j6 NEW YORK STATE MUSEUM 



thinned somewhat, and has a very flat top, while the western 

 shoulder has narrowed. It is very near the point where the Joker 

 shaft first grounded in the ore. In No. 18 the upper western bulge 

 has shrunk still more and the eastern lower shoulder has almost 

 disappeared. Deeper mining has shown the true relations lower 

 down on the limbs. We find them pinched together, so as to 

 entirely circumscribe the horse of rock. In No. 18 also the 

 sections first intersect the Miller pit as a small end of what soon 

 becomes a large ore body. This can best be followed up by itself. 

 In No. 17 the limbs have parted again, so far as yet indicated 

 and the horse of rock has widened. The upper left-hand bulge 

 has drawn in a little more. In No. 16 there is a bulge in the 

 western limb, low down, but no very marked change in the other 

 parts. In No. 18 we first encounter the property line and as 

 developments have not been extensively made on the east side 

 the data are not yet available. It is not an unreasonable expec- 

 tation that the bulge in the lower right-hand limb of the earlier 

 sections should manifest itself in depth to some extent in the as 

 yet undeveloped portions to the north. 



In No. 15 there is little change, but additional data as gained in 

 the future will be of great interest. Between 15 and 14, a very 

 remarkable change takes place. Apparently by a pinch and thrust 

 from southeast to northwest a great bulge or wrinkle was rolled up 

 on top of the anticline hitherto described, and just above its horse 

 or core of rock. The old anticline soon pinches out but the new 

 wrinkle bulges into a great second shoulder or roll, higher up than 

 the one which we have hitherto followed. The latter gradually 

 diminishes and in the end practically disappears between Nos. 1 2 

 and 1 1 . Meantime the increasing bulge of the new wrinkle makes 

 the noble ore body which was opened up originally in the TefTt 

 shaft and in the great open cut of the " 21 " pit. The central horse 

 of rock itself turns up to the vertical and, in the No. 13, even rolls 

 over beyond it. All these features appear in sections 14 through 11. 

 The upward trend or pitch of the axis of the fold now asserts itself 

 strongly, and in Nos. 10 and 9 we see it almost reach the surface. 

 Between 9 and 8 it emerges and thereafter the ore is in two separate 

 limbs which run through No. 6. Beyond this point they have not 

 been much mined in recent years, but, leaving faults out of consid- 

 eration, we should expect the ore to be terminated only by the 

 upward rise of the original outer or eastern edge of the great sheet 

 of magnetite. This edge has been nowhere reached as yet in the 

 deeper mining of the southern sections. It constitutes one of the 



