Newfoundland and Nova Scotia. 391 



eustatic shift of ocean-level to the extent of about 6 meters 

 (20 feet) J "^ The shift is tentatively placed in late Neo- 

 lithic times. The complete failure of the corresponding 

 bench to appear in southern Nova Scotia and southern 

 Newfoundland suggests that the local drowning pro- 

 gressed after the eustatic shift of sea-level took place, 

 that is, within the last three or four thousand years. Bar- 

 ren's reasoning on the march of events during isostatic 

 adjustment following the melting of an ice-cap would 

 agree with this suggestion. The warping of the ' ' 25-foot ' ' 

 post-Glacial bench of the British Isles and the drowning 

 of Neolithic deposits outside the zero isobase in England 

 and Denmark may conceivably be explained in the same 

 way, if the local British and Scandinavian ice-caps caused 

 deformation like that connected with the Labrador ice- 

 cap.^ ^ If, in each of the three regions, the local sinking- 

 occurred during post-Neolithic time, none of the regions 

 would be likely to give convincing evidence of an earlier 

 eustatic change of sea-level. On the other hand, strand- 

 marks, corresponding to the higher position of sea-level 

 in the glaciated area well inside the zero isobase, should 

 not have been greatly disturbed during the final collapse 

 of the marginal bulge. The remarkable low bench along 

 the shore of the St. LaAvrence estuary is a case in point. 



The various facts and suggestions noted in the last 

 few paragraphs suffice to show that the character and 

 exact dating of the deformation in the marginal belt 

 represent a delicate problem, which for geodynamics has 

 scarcely less importance than a similar understanding 

 of the uplift in the central area of a vanished ice-cap. 

 Because of their specially favorable relations to the zero 

 isobase and to the level-marking ocean. Nova Scotia and 

 Newfoundland seem to be among the best of all the 

 large areas in which to seek compelling evidence as to 

 what really happened in the marginal belt. 



"E. A, Daly, Geol. Mag., vol. 57, p. 246, 1920. At many well exposed 

 headlands of Newfoundland the nearly or quite vertical sea-cliffs were seen 

 to be continued under low- tide level from one-half fathom to two fathoms or 

 a little deeper. This prolongation of the cliff below sea -level is the result of 

 marine erosion and does not mean so much sinking of the land. The princi- 

 ple illustrated is important in connection with the problem of locating former 

 sea-level from elevated rock-benches. At exposed places the bench levels are 

 likely to be three to twelve or more feet below the high-tide level ruling at 

 the time when the benches were cut. 



" Cf. W. B. Wright, Geol. Mag., vol. 57, p. .382, 383, 1920. 



