ON THE GEOLOGY OF ST. JOHN. 245 



Mispeck Group (No. 1 of Daw.), thickness 1800 feet. 



a. Coarse subangular conglomerate. 



b. Fine-grained purple clay slate and grits surmounted by 

 slate conglomerate. 



(?) Red and green slate, basalt (stratified?). 



Topography. — The indentations in the coast line of the Bay of 

 Fundy at Port Simonds and St. John harbour, cut directly across 

 all the groups of rocks mentioned above, except those of the Port- 

 land series, which are crossed by the outlet of the St. John river. 



In the peninsula thus formed between Kennebeckasis Bay and 

 the Bay of Fundy, two hilly ridges, one skirting the former and 

 the other the latter Bay, with an intermediate valley, are the most 

 prominent topographical features. 



The valley in its upper part forms the basins of several lakes 

 (Loch Lomond, <fec), and forks as it approaches the sea. One 

 branch through which the Mispeck flows, ends at Port Simonds °, 

 the other extends to the harbour of St. John, and is drained 

 by Little River. An intermediate ridge of land, which extends a 

 short distance into the Bay between the two ports, consists princi- 

 pally of the highest group of Devonian rocks, (see Section). 



The uneven and hilly tract on the northwestern side of the pe- 

 ninsula is underlaid by the Portland series and Coldbrook group, 

 and its surface is diversified by numerous lakelets and ponds. 



The shales of the St. John group, being much softer than the 

 deposit on either side, have suffered more from denuding agencies. 

 They lie at the bottom of that branch of the central valley which 

 ends at the harbour. Advantage has been taken of (his depres- 

 sion to supply the city with water from lakes in the vicinity of 

 Loch Lomond. 



The volcanic and sedimentary beds of the succeeding group 

 stand out boldly above the general level of the country wherever 

 they attain a considerable thickness, and usually bear a generous 

 forest growth. 



In passing from the wooded slopes underlaid by rocks of this 

 group to the arenaceous beds which succeed them, a notable 

 change is apparent in the vegetation. Barren wastes and bare 

 ledges of sandstone take the place of thick woods wherever the 

 influence of the subjacent rock is not modified by the presence of 

 a foreign soil. 



