402 Newer Pliocene and Post Pliocene Deposits. 



In the present paper I propose to notice ^ 

 the arrangement of the beds ia the vicinity § ^ 

 of Montreal, and the assemblage of fossils g-| 

 which they contain, in connection with the g o. 

 distribution of the species as inhabitants of e^g- 

 the modern seas, and the inferences as to %. 

 climate and other conditions deducible from g 

 them. g 



The isolated -eminence of trap which rises t: 

 in the mountain of Montreal to a height of %_ 

 about 700 feet, forms up to that elevation, | 

 a tide-guage of the Post Pliocene sea, mark- „ 

 ed on its sides by a series of sea cHfFs and 5 

 elevated beaches, indicating the stages of i 

 gradual or intermittent elevation of the land ^ 

 as it rose to its present level. The most | 

 strongly marked of these sea margins are ' 

 at heights of 470, 440, 386 and 220 feet ? 

 above Lake St. Peter on the St. Lawrence ;"* \ 

 or 450, 420, 366, and 200 above the river \ 

 at Montreal. < 



The hiohest of these 'beaches contains : 

 sea shells of existing species. Below the ■ 

 lowest, and at an elevation of about 100 feet \ 

 above the river, spreads the great tertiary \ 

 plain of Lower Canada, everyw^here con- 

 taining marine shells, and presenting a 

 series of deposits partly unstratified and 

 partly assorted by water. In this vicinity 

 the regular sequence is as follows : 



1. Fine uniformly grained sand, in some 

 places underlaid or re-placed by stratified 

 gravel. Marine shells in the lower part. 



2. Unctuous calcareous clay, of gray and 

 occasionally of brown ajnd reddish tints. 

 A few marine shells. 



3. Compact boulder clay filled with frag- 

 ments of various rocks, usually partially 

 rounded and often scratched and polished. 



-Kg:. 1. 





PW 



* The first of these measurements is given on the authority of the 

 Geological Survey. The others were ascertained for me by Professor 

 Hamilton of McGill College, by levelling. The terraces are not quite 

 level nor their limits always very distinct. 



