4 8 



with Beekmantown fossils, and it is thought that the 

 two conglomerates are identical, and form the arch of an 

 overturned and eroded anticline. The two conglomerates 

 exposed to the north in the lane are duplicated in the 

 cemetery back of this ridge. 



This ridge is the "ridge north of the St. Joseph cemetery" 

 mentioned by Ells, and it was here that Walcott first found 

 fossils in the matrix and was thus enabled to make a 

 definite correlation with the Beekmantown at Philipsburg. 



QUEBEC AND VICINITY: PHYSIOGRAPHIC AL 



NOTES. 



(J. W. GOLDTHWAIT.) 



The commanding position of the old city of Quebec, 

 on the heights above the St. Lawrence, affords opportunity 

 for observing to best advantage the broader features of 

 the St. Lawrence plain. From Dufferin terrace and the 

 citadel, as one looks down the estuary, he sees on the left 

 the massive forms of the Laurentian mountains stretching 

 away into the distance behind the north shore. Along 

 their irregular border Pre-Cambrian gneisses disappear 

 under the steeply upturned edges of Palaeozoic limestones 

 and shales, showing how the long continued denudation 

 of Tertiary time failed by several hundred feet to reduce 

 the crystallines to the level of the adjoining sediments. 

 Midway in the estuary the Island of Orleans with its 

 flat top 250 feet (76 m.) above the St. Lawrence, appears 

 as a connecting link between the narrow plain that lies 

 at the foot of the mountains on the one hand, and the 

 broad lowland of the St. Lawrence on the other. Beneath 

 the smooth skyline of this St. Lawrence plain the river 

 and its small tributaries are deeply intrenched. Here 

 at the narrowest point on the estuary the Plains of Abraham 

 on the north side and the Levis hills on the south, stand 

 about 300 feet (90 m.) above tide, with precipitous cliffs 

 bordering the St. Lawrence. From the river south- 

 ward the plain rises slowly and steadily 12 or 13 miles 

 (19 or 21 km.) before it reaches the first definite line of 

 ridges on the southeast. This great St. Lawrence low- 

 land appears to be a peneplain, like the Cumberland, 

 Colchester, and Eastern New Brunswick lowlands, de- 

 veloped on the soft Palaeozoic sediments that lie between 



