GEOLOGICAL RELATIONS. 35 



road. In Township No. 4, R. 18, the hydro-mica schists reappear, and form a high 

 ridge, through which the west branch has excavated a deep gorge. The same roclc is 

 supposed to continue across the highland boundary between Maine and Quebec into 

 the valley of the Du Loup river, one of the tributaries of the Chaudiere. 



The first formation in Canada consists of fine and coarse micaceous clay slates, with 

 gray micaceo-argillaceous sandstones, weathering greenish in the air, and turning red- 

 dish when exposed to running water. They are supposed to be Huronian. Next 

 succeed the Gaspe slates. The rocks resemble those just described, consisting chiefly 

 of gray sandstones, approaching a coarse mica slate. These sandstones are interstrati- 

 fied with calcareous beds, too siliceous to be used for the manufacture of lime, and 

 crop out along the lower three miles of the course of the Rivifere du Loup. They com- 

 monly dip 62° S. -^7° E. These beds resemble the Calciferous mica schist of Vermont. 



The section next crosses a band of fossiliferous Helderberg, having the same position 

 as the preceding formation. The best localities are on the Touffe des Pins and Famine 

 rivers. This would naturally occupy the place of a synclinal in the Gaspe series ; and 

 consequently the rocks which follow, extending as far as the parish of St. Francis, a 

 few miles above the Guillaume river, are repetitions of those adjacent to the Helder- 

 berg on the south-east. As they all dip south-easterly, those nearest Maine must have 

 been inverted. 



The section now runs parallel to the Chaudiere river, and, after reaching St. Etienne, 

 follows Section No. 9 of the maps and sections published by Sir William E. Logan to 

 illustrate the report of progress of the geological survey of Canada, from its commence- 

 ment to 1863. The formation succeeding the Gaspe slates is referred in the Canadian 

 report to the Quebec group of the Lower Silurian, but it is the same with what is called 

 Huronian elsewhere upon this section. The first outcrop is the north-easterly continua- 

 tion of the ridge from Memphremagog lake towards Sherbrooke. This is followed by 

 the Sutton and St. Joseph anticlinal. The width of the Shipton and Leeds synclinal 

 is about fifteen miles. Magnesian limestones, quite crystalline, occur on both sides of 

 the basin, interstratified with chloritic slates, specular, and hydro-mica schists, epidotic 

 rocks, and red slates. Extensive beds of copper sulphuret are connected with these 

 schists. The upper part of the basin is referred to the Sillery sandstone. The next 

 axis, called the Bayer and Stanbridge anticlinal, is situated in the edge of Lauzon, un- 

 derlying the Lauzon and Farnham synclinal. The rocks are like those just described ; 

 and both these synclinals are represented to be very complex. In Gaspe there is 

 another anticlinal, and the upper division of the Quebec group soon follows. In Tilly 

 occurs the great fault separating the Huronian strata on the east from the fossiliferous 

 formations bordering the St. Lawrence river. The Huronian rocks are apparently 

 above the newer formations, there being an overturn. The formation coming to the sur- 

 face, and underlying the St. Lawrence river, is the Lorraine group. Following this are 

 the inferior members of the Lower Silurian, resting upon the upturned edges of the 

 Laurentian. These ancient strata are overturned, dipping north-westerly to the end of 

 the section in Bourg Louis. 



