314 THE MAllQUETTE IKON-BEAEIifG DISTEICT. 



DISTRIBUTION, EXPOSURES, AND TOPOGRAPHY. 



Beginning at the north and west (Atlas Sheet IV), the first exposures 

 of this rock occur between the Ajibik (juartzite and the Xegaunee formation 

 north of the Michigaiume mine. From this place the formation stretches in 

 a general easterly course for a number of miles to sec. 33, T. 48 N., R. 26 W., 

 east of Teal Lake. East of sec. 33 is a. broad area of the formation, 

 extending to sec. 5, T. 47 N., R. 25 W., the slate being the topmost member 

 of the great westward-plunging syncline. On the south side of this area 

 the formation divides into two parts. The eastern arm swings to the south 

 and southwest, past the northwest arm of Goose Lake; thence west, south- 

 west, and south to sec. 29, T. 47 N., R. 2G W. ; thence south about the west 

 end of the anticline made bv the Ajibik (juartzite; and thence east to the 

 sand plain in sec. 23, T. 47 N., R. 26 W. The western area extends west 

 through sec. 3, and in sees. 4, 5, 8, and 9, T. 47 N., R. 26 W., constitutes a 

 broad dome with minor folds. From sec. 9 an arm extends southwest, 

 terminating as a plunging anticlinal dome in sec. 20. Farther southwest, in 

 sees. 19 and 30, is another area, which was probably originally continuous 

 with the area terminating in sec. 20. 



The slate, being a soft formation, is not well exposed tlu-oughout, but 

 at various localities where it is a mica-slate or a coarse graywacke the 

 ledges are numerous. Upon the whole, however, the formation occupies 

 the lowlands lietween the more resistant Ajibik quartzite and Negaunee 

 formation. North of the Michigamme mine there are a number of expos- 

 ures; from this place to Teal Lake there are few. However, south of the 

 west arm of Teal Lake are the Siamo Hills, which give the name to the for- 

 mation and upon which outcrops are abundant. The iron formation is here 

 soft, and occu^jies even lower ground than the slate. East of Teal Lake there 

 are many exposures of the formation south of the quartzite range. The 

 exposures become more and more sjiarse in passing- east, but they are still 

 frequent to sec. 35, T. 48 N., R. 26 W. From this place southward there are 

 no more natural outcrops until the Carj) River is reached, south of which 

 a number of exposures occur, but with long intervals between them. As 

 the belt swings to the west, following the western arm, the outcrops in 



