176 THE CRYSTAL FALLS IRON-BEARING DISTRICT. 



alxiur 12 miles to the north uud east. By means of this line of magnetic 

 attraction, with the assistance atforded by occasional outcrops of Lower 

 Hurouian, Hemlock volcanics, the 2)0ssible continuation of the iron-bearing- 

 l)elt was approximately located. 



I shall take up the four localities mentioned in which au iron-bearing 

 formation has been found, and discuss them in some detail, beginning at tlie 

 northern and least important and passing to the southern and most important 

 part of the district. 



AVESTEBN HALF OF SEO. 34, T. 4*5 N., R. 33 W. 



. In the western half of sec. 34, T. AG N., R. 33 W., there are outcrops 

 of a magnetic graywacke which grades into a rock that might properly be 

 called a magnetite-schist but for the fact that its partial fragmental nature is 

 still apparent. The rock contains a varying quantity of magnetite, always 

 enough to exercise great infliience over the magnetic needle. However, in 

 no case have true ore deposits been found iia it, although the vicinity has 

 been extensively test pitted. The .strike is in general north and south, with 

 a high dip to the west, thus agreeing in general character with the trend of 

 the Hemlock volcanics. The highest outcrop of the volcanics is a schistose 

 amygdaloid. After an interval of no exposure of about 30 feet, graywacke 

 appears, and this grades up into the magnetitic beds. 



SBC. 20, T. 45 N., R. 33 AV. 



To the south, in sec. 20, T. 45 N., R. 33 W., are outcrops of ferruginous 

 chert, which in places contains "bands and sliots" of ore, the thicker bands 

 being an inch and a half across. These outcrops haA^e tempted prospectors 

 to do considerable exploring by means of both test pits and diamond-drill 

 holes. . The results have been negative. The general map, PI. Ill, shows 

 tliat the Upper Huronian at this place indents the Lower Hurouian series, 

 indicating, as has already been said, the presence of a westward-pitching- 

 syncline. The })reseuce of this S3aicline is further shown by the strike 

 obtained on the outcrops of chert found at this locality. For the most 

 part, a nearly north-south strike prevails. The greater part of the northern 

 ledges give an east- west strike, Avith a variation of but a few degrees to the 

 north of east. The southernmost outcrops show a strike which A^aries from 

 N. 27° E. to N. 34° AV. Tlie di]) is in all cases high, ranging from 80° to 



