902 THE GEOLOGY OF MINNESOTA. 



[Conglomerate. Granite . 



No. 630G. CONGLOMERATE. ( Metamorplwsed. ) 



N. W. 14 S. E. % sec. 31, T. 65-6, south of Kekequabic lake. 

 Ref. Annual Report, xx, pages 79, 107. 



Meg. Rather fine, conglomeratic, with much feldspar, making a speckled-gray 

 rock, with no evidence of sedimentary bedding in the field. 



Mic. The original quartz is entirely reformed, and no trace of the clastic shapes 

 remains. The forms of the feldspars are preserved, especially of the larger ones, but 

 frequently the finer feldspars are much changed by regeneration, having a narrow 

 rim of new growth. The larger feldspars are zoned, but not by new increments. The 

 impurities are, for the greater part, arranged in belts that run parallel with the 

 margin. The marginal or first belt is most conspicuous, and gives outline to the 

 grain. Occasionally a second belt is formed parallel with the first, but usually the 

 whole of the interior is irregularly crowded, though less thickly than in the margin, 

 with the same fine inclusions as seen in the marginal belts. These consist of musco- 

 vite, epidote, chlorite and apparently of zoisite. There are in the matrix of these feld- 

 spars abundant epidote, some calcite, hornblende, sphene, chlorite as well as quartz. 

 One section. 



Age. Upper Keewatin. N. H. w. 



No. 638G. CONGLOMERATE. (Crystalline.) 



S. E. % S. W. y sec. 7, T. 64-6, south of Kekequabic lake. 

 Ref. Annual Report, xx, pages 80, 107. 



Meg. A gray, plainly fragmental rock, holding pebbles. Some red granitic 

 pebbles seem to have been fused or plastic, and are distorted and diffused more or 

 less amongst the surrounding matrix; but the dark pebbles, whether coarse or fine 

 grained, maintain their round outlines. 



Mic. This rock has very noticeably the muscovadyte structure, i. e., the min- 

 erals have globular shapes, and when large they act poikilitically toward each other. 

 Hornblende and hypersthene are the coarsest and most conspicuous of these poikilitic 

 minerals, but there is a feldspar (or cordierite?) which also plays the same role 

 toward the finer grains. Quartz in small quantity mingles in the interlocking mosaic. 

 One section. 



Age. Keewatin. 



Remark. Gabbro exists on the south half of the southeast quarter of the same 

 section (No. 639G) on the east shore of a small lake, but is rather fine grained. 



N. H. w. 

 No. 686G. GRANITE. ( Hornblendic. ) 



Saganaga lake, S. W. y N. E. % sec. 22, T. 66-5 W. 



Ref. Annual Report, xx, pages 88, 109 ; Annual Report, xxi, page 43. 



