246 



CAPE COD GEOLOGY 



in 1905, it is not certain that the clay bed at Barnstable lies at the same horizon 

 as the Gardiners clay, or which of the other clay beds of the district can be 

 correlated with the clay bed at Barnstable. 



In 1906 M. Maurice Allorge, : then a student working under William Morris 

 Davis, visited the Cape, and wrote a sketch of its geography, which included 

 a brief account of the moraines. 



In the same year J. Howard Wilson, 2 in a thesis prepared for a doctorate, 

 described in considerable detail the glacial deposits of Cape Cod and presented 

 an argument for the former existence in Cape Cod Bay of a glacially barred 

 lake, which he named "Lake Shaler." In the same paper he advocated the 

 hypothesis that the glacial drift on Cape Cod and Nantucket had been brought 

 to the district by a glacier that moved southwestward along the front of the 

 main ice sheet on the continent from a source in Newfoundland, a view that 

 has not received acceptance. In 1914 Fuller, in attempting to correlate the Pleis- 

 tocene deposits north and east of Long Island with the formations worked out 

 on that island, referred the bed of dark clay on Cape Cod to the same horizon 

 as the Gardiners clay — a horizon in the older Pleistocene. He thought that 

 the sandy upper part of the bed on the Cape represented, as an inseparable 

 member, the Jacob sand of the islands on the southwest. He referred to the 

 younger Herod gravel several deposits of gravel and sand in the coastal bluffs 

 of the Cape. The banded pebbly clay till in these bluffs, as he thought, represents 

 the Montauk till, and the beds of gravel overlying this till he regarded as of the 

 age of the Hempstead gravel. Fuller's 3 paper was the first one to attempt to 

 correlate the various glacial deposits throughout the New England Islands, 

 Cape Cod, and adjacent parts of the mainland about Boston and even farther 

 north. 



It is now believed that, so far as known, the entire district that lies above 

 sea level is composed of Pleistocene glacial or closely allied formations nearly 

 identical with those on the islands to the south. 



1 Maurice Allorge, Esquisse geographique du Cap Cod, Annales de Geographic, No. 84. xv e Annee 

 15 Nov., 1906, pp. 443-448; pi. xxii. 



2 J. Howard Wilson, The glacial history of Nantucket and Cape Cod, with an argument for a fourth 

 centre of glacial dispersion in North America. New York, The Columbia University Press, 1906. See 

 pp. 4-50 on upper Cape Cod; ch. VIII, at pp. 52-66, on Lake Shaler, a glacial lake in the Cape Cod 

 region; ch. IV, at pp. 67-89, on An argument for a fourth centre of glacial dispersion in North America. 



3 M. L. Fuller, The geology of Long Island, Prof. Paper 82, IT. S. Geological Survey, see pp. 219- 

 222, and table at p. 220. 



