neither was accessible at time of visit. The Excel- 

 sior is said to have found a heavy body of iron-stained vein material, but 

 not sufficient pay ore to encourage further developments. The Modoc shaft 

 had filled with water while awaiting better pumping machinery, but from 

 data obtained from miners and from evidence afforded by the dump it 

 appears that contact with a certain amount of vein material was struck at 

 about five hundred feet. In the little drifting that was done no rich ore 

 was found. The shaft was sunk 100 feet farther, passing through the Blue 

 Limestone and two intrusive sheets of Gray Porph3'ry included within it, 

 as ideally shown in Section I, Atlas Sheet XXX. It would thus appear 

 that the sheet of Gray Porphyry, which on Iron Hill occurs near the base 

 of the Blue Limestone, is here either cutting across this formation to a 

 higher horizon or sending off oft'shoots, such as are found in some of the 

 Iron Hill workings. 



Area west of Carbonate fault. — In the .iEtna and Glass-Pendery claims, which, 

 with the exception of a small corner of the former, lie west of the Carbon- 

 ate fault, little pay ore has been found on the contact ; but the main ore 

 bodies occur within the mass of the limestone, extending to a depth of fifty 

 feet or sixty feet below its surface. 



Ore was first discovered in a nearly vertical body, crossing the lower 

 part of Glass No. 2 shaft in a southeast direction. The development of 

 this body led to the discovery of other larger and more irregularl3'-shaped 

 bodies extending beyond the ^tna line. These were worked by the Glass- 

 Pendery owners, and much ore was taken from the ^tna ground before 

 the owners of the latter were aware of its existence. It was on account of 



