" BATHOLITHS" OF HALIBURTON-BANCROFT AREA 787 



stoping, blocks of limestone were torn from the roof of the invading 

 granite batholiths and elongated parallel to the contact of the 

 granite and limestone by movements of the granite as it con- 

 solidated. 



Daly believes that static metamorphism produced planes of 

 weakness within the Shuswap series and that sills of granite were 

 intruded along these planes. 



Fenner, 1 discussing the method of intrusion of the granites of 

 the New Jersey Highlands, states that in his opinion gaseous 

 emanations from the granite magma penetrated the sedimentary- 

 rocks along planes of weakness and prepared the way for the 

 intrusion of granitic fluids. The intrusion of these fluids produced 

 banded gneisses. 



It is, of course, entirely possible that intrusion in the Haliburton- 

 Bancroft region took place by magmatic stoping and that this 

 region is not analogous to the others described. The rock types 

 vary within the several areas and there is, necessarily, a corre- 

 sponding change in the structural relations. The limestones of the 

 Grenville series would undoubtedly be more altered by the meta- 

 morphic effects of the granite than the quartzose rocks of the New 

 Jersey Highlands and the Shuswap series. 



It seems to the writer, however, that the facts shown by the 

 study of the Glamorgan gneissic area favor the theory of intrusion 

 by parallel penetration along planes of weakness rather than the 

 theory of intrusion by magmatic stoping. 



If intrusion took place by magmatic stoping, the following 

 conditions must be postulated. The objections to each of these 

 conditions are noted. 



1. The blocks from the roof of the 1. Intrusion by magmatic stoping 



batholith were stoped off and elongated usually produces an irregular molar 

 parallel to the contact. contact. The igneous rock cuts the 



sediments. Though the blocks were 

 elongated parallel to the contact, this 

 would not, except by chance, be parallel 

 to the stratification of the sediments, 

 and yet this is the relationship of the 

 banded structure of the rocks of the 

 Halibur ton-Bancroft area. 



1 Journal of Geology, XXII (1914); 594 &"• 



