i s I A. < . | v\\ x ».\ — RELATIONS OF THE AK< II KAN OF I AN AHA. 



tinuous. tunning a groat anastomosing mesh-work, the general strike being 

 always concave to the Lauren tiaa areas which they encircle. 



Sometimes, however, where denudation has exposed their deeper portions 

 along anticlinal or synclinal ares, as in parts of the Lake of the Woods and 

 Rainy lake regions, and better in Hunter's island, the formations in contact 

 with the Lanrcntian granite-gneiss are found to be excessively shattered, and 

 countless numbers of fragments are strewn throughout the mass of the ir- 

 ruptive rocks. The country is well bared, and what i.- stated is clearly visi- 

 ble on well-exposed continuous rock surface - These included detached 

 fragments of the formation- overlying the granite-gneiss range in size from 

 piece- a few inches across to immense masse.-. Their longest diameters are. 

 as would be expected, in the plane of Bchistosity. Where the enclosing rock 

 is gneissic, the inclusions have usually a constant orientation parallel to the 

 foliation of the gneiss, which also coincide-, a- a ride, with the nearest edge 

 of the Ink through which it breaks, where not too remote from the edge. 

 Other inclusions in the Lauren tian have beeu observed whose derivation 

 from the Ontarian rocks cannot he established. Suggestions as to their 

 origin have been thrown out by the writer in his report on the Rainy lake 

 on. 



Along the edges of the belts of the Ontarian rocks, there may frequently 

 he observed, running out from the main belt and in continuous strike with 

 it. tou-ue- of Bchisl which taper more or less gradually and eventually end 

 in point.-. These also are seen to be immersed and congealed in the granite- 

 gneiss; and many of the larger detached inclusions are doubtless portions 

 of such tongues which have In-eii separated from the main belt by the low- 

 ering of the plane of surface truncation by denudation, rather than by actual 

 detachmenl at the time of disturbance. This would in a large measure 

 amount for the fact that the common orientation of the larg< r fragments, 

 ami their parallelism with the edge of the belt, holds tor the dip as well as 

 tin- strike. 



Numerous long, attenuated, parallel tongues are also formed at the edges 

 of the schist belts by the injection along the planes of schistosity of portions 

 of the granite-gneiss magma, forming an evenly ribboned alternation which 

 simulates bedding. It- formation by injection is, however, sufficiently 

 apparent. Similar ribboned alternations are described ami figured by Bar- 

 rois a- occurring at the edge of the Cambrian schists of Brittany, when 

 pierced by irruptive granites. The detached inclusions are, also, not in- 

 frequently ribboned, parallel to tin schist planes, with apophyses from the 

 main area ot' the enclosing granite-gneiss. 



If. at the base of the Ontarian system, we had bedded rocks whicl 



metamorphLsm u r av<- rise to crystalline limestones, quartzites, etc.. we would 



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