No. 3.] ROBB — GEOLOGY OF ST. IGNACE ISLAND. IT.j 



city. Partly to aid in the object of my visit and partly with the 

 idea thnt it might be interesting in a scientific point of view, I 

 took occasion to make a somewhat minute and careful o-eolo- 

 gical and topographical examination of the coasts «»f the location, 

 which are, in fact, almost the only parts available or accessible 

 for such a purpose; and I have thought the results mi^ht be of 

 Fufficient interest to lay before this Society, having been invited 

 ;!nd encouraged by our worthy president. Dr. Dawson, to do so. 

 So I'ar as I am aware, no minute or detailed examination has 

 hitherto been made of this island, or indeed of any part of the 

 North Shore of Lake Superior. Many important points in regard 

 to its structure are involved in considerable obscurity from the 

 want of such details; and I hop?d that my humble efforts might 

 .serve as a contribution, however slight, to such knowledge, and 

 as an addition to the general stock of information on the subject. 

 The Island of St. Ignace is, as already stated, one of the three 

 largest on Lake Superior; the largest, Isle Koyale, is on the 

 American side, or at least claimed by and conceded to the State 

 of Micliigan, and the other two, Michipicoten and St. Ignace, are 

 very nearly the same size, or about 16 miles long b}' 8 miles in 

 width, or 128 square miles area. The Island of St. Ignace fronts 

 the mouth of the Nipigon River, being separated therefrom by a 

 wide bay or channel ; and is distant about 230 miles from Sault St. 

 Marie, at the eastern end of the Lake, which is here nearly 100 

 miles wide. In approaching St. Ignace from the east, one is at 

 once struck, at the distant view, with the change from the some- 

 what tame and monotonous contour of the Laurentian and 

 Huronian hilis, to the extremely rugged and picturesque outlines 

 of the Volcanic Mountains; and a closer inspection suffices to 

 show these features in all their wild grandeur. Being still, for 

 the most part, unexplored and very rarely visited, and being 

 entirely devoid of human occupants, it is almost in a wilderness 

 condition, and is exceedingly rough, rocky and mountainou.- , and 

 being, moreover, densely covered with timber, undeibrusa, mat- 

 ted roots, moss, etc., it is very dilficuit to penetrate into the 

 interior. The coast is also much exposed to the storms from the 

 lake, and is generally fringed with steep rocky cliffs, rising 

 abruptly from the deep waters of the lake, but varied frequently 

 by bays and beaches ; and the numerous small islands and pro- 

 jecting promontories existing along its southern shores afford 

 occasionally deep and sheltered harbors, althougii, by roson of 



