834 THE GEOLOGY OP MINNESOTA. 



[Quartzy te. Mica schist. Qabbro . 



No. 2059. QUARTZYTE. 



Same place as No. 2057. 



Ref. Annual Report, xxiv, page 28. 



Meg. Another phase of the fragmental rock. 



Mic. As in the other contact rocks at this place the original quartz is entirely 

 re-wrought, so that no clastic structure remains. There are a few feldspars, but 

 dimmed by inclusions presumed to be due to weathering, and a subordinate amount 

 of biotite. One section. 



Age. Animkie. 



Eemark. It is worthy of remark that the clastic structure of the quartz has 

 given place universally, as in the Pewabic quartzyte, to an interlocking granular 

 plexus, in which are a few grains of triclinic feldspar. Instead of pyroxenic minerals 

 the contact here has produced mica. Whether at points near the gabbro the same or 

 similar ferromagnesian minerals would make their appearance at this place, there 

 is no means of stating, as the immediate contact was not seen. N. H. w. 



No. 2060. QUARTZYTE. ( Gneissic. ) 



Same place. 



Ref. Annual Report, xxiv, page 29. 



Meg. A coarser rock, presenting a gneissoid aspect. 



Mic. The rock is essentially the same as the foregoing, but it exhibits a greater 

 variation in size amongst the quartz grains. The same is true also of the feldsparx. 

 Thus the rock approaches a perfect granitic structure. In this slide the biutitf is 

 associated intimately with pennine. One section. 



Aye. Animikie. N. H. w. 



No. 2061. MICA SCHIST. 



At a point a little further east (southwest end of Loon lake). 

 Ref. Annual'Report, xxiv, page 29. 



Mey. A part of the less siliceous portion of the Animikie, but very finegrained; 

 " black rock." 



Mic, The rock is in all respects like the foregoing except being finer. The 

 biotite micas are older than the interlocking quartz, but the muscoviti- is later. One 

 section. 



Age. Animikie. 



Eemark. It is evident that these clastic beds belong to the upper part of the 

 Animikie. N . H . w. 



No. 2064. GABBRO (with olivine). 



The rock of the great sill at mount Reunion, forming the summit, Rove lake. 

 Ref. Annual Report, xxiv, page 30. 



Mey. Medium grained, from one of the fallen blocks. 



