GENERAL FISSUllE SYSTEM. 



329 



cross-courses, but this would be substantial continuity. If I am right, the 

 New Almaden deep fissures connect with the ore-bearing fissures south of 

 the ridge and cross the ridge near the America. Considering the amount of 

 disturbance on the New Almaden fissures they would seem to represent the 

 main line of fracture, and in that case the crack leading to the Washington is 

 in the nature of a cross-course. The apparent strike of the America accords 

 with this view, which is strengthened by the relations to the dike to be men- 

 tioned presently. As for the Cora Blanca, the fact that the deposit is largely 

 bedded or that it follows the stratification complicales its relations, for its 

 strike is very likely to diff'er considerably from that which it would have if the 

 structure of the country had not presented a local line of weakness. It may 

 be that this mine is on a cross-course nearly parallel to the Washington, but 

 the evidence is hardly sufficient to justify speculation. The following sketch 

 shows the approximate positions of the several deposits of the ridge and of 

 the dike. The strike of the main deposits is also indicated and a fine line 

 is drawn through all except tlie Cora Blanca. The upper portion of the 

 south fissure of the New Almaden is not represented on the sketch for lack 

 of data. The croppings of this fissure probably curve rapidly toward those 

 of its northerly companion, but the soil and artificial disturbances obscure 

 the line (Fig. 13). 



Fig. 13. R. deep Assures of the New Almuden near the Eandol shaft; IT, -WashiDgton deposit: A. America; B, Cora 

 Blanca; P, Piovidentia; £, Euriquita; SJ, Saa Antouio ; Jf , San Matoo ; G, Guadalupe; dd rbjolite dike. 



The straightness and persistence of the dike seem to show that its crop- 

 pings have the same strike as the main fissure through which it reached 



