A SKETCH OF THE LIFE AND LABOURS OF DR. ROBB. I 



mere statement of the differences presented by the latter, as compared 

 with the earlier map of Gesner, on which it is avowedly based. 



The first feature to attract attention in such comparison is the 

 larger area embraced in the map of Dr. Eobb, the latter including 

 the whole Province, while that of Gesner did not extend, except along 

 the St. John river, north of a line connecting Woodstock and Chatham. 

 Gesner's map, however, represents the results of his first four season's 

 work only, while in the following year he made explorations of the 

 northern counties sufficient to indicate their general character, and it 

 is upon these, no doubt, that the completion of the work by Dr. Robb 

 is based. 



In his representation of the distribution of the granites which are 

 so conspicuous a feature in the geology of New Brunswick, Dr. Robb's 

 map — at least as regards the southern part of the Province — is less 

 fortunate than that of Dr. Gesner, the more recent explorations em- 

 bodied in the maps of the Geological Survey showing, especially in 

 Charlotte County and Western Kings, a much closer approximation to 

 the outlines as given by the latter than to those of the former. Gesner 

 also indicates the existence of an axis of such rock extending from the 

 Kennebeccasis River, near Hampton, to Eastern Albert, which in the 

 map of Dr. Robb is represented by a corresponding band of " Trap, 

 Syenite, Felspar Rock and Porphyry." As a matter of fact, this ridge 

 includes but little true granite. 



The northern granite belt, represented in Gesner's map only between 

 the St. Croix River and the St. John, in that of Dr. Robb is extended 

 across the Province to Bathurst. The granitic area of the Serpentine 

 is also indicated. 



The including of so many different rocks under a common colour, 

 irrespective of age or origin, as in the case of the Trap, etc., referred 

 to above, is, in the maps of both authors under review, an unfortunate 

 feature, but is far more conspicuous in that of Dr. Robb than in that 

 of his predecessor, the former being in almost all parts, not occupied 

 by the coal-formation or red sandstones, blotched with small patches 

 represented as occupied by one or other of these rocks, and which 

 include intrusives of every age from the Laurentian to the Trias. 



As regards the earlier Palaeozoic rocks, the two maps differ widely, 

 the Cambrian system being made, in that of Dr. Robb, to include 

 large portions of Charlotte and Kings Counties, which in that of Dr. 

 Gesner are represented as granitic or trappean, while the great band 

 of slates and quartzites north of the York County granites, and includ- 



