Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/658

 first sight, but little of the aspect of stratified rocks, and might be mistaken for intrusive granites"*.

Cape Breton. — In Cape Breton I saw, in 1866, the black corrugated slates forming the summit of the gold-bearing series of Nova Scotia, about five miles north of Chetican Island, on the Gulf-coast ; and on the Mackenzie River, near Red Cape, I crossed part of a great gneissoid series†.

In various parts of Cape Breton I have seen similar gneisses, as for instance, near the mouth of North River, St. Ann's Bay, and on the peninsula opposite Baddeek.

Dr. Honeyman informs me that he considers the gold-bearing rocks of Middle River, in Cape Breton, to be of the same age as those of Nova Scotia. Hence it becomes more than probable that a very large portion of the area coloured by Dr. Dawson to represent Upper Silurian in the northern part of the island is occupied by rocks of Huronian and Laurentian age‡.

Three Subordinate Laurentian Axes. — The sketch section of part of Canada, New Brunswick, and Nova Scotia (fig. 3), showing the outcrop of the gneissoid rocks, points to three subordinate undulations which have brought up the gneissic rocks between the Atlantic coast of Nova Scotia and the great Laurentian axis of the American continent on the north side of the St. Lawrence.

The first of these is the central belt of New Brunswick, which is parallel to the great axis north of the St. Lawrence. In the trough between the St. Lawrence and this belt the newest rock known is an outlier of Lower Carboniferous age.

The second axis trends slightly to the eastward, and the rocks are exposed from the coast of Maine to a considerable distance beyond the city of St. John, enclosing a wedge-shaped trough in which the New-Brunswick coalfield is situated.

The third axis is in Nova Scotia, and the newest rock in the intervening trough is the New Red Sandstone,

On the Atlantic coast of Nova Scotia, and on the south-east side of the Nova-Scotian axis the newest rocks consist of patches of the Lower Carboniferous, so that in each trough we find a recurrence of the same rock-series.

From the horizontal attitude of the Carboniferous series in Nova Scotia and New Brunswick, sometimes resting on the gneiss, sometimes on tilted Devonian or Silurian strata, it appears probable that these great undulations occurred at the close of the Devonian period. The three great axes just enumerated represent the main undulations ; but they are themselves thrown into minor corrugations,


 * Geology of Canada, 1863, p. 587.

† See page 11 of a ; Preliminary Report on a Gneissoid Series underlying the Gold-bearing Rocks of Nova Scotia, and supposed to be the equivalent of the Laurentian System,' by the Author.

‡ In the counties of Addington, Hastings, and Peterboro'. Ontario, there is a series of rocks provisionally placed by Sir W. E. Logan as Lower Laurentian, " at the base of which there appears to be an auriferous band." See page 5, Summary Report of Progress in Geological Investigations, May, 1869 (Geological Survey of Canada).