SOUTHERN GEOUP OF MINES. 415 



founded with actual waves in the limestone itself Careful examination in 

 such cases discloses the fact that the contact line is either not curved at all 

 or only to a comparatively limited extent, while the ore impregnation 

 extends downward abruptly to a very considerable depth, sometimes sixty 

 or seventy feet, into the body of the limestone, from which it is separated 

 by a transition zone, barren in general of pay mineral and consisting of 

 limestone more or less impregnated with oxides of iron and manganese. 



The first ore discoveries on Carbonate Hill were made on the ground 

 of the present Carbonate claim in the vicinity of the Old incline. The 

 claim forms part of the property belonging to the Leadville Consolidated 

 Mining Company, which owns as well the adjoining claims of the Shamrock 

 and West Shamrock, and also, by a recent consolidation, the Little Giant. 

 For purposes of description the adjoining claim of the Yankee Doodle will 

 be considered as forming part of this gi'oup, as the workings of this mine 

 are connected with the others and the ore bodies in all these different 

 claims are practically continuous. They are situated on the western slope 

 of Carbonate Hill, midway between its steeper southwestern and more 

 gentle northwestern inclinations. In the southern portion of the Carbonate 

 claim, as will be seen by reference to the map, by the divergence of the 

 line of fault from the line of contact of the upper surface of the limestone 

 and porphyry, a zone of limestone, widening to the southward, is exposed 

 beneath the slide. The actual position of the main fault line has not been 

 traced beyond the No. .5 shaft of the ^Etna mine. Its exact position to tlie 

 south of this point is therefore somewhat hypothetical, the general direction 

 being given by the developments of prospect shafts on the south slope of 

 the hill, beyond the limits of the map. The actual outcr(ip of tlie ore body 

 along the southern line of the Carbonate claim is also somewhat difficult to 

 define, there being here one of the slight flexures in the limestone, of which 

 mention has already been made, whose axis is at an angle with the fault 

 line, crossing it somewhere in the neighborhood of the new (Meyer) shaft 

 of the ^Etna and from that point diverging to the southward. In the 

 workings of the ^Etna mine, which were parallel with and contiguous to 

 the side line of the Carbonate, the ore body is said to have been practically 

 horizontal on an east-and-west line for a short distance, and even to have 



