18 ILLUSTRATIONS. 



Page 



FIG. 53. Diagram showing the line of equal displacement when the fault systems are oblique 

 to each other instead of being at right angles, the conditions otherwise being like 

 those in fig. 50 160 



54. Diagram showing the effect of cross faults when the faults of one system have twice 



the displacement of those of the other system 160 



55. Diagram showing trend of zones of equal displacement with given directions of 



downthrow 161 



56. Section of Good Enough shaft, Gold Hill 166 



57. Cross section of Good Enough vein, Gold Hill, as exposed in openings just west of 



shaft, showing same characteristics as in fig. 56 167 



58. Horizontal plan of faults and vein on the 392-foot level of the Montana Tonopah.. 169 



59. Vertical section along north drift, 392-foot level, Montana Tonopah 169 



60. Horizontal plan showing veins and faults on the 460-foot level of the Monana 



Tonopah 170 



61. Sketch showing face of ore of the Montana vein on the west drift, 460-foot level, 



Montana Tonopah mine 171 



62. Horizontal plan to show relations of the Mizpah and Montana veins on the 400- 



foot level of the Mizpah 173 



63. Vertical cross section (sketched) of cross wall limiting chief ore shoot of Montana vein 



below, as displayed on the 512-foot level of the Montana Tonopah 174 



64. Vertical cross section (sketched), showing effect of curving and branching faults 



on MacDonald vein in stopes above the 615-foot level on the Montana Tonopah. 174 



65. Vertical cross section (sketched), showing effect of curving and branching faults 



on MacDonald vein in stopes above the 615-foot level on the Montana Tonopah. 175 



66. Cross section showing geology exposed by Montana Tonopah workings 176 



67. Section on plane of Desert Queen and North Star shafts 177 



68. Section showing geology exposed by Midway workings 180 



69. Diagrammatic vertical cross section of Tonopah Extension vein 182 



70. Map showing principal earlier andesite veins now developed underground within the 



main productive area; shown on the horizontal plane of the Mizpah 500-foot level. 183 



71. Vertical section through MacXamara and Tonopah Extension shafts 191 



72. Vertical sketch section of shallow trench just north of Belmont shaft, showing 



contact of the Oddie rhyolite intrusion with the later andesite 193 



73. Diagram to show changes in amount* of commoner elements during stages of altera- 



tion of earlier andesite 218 



74. Diagram showing relative proportions of the less common elements during the stages 



of alteration of the earlier andesite 234 



75. Diagram showing changes in composition during alteration of the later andesite 242 



76. Diagram showing changes in composition during alteration of the later andesite 243 



77. Plotting of temperature observations in the Ohio Tonopah, Mizpah Extension, and 



Montana Tonopah mines, showing increase of temperature with depth 265 



78. Vertical cross sections of ore bodies or bonanzas in De Lamar district, Idaho; Corn- 



stock lode, Nevada; and Cristo vein, Pachuca, Mexico 277 



