PALEOZOIC TERRANE BENEATH CAMBRIAN. 



51 



Sound, the author took opportunity to spend 

 a day at Manuel's and on Conception Bay. 

 The section in the gorge at Manuel's Brook 

 has been so well and so fully described by Mr. 

 Walcott that the author had no occasion to 

 seek for other data ; he has, therefore, for com- 

 parison with the section at Smith Sound, con- 

 structed the accompanying section (Fig. 4) on 

 ■the data given by that author.^ 



As in the case of the Smith Sound sec- 

 tion, the difference between the Olenian and 

 Paradoxidian is arbitrary, but the limit between 

 the two lower Cambrian zones is fairly well 

 •defined by fossiliferous outcrops. The dip 

 of the beds as given by Mr. Walcott is 12°. 

 Here, as at Smith's Sound, it will be noted 

 that the Cambrian begins with a conglomer- 

 ate, but this, in place of resting on the soft 

 shales of the Etcheminian, as at that place, is 

 based on Huronian gneisses, felsites and ash 

 rocks, and from these the pebbles of the 

 •conglomerate have been derived. But it 

 seems highly probable that the ruins of the 

 Etcheminian are also represented in these 

 boulder-beds, as Mr. Walcott says that 

 there are " irregular masses of limestone on 

 and among the boulders of gneiss, forming 

 the base of the Olenellus zone at Manuel's 

 Brook," and these are said to contain fossils. 



There are also certain red slates in the lower 

 part of the Cambrian here which are similar to 

 those at the same horizon on Smith Sound, 

 but at the latter place the red shales are in 

 much greater mass. 



The correspondence of these two sections is 

 ■obvious, as the genus Protolcmis is found in 



lU. S. Geol. Survey Bull. 81, p. 260. 



\ 



