16 ILLUSTRATIONS. 



Page. 



FIG. 1. Vertical section of shaft about 1,600 feet east of Tonopah and California shaft, 



showing Fraction dacite breccia and interbreccia tuffs 40 



2. Vertical sketch section of trench just west of Brougher Mountain, showing Tonopah 



glassy rhyolite-dacite, intrusive into Fraction dacite breccia 41 



3. Vertical section of part of tunnel north of Brougher Mountain and southeast of 



Ohio Tonopah shaft 43 



4. Vertical sketch section showing contact of intrusive dacite with tuff, southwest base of 



Butler Mountain 44 



5. Vertical section showing contact of Golden Mountain dacite with Siebert tuff (lake 



beds) east of Golden Mountain 45 



6. Horizontal plan showing eddying in the cooling lava of a volcanic (dacite) neck; 



plotting of strong flow structure on top of eastern shoulder of Golden Mountain. 46 



7. Vertical sketch section of mud dike at dacite contact at a point on the east side 



of Butler Mountain 48 



8. Vertical sketch section taken at a point on the east side of Butler Mountain, 



showing mud dike in lake beds 49 



9. Vertical cross section of southeast side of Siebert Mountain, showing relations of 



Siebert tuffs (lake beds), basaltic flow and agglomerates and Brougher dacite 53 



10. Ideal cross section of Tonopah rocks 71 



11. Cross section of water runway (usually dry) of Plate XII 76 



12. Map showing outcropping veins of Tonopah 84 



13. Rhyolitic veins (later period) in Tonopah rhyolite-dacite, 814-foot level, Desert 



Queen shaft, showing irregularity and lack of persistence (horizontal plan) 98 



14. Cross section of outcropping fissure vein in Ararat rhyolite neck near margin, 



Reptile claim, north of Boston Tonopah shaft 102 



15. Vertical cross section of outcropping fissure vein 20 feet west of section shown in 



fig. 14 103 



16. Vertical cross section of a portion of Mizpah vein as exposed in the Oddie shaft, 



showing reverse dip near the surface 116 



17. Vertical cross section of Mizpah vein along Brougher shaft and inclines 116 



18. Vertical cross section of Mizpah vein, Oddie and McMann lease, showing diverging 



walls 11" 



19. Detail sections from Mizpah vein, showing the effect of pre-minend cross fractures. 119 



20. Sections showing the splitting of the Mizpah vein 120 



21. Diagram showing the distribution of the richer ores in Mizpah vein 121 



22. Sketch of faulted quartz veinlets in andesite, 300-foot level, Mi/,pah, just south of 



the Valley View shaft 122 



23. Horizontal sketch plan of [>ortion of the Mizpah vein in stopes east of Lease ">:.'. 



about 70 feet from surface, showing probable compensating faulting 123 



24. Reproduction of drawing of model showing the principal post-mineral fractures and 



faults olwerved in the Mizpah mine workings 123 



25. Horizontal d'mgra mtic plan of Mi/.pah vein as exposed in the Oddie and McMann 



lease, 20 to 30 feet Iwlow the surface 124 



26. Horizontal plan of mine workings, showing the relation of the vein in the Desert 



Queen workings to that on the corresponding level of the Mizpah mine 12ti 



l!7. S.-.-tioiis slmwinu the structure of the Burro No. 1 vein l- s 



