THE IRON BEARING MEMBER. 2(59 



number of the larger deposits are found in the central half of this area. 

 Also, most of the known deposits lie at the base, or very near the base of 

 the Iron-bearing member; that is, they rest upon or close to the coarse 

 grained fragmental quartzite, which constitutes the uppermost horizon of 

 the Quartz-slate. The number of shipping mines is about twenty, and in 

 them all the deposits lie upon this fragmental quartzite except the follow- 

 ing, which are given in order from west to east: (1) The Tyler's fork mine, 

 in the E. .V of Sec. 33, T. 45 N., R. 1 W., Wisconsin. (2) The Iron Belt 

 mine, NE. \ Sec. 11, T. 45 N , R. 1 E., Wisconsin. (3) The Montreal 

 mine, a short distanjse east of the west quarter post of Sec. 33, T. 46 N., R. 

 2 E., Wisconshi. This mine has shipped quite a large quantity of ore from 

 a deposit which was at first an open pit and which has not been carried to 

 the fragmental quartzite. This deposit at the present time is not the more 

 important one upon the property, the main ore body resting iipon the frag- 

 mental quartzite. (4) The Mount Hope mine, NW. ^ Sec. 24, T. 47 N., R. 

 47 W., ]\Iichigau. This mine has a large deposit of ore, situated some 300 

 feet north across the formation from the underlying quartzite. Tliis body 

 is one of the two large deposits which have been developed above the base 

 of the foi-mation. South of it, and a short distance to the east, is another 

 deposit of ore which rests on the quartzite. (5) The Bonney mine, NE. ^ 

 Sec. 24, T. 47 N., R. 47 W., Michigan. (6) The Colby mine, NE. i Sec. 

 16, T. 47 N., R. 46 W., Michigan. This is the second of the two large 

 known deposits which do not rest upon the Quartz-slate formation. Directly 

 south of this body is, however, a still larger one which lies upon the quartz- 

 ite, and the deeper workings of the mines show that these two deposits 

 approach very close to each other, if they are not actually connected. (7) 

 East of Sunday lake, in T. 47 N., R. 45 W., several mines— including the 

 Brotherton and Sunday lake — which are a considerable distance north of the 

 fragmental (juartzites. These mines have peculiarities which distinguish 

 them from other working deposits to the west. The ore bodies lie in isolated 

 and irregular patches, which are generally not more than 10 to 30 feet hi 

 thickness. These lenses are separated by barren rock which is at times as 

 much as a hundred feet thick. With the exception of the Mount Hope and 

 Colby none of the above mentioned mines are of large size. 



