436 GEOLOGY AND MINING INDUSTEY OF LEADVILLE. 



fault, there is no certainty that there may not be a decided shallowing in 

 the dip of the formation as it approaches the assumed fault line. 1 No 

 explorations have been made between this and the Main shaft except the 

 Old Discovery shaft, which was sunk for a few feet in vein material and 

 has long since been filled up and obliterated. 



The ore of the Evening Star mine consists largely of sand carbonate 

 and hard carbonate, but contains also a considerable amount of unaltered 

 galena, Although less rich than that of the Catalpa, its working results 

 give a high average, which may be estimated at 60 to 70 ounces of silver 

 a ton. As compared with the Morning Star ore it runs lower in lead, but as 

 a rule contains less silica and more iron and manganese, and is, therefore, 

 more easily smelted. The hard carbonate, which is the characteristic ore 

 of the western half of the mine, is a granular silicious material of peculiar 

 steely or adamantine luster, either compact or porous and full of cavities. 

 An examination of the cavities with a lens shows that they are more or less 

 completely filled with transparent crystals of cerussite and little flakes of 

 chloro-bromide of silver of pale-green color. The sand carbonates occur 

 in streaks and lenticular bodies, generally not more than one or two feet in 

 thickness. Chinese talc is occasionally found, but cannot be traced so reg- 

 ularly as when the ore bodies are thinner and the actual contact conse- 

 quently more readily defined. 



Morning Star mine. To this mine belong both the Morning Star and Water- 

 loo claims, the ground of the latter above the fault being as yet but little 

 explored. In this mine, as in the Catalpa, no systematic levels were run, 

 and, as many of the old workings were inaccessible at the time of visit, the 

 data obtained as to details of form and occurrence of ore are less accurate 

 than in the case of the Evening Star mine. The ore body continues its 



'According to Mr. Kicketts (The Ores of Loadville, Princeton, 1883) the data furnished by the 

 sinking of this shaft through the Gray Porphyry and by a bore-hole drilled from its bottom as far as 

 the Lower Quartzite show that the thickness given for the Gray Porphyry sheet in our ideal Section D 

 is too great, its actual thickness being about fifty feet. Ho also states that he found no Parting 

 Quartzite. As his information with regard to rocks passed through was obtained by examination of 

 the dump, it might readily have escaped his observation. On the other hand, on the supposition that 

 there was a nonconformity by erosion between Silurian and Carboniferous formations, it might have 

 been eroded away at this point and be actually wanting ; this would also account for a supposed less 

 than normal thickness of the White Limestone. 



