268 GEOLOGY AND MIXIIS^G INDUSTRY OF LEADVILLE. 



eastern end it shows the Mosquito fault and a patch of Lower Quartzite 

 left to the east of it, on the slope of West Dj^er Mountain. In the block 

 between Mosquito and Ball Mountain faults the easterly dip prevails; but 

 in the neighborhood of the latter fault the influjence of the anticline at the 

 north foot of Ball Mountain is seen in a slight curvature of the beds. Be- 

 tween Ball Mountain and Weston faults the Colorado Prince fault cuts 

 through the southern extension of the South Evans anticline ; and the sec- 

 tion shows a minor anticlinal and synclinal structure between this and the 

 Weston fault, which is shown by the developments of the Highland Chief 

 and Lowland Chief shafts and the Chemung tunnel. Replacement in the 

 Highland Chief mine is supposed to have extended through the entire 

 thickness of the Blue Limestone horizon and to have been influenced by 

 the dike of Gray Porphyry which is shown in that mine. The recent for- 

 mation (r) east of the Highland Chief mine is a portion of the moraine 

 left by the South Evans glacier on the shoulder now called Idaho Park. 



In the block west of Weston fault the shallow anticlinal and synclinal 

 structure developed in the two previous sections is supposed to extend into 

 the plane of this section, the underground data confirming this idea as 

 far as they go. The plane of the section is very nearly coincident with 

 the line of the Breece cross-fault, which, however, in its curves crosses it 

 at an extremely acute angle. The projection of the intersection' of these 

 two planes, as shown on the section, is a line cutting the surface between 

 the Breece Iron and Louisville shafts, which has a certain parallelism with 

 the formation lines, with which it might be confounded. The plane of the 

 section passes just north of the extremity of the Mike fault, whose move- 

 ment is therefore not shown. The body of Adelaide Porphyry is repre- 

 sented as coming up across the Lower Quartzite and White Limestone, and 

 then spreading out, sending an offshoot between the beds of the latter. At 

 this point the plane of the section crosses the moraine ridge, north of 

 Adelaide Park, forming a portion of the Evans south moraine. In the 

 block between Iron and Carbonate faults the line of section illustrates 

 plainly the synclinal structure and the splitting of the Blue Limestone into 

 two sheets, as proved in the Cyclops, Gone-Abroad, and adjoining shafts. 

 On the west slope of Carbonate Hill the section passes through the 



