144 



GEOLOGY AND QUICKSILVER DEPOSITS, NEW ALMADEN DISTRICT, CALIFORNIA 



FIOURI 95. Stope on the 1500 level In the Randol part of the New Almaden mine. Note the numerous narrow steep veins, 

 known to the miners as "hilos," In the silica-carbonate rock of the working face. These were followed as a guide to 

 ore. Also note the size of the timbers necessary to hold up the back of alta after the removal of the silica-carbonate 

 rock ore. 



SOUTH RANDOL AREA 

 Location and extent or workings 



The South Randol area includes the three principal 

 South Randol ore bodies and outlying exploratory 

 drifts and crosscuts near them. (See fig. 92.) Most 

 of the workings of the area lie west of the Randol 

 shaft, south of the Santa Isabel shaft, and north of 

 the St. George shaft, and they are fairly evenly 

 spaced, at intervals of about 100 feet, from the 1000 

 level down to the 2300 level. The workings are con- 

 nected on most of the levels with the North Randol 

 workings to the east, and they also connect through 

 raises with the workings of the Victoria area to the 

 south. Most of the ore taken from the stopes was 

 hoisted in the Randol shaft to the 800 level and 

 trammed from there through the Randol tunnel to 

 the surface, but some ore from the deeper stopes a> 

 hoisted through the Santa Isabel shaft, and a little 

 through the St. George shaft. 



The South Randol workings include two long ex- 

 ploratory crosscuts on the 1400 level. One of these 

 extends south from the Santa Isabel shaft for half 

 a mile and connects with the 1100 level from the 

 Washington shaft through a long incline. The other 



branches from the first at a point 150 feet south of 

 the Santa Isabel shaft and extends westward for 580 

 feet, then runs southwestward toward the America 

 shaft for 1,400 feet. (See pi. 4.) Including these 

 long crosscuts, the total length of the South Randol 

 workings is about 6 miles. 



History and production 



The development of the South Randol area may be 

 said to have begun with the sinking of the Randol 

 shaft in 1871. At that time the ore bodies of the 

 central stope area had been followed northward and 

 downward into bodies lying below the 800 level, and 

 the ores were being removed by tramming through the 

 long, circuitous route by way of the Day tunnel. The 

 new shaft was intended to provide access to these 

 workings and to explore the area at greater depth, but 

 by the end of 1872, when connections had been driven 

 from the shaft to the stope area on the 900 and 1000 

 levels, the ore bodies were apparently (lying out down- 

 ward. By 1874 the production of the mine had fallen 

 to its lowest level since the first year of recorded pro- 

 duction some 24 years earlier. In the same year the 

 1100 west crosscut struck the "vein" (silica carbonate 



