[MATTHEW] GEOLOGICAL CYCLES IN A.ARITIME PROVINCES 127 



Professor Walcott has examined the jS'ewfoundlaiid pre-Cambrian 

 rocks described above, and called them the Avalon terrane, giving 

 Murray's description and thicknesses of the several portions and apply- 

 ing names to these groups. 



He has also distinguished an overlying terrane, the Eandom terrane, 

 occurring at Smith and Random sounds in Trinity Bay, and having a 

 thickness of about 1,000 feet; these rocks are chiefly gray sandstones. 



If the lower portion (8,200 feet) of Mr. Murray's Kewfoundland 

 pre-Cambrian rocks be compared with the gold-bearing series of Nova 

 Sootia, a similarity of succession will be observed, especially if com- 

 pared with the series as developed in the western part of that province. 



This is clearly seen if the deposits of the jSTewfoundland area 

 be compared with that of the western part of ISTova Scotia, where Prof. 

 L. W. Bailey found a group of variegated slates interposed between the 

 quartzites and the black slate group of the eastern part of that penin- 

 sula. This resemblance may be presented as follows : — 



Newfoundland. Nova Scotia. 



1. Quartzites, diorites, etc., slate 1. Quartzites, some clay slates, 

 conglomerate and slate. 2. Greenish gray, purple and blu- 



2. Green, red and purple slates in ish gray slates, the latter with 



frequent alternation. , conspicuous banding. 



3. Dark brown or blackish slates. 3. Black, with some blue and gray 



slates, very rusty-weathering. 



Of the Nova Scotian terrane Dr. Bailey states the thickness of 

 the two lower members at 5,000 feet or more, and the highest member 

 to be at least 3,000 feet. His assistant, Mr. Prest, found for the whole 

 system on the Sissaboo river a thickness of 28,000 feet,^ which is some- 

 what in excess of the thickness found by Mr. Faribault in the eastern 

 part of the province. 



Yet, from this enormous thickness of widespread sediments, not a 

 characteristic Cambrian fossil has been taken, while in both areas of 

 sedimentatnon of the true Cambrian rocks, St. John, N.B., and Cape 

 Breton, ample pafeontological proof of the age of the rocks is forth- 

 coming. Therefore, both on stratigraphie and palgeontological grounds, 

 we are compelled to admit that this is a separate series from the Cam- 

 brian, and as we shall see further on, must be of an older cycle of 

 deposition. 



' Rep. Prog., 1898, p. 83M. 



