CAPE COD GEOLOGY 



239 



Coastal Plain, but it is of more recent date than the Coastal Plain south of the 

 glaciated area, and some geologists would not consider it a part of the coastal 

 plain. 1 J. W. Powell, 2 founder of the modern science of physiography in the 

 United States, specifically included in the region within the "Atlantic plain," 

 a region lying east of the Piedmont Plateaus. Keith 3 assigns to the Coastal 

 Plain the Cape Cod peninsula and a "narrow tract along Massachusetts Bay 

 east of a line running through Onset, Kingston, and Scituate." 



HYDROGRAPHY 



Lakes and Lakelets 



The Cape includes many lakes but only a few rivers. The plains of the 

 southern part of the Cape are dotted over with lakes of many sizes, the largest 

 a mile or more in length. The bodies of water that are locally called "ponds," 

 probably because they differ from the lakes, which may be considered expansion 

 of streams, occupy depressions that were left by the melting of masses of former 

 glaciers and may be classified as ice block holes and kettlehole lakelets. A few 

 of the lakelets, such as those in the towns of Mashpee and Falmouth, are sources 

 of streams, partly because ancient channels of outflow have been so adjusted 

 to the water level as to permit this mode of discharge. Other basins form more or 

 less open channels or chains of lake-like stretches of water which open south- 

 ward to the sea. Bass River, which lies between the towns of Yarmouth and Den- 

 nis and forms an inlet into the Cape from the south, approaches within a little 

 less than 3 miles the north shore of the Cape. A small creek at the east side of 

 the entrance of Barnstable Harbor reduces the portage for small boats to about 

 two and a third miles. A similar short portage across the main arm of the Cape 

 was used by Governor William Bradford in the winter of 1627 in going to the 

 aid of an English ship that was wrecked on the bar at Chatham while she was 

 on her way with passengers to Virginia. Bradford appears to have crossed 

 southwest of Orleans to one of the coves at the head of Pleasant Bay. 



The inlets and coves about Chatham and Orleans are unfilled depressions 

 in glacial deposits. A small group of lakelets lies east of Wellfleet, and there 



1 See N. M. Fenneman, Physiographic divisions of the United States, Annals Assoc. American Geog- 

 raphers, 6, p. 45, 1917. Fenneman writes: "If it be assumed that they [the New England Islands] are 

 purely accumulations of glacial drift on the sea bottom they are not technically coastal plain." 



2 J. W. Powell, Physiographic regions of the United States. Nat. Geog. Monographs, 1, No. 3, May, 

 1895, pp. 75-76. 



3 Arthur Keith, Topography; in Surface Waters of Massachusetts, by C. H. Pierce and H. J. Dean: 

 Water Supply Paper 415. U. S. Geol. Survey, 1916, p. 18. 



