442 THE PENOKEE IRON-BEAKINU SERIES. 



logical cliaractor.s with the various rock belts ot the Penokee t^iiccession. 

 It has been seen that these rocks are of two general types: first, massive 

 granites and gneissoid granites, and, second, fine grained schists, wluch 

 technically are gneisses. None of them can properly be said to have a sedi- 

 mentary strike and dip. All but the granites have a foliation. In the case 

 of the gneissoid granites this foliation is of the coarsest character, but the 

 foliation of the rocks varies from this to that so fine that it is only possible 

 to detect it in the hand specimen b>' tlie direction of readiest cleavage. In 

 these latter cases, however, in thin section the schistose structure is just as 

 distinct as in the coarser phases yi which it is so easily recognizable. 

 While, then, these rocks have no strike and dip in a proper sense, they 

 have a foliation to which the terms may be ap})lied. It has been said" that 

 more often than not this foliation is approximately east and west. How- 

 ever, it has wide variations within.narrow ranges (as will be seen l)v look- 

 ing at the detailed maps, Pis. v to xiii), and at times the foliation is almost 

 directly perpendicular tt) the strike of the rocks of the Penokee series. If 

 there are abrupt and sudden changes in the direction of strike, the varia- 

 tion in dip is still more marked, frequently within a few rods varying from 

 a dip in one direction to that in the reverse. Fui-ther, wdiile on the maps there 

 are sharp lines of separation drawn between the fine-grained gneisses and ' 

 the granites and granitoid gneisses, in the field there is at times an apparent 

 transition rather than an abrupt change (pp. 123-125). More often, along 

 the border of the schists are granitic intrusions, and these become more and 

 more numerous in passing toward the granite, until this I'ock becomes pre- 

 dominant. The great variation in the direction of foliation in the gneisses 

 is readily understood when some of the larger exposures are examined, 

 their banding being extremely contorted and consequently varying greatly 

 in dip within a single ex])osure. From the foregoing it will be seen that if 

 the rocks included within this belt have a distiiu;t succession it is an 

 extremely complicated one, and that at present we have no data which will 

 enable us to reach even an approximate notion of it. The only structural 

 fact that can be certainly stated is that some of the massive granites and 

 gneissoid granites arc intrusives of Inter ai^c than the green schists. 



When the rocks oi' the Southern ( 'oiiipK^x are examined in thin section 



