504 A. J. Jukes-Brouiie — Cambrian Geography. 



It will be seen that the statements in this passage are not consistent 

 Avitli one another. A trough which passed across the Atlantic from 

 Scotland to Newfoundland would, if prolonged, extend to Iowa and 

 not in the direction of Alabama. The line from Alabama to New- 

 foundland is very nearly south-west to north-east, and if prolonged 

 would pass through Iceland, but would not touch Scotland nor even 

 the extreme north of Norway. 



The Appalachian ranges and the Caledonian flexures are parallel 

 to one another, not parts of a continuous ge-anticline. Moreover, they 

 were formed at a much later date in the world's history, and there is 

 no reason for supposing that they were in any sense initiated in 

 Cambrian time, or that there was a corresponding geosyncline " which 

 remained a line of weakness throughout Palaeozoic time". I need 

 hardly point out that parallel ge-anticlines, one in Europe and one 

 in North America, would not form a connecting shore-line between 

 the two regions. 



The fact is that Professor Peach is only correct so far as the 

 W.S.W. line from Scotland to Newfoundland is concerned, and there 

 is no need for the introduction of a geosyncline of any kind. All 

 that the facts warrant is the inference that there was a contimious 

 coastline from Norway to Canada with open sea to the south of it. 

 This coastline would have a general trend from E.N.E. to W.S.W., 

 but may in many places have run nearly due east and west. 



If this is granted the rest of Professor Peach's restoration becomes 

 comprehensible and probable. Instead of the Cambrian rocks of the 

 North- West Highlands being "laid down along the N.W. side" of 

 a trough or geosyncline, they were really formed along the northern 

 border of a North Atlantic sea, that is, on the southern side of an east 

 and west tract of land extending from Norway to Greenland and 

 Labrador. 



Further, he now agrees with me that the Cambrian strata of Wales 

 were deposited along the southern side of this sea, and he thinks that 

 "this southern land area in Western Europe was continuous across 

 the Atlantic with Appalachia ". Presumably the northern shore of 

 this land ran from Cornwall to Nova Scotia, crossing the Atlantic 

 in a general east to west direction, more or less parallel to that of the 

 northern land. It is of course a big assumption to bridge the Atlantic 

 for more than 2,000 miles with continuous land, but, being myself 

 convinced that Palaeozoic lands and seas were entirely different botli 

 in position and in trend from those of the present day, I see nothing 

 unlikely in the existence of such a land area during the Cambrian 

 period. 



I do, however, protest against the hypothesis of a single trough 

 formed by a geosyncline and extending from Norway to Alal)ama, 

 a distance of nearly 4,000 miles. There is really no evidence on 

 which to base such a piece of imagination, nor can I see any necessary 

 connexion between the geographical extension of the Cambrian sea 

 and the subsequently formed Caledonian system of flexures. An 

 oceanic area is not necessarily a geosyncline, and even the North 

 Atlantic of the present day comprises two troughs separated by 

 a median ridge. 



