﻿Origin of the Grenville and Hastings Series. 311 



altered form. In other words, the Hastings series, when 

 invaded, disintegrated, fretted away and intensely 

 metamorphosed by and mixed up with the underlying 

 magma of the Fundamental Gneiss, constitutes what has 

 elsewhere been termed the Grenville series. The Grenville 

 series may, however, represent only a portion of the 

 Hastings series, and the work so far done in this district 

 has not been sufficient to determine the stratigraphical 

 position of this portion. 



Concerning the age of the Hastings series but little 

 is known as yet. To the south-east of the area under 

 consideration, however, its clastic character is well 

 marked, breccias and conglomerates, often greatly 

 deformed by pressure, being present as well as certain 

 fine-grained and comparatively unaltered limestones, in 

 which a very careful search may yet be rewarded by the 

 discovery of fossils. Both lithologically and strati- 

 graphically the rocks bear a striking resemblance to 

 rocks mapped as Huronian in the region to the north and 

 north-east of Lake Huron, and it seems very likely that 

 the identity of the two series may eventually be 

 established. The two areas, however, are rather widely 

 separated geographically, so that the greatest care will 

 have to be exercised in attempting such a correlation. 



Like the Grenville series, the rocks of the Hastings 

 series are uncon form ably overlain by and disappear 

 beneath the Hat-lying Cambro-Silurian rocks of the 

 plains, which limit the protaxis on the south and are 

 separated from it in time by an immense erosion interval. 

 Further investigation in this area, as well as in that 

 adjoining to the east, now being mapped by Dr. E. W. 

 Ells, will, however, it is hoped, before long throw 

 additional light on the age of this very interesting 

 and important series of rocks. If further investigation 

 proves that the relations of the several series have been 

 correctly diagnosed, and that the explanation of these 



