OWL'S HEAD. 



449 



relations to the other belts of limestone in northern Vermont. Like this that is very near 

 the top of the clay slate series, and is overlaid by a conglomerate. These two deposits of 

 limestone occupy the same positions upon the opposite sides of an anticlinal axis. The 

 axis is in the calciferous mica schist, which is overlaid by clay slate. In the upper part of 

 each band of clay slate occurs the limestones. If now the Memphremagog limestone is to 

 be considered from palseontological evidence upper Helderberg limestone, then the Ber- 

 nardston limestone should be ranked with it. The other belt of upper Helderberg lime- 

 stone is much more extensive. Just over the Vermont line near Jennings' Hotel, 

 upon the west side of Lake Memphremagog, it is developed better than in Vermont, 

 where also the only fossils in it we have seen have been found. The same belt of lime- 

 stone runs into Vermont, and may be seen in Newport, Coventry, Irasburgh, Albany, 

 Craftsbury and Wolcott. Its northeasterly extent in Canada is unknown to us. 



FIG. 267. 



East. 



nut. 



Section at Owl's Head. 



Explanation of Fig. 267. 



1 Talcose schist, middle range. 



2 Coarse conglomerate. 



3 Clay slate. 



4 Upper Helderberg limestone. 



5 Clay slate. 



6 Calciferous mica schist. 



Fig. 267 represents the order of rocks at Owl's Head and vicinity. The section extends 

 across Lake Memphremagog to show the relations of the limestone to the calciferous 

 mica schist. The rocks all dip west, and thus this fossiliferous limestone is seen to 

 plunge under the great range of talcose schist. It is not the usual position for inverted 

 strata ; for in New England and Canada, such strata invariably dip to the east. On this 

 account the position of the Memphremagog limestone is extremely interesting ; for upon 

 its age depends perhaps the age of the talcose schist. No one could ask for a clearer case 

 of superposition than that of the talcose schist over this limestone. If the position of 

 the strata is abnormal, the irregularity is occasioned by plication, and not by faults. 

 The dip of the limestone is 53 W., and the strike N. 35 E. The most important fossils 

 in this rock are Atrypa reticularis and a Zaphrentis. 



There is a great thickness of this limestone in Coventry, probably more than 200 feet. 

 At a saw mill in the west part of the town, it is quite dark-colored, rings when struck 

 with a hammer, and is very slaty. It here dips 50 W., and runs N. 30 E. In another 

 place in Coventry it runs N. 40 E., and dips 46 N.W. 



FIG. 2G8. 



East. 



West. 



Section in Coventry. 



Explanation of Fig. 268. 



A Clay slate. F Bright green talcose schist, with scarcely any 



B Upper Helderberg limestone. planes of stratification : like 1 of Fig. 2f7. 



C Clay slate. G Novaculite. 



D Rocks concealed by drift. H Common talcose schist. 



E Talcose conglomerate. 



