UNSTRATIFIED CONDITION. 



121 



by the author from granitic rocks near Valparaiso). The veins undergo con- 

 stant changes of size, and in some places encircle masses of rock resembling 



Fig. 121. 



122. 



the rock outside. The rock adjoining the vein is more micaceous than that at 

 a distance, and the direction of the lamination (as indicated in the figures) varies 

 with some reference to the intersecting veins, curving approximately parallel 

 to the veins on two opposite sides m and n, and not at all so on the other two 

 o and p. The subdivisions of the veins in fig. 121 cross one another in an alter- 

 nate manner, a cutting d and e but cut by c, and b cut by c, d, and e ; and in 

 122, although the veins are similar in constitution, one cuts the other; and in 

 120 the two crossing veins are broken and subdivided at the intersection so as 

 to appear like one vein stretching off in two directions like a letter X. 



Fifr. m. 



Fig. 123. A vein a faulted by b, — whence it is inferred that b is subse- 

 quent to a in age. Also a vein 1 faulted by 2 and again by 3, and 3 faulted 



Fig. 124. Fig. 125. Fig. 126. 



Fig. 127. 





by 4 : 2 and 3, therefore, were subsequent in age to 1, and 4 was subsequent to 3. 

 The faulting is exhibited also in the layers of the stratified rocks which the 

 .veins intersect. 



