TROCEEDINGS FOR 1898 XCV 



ground, and alroad}' acted on by the internal heat of tht^ cartli in a 

 degree proportionate to their depth." 



Now if we omit from the foregoing tlie purely theoi-etical doctrines 

 of fusion, injection, intrusion and central Iwat, we have a ])erfectly con- 

 sistent and easily understood theory and explanation of the facts con- 

 nected with the origin and formation of granite. 



In 1866^ I wrote: "In the steep, hilly country east of the Snowj- 

 Eiver, Victoria, Australia, the relation' of the granite to the older rocks is 

 well exhibited. The beds of the creeks and the bottoms of the valleys 

 are all granite, and the tops of the ranges vertical Silurian slates and 

 sandstones, so that an accurately constructed geological map of the dis- 

 trict the boundaries between granite and slate would present contour 

 lines much the same as in deeply eroded oolitic or other nearly horizontal 

 strattv Occasionally the strata dip at angles off the granite ; but, so far 

 as I have observed, this relation is purely accidental, and occurs only 

 when the line of strike happens to coincide with the more or less meri- 

 dional strike of the stratitied rocks. Quite as often the dip is either 

 directly on to, or against the granite, or the beds are vertical and end 

 abruptly along a granite boundary that runs at right angles to the strike 

 of the Silurian strata. And it appears as if the origin of the gnxnite had 

 no inflitence in determining the direction or the amount of the disturb- 

 ances that have affected the older rocks. This, I conceive, could hardly 

 be the case had it been intruded or irrupted, whether in a fluid, gaseous 

 or solid state, in such large masses as exist in all jjarts of Victoria." 



" There is, however, often seen along the contact-lines of the granite 

 and the stratified rocks a considerable breaking up and crushing of the 

 latter, and this has been held to indicate and be the result of the intru- 

 sion of the granite. It appears to me to be mainly due to the unequal 

 resistance that the two rock-masses have offered to the disturbing forces 

 of upheaval, depressions and consequent pressure, which have repeatedly 

 affected them long after the formation of the granite. The effect thus 

 produced is analogous to that which occurs when the forces producing 

 cleavage encounter interstratified hard layers of sandstone, v,-hen the 

 elsewhere perfectly regular and parallel cleavage planes are immediately 

 crushed, crumpled and deflected.'" 



In 1879^ I wrote respecting the gi^anites of Nova Scotia: "It has 

 been customarj^ and orthodox to regard these granites as intrusive, and 

 they are so designated by Logan. 1 hold there is absolutely no proof of 

 this being so, either in the Eastern Townshijjs of Canada, in Nova Scotia 

 or in Australia. All the j^henomena connected with them may be more 

 rational!}^ explained and understood if we regard them as completely- 

 metamorphosed portions of the strata which now surround them ; while 



' " Notes on the Geology and Mineralogy of Victoria." 

 - " Geological Survey of Canada," 1879-80, pp. 5-6. 



