216 A. S. PACKARD, Jr., ON THE GLACIAL PHENOMENA 



The shores of the hay where they are not of rock are generally composed of rolled 

 fragments of syenite, mica-slate, quartz, hornblende, sometimes in large masses, feldspar &c 

 Magnetic iron in the form of sand was also met with in some of the small coves l 



Laurentian Trap Rocks. At Henley Harbor is a system of trap rocks which have been 

 upheaved m a N.N. E. and S. S. W. direction, in a course much more northerly than the di- 

 rection which the Straits of Belle Isle assume. These rocks consist of three masses of co- 

 lumnar basalt, capping the syenitic gneiss. It is a hard fine compact diorite, breaking with 

 a conchoidal fracture and metallic ring, and contains much iron. The mass is 255 feel high 

 on Henley and Castle Islands, and consists of two layers of vertical columns. West of the°se 

 basaltic rocks, on the opposite side of the harbor, is a large trap overflow forming a hill 

 over 300 feet high, and apparently of the same age. It should be remarked that the two 

 layers of basalt representing successive overflows, incline at a very slight angle towards 

 the S. W. The third mass of basalt is seen rising out of the ocean a few miles northerly 

 nearly in a line with the basalt of Henley Harbor. 



Dykes of this age are likewise seen at Strawberry Harbor, Cape Webuc, and at Hopedale 

 intersecting the Laurentian gneiss and syenite. Its age is plainly anterior to the deposition 

 of the undisturbed Taconic, « primordial " strata at Anse an Loup, and on the Newfound- 

 land coast opposite. 



Huronian Group. A system of quartzite and trap rocks which lie in a depression of the 

 Laurentian rocks, about one hundred and twenty-five miles long, and probably twenty-five 

 miles broad, stretching along the coast between Domino Harbor and Cape Webuc I refer 

 with some hesitancy, to the Huronian series of Sir W. Logan, and consider as probably 

 equivalent to the "Quartzose Division of the Primitive Slate formation" of Naumann and 

 Keilhau." It agrees in part with the " Domino Gneiss " of Mr Lieber 



At Domino Harbor in kit. 33° 30", the quartzose rocks attain their greatest development 

 occurring as a slightly schistose light colored quartzite, the base of which is a white 

 granular vitreous quartz, with speckles of black hornblende, and more rarely still minute 

 particles of hypersthene, with a few particles of a lilac colored mica. There are also minute 

 rude crystals of yellow garnet, or cinnamon stone, disseminated through the mass No 

 feldspar was detected in this rock. In some places the rock was exceedingly fine in 

 others, it assumed almost a conglomeritic aspect, from the presence of smalf pebbles of 

 quartz. The quartz is often colored green. This rock weathers easily, leaving masses of 

 quartz projecting on the surface ; it is comparatively soft, and has been greatly denuded 

 It thus forms at this locality a broad low flat plain about ten miles broad and fifteen to 

 twenty miles long, through which rise bosses of diorite. Its surface is but a few feet above 

 the level of the sea, and to one just coming from the high coast to the southward, this 

 broad naked flat, almost wholly destitute of vegetation, with no valleys to shelter even a 

 growth of spruce trees, and but slightly farrowed by glacial action, with patches of white 

 rock glistening m the sun from between the dull green morasses and ponds that are every- 

 where scattered over its surface, - presents a strange and foreign feature of the coast 

 scenery, startling from its very tameness. When in contact with the trap hills the rock 

 is much harder, rising into higher elevations. 

 _ Nowhere was I able to see the juncture of this rock with the Laurentian gneiss, which 

 rises from the edge of this formation into high hills and mountains. So smooth had this 



1 Loc. cit., p. 81. , . „ 



2 «5<,« T tu c i .i r, • • . „ y a " d ln Canada. Canadian Nat. and Geo!., vol vii 

 bee T. Macfarlane, on the Primitive Formations in Nor- 1862. 



