240 



CAPE COD GEOLOGY 



are others farther north, toward Truro, deep-set in the wooded, high glacial 

 plain. 



Two ponds that lie close together may be separated by a narrow bar or strip 

 of land formed by the waves. These interlake bars are formed by the cutting 

 down of slender ridges of drift or knolls and the filling up of narrow passages 

 between the ridges. A good example of this action may be seen along the rail- 

 road between Harwich and Brewster, where a bar separates Long Pond from 

 Bangs Pond. Another such bar lies west of "Great Hill," near Chatham. 



Most of these glacial lakelets have steep banks of gravel or sand. Some 



of those on the south side of the Cape once had outlets at levels several feet 



above their present surfaces, and from a few of them, as noted above, the water 



flows out. Several of these lakelets are more than 50 feet deep. 



Mr. William Gould Vinal x gives the following figures showing the areas and 



the maximum depths of several ponds on the Cape : 



Estimated Greatest 



depth in 

 Township acres feet 



Name 



Moon 2 Provincetown 



Long Wellfleet. . . . 



Great Eastham 



Little Cliff. ... Orleans 



Cliff Brewster .... 



Baker's Brewster .... 



Cobb's Brewster .... 



area in 

 acres 

 ?. . 

 .. 34.. 

 ..112.. 

 .. 20.. 

 ..141.. 

 .. 88.. 

 .. 21.. 



Mill Brewster 110. 



Long Harwich 778 . 



White Chatham 35 . 



Fresh Dennis 25 . 



Scargo Lake Dennis 60 . 



Long Centreville 69 . 



Peter's Sandwich 176 . 



Spectacle Sandwich 151 . 



Mashpee Mashpee 395. 



. 3 



.44 

 .32 



.54 

 .81 

 .63 

 .11 

 . 9 

 .66 

 .55 

 . 9 

 .48 

 .23 

 .48 

 .39 

 .68 



Harbors and Creeks 



The only large harbor on Cape Cod is at its extreme north end, inside the 

 curved sand spit formed of waste worn from the cliffs and thrown up by the 

 winds and waves on what appears to have been, at least in part, a shoal. Pro- 

 vincetown Harbor, which was known to navigators on this coast before Pilgrims 



1 William Gould Vinal, Cape Cod Ponds, Cape Cod Magazine, 3, Sept. 1917, pp. 9-14. The Cape 

 Cod Publishing Co., Wareham, Mass. This article contains a brief popular account of the formation 

 of swamp vegetation in the shallow ponds. 



2 Moon Pond is in Truro, east of the Province Lands. 



