ORIGIN AND RELATIONS OF GRENVILLE-HASTINGS SERIES. 401 



the gneissic magma of the Fundamental gneiss, into which it had sagged down, 

 gives rise to the Grenville series described above. 



Age of the Hastings Series 



Concerning the age of the Hastings series, bat little is known as yet. In the 

 extreme southeast corner of the area, however, as above mentioned, its clastic char- 

 acter is well marked, breccias and conglomerates, often greatly deformed by press- 

 ure, being present, as well as certain fine grained and comparatively unaltered lime- 

 stones, in which a very careful search maybe rewarded by the discovery of fossils. 

 Like the Grenville series to the east and west, it is unconforinably overlain by and 

 disappears beneath the flat lying Cambro-Silurian rocks of the plains, which limit 

 the protaxis on the south, and is separated from these latter by an immense erosion 

 interval. 



Tentative Conclusions 



Further investigations in the area as well as in that adjoining it on the east, which 

 is now being mapped by Dr R. W. Ells, will, however, it is hoped, before long 

 throw additional light on the age of this veiy 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 relations given above 

 is correct, the Laurentian system of Logan will resolve itself into an enormous area 

 of Fundamental gneiss, which is essentially of igneous origin, and which there is 

 every reason to believe forms part of the original crust of our planet, perhaps many 

 times remelted and certainly in many places penetrated by later enormous intru- 

 sions of igneous rocks, into which Fundamental gneiss when in a softened condition 

 there have sagged down in certain places portions of an overlying series consisting 

 chiefly of limestones of unknown age. 



In connection with the foregoing, there was read the following : 



NOTE ON "ORIGIN AND RELATIONS OF THE GRENVILLE-HASTINGS SERIES OF 



THE CANADIAN LAURENTIAN" 



BY K. W. ELLS 



In connection with the statements advanced in the preceding paper by Messrs 

 Adams and Barlow, it is but right that the conclusions reached from the study of 

 the similar rocks in their eastern and northern extension should be stated. 



The investigations in this quarter have now been carried on for six years, and 

 have covered a very large area to the north of the Ottawa, in which is included 

 the typical Grenville series of Sir W. E. L. Logan, and extended far up the Gati- 

 neau river, while to the westward the work has been carried on till the vicinity of 

 the area described in the accompanying paper has been reached. It may be said, 

 therefore, that the detailed examination of the rocks which make up the Grenville 

 and Hastings series has extended over an area about 250 miles in length by 75 miles 

 in breadth. 



The more recent and probably sedimentary origin of the limestones and asso- 

 ciated gneisses of the Grenville series as distinct from the great mass of the under- 



