A POPULAR EXPOSITION OF THE 



the strata within this area have a general westerly dip, extending as 

 far as the central part of Michigan, in consequence of which, on pro- 

 ceedino- from the gneissoid belt of the Upper St. Lawrence, just east 

 of Kingston, towards the southern extremity of Lake Huron, the 

 various formations (exclusive of the Calciferous and Chazy series ?) 

 from the Potsdam to the Hamilton beds, with those also of Kettle Point, 

 are successively traversed. The dip of these strata, however, (except 

 here and there, under local conditions) is exceedingly slight, rarely 

 exceeding two or three degrees, and averaging in general less than 

 half-a-degree, or about 30 or 40 feet in a mile. The annexed section 

 will serve to convey a general idea of the sequence of these formations, 

 as shewn on the map, between the gneissoid belt east of Kingston, and 

 the coal strata of central Michigan. The thickness of intervening rock 

 between the top of the Hamilton formation and the lowest of the 

 Michigan coal seams, is about 840 or 850 feet. 



.Pig. 250. 



SKETCH-SECTION OF FORMATIONS OF WESTERN PART OF CANADA 



AND EASTERN MICHIGAN. 



(The dip necessarily exaggerated.) 



161514^ 1^12. n 10 S 8 



Michigan. Lake Erie district. 



7 6 5 



Niagara dist. 



Lake Outario dist. 



At the extreme east of this basin, a little beyond Kingston, a narrow 

 band of Potsdam sandstone rests on the western slope of the gneissoid 

 or Laurentian rocks. This is followed to the west — the Calciferous 

 and Chazy formations being apparently absent — by the strata of the 

 Ontario group, comprising the Birds-eye, Black River, and higher 

 limestones of the Trenton formation, the dark bituminous Utica schists, 

 and the arenaceous shales, &c., of the Hudson River Series. The 



