86 Revieios — Geological Survey of Canada. 



quartzose, and talcose in the central portions of the range, or that 

 in which the axis of the anticline is situated ; while the flanking 

 rocks are green, chloritic schists ; these extend from the Vermont 

 boundary to the St. Francis in the vicinitj' of Richmond, and they are 

 also recognized at various points on the eastern slope of the range. 



Volcanic and plutonic rocks, including granites, syenites, diorites, 

 dolerites, diabases, serpentines, traps, etc., evidently of different 

 ages, are met with. They occur in low-lying outcrops, or they 

 may rise into elevations, and constitute some of the most prominent 

 mountains in the province of Quebec. 



The Laurentian area in the north-west corner of the sheet 

 comprising Dr. EIls's report is described by Dr. F. D. Adams. It 

 forms a portion of the southern margin of the great northern 

 " protaxis " of the continent, and thus represents a part of an 

 extremely ancient land area, from the waste of which the clastic 

 Palaeozoic strata to the south were derived. The area hei'e described, 

 amounting only to about 400 square miles, is about equally divided 

 between the rocks of the Laurentian system and intrusions of 

 anorthosite which break through them. 



The Laurentian consists of red and gray orthoclase gneisses, 

 presenting great variations both in structure and composition, with 

 which are associated crystalline limestones, quartzites, and amphibo- 

 lites. Certain parts of the area can be recognized as belonging to 

 the " Grenville series" of Sir W. E. Logan. This consists typically 

 of an upper series of crystalline limestones, quartzites, and gneisses, 

 having the chemical composition of ordinary sediments and 

 a preponderating banded structure. There is also a lower series 

 of gneisses, in which there are no limestones, etc. The latter is 

 known as the Fundamental Gneiss, and it is this which is probably 

 represented in the region described by Dr. Adams. Breaking 

 through the gneisses are four masses of anorthosite, which are now 

 known to be intrusive. Although intruded through the Laurentian 

 at a time long preceding the Potsdam, the appearance of these 

 anorthosites antedated at least the termination of the great earth- 

 movements which affected the Laurentian in pre-Potsdam times, so 

 that they have been squeezed and foliated together with the gneisses 

 through which they cut. On the upturned edges of these deeply 

 eroded Archaean rocks, both gneiss and anorthosite, the Potsdam 

 sandstone and other Cambro-Silurian rocks repose in flat and 

 undisturbed beds. 



A voluminous Appendix by Dr. H. M. Ami, Assistant Palae- 

 ontologist, concludes Dr. EIls's report. The Appendix contains 

 preliminary lists of the organic remains occurring in the various 

 geological horizons referred to in the report. Short descriptive 

 notes on some of the fossils enhance considerably the value of these 

 lists, and testify to the experience and assiduity of their compiler. 



Mr. Robert Chalmers' report (pp. 1 m to 149 m) on the surface 

 geology of eastern New Brunswick, north-western Nova Scotia, and 

 a portion of Prince Edward Island, contains a detailed account of 

 this urea, which is described as " one of the most interesting and 



