690 ABSTRACTS OF PAPERS 



character, having been rather well developed and still preserving well charac- 

 terized remnants. This series of terraces is shown to have been developed on 

 the eastern side of the Appalachians over the whole region studied, from north- 

 ern Massachusetts to the Potomac River. They have been named by the author 

 in descending order from localities in western Massachusetts and Connecticut, 

 where they are preserved in recognizable state. Their names and the approxi- 

 mate elevation of their inner margins in their type localities are as follows : 



Becket terrace. . - - ' 

 Canaan terrace. 



Cornwall terrace : 720 



Goshen terrace. • 1,380 



Litchfield terrace 1140 



Prospect terrace 920 



Towantic terrace 130 



Lower terraces of less perfect development are also noted at the following 



Feet 



Appomattox (Lafayette) terrace 500 to 540 



»w Canaan terrace. 340 to 380 



Sunderland terrace. . 200 to 240 



i^Hnico terrace 80 to 120 



In regard to mode of origin these terraces are shown to still preserve in a 

 measure the forms resulting from wave planation. the features of cliff and 

 terrace developed across various structures and rock formations at right angles 

 to the drainage system indicating that they cannot be reasonably ascribed to 

 river erosion or subaerial denudation. The latter agencies, however, worked 

 preparatory to the marine planation, and have in later time through their 

 destructive effects largely masked the evidence of the former invasions and 

 retreats of the sea. 



Certain independent tests of these conclusions are derived from the drainage 

 of eastern Pennsylvania and the finding of scanty gravels remaining at an 

 elevation of 700 to 730 feet in Maryland. 



The demonstration of the theses of this paper depend very largely on the 

 maps and profiles shown in the stereopticon slides. 



P08T-JURA£> .7 THE SORT HERS APPAJLACHI^ 



BY JOSEPH W ARRET T 



(Abstract) 



The previous paper develops the evidence of an alternating series of uplifts 

 and strand lines. The present paper seeks to determine their place in geologic 

 time by correlating them with the strata of the Coastal Plain. An outline of 

 the results is as foil 



The dates of the piedmont terraces may correspond with those of certain 

 formations of the Coastal Plain. The dates of the uplifts, on the other hand, 

 should be marked by the intervening planes of unconformity : or. if the uplift 



