718 THE GEOLOGY OP MINNESOTA. 



[Granite. Greenwacke. 



clear and glassy, in isolated grains of considerable size, generally angular, and quartz 

 in a granitic grouping of several grains interlocking. Then are to be noted ragged, 

 much twinned, old /r/</.vy^/-x. evidently of the same kind as seen in the granite and 

 in the porphyry a little further south. One section. 



Age. Archean (Upper Keewatin ). N. H. w. 



No. 140"). GRANITK. 



Point on the south side of Kekequabic lake, N. W. V4 S. W. 14 see. 31, T. <iT> C, \V, 

 Kef. Annual Report, xvi. pages KfJ, lL'4. 



Meg. A very fine-grained, light pinkish-gray rock which seems to be a phase of 

 the granite of Kekequabic lake. Much like the light-colored dike near Ely. No 

 section. 



Age. Archean (Keewatin K u. s. G. 



No. 1406. GREENWACKE. 



From the point, N. W. y S. W. ^ sec. 31, T. 65-6, south shore of Kekequabic lake. 



Kef. Annual Report, xvi, pages 192, 124. 



* 



Meg. Greenish schist-conglomerate. Compare No. 1 <>(}(). 



Mic. This rock is almost identical with No. 1404, but with a less number of 

 large quartz grains and many more of old feldspars, and of larger hornblendes. The 

 margins of the large hornblendes are converted into a fringe of dirty yellow fibres, 

 largely of hornblende still, but apparently also in part of biotite. These marginal 

 parts have their fibres confused and bent, and appear to have been formed by friction 

 against the hornblendes. This yellowish disintegration product sometimes enters 

 along the fissures of the hornblende and appears sometimes in isolated areas in the 

 hornblendes. It is also rather widely disseminated in the rock in general, becoming 

 stained by hematite( ? ) so as to have an orange yellow color. The rock is plainly 

 pebbly, but at the same time amongst the old feldspars, which are so much decayed 

 as to be hardly discernible in some parts of the slide, there has been developed a 

 fresh growth of secondary interlocking quartz of granitic structure. This is some- 

 times in isolated areas and is sometimes within the areas of the old feldspars. In the 

 former case it might be interpreted as constituting pebbles or other debris of the 

 clastic rock, but in the latter position it must have been developed within the rock. 

 The pebbles in this rock are, so far as observed, of a fine micro-granulitic association 

 of quartz or of quartz and feldspar. One section. 



Age. Archean (Upper Keewatin). N. H. w. 



NO. 140!t. (JltEENWACKE. f PelihltJ. ) 



From the little island just west of the narrows near the north shore of Kekequabic lake. 

 Ref. Annual Report, xvi, pages 102, 105, 125 ; Annual Report, xvii, pages 'JOO, l!0fi. See. also. Annual 

 Report, xxi, pages 23-26. 



