U.S. GEOLOGICAL SURVEY 



GEOLOGY OF LEADVILLK PLXIX 



FIG I. PLAN OF EASTERN EDGE OF MOUNTAIN SHOWING OUARTZITE MIC PORPHYRY DIKE ENCLOSED IN EHYOUTE 

 R. RHYOLITE QUARTZITF, P. PORPHYRY 



FIG. H NORTH SIDE OF RR CUT AT SOUTH END OF CHALK MT SHOWING PORPHYRY CUTTING THROUGH SANTSTONF. 



FIG 11 SAME CUT SOUTH SIDE P PORPHYRY S. SANDSTONE Sh SHALE 



Julius Bien 4 Co.lilh. 



RHYOLITE AND PORPHYRY 



CHAL.K MOUNTAIN 



s F Kniniona, GeologiHt-in . r 



