SOUDAN FOKMATION. 203 



schist contains a few small lenses and stringers of jasper and chert, which 

 extend along the planes of schistosity and clearly have been introduced into 

 the rock since it was rendered schistose. The surface exposures of the schist 

 east of the jasper are disconnected, but it is reported by the mine captain 

 who had charge of the North Lee pit, now filled with water, that under- 

 ground the jasper is ciit off by the greenstone which surrounds it to the 

 east. The jasper exposed, especially to the west of the North Lee pit, is 

 very badly fractured, and ore has been introduced since the fracturing, 

 healing the cracks and filling the cavities. Moreover, along the edge of 

 the pit from which the ore body has been removed there can be seen 

 remnants of banded lean ore. These bands are continuous with the bands 

 in the jasper lying next to and continuous with the ore. There is here a 

 gradation from a small mass of rich ore through a very hematitic jasper 

 into the normal jasper. The fracturing and brecciation of the jasper are 

 indicative of the extreme folding to which it has been subjected. This 

 is further shown by the presence of a fairly extensive breccia along the 

 contact between the southern wall of green schist and the jasper. Along 

 this contact has occurred brecciation of the chert and jasper, and angular 

 to subangular fragments of these form the pebbles for the most part, with 

 the green schist occurring chiefly as the matrix. Occasionally a fragment 

 of the green schist occurs, also as a pebble, in the matrix. Since the 

 formation of the breccia, iron has been infiltrated into it, and this has 

 tended in many places to cement it together, so that at some localities it 

 contains very nearly enough hematite to be considered a lean ore. In 

 places along this contact a great deal of white quartz has been infiltrated, 

 showing that water has been very active here. 



In the SW. i of the NW. i of sec. 3, T. 61 N., R. 15 W., there are 

 a number of exposures of jasper which show extreme plication and 

 infolding of jasper and green schist. Here also there is a band of breccia 

 consisting of fragments of jasper and chert in a green schist matrix. 

 Similar breccias have been observed also at other places throughout the 

 district. The jasper upon these exposures is for the most part that which 

 is usually called the black or hungry jasper. It is a magnetitic chert. 

 This in places shows a fine banding, probably sedimentary banding. In 

 the NE. i of the SE. ^ of sec. 1, T. 61 N., R. 15 W., there is an occurrence 

 of jasper which has been explored by means of test pits and diamond di'ill. 

 The jasper belt here has a width of from 15 to 30 feet, strikes N. 70° W., 



