DATA AFFECTING SUBMERGENCE THEORY 



239 



Locality. 



Dana's 

 marine 

 plane. 



Dana's 

 flood 

 level. 



Theoretic 

 plane. 



Upham's figures. 



Montreal 



Stratford Hollow... 



Lancaster 



Low. Waterf ord 



Barnet 



Wells River , 



Haverhill 



Hanover 



Hartland 



Windsor 



Bellows Falls 



Brattleboro 



South Vernon 



North line of Mass. . . 



Northfield 



North Hatfield 



Springfield 



South line of Mass . . . 



Hartford 



Middletown 



Long Island Sound. 



Riverhead, L. I 



Southampton plains. 



520 

 345 



318 



295 



272' 



160 



25 



960 

 910 

 843 

 677 

 660 

 655 

 580 

 550 

 520 

 480 

 410 

 396 



"396* 

 812 

 240 

 230 

 210 

 195 

 25 



830 



710 



675 



650 



640 



620 



605 



555 



530 



520 



465 



425 



405 



400 



395 



350 



300 



288 



250 



215 



160-125 



115 



100 



Valley above the ma- 

 rine level. 



618, "normaL" 

 600-660, "tributary." 



540, normal. 



540, tributary. 

 465-480, tributary. 

 409-425, tributary. 



375-390, tributary. 



PHENOMENA OF THE SUMMIT LEVEL 



The features marking the highest stand of the waters are the ordinary 

 shoreline phenomena, beaches, and deltas. The beach phenomena, as 

 bars and cliffs, are usually not conspicuous, because in the sections of the 

 valley having sufficient width for effective wave-work the marginal waters 

 were either too shallow or too secluded. However, close examination of 

 the valley sides along the theoretic plane will probably discover definite 

 shore features at many localities. Two heavy gravel bars lie northeast 

 of Middletown, on the west side of the hill at Portland, which were found 

 by using the theoretic level. By the map contours the higher bar is 220 

 feet, which is the precise theoretic altitude of the. marine plane. 



It needs to be emphasized that absence of expected shore phenomena 

 at any locality, or even along a stretch of shoreline, is not conclusive nega- 

 tive evidence. Shore features are capricious and are often lacking where 

 most confidently expected and where the fact of water is demonstrable by 

 good features on both sides of the negative locality. On the other hand, 

 strong features are frequently discovered where not expected. 



Bars and deltas may occur at all altitudes inferior to the summit or 

 initial water level, and more abundantly ; hence it is not safe to take the 

 highest feature in isolated localities as marking the summit. Only by 



