PETROGRAPHIC GEOLOGY AND DESCRIPTIONS. 671 



Schist. Granite. Amphibolyte.] 



No. 1128. GREEN SCHIST. (Regenerated.) 



East shore of White Iron lake, N. W. J^ S. E. ) sec. 6, T. 62-11. Cut by intrusive granite. 

 Ref. Annual Report, xv, pages 331, 399 ; Annual Report, xvii, pages 198, 208. 



Me;/. Coarse-grained, crystalline, fresh rock, of dark color. 



Mic. The rock is wholly crystalline, in a secondary sense, appearing like a 

 massive rock, and furnishes a fine instance of the effect of metamorphism on the 

 green schists when carried to the extreme. It consists of honihli-m/e, biofite, mirro- 

 rline and a triclinic finely twinned feldspar which is probably oligoclase, and the 

 same yellow mineral as mentioned in No. 1123, i. e., epidote. Scattered throughout 

 the slide, and sometimes clustered, are also numerous globular grains of some 

 pyroxene, perhaps (liu/ixi</c. These minerals, excepting the epidote and pyroxene, 

 are interlocked in a truly massive or granitic manner. The diopside(?) is more 

 isolated, yet is sometimes developed into larger crystals. The fresh feldspars are 

 so glassy that they appear like quartz, but so far as tested they all give a biaxial 

 figure in convergent light. The biotite and hornblende are also conspicuously 

 ingrown in a micropegmatitic manner, and in other places the hornblende embraces 

 the biotite poikilitically. One section. 



Age. Archean (Keewatin recrystallized). 



Remark. It seems impossible to give a current name to this rock. It perhaps 

 could be called amphibolyte, but is too nearly a massive rock, and it has too much of 

 other minerals for that. Still, it has the same origin as many amphibolytes. It 

 might be designated a biotite-hornblende-pyroxene-plagioclase gneiss, but such 

 would hardly be a name. It is rather a description; and, further, the rock is not 

 distinctly gneissic. Perhaps the term tonalyte is appropriate, or mica-dioryte. 



N. H. w. 

 No. 1129. GRANITE. 



Same place as No. 1128, and cutting No. 1128. 



AV/'. Annual Report, xv, pages .331, 399 ; Annual Report, xvii, pages 198, 208. 



Meg. Granitic. 



Mir. Quartz, niicroc/ine, oligoclase, hornblende make the bulk of this rock, but 

 there are scattering grains of sphene, the last being included in the hornblendes 

 and in the feldspars. Many of the large feldspars are much altered at their centres 

 with interpositions of Muscovite and of kaolin( ?) and some are wholly changed. In 

 others there is a micro-intergrowth of another feldspar in the manner of mirro- 

 One section. 



Aye. Archean granite. N T . IT. w. 



No. 1132. AMPHIBOLYTE. 



South of the meander line between sees. 6 and 7, T. 62-11, White Iron lake. 

 Ref. Annual Report, xv, pages i31, 399 ; Annual Report, xvii, pages 198, 208. 



