804 SIE J. W. DAWSON ON THE EOZOIC AND PALEOZOIC 



Huronian or Kewenian or intermediate, will be common to the- 

 coastal and interior regions, thus differing from the true Paradoxides- 

 zone. 



III. The Cambeian System. 



For a long time the base of the Palaeozoic, in the eyes of the geolo- 

 gists of America, was the Potsdam Sandstone, which over great areas 

 of Canada and the United States rests unconformably and directly 

 on the Laurentian. 



The marginal areas of the continent have since afforded a great 

 series parallel to the Cambrian of Wales and of Scandinavia. 



In southern N'ewfoundland the Huronian rocks, or the Signal- 

 Hill red sandstones and conglomerates overlying them, are succeeded, 

 according to Jukes and Murray, by a thick formation of sandstones 

 and slates with a little limestone and conglomerate, and near the base 

 of this the gieoX Paradoxides Bennetii and other forms of like age are 

 found. These are Lower Cambrian and obviously parallel with the 

 beds holding the rich fauna of this age in ]^ew Brunswick, originally 

 described by the late Prof. Hartt*, and more recently and more 

 fully by Mr. Matthew t. The strata holding these fossils in iN'ew- 

 foundland have conglomerate, slate, and limestone below, and a great 

 thickness of variousl}' coloured slates above, overlain by sandstones 

 and slate. Very similar beds constitute the lower Cambrian series 

 of St. John, New Brunswick. 



I have already stated that there exists in southern j^ew Bruns- 

 wick a series of red, purple, and grey conglomerates and sandstones 

 not unlike the Signal-Hill series, unconformable to the Huronian 

 below and the Paradoxid€sA)ediQ above, and holding not only worm- 

 tracks, but Linguloid shells. These are regarded as a basal Cambrian 

 series, perhaps equivalent to the Caerfai group of Hicks, while above 

 this are the equivalents of the Solva and Menevian groups of the 

 same geologist, corresponding in mineral character and fossils so 

 closely as to indicate portions of the same sea-bottom +. The 

 Braintree slates in Massachusetts with their underlying conglomerates 

 may be considered a continuation of the 'Bqw Brunswick beds §. 



Above these in ^Newfoundland is a slender representation of the 

 lower part of the Upper Cambrian, now called Middle Cambrian by 

 some, and consisting of sandstones and flags, often micaceous, with- 

 Lingulce. Similar beds cap the Lower Cambrian in southern Xew 

 Brunswick. Mr. Pletcher, of the Canadian Survey, has found fossils 

 indicating what is probably the same horizon in the slaty districts of 

 southern Cape Breton. Mr. Matthew regards these series as covering 

 the whole succession from the Caerfai group of Hicks to the Lingida- 

 flags, and the two great zones A and B of Angelin in Sweden. 



* Acadian Geology, 1868. 



t Trans. Eoyal Society of Canada, 1885 to 1888. 

 X Matthew, ' Canadian Record of Science,' 1888. 

 § Crosby, ' Boston Society of IS'at. History,' 1884. 



