298 THE VERMILION IRON-BEARING DISTRICT. 



the intrusive granite and continues eastward into sec. 29, T. 63 N., R. 10 

 W. The continuation of these sediments to the east is also interrupted 

 by the intrusive granite. The same series of sedimentary rocks is 

 again found east of the above-mentioned granite in sec. 20, T. 63 N., 

 R. 9 W. From here they have been traced to the northeast, where they 

 are fonnd to connect with and to form part of the same large area south 

 of Moose Lake into which the northerlj^ tongue previously mentioned 

 merged. In this portion of the district, that is, in the vicinity of Moose Lake, 

 the Lower Huronian sediments are found to extend over the greater por- 

 tion of the area surveyed. These sediments are, however, subdivided into 

 several partly disconnected areas or tongues by intervening areas underlain 

 by Archean rocks as well as by intrusive masses of acid rocks somewhat 

 younger than the sediments. Continuing our observations on the dis- 

 tribution of the Lower Huronian sediments from the area Avest of Snow- 

 bank Lake, we note first that on the south this area is disconnected from 

 an area imderlain by related rocks on the southeast side of Snowbank 

 Lake by the intervening Snowbank granite. This belt, however, extends 

 around the east side of the Snowbank Lake area and connects on the 

 northeast with the similar sediments which sweep around the northwest 

 side of the lake. Where these join, to the northeast and east of Snow- 

 bank Lake, thej underlie an area which has very nearly the same 

 width as the Vermilion district. This main mass of the sediments 

 continues on east over Ensign and Knife lakes. To the south of Knife 

 Lake the main area underlain by the sediments is interrupted by small 

 areas of Archean rocks as well as by the Cacaquabic granite, which is 

 younger than the sediments. To the east of Ogishke Muncie Lake the 

 Lower Huronian sediments are divided into two main belts by a west- 

 ward-projecting massive of Archean greenstone which lies immediately 

 south of the granite of Saganaga Lake and in juxtaposition with it. These 

 belts, a southern and a northern one, can be traced around the interrupting 

 Archean greenstone and granite of Saganaga Lake for a g-reat distance 

 beyond the Canadian border to the north of this sejDarating area. On the 

 south this sedimentary series ends just east of Grobbemichigamma Lake, in 

 sec. 30, T. 65 N., R. 4 W. 



Exposures. — The country underlain by the conglomerates and slates is 

 cut up by numerous lakes and is for the most part bare of timber of large 



