bareell: movements of the strand line 415 



leys point in the same direction, but the method of investigation 

 here suggested is of independent value and should give much 

 information for regions such as oceanic islands where the embay- 

 ments do not give the depth nor duration of submergence. 



Pliocene and Pleistocene marine terraces. A second line of 

 investigation which has brought the writer to an intersection 

 with the problem of recent movements was in connection with 

 areal geologic work in southern New England. The topog- 

 raphy in this region indicated a series of descending base 

 levels. The methods applied in their study and the results 

 have been pubhshed in abstract.^ Each base level would be 

 recorded in the interior by surfaces of subaerial denudation, 

 on the seaward side by surfaces of marine planation. The 

 latter were cut as benches across the harder rocks and are conse- 

 quently better preserved than the former. A method of pro- 

 jected profiles, looking along the line of the shore, restores these 

 ancient levels, gives the appearance of a wide flight of giant stairs, 

 and hides the effects of later dissection. It is thought that the 

 Goshen level, reaching to the height of 1380 feet in western 

 Connecticut, dates from the earlier Phocene. The terraces 

 below descend by steps many miles broad and lying approxi- 

 mately at 1140, 920, 730, and 520 feet. The Pleistocene terraces 

 below were, in comparison, very imperfectly developed, but a 

 number can be traced. They show briefer periods of crustal 

 rest and appear to represent an acceleration of the diastrophic 

 rhythm in Pleistocene time. This crustal unrest is continued 

 to the present, and the present is diastrophically as well as cli- 

 matically a part of the Pleistocene. * 



The broader Tertiary rhythm shown by these wide terraces 

 must have been complicated in the Pleistocene by special effects^ 

 such as the weight of the ice-sheets, the changes in volume of 

 ocean water related to glaciation, and minor diastrophic move- 

 ments. These complications, however,' do not hide the facts 

 which lead to the conclusion that on the Atlantic coast an ab- 

 normal crustal unrest beginning in the Phocene has marked 

 especially the entire Pleistocene period. 



3 Bull. Geol. Society of America, 24: 688-696. 1913. 



