Section IV, 1888. [ 3 ] Teans. Eot. Soc. Canada. 



I. — Presidential Address: The Huronian System in Canada. 

 By Robert Bell, B. A. So., M. D., LL.D. 



(Read May 22, 1888.) 



At the present time, geologists are taking an uunsual interest in the study of the 

 Archaean rocks. In America this is especially the case with regard to the Huronian 

 System. It has occurred to me, therefore, that I could not do better than to select this 

 subject for the present address, particularly, as I have devoted much time to its study, 

 both in the field and the oifice. Among recent authorities. Prof. R. D. Irving, of the 

 United States Geological Survey, has written several valuable papers, and much credit is 

 dïie to him for the attention he has given to some of the unsettled problems in connection 

 with these rocks. "While I agree with much of what he says, I hope he will pardon me 

 for stating plainly my objections to his views on other points. 



In order to understand my meaning, it will be necessary to go back for a few moments 

 to what may appear to be elementary definitions, with which Canadian geologists may be 

 supposed to be already familiar. In Canada, especially north of the Great Lakes, and 

 in those States of the Union in which Prof. Irving has worked, there is a great series 

 of rocks above the Lavirentian and below the Cambrian which, for more than thirty years 

 has been known to the Canadian Geological Survey as the Huronian System — sometimes 

 also called the Huronian Series. The lower portions of these rocks consist largely of green- 

 stones, conglomerates, and crystalline schists in great variety, characterized for the most 

 part by dark greenish and grey colors, forming a striking contrast to the reddish and 

 lighter greys of the Laurentian gneisses; while in the upper portions, in addition to such 

 rocks, quartzites, greywackes, or volcanic ashes, and clay-slates are also to be found in 

 some regions. Among the rocks of minor volume, which are met with in various parts 

 of the series, may be mentioned limestones and dolomites, iron ores, hornblende rock, 

 jasper and chert rocks, sometimes brecciated, a peculiar jasper conglomerate, serpentine, car- 

 bonaceous or plumbaginous slates, imperfect gneisses, breccias and amygdaloids. Granites 

 and syenites, form considerable masses in the midst of the Huronian areas and consti- 

 tute an important feature in connection with these rocks. 



The most extensive Huronian areas yet known are the one whose centre lies between 

 Lake Huron and James Bay, and another on the north-west side of Hudson Bav, oi 

 which, however, little is yet known, except what can be gathered from a visit paid to 

 one part of it by myself, but more particularly from several collections of its rocks which 

 have beent sent me, showing that it is of very wide geographical extent, and that it 

 embraces a great variety of interesting rocks. The Huronian is also well developed on 

 both sides of Lake Superior, and similar strata occur in the Eastern Townships and in 

 in Newfoundland. It is possible also that some of the less altered of the crystalline rocks 



