Origin of Granite. 



511 



is intruded among the stratified rocks. This argument is far more 

 striking in the case of granite than in that of greenstone. For it is 

 hardly possible to conceive of any anomaly of position which the for- 

 mer rock has not assumed in relation to the stratified ones. Its veins 

 are of every size and shape, and they run in all directions through 

 the superincumbent strata ; and similar irregularities exist in its 

 larger and less ramified masses. True, they are rarely superincum- 

 bent upon the stratified rocks ; and hence some have inferred that 

 they could not have been erupted like trap and lava, which often 

 spread over the surface to a great extent. There is, however, one con- 

 sideration, — to waive all others, — which it seems to me obviates 

 this difficulty. We have abundant evidence that the surfaceof the 

 earth has suffered powerful abrasion in past ages ; and since granite is 

 confessedly older than the traps, it must have suffered most from this 

 cause. Now who can tell but granite did once exist in overlying 

 masses, and that those have been mostly worn away, and their re- 

 mains entombed in the later rocks which so abound in nodules of 

 granite ? If existing causes operate long enough, the overlying mas- 

 ses of trap, now so common in various places, must be thus swept 

 away, and its veins and protruding masses alone remain. 



This argument, however, cannot be felt in all its force without 

 connecting it with another circumstance which forms my next argu- 

 ment. 



3. I infer the igneous origin of granite from the mechanical effects 

 which it appears to have exerted upon the stratified rocks in its imme- 

 diate vicinity. 



To illustrate these effects is a principal object which I have had in 

 view in giving so many sketches of veins and protruding masses of 

 granite. Most of these cases seem to me totally inexplicable on any 

 other supposition than that of the protrusion of the granite while in a 

 fluid or semi-fluid state. But after all, such sketches convey only a 

 very imperfect conception of the actual marks of disturbance, which 

 the stratified rocks in the vicinity of granite exhibit. Their dip and 

 direction are changed in every possible manner,and larger or smaller 

 masses of the stratified rocks are partially or entirely separated from 

 the parent rock, and more or less enveloped in the granite, which is 

 united to them chemically. If any candid man will go into the 

 towns of Williamsburgh, Whately, Conway, Chesterfield, Goshen, 

 West Hampton, Norwich, Chester, Granville, or many others that 

 might be named, and carefully examine the irregularities which the 



