CURRENT PRE-CAMBRIAN LITERA TURE 44 1 



gneisses are present in this area. Mr. Barlow cites no evidence tO' 

 show that softening of the granites and gneisses has anywhere occurred 

 immediately subjacent to the sediments, resulting in the invasion of 

 the sediments by the granites and gneisses ; that any eruptive relations 

 now found are not those of the normal intrusion of granite magmas 

 into both the original, basement and the overlying sediments. 



Ells 1 gives an historical account of the geological nomenclature of 

 that part of Canada which extends roughly from the Red River of 

 Manitoba eastward over Canada. The present usage with reference to 

 pre-Cambrian rocks may only be mentioned. 



In Nova Scotia the- term pre-Cambrian has been given to certain 

 old crystalline rocks which were found to underlie the recognized Cam- 

 brian of the coast or of the gold-series, and which were found to 

 strongly resemble certain portions of the Laurentian or Huronian of 

 the western provinces. 



In New Brunswick there has been little change in the nomenclature 

 proposed by Matthew, Bailey, and Hunt. The lowest division of the 

 crystalline rocks was held to conform most closely in its details to the 

 Laurentian of the Canadian Survey. This series was divided into a 

 lower and an upper division, the former of which was regarded as the 

 equivalent of the Lower or Fundamental Gneiss of the Ottawa district,, 

 while the latter was supposed to represent the limestone and gneiss of 

 the Grenville series of Quebec. The Huronian was made to include three 

 divisions, viz., the Colebrook, the Kingston, and the Coastal. Since 

 this time Matthew has introduced the term Etcheminian to designate 

 certain fossiliferous sediments found beneath the middle Cambrian,, 

 probably belonging to the more recent portion of the pre-Cambrian 

 formations. 



In Ontario and Quebec the oldest granite-gneiss may be styled 

 Laurentian. The second member of the scale, or the Huronian, may- 

 be made to include, as its lowest portion, that part of the crystalline 

 series, once regarded also as part of the Laurentian system, and known 

 locally under the names Grenville and Hastings series, the relations of 

 which to the Laurentian proper are apparently of two kinds, either a 

 stratigraphical sequence, with a probable unconformity, owing to their 

 difference in origin ; or a contact of intrusion ; and that portions of 

 the Grenville and Hastings series correspond, while the latter is carried 



1 Canadian Geological Nomenclature, by R. W. Ells : Trans. Royal Soc. of 

 Canada, 2d series, Vol. V, sec. IV, 1899, pp. 3-38. 



