The IRON BEARIN(} MEMHEK. 277 



eastern ])itcli of the dike in f|Uosti(>n, mav run oast far ('nouyli to l)o found 

 uj)on tile adjoining |)ro]H'rty. A well tletined dike thus located would 

 warrant i)uttiiio- down a shaft throiigh a considerable thickness of ferruai- 

 nous chert, in order to strike an ore body which luiyht he lielow. l)Ut in 

 general a property ouiiht to l)e well explored hv test pits which (hi not 

 go below the surface of the rock, unless there is a <i;reat thickness of drift 

 above it. If heavy drift overlies the rock surface, it is best to make the 

 most of *a shaft once down to rock in exploring- the area adjacent to it, either 

 by drifts in the rock, or by means of th<' diamond drill. As a matter of 

 course such explorations are much more expensive than in the cases in 

 which the country rock is near the surface. Under no cuTumstances should 

 money be expended in exploration south of the fragMuental quartzite, oi- 

 farther "north than 400 or 500, or at ihe outside 600 feet north of it; and 

 woik done such distances north of the quartzite should only foUow failure to 

 find an ore deposit resting upon tlie fragmental quartzite. 



,The large number of the working shafts upon the Penokee-Gogebic 

 range rest ujxiu the foot-wall ([uartzite, dipping north at its angle. When 

 a shaft thus sunk comes in contact with the underlying dike of the ore 

 body, it is useless to go farther for the purp(»se of working the deposits 

 under ccmsideration, unless the pitching ore l)od\' is to lie reached at lower 

 levels 1>\' means of h)ng drifts. It is <if coui'se the i)art of wisdom to carry a 

 shaft through the dike a short distance into the underlyino- rock in order to 

 be sure that it has struck a l»as;il dike. It might l)e the case that, if the shaft 

 were carried deep enough, it w<iidd strike another deposit of ore resting 

 ujion another dike, and this wnuld l)e especialU' probalilc if an ore deposit 

 has alreadA' been (hnelopeil within a shcii-t distance to the west.' It is a 

 good maxim among" mining men in ex]ilMriiiL;- \\(irk to follow a deposit 

 already found rather than look for <ithers at greater depth. After the 

 deposit thus found has been develope<l it is advisable to look ahead for 



'Since the above was writteu. shafts imt ihiwii thrmijjh tin- liist liasemciit dike havi-, in soiuu 

 cases, struck the on- ileposit <il' an uuileilv lug ilikc al'tiT pa.ssiiip, thrniiftli .i coii.sich'iahlc thickness of 

 ferruginous chert. The most notable instance of this is the di.scoverv of the Ashland ore body by the 

 Norrie mine, which lies to the east. Here, after the base of tlie original Norrie deposit was reached, 

 200 or 300 feet of chert was passed before the eastward-pitching Ashland body was found. 



