CAPE COD GEOLOGY 



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and the gravel under the Eastham plain may have been laid down in the same 

 manner at nearly the same time. The creases here are of the type formed by 

 streams carrying little or no sediment and not heavily loaded distributary wan- 

 dering streams, such as are found on deltas and alluvial tracts that are being 

 actively aggraded. 



Wilson 1 supposed that the Wellfleet high plain was formed by glacial streams 

 just before the Eastham plain was formed. He held that, at his Wellfleet stage 

 of Lake Shaler, the site of the Eastham plain was occupied by a tongue of ice 

 that extended eastward from an off shore lobe of the ice sheet. This explanation 

 of the kame field between the till-covered ground in Orleans and the creased 

 plain north of it overlooks the probability that ice from the Falmouth substage 

 remained there in stagnant patches. Abundant evidence of the existence of such 

 remnants of ice is found in the lakelets in the moraine, such as Cliff Pond and 

 the neighboring ponds in Brewster. The ice certainly stood on the sites of these 

 ponds until the end of the Falmouth glacial substage. The remnants of ice 

 about Eastham Centre were probably parts of the interlobate ice at the Falmouth 

 substage. Most of the ice on the site of the unbroken plain had no doubt then 

 melted except that in the creases about Eastham. The clear evidence that the 

 water which formerly discharged across the plain in the creases, the necessity 

 of admitting the existence at this time of ice on the east side of Cape Cod and 

 in the depressions and ice-block holes in Chatham, Orleans, Brewster, and else- 

 where in the low places of the moraine as far west as Sandwich appears to permit 

 no escape from the theory of Wilson that the water which gathered in the space 

 vacated by the ice back of the moraine found exit from the ice-barred growing 

 crescent in the southern part of the site of Cape Cod Bay to a lower level through 

 the Manomet channel or fosse. 



To the water thus confined between the moraine and the receding ice front 

 in Cape Cod Bay Wilson gave the name "Lake Shaler." The water level of this 

 glacial-dammed lake, whatever may have been its extent, was controlled by the 

 sill of sand in the Manomet fosse at Sagamore, which stood nearly 32 feet above 

 mean low water in Buzzards Bay and more than 34 feet above mean low water 

 in Barnstable, or Cape Cod Bay, or a little more than 25 feet above mean sea 

 level. 2 This col is 27 to 28 miles south by west of the western limits of the East- 

 ham plain. The bottom of the Manomet valley is composed of stratified drift 



1 Wilson, J. Howard, The glacial history of Nantucket and Cape Cod, pis. 36-37. New York, 1906. 



2 Report of the Joint Committee of 1860 upon the proposed canal to unite Barnstable and Buzzards 

 Bays, Public Document No. 41, pp. 26, 31. Boston, State Printers, 1864. This report includes a profile 

 along the line of the proposed canal and a small-scale hachured chart. 



