XIV GEOLOGY AND MIXING INDUSTRY OF LEADVILLE. 



Chapter III. 



Page. 



Rock formations 45 



Sedimentary rocks 45 



Arcbeau formatious 45 



Granite 46 



Gneiss 48 



Amphibolite 50 



Relative age 51 



Paleozoic formatious 53 



Cambrian 58 



Lower Qiiartzite 58 



Silurian <>0 



White Limestone CO 



Parting Quartzite 61 



Corresponding beds in Colorado Range C"J 



Carboniferous ()'•! 



Blue or ore-bearing limestone 03 



Its composition 04 



Weber SbalPS 67 



Weber Grits 68 



Upper Coal Measures 69 



Mesozoic formations *0 



Quaternary formations Tl 



Glacial or Lake beds Tl 



Recent or post-glacial ''i 



Distribution of sedimentary formatious 72 



Eruptive or igneous rocks 74 



Secondary eruptives 74 



Mount Ziou Porpbyry — White Porphyry 76 



Lincoln Porpbyry 78 



Gray Porphyry 80 



Sacramento Porphyry 81 



Pyritiferous Porphyry 8'Z 



Mosquito Porphyry — Green Porphyry — Silverheels Porphyry 8:5 



Diorite 84 



Porpbyrite 6'o 



Tertiary eruptives 86 



Rbyolite 87 



Trachyte — Audesite 88 



Chapter IV. 



Descriptive geology of the Mosquito Range 90 



Introductory 90 



Surface features 91 



Glacial formations i*2 



Post-Glacial formatious — Archean exposures 93 



Northeastern division 94 



Platte amphitheater 94 



Quandary Peak 9S 



Hoosier pass ridge 1 00 



Silverheels Massive 104 



Lincoln Massive 107 



Cameron amphitheater HI 



