14 Barrell — Movements of the Strand Line 



The results of that investigation in so far as they bear 

 upon the post-glacial crustal movements may here be touched 

 upon, but within a short article the detailed arguments cannot 

 be given. These results cannot therefore logically be used here 

 as proofs regarding the nature of recent movements, but may 

 serve as suggestions : the deductive conclusions from a hypoth- 

 esis must be subordinated to the direct inferences from 

 established facts, but the deductions may serve, nevertheless, 

 to emphasize, explain, and coordinate such inferences. 



This theory of the distribution of crustal strength was 

 applied to the data regarding water levels during the retreat 

 of the ice, and their correlations as given by Woodworth for 

 the Champlain and Hudson valleys.* The accuracy and 

 clearness of presentation of this difficult subject by "Woodworth 

 when combined with this theory permitted the determination 

 of the sea level in latitude 40° north for each stage of the ice 

 retreat. This is at a distance where the weight of the ice 

 should have had no direct influence and represents the 

 movements in a belt beyond the terminal moraines. As 

 previously noted, however, the results of such an investigation 

 are to be regarded as suggestive rather than conclusive. 

 When the ice had retreated about to lat. 42° 45', some 150 

 miles back from the terminal moraine, the sea level near the 

 ice front stood 430 feet above the present level. The projec- 

 tion of the curve of flexure points to a sea level at latitude 

 40° 40 feet lower than at present. When the ice had retreated to 

 lat. 43° 30' the sea level there stood at +560 feet; at latitude 

 40° the appropriate curve suggests a sea level at — 90 feet. 

 When the Champlain marine water body existed, its slope and 

 the appropriate curvature point to a water level of — 220 feet 

 south of the terminal moraine. These figures have of course 

 no exact value, but if they are in the direction of the truth they 

 mean that south of the limit of glaciation the coastal plain of 

 the Atlantic shore was higher than at present and rising, the 

 sea sinking, during the retreat of the ice, and that in later 

 post-glacial time a marked submergence of this region has taken 

 place to the present level. This emergence and submergence 

 are of an opposite character to the effect of the addition of 

 water to the ocean by deglaciation and are distinct from the 

 marked isostatic rise of the glaciated region toward the 

 present level, a rise which accompanied the removal of the 

 load of ice. 



Are there independent lines of evidence pointing in this 

 direction, evidence strong enough to make a real case and not 

 depending upon the grist of a mathematical mill, grinding out 



* Ancient Water Levels of the Champlain and Hudson Valleys, Bull. 84, 

 N. Y. A State Education Department, 1905. 



