Of Maimanse, L. Superior. 11 



"Whatever tlieir precise age, it cannot be doubted tliat the cu- 

 priferous rocks of Maimanse occupy the same position, in relation 

 to the older Laurentian and newer Silurian series, with the Hu- 

 ronian beds of Georgian Bay, and that they also bear a certain 

 general resemblance to them in mineral character. 



The red sandstone of Maimanse is represented at the Bruce 

 Mines by quartzite ; the conglomerate by a rock with similar peb- 

 bles, but much more indurated ; the calcareous sandstone by 

 arenaceous limestone. Veins of copper occur at both places ; 

 but at Maimanse, native copper prevails, while at the Bruce Mines, 

 the sulphurets alone occur ; at Maimanse, the veinstone is mainly 

 calcareous, while at the Bruce, it is mainly silicious. The trap 

 and tufa of Maimanse are at the Bruce represented by greenstone. 

 While the Bruce sedimentary rocks may thus have originally 

 been similar to those of Maimanse, they have been far more alter- 

 ed, and are associated with the deep-seated crystalline products of 

 volcanic agency, instead of with those that are superficial. Dif- 

 ferences of this kind imply, however, no difference in age. 



These Huronian rocks, including under that name both those 

 of Maimanse and Georgian Bay, mark a long continued period of 

 igneous action and mechanical degradation, proceeding along the 

 coasts of that old azoic land, which formed the nucleus of the 

 American continent. This great series of physical operations 

 constituted the preparation for the Silurian period, and no doubt 

 formed the sea bottoms on which its sea-weeds and shell-fish be- 

 gan to live. In Lake Superior, we have the deposits of the shore 

 margin only of these old seas ; what n:iay have been proceeding 

 in their profound depths, we know not, nor have we any infor- 

 mation as to the occurrence in their more tranquil waters, or on 

 the neighbouring land, of any form of animal or vegetable 

 life; and the rocks themselves are not of a character to warrant 

 any very sanguine hopes of the discovery in them of organic re- 

 mains. In a geological point of view, they merely inform us, 

 that at the dawn of the Silurian period, and immediately before 

 the deposition of the oldest rocks in which we find animal life, 

 there occurred along the sea margin of this most ancient part of the 

 American continent, enormous volcanic outbursts ; and that thc-se 

 very closely resembled in their character the volcanic phenomena 

 of every succeeding geological period, and even of modern times; 

 and were associated with the extensive deposition of beds of red 

 sandstone and conglomerate, similar to those which, at various 



