410 GEOLOGY AND MINING INDUSTRY OF LEADVILLE. 



Where these cross the beds, either as dikes or sheets, there is a Doticeable 

 enrichment of the ore bodies. One main sheet of Gray Porphyry is found 

 at or near ihe base of the Bhie Limestone, which apparently cuts up to a 

 higher horizon in different poi'tions of the hill. A second sheet is found in 

 White Limestone in California gulch, as shown on the map ; but as none 

 of the underground workings has penetrated as yet to this depth, there is 

 no evidence to show whether this is a distinct sheet or merely an offshoot 

 from the main body. 



Carbonate fault. — The movement of displacement by faults on Carbonate 

 Hill is considerably less than on Iron Hill, though its total amount cannot 

 be definitely determined. As in the case of the former, the movement 

 decreases to the north and the fault gradually passes into an anticlinal fold. 

 In the southern portion of the area represented on the map this movement 

 is distributed between two faults, the Carbonate and the Pendery. The 

 Carbonate fault here runs nearly on the dividing line between the Car- 

 bonate and yEtna claims, cutting across the extreme southwestern corner 

 of the former and the northeastern corner of the latter. It is proved in the' 

 No. 5 shaft of the ^tna claim, and in the Me3'er shaft, which has been sunk 

 following its plane till the contact on the west side was reached. As here 

 shown, it stands with an inclination of about 60° west, shallowing somewhat 

 in depth and having a movement of displacement of only about two hun- 

 di'ed and fifty feet. The hanging wall has smooth and clearly defined slick- 

 ensides surfaces, while the limestone in the foot wall is somewhat altered. 

 The plane of the fault is occupied by selvage material, which is slightly im- 

 pregnated with chloride of silver and contains occasional fragments of ore. 

 The plane of the Carbonate fault has also been cut in the lower shaft of the 

 Yankee Doodle claim. Beyond that j)oint to the northward it has not 

 actually been proved, and is located simpl)- by discrepancies of level 

 between adjoining underground workings. There is some reason to assume 

 that to the northward, in the Waterloo claim, the movement of the fault 

 has become nil, or is even reversed, that is, that there is a slight down- 

 throw to the east, as shown in the Henriett-Waterloo section, Atlas Sheet 

 XXLX. 



