OF LABRADOR AND MAINE. 217 



plain been levelled and worn by glacial and aqueous agents, that it was difficult to observe 

 the dip and strike of the beds, which, when undisturbed by eruptive rocks, I am inclined 

 to believe, dip easterly at a slight angle. At Dumplin Harbor, which is a bight in an 

 island lying just S. E. of Huntington Island, the quartzite, when lying next to trap, approxi- 

 mates to gneiss in its character, under which it dips at an angle of 35° S. E., the strike of 

 the beds being northeasterly. At Tub Harbor these rocks come in contact with the 

 Laurentian syenite. Between the quartzites were beds of a dark fine-grained hornblendic 

 quartzose gneiss, capped by the syenite. At Indian Harbor, about thirty miles north of 

 Tub Harbor, and on the opposite side of Hamilton Inlet, these same rocks appear. These 

 rocks occur also at Sloop Harbor, rising two hundred feet high, and are capped by syenite, 

 which is very pale in color, with particles of black hornblende. Here, as at Tub Harbor, the 

 quartzite at the point of contact with the syenite becomes a dark gneiss. The Esquimaux 

 Islands which lie off this coast, are composed of the light colored quartzite which here seems 

 to assume the character of a true gneiss. At no point was I enabled to observe whether 

 these quartzites rest unconformably upon the older Laurentian gneiss, though strongly 

 inclined to think so. 1 



Invariably accompanying these rocks is a dioritic trap of a peculiar mineralogical charac- 

 ter, occurring in overflows of a peculiar physiognomy, and upheaved in a direction at nearly 

 right angles to that of the Laurentian dykes, thus following the general northwesterly 

 trend of the Atlantic coast of the Peninsula. 



This rock differs from the hard fine-grained trap at Henley Harbor, in being coarsely 

 porphyritic. It is composed of large crystalline masses of hypersthene and labradorite, 

 this last being of a dark smoky color, and precisely such as described as occurring in the 

 hyperite of Square Island. It seems to follow that this porphyritic trap is the result of the 

 refusion of the anorthosite rock, which must consequently underlie this Domino quartzite. 

 This is an argument for the unconformable bedding of this quartzite upon the lower 

 Laurentian gneiss, while this trap rock is evidently of the age of the former quartzose rock, 

 which it has somewhat disturbed. The Isle of Ponds is largely composed of these trap 

 hills. Huntington Island is a large mass of trap. Tub Island, as its name betokens, is a 

 peculiar, truncated cone of trap, resembling an inverted tub. These trap overflows extend 

 northward to Cape North, which is a lofty headland of trap capping the gneiss, and thus 

 adding very materially to the elevation of this, as of all the other numerous gneiss 

 promontories which run out from the main land. Occasionally an island is seen half black 

 and half white, one side being composed of the dark trap rock, and the other of the light 

 colored quartzite. Such is " Black and White," a very prominent island near " Indian 

 Tickle," a harbor at the northern side of Hamilton Inlet. Here are some remarkable 

 dykes which ascend the gneiss hills in huge irregular zigzag crests, often crossing each 

 other at right angles. 



Beyond this point the Laurentian gneiss again appears, and forms the high bold shores 

 extending to Hopedale, rising in the interior into lofty imposing mountains on whose tops 

 lie patches of snow. 



Among the erratic rocks at Domino Harbor were some which show that in the interior 

 are beds of jasper and chert. There occurred several small boulders of jasper and gneiss. 

 The jasper was pale green, banded and striped by darker shades of green, while the 



1 The Canadian Geologists likewise state that the strata of on tilted Laurentian rocks ; it is as yet a matter of hypoth- 

 the Huronian system have not been observed resting directly esis. 



