354 C. W. HALL — KEEWATIN OF EASTEllN AND CENTKAL MINNESOTA 



places markedly fibrous with a decidedly hornblendic habit. Some 

 narrow and unobtrusive veins appear, carrying pyritous contents. The 

 most conspicuous veins, however, are the white quartz. The veins vary 

 from a foot or two in thickness to paper thinness, are quite irregular 

 in direction, locally are considerably contorted, as a rule free from 

 pyritous or other metallic accessories, and very frequently assume a len- 

 ticular aspect, when are found quite liberal proportions of coarsely crys- 

 talline feldspathic content. 



The strike of this group of rocks shows some variation. Along the 

 road between sections 19 and 30 the strike of the foliation is north 80 

 degrees east, with a dip of the laminae partly south and })artly north. 

 Passing south of the road 200 paces, and the strike is north 70 degrees 

 east and the di[) 80 degrees north ; 200 paces north of the road the strike 

 appeared to be north b5 degrees east and the dip 75 degrees north. The 

 rock at this i)()int is more coarsely crystalline than elsewhere. An abun- 

 dance of garnets is present, strongly suggestive of contact alteration. 

 The rather small crystals are of the ordinary variety. 



Farther south, in section 30, township 45, range 20. the rock is more 

 finely crystalline than to the north, and exhibits some variety of texture 

 and color. Instead of the dark green, so dark as to appear black to the 

 eye, the rock has a pea-green color in many of its bands. The direction 

 is nearly east and west. This determines the direction of the ridges 

 which stretch across these sections. ^J^he hornblendic rock is locally^o 

 fibrous that slender pieces G to 7 feet long are seen lying about. The 

 strike over all these, long parallel hillocks is nearly the same, and the 

 di)) varies from vertical to north 40 degrees. 



Through section 25, extending nearly north and south, is a creek val- 

 ley. At present it is little more than a long narrow marsh, yet its walls, 

 its width, and depth suggest at an earlier date a much larger stream. It 

 may be an old channel of glacial origin. The seeping water at present 

 moves northward, but at the time of its cutting very likely a large stream 

 flowed toward the south. Its nearly vertical walls, from 20 feet to 40 

 feet high, show interesting structure lines, joints, folia, possible bedding 

 planes, and other phenomena. The valley exhibits all of the characters 

 of an abandoned valley of erosion. 



The most interesting lithologic feature of this locality is the i)resence 

 of several exposures of limestone. This rock, approached from the north, 

 is disclosed by the fragments which lie in the bed of the stream. The 

 most northerly exposure of the rock in j)lace is in the east half of sec- 

 tion 25, township 45, range 21 west. It lies 8 to 10 feet in thickness, 

 dipping southward at about 20 degrees. The rock is rather fine grained 

 and thoroughly crystalline. Its color is a light pink with a faintl v trans- 



