2 9 



with the granites that throughout this region have been 

 referred to the Laurentian. 



Lower Huronian and Keewatin. — Considerable differ- 

 ence of opinion is shown by those who have made a careful 

 study of the formations in this region as to the dividing 

 line between these two series. The writer has visited 

 only one of the outcrops, which lies about a half mile south 

 from Loon station and in his opinion it would be referred 

 to the Keewatin if seen in a region where the bulk of the 

 rock belonged to that age. The difficulty of making a 

 distinction between the rocks of the two formations in 

 this region is increased by the highly altered condition 

 of the rocks, few of which show much trace of their 

 original character. The two series consist of quartz 

 porphyry exhibiting flow structure; greywacke, which 

 has been altered to a considerable extent to schist; green- 

 stone and a conglomerate, which, from the one illustration 

 given (8) and the description of the constituents, may be 

 compared with the Keewatin agglomerates of the friction 

 breccia type. 



ITINERARY. 



In a southeasterly direction from the station at Loon 

 is an outcrop of highly altered Keewatin or Lower Huronian 

 which is exposed near a fork in the road. At Wylie's 

 camp the same rock is well exposed. This rock shows 

 considerable contortion and some minor faulting and is 

 very similar to the more highly altered phases of the 

 Keewatin. Along a trail to Silver lake from this exposure 

 Animikie iron formation is well exposed at several places. 

 The alteration of taconite to iron ore is well exemplified 

 in an exposure on the south side of the trail and in the 

 old shaft near Flaherty's camp. Good hematite (kidney 

 iron) and taconite are well exposed at the tunnel on Fla- 

 herty's claim. Near this tunnel a fault is said to separate 

 the Animikie from the Keweenawan. Some time will be 

 devoted to the contact of Animikie and Keweenawan and 

 to the character of the more marl-like material of the 

 Keweenawan. 



Returning southward along the trail the contact of the 

 Animikie slates with the Logan sills may be noted. Con- 

 tinuing along the trail the Animikie may occasionally be 

 found lying on the top of this sill. A view of Lake Decep- 



