588 



WILLET G. MILLER AND CYRIL W. KNIGHT 



that lie below one of the greatest known unconformities, that 

 between the Timiskamian and Animikean of our classification, as 

 well as to those above it. Again, rocks have been classed as 

 Upper Huronian, or Animikie, which have not been proved to be 



Keweenawan 



Unconformity 

 Animikean 



Great unconformity 



(Algoman granite and gneiss) 

 Igneous contact 



Timiskamian 



Great unconformity 



TABLE I 

 Pre-Cambrian 



Under this heading the authors place not 

 only the rocks that have heretofore 

 been called Animikie, but the so-called 

 Huronian rocks of the "classic" Lake 

 Huron area, and the Cobalt and Ram- 

 say Lake series. Minor unconformities 

 occur within the Animikean. 



Laurentian of some authors, and the Lor- 

 rain granite of Cobalt, and the Killarney 

 granite of Lake Huron, etc. 



In this group the authors place sedimen- 

 tary rocks of various localities, that 

 heretofore have been called Huronian, 

 and the Sudbury series of Coleman. 



There is no evidence that this unconform- 

 ity is of lesser magnitude than that 

 beneath the Animikean. 



(Laurentian granite and gneiss) 

 Igneous contact 



Grenville 

 {Sedimentary) 

 Keewatin 

 (Igneous) 



LOGANIAN 



The authors have found the Keewatin to 

 occur in considerable volume in south- 

 eastern Ontario and have determined 

 the relations of the Grenville to it. 



different in age from certain so-called Lower and Middle Huronian. 

 It may be added that for many years the Keewatin also was called 

 Lower Huronian. Even at the present time when making use of 

 the name Huronian, in order to secure clearness, it is necessary 

 to say in what sense the name is employed, whether in that of the 

 United States Geological Survey or in that of Coleman or Lawson 



