444 GEOLOGY AND MINING INDUSTRY OF LEADVILLE. 



In the Wild Cat the bottom of the shaft was in the same hght- colored 

 limestone. At a depth of about one hundred feet a level ran east along a 

 waving contact, with considerable though irregular development of con- 

 tact vein material and the same white quartzite above it that was found in 

 the Forsaken mine. A north drift from this level followed a similar barren 

 contact, the Wash at one point coming down into the roof of the drift. A 

 cross-cut west from the end of this drift passed over a ridge in the formation 

 and stopped just as it commenced to dip sharply westward. 



Lower Crescent, — The workings of the Crescent Lower shaft were platted 

 from a compass survey, and, while not as accurate as those from actual sur- 

 veys, are sufficiently so for the purposes of this work. The shaft, which is 

 145 feet deep, passed through Wash 22 feet, iron-stained clay 10 feet. White 

 Porphyry (soft above and hard block porphyry at bottom) 113 feet. The 

 drifts followed clayey ii-on-stained material, with some development of spec- 

 ular iron, but no unaltered limestone was found. The east drift at the end 

 had a dip of 45° east. The west drift passed over a slight ridge and stopped 

 in a gentle westerly dip. Here the calculated down-throw of the Carbonate 

 fault is about one hundred and forty feet. 



The deductions made from the observations in these workings are, first, 

 that there is a probable western dip in the formation on the lower slopes of 

 the hill and, second, that an anticlinal structure is developed just west of 

 the line of Carbonate fault, which to the north gradually merges into the 

 axis of the fault, without, however, becoming strictly identical with it. The 

 sections show a single anticlinal structure south of the Henriett- Waterloo 

 line and a double anticline with a sharp included syncline on that line. It 

 is possible that the structure south of that line will not prove exact in its 

 details when more extended explorations shall be made ; but errors of detail 

 are in a measure unimportant, the great object being to determine whether 

 there be a western dip in the formation along the lower slopes of the hill, 

 which seems reasonably probable. 



