518 GEOLOGY AND MINING INDUSTRY OF LEADVILLE. 



rial brought down by post-Grlacial erosion has been carried, has a sufficiently 

 hard and permanent bed-rock to allow of the concentration of gold on its 

 surface; at any rate, such bed-rock has not yet been found. It is probable 

 that the actual rock surface, which formed the bed of the Glacial valley, 

 may be found gold-bearing if it is ever explored; but it could hardly be 

 expected that in it gold will be found so concentrated as it was in California 

 gulch, and its exploration will necessarily be attended with many mechan- 

 ical difficulties, owing to its probable depth below the present surface. 



The Lake bed deposits themselves undoubtedly contain a large amount 

 of free gold, and it is probable that this may be sufficiently concentrated 

 at some points on the bed-rock of the original lake to be worked with profit; 

 but the form of this bed is as yet too little known to give any definite idea 

 of where such points ma}- be. Probably the valley of the east fork of the 

 Arkansas would be the most favorable point for such an exploration, since 

 its drainage area is the most extensive of any of the valleys tributary to this 

 ancient lake; but it would be impossible to determine beforehand how far 

 up this valley the ancient shore-line of the lake extended. 



ORE PROSPECTS IN* UNEXPLORED AREAS. 



Besides the regions mentioned in the above description there are a few 



other unexplored areas in which the contact may be reasonably expected 



to be found productive which will be enumerated below in the order of 



theirrelative availability, or of the proximity to the surface or to known 



deposits at which the contact may be found. 



On Dome Hill, as shown in Section H, Atlas Sheet XIX, the contact 

 is near the surface on either side of Dome fault, and is practically unex- 

 plored south of the Dome workings on the one side and of the Ben Burb 

 on the other. From the Dome mine southward to Iowa gulch, east of the 

 fault and along the west side of the fault for a corresponding distance, there 

 is good reason to assume that the contact will be found productive, and 

 explorations should be conducted on the dip in either direction, though to 

 the westward the assumed limit of probable mineralization will soon be 

 reached, and on the lower part of Dome Ridge, beyond the Coon Valley, 

 present indications do not promise any large ore bodies. 



