10 CONTENTS. 
Descriptive geology — Continued. Page. 
Amargosa Mountain system — Continued. 
Amargosa Range — Continued. 
General geology — Continued. 
Igneous rocks 1C>7 
Granite porphyry KIT 
Diorite porphyry KIT 
Biotite andesite ir>7 
Earlier rhyolite 168 
Earlier basalt— 170 
Later rhyolite and biotite latite 17<> 
Later basalt 171 
Structure 1712 
Economic geology 173 
Happy Hooligan mine 173 
Chloride Cliff 173 
Lee's < "amp 1 7o 
Areas favorable for prospecting 175 
Bullfrog Hills 170 
Topography and geography 17(5 
Genera] geology 17(5 
Sedimentary rocks 177 
Pre-Silurian schist. 177 
Eureka quartzite 177 
Lone Mountain limestone ' 17S 
Sieberl lake beds 178 
Older alluvium 17,8 
[gneous rocks 178 
Post-Jurassic pegmatite and alaskite 178 
Pre-Tertiary diorite porphyry 17!) 
Biotite andesite 171) 
Rhyolite 180 
Earlier basalt 181 
Later basalt 181 
Structure 181 
Economic geology 182 
Gold Mountain ridge and the hills to the north of Grapevine 
Canyon 182 
Topography and geography 182 
General geology 183 
Sedimentary rocks 1 183 
( Jambrian 183 
Igneous rocks 184 
Quartz-monzonite porphyry IS! 
Post -Jurassic granite 18| 
Diorite porphyry L8q 
Rhyolite 18d 
Basalt l s« ; 
Structure : . 187 
* Economic geology 187 
Old Camp 188 
Tokop 18!) 
Oriental Wash 190 
