ORE DEPOSITS 



121 



CORA BLANCA PORTAL 



Altitude 1191.2 feet 



EXPLANATION 



imbered 



KJt 



Tuffaceous greenstone of the 

 Franciscan group. KJt; shale 

 of the Franciscan group, KJsh 



122? 



Hilo, or quartz-dolomite vein, 

 showing elevation and dip 



Locally contain cinnabar 



Vertical hilo 



55 



A?/5- 



Contact, showing elevation 

 and dip 



Dashed where indefinite 



Vertical contact 



H9O I 



Fault, showing elevation 

 and dip 



Dashed where indefinite 



H 



Top of vertical or near 

 vertical wall 



Chevrons point down incline at 

 5-foot vertical intervals 



a 



Head of raise or winze 



Foot of raise or winze 



CZ3 



Slope 



O 



1 19 5-S 



Altitude of point in floor 



Backfilling in workings 



80 FEET 



KJt 



tf\ "*""/ X* 



KJsh 



By E. H. Bailey and D. L. Everhart 



DATUM IS MEAN SEA LEVEL 



FIGURE 90. Map showing the upper slopes and workings of the Cora Blanca area of the New Almaden mine where the ore occurred in veins 

 and in fault gouse in tuff. The map also shows the difficulty of mapping closely spaced overlapping inclined workings, and how the 

 veins and faults were mapped by means of contours drawn wherever exposures were continuous enough to provide control. 



686-671 O 63 



-9 



