96 REPORT OF THE SPECIAL COMMITTEE 



of rocks seemed to be no more than the metamorphosed ellipsoidal 

 greenstones and tuffs, but some of them may be altered felsite. 

 However, we do not assert that larger areas may not be sedimentary 

 in the sense of being deposited under water. Aside from the belts 

 mapped as slate, there are great areas of what Lawson calls agglom- 

 erate. These belts, mapped as agglomerates, seem to us to be 

 largely tuff deposits, but also include extensive areas of ellipsoidal 

 greenstones. At a number of places, associated and interstratified 

 with the slaty phases are narrow bands of ferruginous and siliceous 

 dolomite. For the most part the bands are less than a foot in thick- 

 ness, and no band was seen as wide as three feet, but the aggregate 

 thickness of a number of bands at one locality would amount to sev- 

 eral feet. 



We could discover no structural breaks between the above for- 

 mations of the Lake of the Woods. The various classes of materials 

 — slates, agglomerate, and ellipsoidal greenstones — all seem to belong 

 together. In short, these rocks in the Lake of the Woods seem to 

 us to constitute one series which is very largely igneous or volcanic 

 in origin, but does, as above mentioned, contain some sediments. 

 This series in the Lake of the Woods area is the one for which the 

 term " Keewatin" was first proposed for the greenstone series, Lawson 

 giving as one reason for proposing this name the statement that 

 there is no evidence that these rocks are equivalent with the rocks 

 of Lake Huron described by Logan and Murray as Huronian. 



The ellipsoidal greenstone-agglomerate-slate series is cut in a 

 most intricate way by granite and granitoid gneiss, which constitute 

 much of Falcon Island at the southern part of the Lake of the Woods 

 and a great area north of the Lake of the Woods. These relations 

 between the granite and Keewatin were seen on the northwest part 

 of Falcon Island and on a small island adjacent. They were also 

 seen north of Rat Portage. At the latter place the rocks adjacent 

 to the granite are banded hornblende and micaceous schists, very 

 similar to the banded rocks of Light House Point, at Marquette. 

 At Hebe Falls the granite and Keewatin series are seen to be in actual 

 contact, the Keewatin being apparently intruded by the granites, 

 although the relations have often been interpreted as conformable 

 gradations. Going north along the Winnipeg River, the relations 



