20 THE JOURNAL OF GEOLOGY. 



(Laurentian) ; a felsite-petrosilex group (Lower Huronian or 

 Coldbrook); and a schistose, chloritic micaceous group (Upper 

 Huronian or Coastal).^ The results of all their work on the 

 rocks of southern New Brunswick is summarized by Bailey, 

 Matthew and Ells, with a general geological map in three 

 sheets.^ 



That portion of the Province of Quebec lying south and 

 east of the St. Lawrence is called the Eastern Townships. We 

 have already considered that portion of it composing the Gaspe 

 peninsula. The portion lying west of Maine and north of New 

 Hampshire and Vermont was supposed by Logan to be wholly 

 occupied by rocks of the Quebec Group. In 1879, Dr. Selwyn 

 divided the rocks of this zone into three groups, which he 

 defined as lower Silurian; volcanic (probably lower Cambrian); 

 and crystalline (probably Huronian). The lower of these divis- 

 ions forms an anticlinal axis extending from Lake Memphrema- 

 gog to LTslet County, 150 miles. It contains a great variety 

 of altered sedimentary beds, associated with " diorites, doler- 

 ites, serpentines, amygdaloids, and volcanic agglomerates," 

 regarded by Hunt as altered sedimentaries. The second divis- 

 ion, said to be intimately related to the last, is largely composed 



" especially on the southeastern side of the axis, of altered volcanic products 

 both intrusive and interstratified, the latter being clearly of contemporaneous 

 origin with the associated sandstones and slates." 



These rocks are designated as 



" dioritic, epidotic, and serpentinous breccias and agglomerates ; diorites, 

 dolerites and amygdaloids holding copper ore ; serpentines, felsites and 

 some fine grained granitic and gneissic rocks." 



They are especially developed along the contact of the last- 

 mentioned group, of which they "may be merely the upward 

 extension." 3 In a later paper on the Quebec Group, Dr. Sel- 

 wyn considers these volcanic rocks thoroughly from the English 

 point of view. He says : 



' lb., DD. p. 2. 



==Ib., 1878-79, D. p. 26. 



3Jb., 1877-78, A. pp. 5-9. 



