57 



On top of the hill may be seen excellent exposures of 

 the Keewatin, consisting of calcareous schists with lenses 

 of ferruginous limestone, and a band of schistose volcanic 

 agglomerate. The road eventually leads to a well, which 

 is the starting-point for the first side trip. 



Limestone Bands in the Keewatin. — From the well, 

 a path 500 feet (152 m) long, marked by yellow flags, 

 leads to an exposure of Keewatin limestone. On the 

 right hand side of this path, before coming to the limestone 

 may be observed ridges of grey-green weathered felsite, 

 much fractured as a result of igneous intrusion. 



The limestone occurs in a series of bands from a few 

 inches to a foot thick, which are interlaminated with 

 discontinuous bands of chert and chert agglomerate. 

 The total width of the formation is about 10 feet (3.2 m), 

 and it can be traced along the strike for 275 feet (84 m). 

 The strike is N 65 E, and the dip 50 to 6o° N. W. The 

 limestone is a highly granular, medium-grained variety, 

 containing an abundance of minute crystals of brown 

 mica scattered through its mass. An analysis shows 

 that it contains only o . 35 per cent MgC0 3 . Resting upon 

 the limestone is a two foot (0.61 m) bed of brecciated 

 chert, which grades upward into a porpyhritic dense 

 felsitic lava. The proof of the contemporaneity of the 

 limestone and the felsite is important in discussing the 

 relation of the limestone to the Seine series. 



Unconformable Contact of the Seine Series with 

 Keewatin Felsite. — The mine road (marked by white 

 flags) is next followed in a southeasterly direction for 200 

 yards (183 m), up a hill of felsite cut by basic igneous 

 dykes. The ruins of the mine, which was destroyed by the 

 Rainy Lake fire of three years ago, may be seen on the right. 

 A path marked by blue flags, leading to the left is then taken. 

 It affords an opportunity of observing the contour of 

 the felsite, and leads to the contact of the felsite with the 

 Seine series near the top of the ridge. The character of 

 the felsite should be noted in order that the pebbles in 

 the conglomerate may be compared with it, and the contact, 

 which is located by red flags, should be followed a short 

 distance to observe the nature of the basal conglomerate. 



Irruptive Contact of the Laurentian with the 

 Keewatin. — The white flag route is followed for a 

 short distance to where it is joined by another road from 

 the west. At this point, a series of green flags marks 



