664 THE GEOLOGY OF MINNESOTA. 



[Crrri'ii srliist. Tuff. Granite. 



No. 1098. GREEN SCHIST. 



N. W. 14 sec. 31, T. 65-6, Kekequabic lake. 



Ref. Annual Report, xv, pages '567, 368, 398 ; Annual Report, xvii, pages 107, 206. 



Meg. "Conglomeratic, chloritic schist; phase of No. 1060." 

 Mir. There are flue fragments of ar/iixifite and a few of f<'/</x/>(/r distributed in 

 a very line pulpy matrix whose constituents cannot easily be differentiated, but 

 which is partly actinolitic, but largely consists of a dirty, yellowish, tine mesh, which 

 is almost wholly dark between the nicols, but which is probably in part chloritic and 

 partly actinolitic, and at first zirkelyte. One section. 



Aye. Archean (Upper Keewatin). N. H. \v. 



No. 1099. TUFF. 



Portage trail from Kekequabic lake northward. Sec. 34, T. 6f> 7. 

 Ref. Annual Report, xv, pages 306, 398. 



Mi'ij. Hornblendic and conglomeratic, sometimes gneissic. 



Mir. The fragmental hornblendes are generally free from secondary enlarge- 

 ments, which, in the form of spicules ot.acfinolite have been disseminated throughout 

 the matrix, but in some cases these secondary attachments are still in their native 

 places. Some of the feldspars are also zoned. These lie in the usual fine fragmental 

 matrix. In one section the elements are all much finer, and much calcite has been 

 generated. Two sections. 



Age. Archean (Upper Keewatin). N. H. \v. 



No. 1100. GRANITE. 



Most westerly island in Kekequabic lake, sec. 3, T. 64-7. 

 Ref. Annual Report, xv, pages 361, 362, 398. 



Meg. Reddish syenitic rock. 



Mic. This rock is like those already mentioned (Nos. 1044 and 1045), made up 

 largely of a recomposed debris of coarse, much twinned and zoned feldspars, lying in 

 a matrix, now recrystallized, composed of secondary felhpars, qtttniz, calcite and 

 actinoUte, with scattering magnetite powder. One section. 



Age. Archean (Keewatin). 



lif-mark. This rock is a special condition of the prevailing tuffs of the region, 

 due to greater effect of a regional metamorphism probably earlier than the advent 

 of the gabbro. It differs from the tuffs in having a coarser interlocked matrix of 

 quartz and feldspar, and in the manner in which the old feldspars are interlocked 

 about their margins with the surrounding matrix by secondary enlargements. 



N. H. w. 

 No. 1101. GRANITE. 



From the north side of the same island, Kekequabic lake. 

 Ref. Annual Report, xv, pages 361, 362, 308. 



