vm, a, 2 



Edding field: Ores of the Philippines 



85 



Faults found on the Ascension 



'r^ 



.vV 



Fig. 1. — Showing faulting of the "Tejon dike" on the Ascension group. 



vein. This case shows conclusively that at least two periods 

 of Assuring occurred in this region. 



The tendency toward parallel arrangement of Assuring is very 

 marked in Aroroy and Paracale, but in Benguet there is little 

 evidence of any regularity, except for a tendency toward east 

 and west directions rather than north and south. A large num- 

 ber of long, strong veins strike almost due east and west, but the 

 most promising veins, so far exploited, strike either northeast- 

 southwest or northwest-southeast. In Aroroy the veins strike 

 almost uniformly northwest-southeast, and in Paracale they 

 strike northeast-southwest. This arrangement of fissures may 

 have been produced by some force acting upon one portion only 

 of the fracture zone. The simplest case would be the subsidence 

 of one side or the elevation of the central portion of the area, 

 thereby producing Assuring on a large scale similar to those on 

 the crest of an anticline. However, in Baguio is found much 

 more pronounced and irregular shattering of the rock, producing 



