Laurentian and lluronian of Lake Huron. 



237 



portions of the line of junction between Lakes Temiscaming 

 and Panache, the latter locality being over one hundred miles 

 east of Thessalon, near which Messrs. Pumpelly and Yan Hise 

 observed the contact. The endeavor to correlate two series of 

 facts concerning rocks so far separated geographically after a 

 brief and hurried visit and over a limited area has only led to 

 more confusion and misunderstanding. Their description of 

 the line of junction between the granite and crystalline schists 

 is a feature very frequently observed in the Laurentian (or 

 basement complex). These schists, however, do not in the 

 least resemble the micaceous schists and quartzites described by 

 me as Huronian in contact with the Laurentian gneiss, for those 

 described by Pumpelly and Van Hise show no clastic structure 

 whatever and seem always to belong to the basement complex 

 (Laurentian) with which they are associated, while the frag- 

 mental origin of those described by me may readily be seen in the 

 field or in thin slice under the microscope. Beautiful examples 

 of the mode of occurrence of the Laurentian schists may be 

 seen at the Murray Mine,on the main line of the Canadian Pacific 



Fig. 1. 



Railway, three miles and a half northwest of Sudbury. Here 

 the hornblende schists or amphibolites are seen embedded in a 

 light colored gneissic granite, the pseudo-conglomeratic appear- 

 ance thus produced being sometimes very marked. (See Fig. 1). 

 In other cases the hornblende schists occur in lenticular patches 

 lying parallel to one another. (See Fig. 2.) Prof. G. H. Williams 

 (see Eeport Geological Survey of Canada, Part F, 1891, p. 73) 

 classes these amphibolites among the undoubted eruptives and 

 thus describes them: "A fine grained, very dark green or 

 nearly black foliated rock containing a much coarser felspathic 

 or granitic vein. This is a closely interwoven aggregate of 



