THE LOWER HUKONIAN. 317 



same material, and as the result of the metamorphism essentially the same 

 new minerals have been produced in them, and this production of new 

 minerals has tended to render the characters of the rock more uniform. It 

 is only here and there, where a pebble occurs, whose mineral composition 

 was not so extremely changed by the metamorphism that the conglomeratic 

 character of the rock can be distinctly recognized. In such cases these 

 pebbles seem to withstand the weathering better than does the adjacent 

 material in which have been produced, as above stated, the basic minerals 

 associated with the gabbro. This portion of the rock weathers more readily 

 than the less affected pebbles which stand out from the rest of the rock 

 and show their true pebble characters. 



THICKNESS OF OGISHKE CONGLOMERATE. 



No data have been obtained that would enable us to make an accurate 

 determination of the thickness of the conglomerate. In places it is wanting 

 or is represented by a few feet of rock at most, and from this it runs up to 

 a thickness of possibly a thousand or more feet. 



INTERESTING LOCALITIES. 



The portage between Moose and Flask lakes is a good place at which 

 to study the Ogishke conglomerate as developed south of Moose Lake. A 

 short distance east of the portage landing on Moose Lake as the hill is 

 ascended we find slates similar to those occurring along the east shore, 

 which appear to grade into a fine conglomerate and then into a coarse 

 conglomerate which crowns the brow of the hill. The rocks along this 

 gradation zone are much mashed, so that one can not be certain that the 

 change is due to actual continuous sediments differing only in coarseness. 

 The conglomerate is very coarse at this place, having bowlders up to 2J 

 feet in diameter. The fragments in the conglomerate are of many different 

 rocks — various kinds of porphyries, granites, many different varieties of 

 greenstone, jasper, an occasional slate fragment, and two fragments of 

 a conglomeratic or brecciated rock, the fragments and matrix in these two 

 pieces being very much alike, and apparently both derived from green- 

 stone. Still farther along the trail the same conglomerate occurs at 

 numerous places, and here and there are exposures of much contorted 

 slates associated with the conglomerates. Some dikes of granite- porphyry 

 with large quartz phenocrysts may also be observed cutting the older 



