310 Goldtkwait — Twenty-Foot Terrace ami 



and forest bods, containing stumps of trees in undisturbed 

 positions of growth, have been found at many plaees, at depths 

 of from to 20 feet below modern high-tide mark. Among 

 the numerous instances of such submerged forests may he 

 mentioned cases at the head of the Bay of Fundy,'* at 

 several places near Boston, Mass.,f and on the island of Nan- 

 tucket4 This evidence coming from many different places 

 on the coast, and reported by many observers, seems to leave 

 no doubt that the seaboard of Acadia and New England has 

 suffered a submergence, since the glacial period, of fully 20 

 feet. The position of these forest beds above glacial drift, yet 

 much nearer the sea level than the beaches which mark the 

 Champlain submergence, indicate that this coastal subsidence 

 came after the extensive emergence of the coast from the 

 Champlain sea. > 



There is difficulty, however, in correlating the Micmac ter- 

 race with these submerged forest beds, in the fact that the 

 terrace has experienced a re-elevation of 20 feet, while the 

 submerged forest beds are not known to have suffered a simi- 

 lar uplift. Indeed, it has recently been urged, that botanical 

 evidence in the structure of the salt marshes overlying the 

 forest beds proves that the subsidence of the coast, in those 

 places, has been uninterrupted since the stumps were first 

 submerged, and that the movement is still in progress.§ 

 Inasmuch as these and other alleged evidences of modern 

 subsidence may to some extent be explained by appealing to 

 other processes than crustal deformations,! and at the same 

 time are contradicted by alleged evidences of modern sta- 

 bility in Acadia and New England, ^[ and of modern elevation 



* Sir William Dawson : On a modern submerged forest at Fort Lawrence, 

 Nova Scotia. Quart. Journ., Geol. Soc. London, vol. xi, 1855, pp. 119-122. 

 (Abstract) this Journal, 2d series, vol. xxi, 1856. pp. 440-442. Also, in Aca- 

 dian Geology, 2d edition, London, 1868, pp. 28-32. 



f J. W. Sears: The physical geography, geology, mineralogy, and paleon- 

 tology of Essex County, Massachusetts. Salem, Mass. Published by the 

 Essex Institute, 1905, pp. 51-58, and fig. 27. 



% A. Gessner : On elevations and .depressions of the earth in North 

 America. Quart. Journ. Geol. Soc, vol. xvii, pp. 381-388, 1861, especially 

 p. 382. 



g C A. Davis : Peat deposits of Maine. Bulletin No. 376, U. S. Geological 

 Survey, 1909, pp. 19-21. Salt marsh formation uear Boston, and its geo- 

 logical significance. Economic Geology, vol. v, p. 625. 



Also, H. H. Bartlett : The Chamaecyparis bog at Woods Hole, Massachu- 

 setts, Rhodora, vol. xi, 1909, pp. 221-235. 



I D. W. Johnson : Personal communication regarding progress of the Shaler 

 Memorial Investigation, 1911. 



*[ Robert Chalmers : Report on the surface geology of southern New 

 Brunswick. Geological Survey of Canada, Annual Report, vol. iv, pp. 

 74-76 N, 1888-89. 



Also, I). W. Johnson and W. G. Reed, Jr. The form of Nantasket-Beach. 

 Journ. of Geology, vol. xviii, pp. 162-189, 1910, especially pp. 187-188. 



