CONTENTS. 5 
Descriptive geology — Continued. 
Region about Goldfield — Continued. 
Mount Jackson and the hills to the northeast — Continued. 
General geology GG 
Sedimentary rocks 66 
Cambrian 66 
Siebert lake beds 67 
Igneous rocks 67 
Diorite porphyry 
Rhyolite <;7 
Basalt 68 
Structure 68 
Economic geology <*>!> 
Valley north of Slate Ridge 71 
Goldtield hills 71 
Topography and geography 71 
General geology 72 
Sedimentary rocks 72 
Siebert lake beds 72 
Later tuffs 72 
Igneous rocks 73 
Post-Jurassic granite 73 
Andesite and dacite 73 
Quartz latite and rhyolite 73 
Quartz basalt 74 
,ater rhyolite 74 
Basalt 75 
Structure 76 
Economic geology 76 
Alkali Spring Flat 76 
Southern Klondike hills 77 
Topography and geography 77 
General geology 77 
Sedimentary rocks 77 
Cambrian 77 
Siebert lake beds 78 
Older alluvium 78 
Igneous rocks 78 
Post- Jurassic granite 78 
Earlier rhyolite _ 78 
Earlier quartz latite 79 
Basalt 70 
Later rhyolite 80 
Later quartz latite 80 
Structure 80 
Economic geology 81 
Gold and silver s ' 
Iron ores 1 — 
Ralston Valley 
Stonewall Flat 
Stonewall Mountain 
Topography and geography 
General geology 
