240 071 the Gcogi'aphy and Geology 



schistose, which it frequently does, that the nodules disappear ; or 

 may be traced only by their colour, as distributed through several 

 layers. This is common in the Lake of the Woods, and is not un- 

 known in Europe. Major Delafield found resting upon the green- 

 stone blufF of Cape Maurepos, a conglomerate, of flesh-red feldspar 

 in small angular fragments, and grains of colourless quartz in 

 about equal quantities, and imbedded in a^'ittle white clay, which 

 is often coloured by iron. It is, in fact, a very coarse variety of 

 the sandstone of St. Mary's and Batchwine Bay ; and, of course, 

 is a part of the same deposition. 



The foregoing sketch of this greenstone applies to the whole of 

 Michipicoton Bay ; the succeeding observations refer only to its 

 north side. The country, about two miles N.E. of Point Perqua- 

 quia, is composed of flat-topped greenstone mounds from 20 to 80 

 feet high, and forming islets along shore. There the mounds run 

 east by north, and without any apparent dip. The rock is in 

 greater part a conglomerate, certain parts being free from nodules. 

 These are of sienite, very quartzy greenstone, often red from iron ; 

 and the greenstones of the bay. They are from very small to 

 40 lbs. in weight, very numerous, mostly oval, rounded, and all 

 firmly set, lengthwise, in the line of the stratification. The matrix 

 is a very dark greenstone. The reticulated fissures above men- 

 tioned, are seen here, but they are coarser and deeper. This con- 

 glomerate extends, to my knowledge, towards the point on the 

 south-west one mile, and forms some of the islets.. Probably it 

 passes through Point Perquaquia (of dark greenstone, reticulated, 

 and obscurely slaty) as it re-appears in the middle of the bay 

 west of that point, and in most, if not all the isles that stud its 

 surface. At Point Perquaquia (famous for the copper said to be 

 once found there), I found a wall (a denuded vein) of white crys- 

 talline quartz ten or twelve feet high and thirty inches broad. It 

 js only seen for a short distance, and is lost in the greenstone. 

 Its sides are covered with green incrustations and small spots of 

 copper pyrites. 



The large indenture, of which Point Perquaquia is the east 

 angle,.is wholly greenstone and its conglomerate, but behind that 



