CHAPTER IV. 



FRYER HILL GROUP. 



GENERAL DESCRIPTION. 



Fryer Hill, which has become so famous in the mining world by the 

 richness of its ore deposits, forms a comparatively insignificant feature in 

 Leadville topography, being simply the extreme shoulder of a minor spur 

 extending to the westward from Breece and Yankee Hills, between Little 

 Stray Horse and Big Evans gulches ; its extreme elevation above these 

 gulches is only 200 feet. At one time the Big Evans glacier probably 

 covered its surface, and the moraine material which it left behind during its 

 retreat, though partially removed by later erosion, still covers the surface of 

 the hill to an average depth of about one hundred feet. For this reason 

 the study of its geological structure has been a very laborious work, and 

 one which could hardly have been accomplished were it not for the exten- 

 sive underground developments made by the numerous mines among which 

 its surface is divided up. As contrasted with the already described groups 

 of Iron and Carbonate Hills, Fryer Hill exhibits an extreme of mineral 

 replacement. The Blue Limestone is represented mainly by occasional 

 detached patches of lime sand or disintegrated dolomite and irregular accu- 

 mulations of iron vein material, more or less impregnated with rich car- 

 bonates of lead and chlorides of silver. The beds, which were horizontal 

 previous to the action of mineralization, have been, during the dynamic 

 movements which followed, compressed into gentle folds, and their crests 

 have since been planed off by the great Evans glacier. These folds con- 

 sist of a main anticlinal fold, whose axis has a northeasterly direction and 

 forms a continuation of the Carbonate fault line, with a synclinal fold nearly 



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