248 THE CANADIAN NATURALIST. [Jail. 



becomes utterly broken up into a breccia, which has pieces from 

 one inch to a foot in diameter invariably angular, and a matrix 

 consisting of the white felspathic substance above mentioned, with 

 occasionally calcspar. Further westward the measures are 

 concealed for two hundred yards ; then strata of bluish-grey 

 calcareous sandstone are exposed, striking N. 40 Q E., and dipping 

 75° S. E. From this point for three hundred yards further north- 

 westward, disturbed sandstone occupies the coast where the 

 measures are not concealed. It is followed by a breccia similar 

 to that already mentioned, with angular fragments of sandstone, 

 and then by beds of trappean rocks, striking N. 75° W., and 

 dipping 40° S. W. Rocks of this nature occupy the coast, where 

 not concealed, for one and a half miles further north-westward. 

 Here sandstone again becomes visible, in strata almost vertical, 

 but nevertheless much bent. It is covered by a breccia consisting 

 of sandstone fragments with a trappean matrix, and this again is 

 surmounted by regular trap. In many places there would seem 

 to be the clearest evidence that the trap lies unconformably upon 

 the upturned and contorted edges of the sandstone. Besides the 

 breccia above mentioned, other rocks of a peculiar nature are 

 found at the junction of the sandstone and trap. One of these 

 is indistinguishable from quartzose perphyry, and another seems to 

 consist of fragments of trap bound together by this same quartzose 

 perphyry. There are good grounds for supposing that the latter 

 rock is the product of the action of the more basic trap upon the 

 sandstone, and results from the igneous amalgamation of the two 

 rocks last named. These confused rocks occupy about a quarter 

 of a mile of the coast. To the north-westward, although the 

 sandstones occasionally protrude, they become much less frequent, 

 while the overlying melaphyres become much more regular, and 

 gradually assume the same strike and dip as the strata on the 

 west coast. The hills to the north of Anse-aux-Crepes consist of 

 the same beds of melaphyre and conglomerate as were observed 

 on the west coast, with similar strike and dip. 



The eruptive origin of the melaphyres and traps of this group 

 is evidenced not only by their crystalline character, and by some 

 of their relations in contact with undoubted sedimentary rocks, 

 but also by their occurring as intrusive masses in the gneiss of 

 Point-aux-Mines, and in the granitoid gneiss of Chippewa Falls. 

 At the latter place the melaphyre is in the form of a d\ke, and at 

 Point-aux-Mines it is seen to form a dome-shaped mass, completely 



