572 



A. W. GKABAU TYPES OF SEDIMENTAKY OVERLAP 



If the correlation of the Smith Point limestone of the two sections 

 is correct, and if the sections contain no unrecognized faults or erosion 

 planes, we have here a case of progressive encroachment of the sea, appar- 

 ently from the west eastward, though, of course, the basal gneiss of the 

 Manuels Brook section ma}? - represent an old reef or island in the Cambric 

 sea, which was gradually covered by encroachment from all sides. The 

 difference in deposition, however, between these two points is about 300 

 feet of basal beds, the basal conglomerates of the eastern section being 

 equivalent to the shales 300 feet above the base in the western section and 

 not to the basal beds there. The following diagram illustrates this point : 



w 



'//> Sound 



& 



s 



R <i 



Q 





/7?a»ue/sj9roo/f 



'.Smith Point Lt rne stone" 



777/dd le 

 Cambric 



erosion p/ane, 

 "^SAalesetLtS" 



^-'f>re 



C* 



r* 



If 



} asa/coJ7g/SS . 



Figure 2. — Comparison of Section at Smith Sound and Manuels Brook, Newfoundland. 



New Brunswick. — In this district the Cambric rocks have long been 

 included under the general term of the Saint John group, from their 

 typical exposure in the region about Saint John, New Brunswick. Mat- 

 thew has subdivided the series as follows :* 



Feet 



Division 3. (Bretonian) at Straight shore, Portland 700 



Division 2. (Johannien) at Kings square, Castleton 1,000 



Division 1. (Acadian) at Alms house, Simonds 650 



Total 2,350 



"The coarser sediments found at the base of the Saint John group are largely 

 derived from those older rocks, chiefly the Huronian (Algonkian), and the line 



* Illustrations of the fauna of Saint John group. 



