MOVEMENTS OF THE EARTh's CRUST AT ST. JOHN. 39 



arc on tlie " stoss '" side of the hill, and so are very dis- 

 tinctlj grooved. Owing to their sheltered position behind 

 this hill the snrf did not reach them, when the country 

 was submerged after the glacial period ; and being non- 

 calcareous, they were not affected by percolating surface 

 water when the country Avas again elevated above the sea. 



It will be noticed that the down-throws along the 

 lines of fault are almost universally on the north side of 

 the fault i^lanes, which in the case of these planes is also 

 tlie under side, for the hade of these faults varies from 

 vertical to seventy degrees inclination to the south-east. 

 We ma}' suppose, then, that the appearance of those 

 faults is due either to a failure of support beneath, i. e., a 

 weakening of the foundations of the earth's crust along 

 the line of this valley ; or to lateral thrust from the south- 

 east, sustaining or lifting the rock along the south side of 

 the faults. 



The former cause has some color of support from 

 various eonsiderations. The valley along the south side 

 of which these faults occur is one of great antiquity, and 

 is itself, in part at least, due to a sinking of the rocks 

 along the course of the valley in ancient times. This 

 sinking between Mill street and the Falls, along the 

 Straight Shore amounted to three thousand or four 

 thousand feet in past Geological ages. The wearing of 

 softer rocks will not account entirely for the scooping 

 out of the valley, as the hard flags of the Johannian 

 division are found in the bottom of it, and the soft slates 

 of the Bretonian division crown the Hospital hill on its 

 south side. But though there are thus plausible reasons 

 for supposing the faults may have been produced by a 

 sinking of the earth's crust beneath the valley, those 

 that favor the view that the faults were produced by 

 lateral pressure from the south, seem more weighty. 



