A Fault Plane of Unusual Aspect. 



291 



Hock forming the Hodadero. 



As seen in the ledge the rock forming the Rodadero is 

 dark grey in color, with a greenish tinge when viewed in certain 

 lights. The weathered portions are light gray or even yel- 



FlG. 



Fig. 2. Weathered diorite forming east bank of Tullnmayo ; compare 

 with figures 4 and 5. 



lowish and spotted with green. Aggregates of yellow-green 

 epidote varying in size from a pea to clusters eight to ten 

 inches in diameter are irregularly distributed through the mass 

 and are particularly prominent along joints. The rock as a 

 whole appears to be massive, fine-grained, and of granitic 



