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CAPE COD GEOLOGY 



271 



The Outwash Plain 



The impressive feature of the Falmouth substage is the great fan of out- 

 wash sand in the towns of Sandwich and Falmouth. This fan spreads out from 

 the boulder-strewn ice-contact surface on the north, which stands at an eleva- 

 tion of 200 feet or more above the sea. Between the 200 and the 160 foot levels 

 this fan slopes southward and southeastward for a short distance at the rate of 

 about 100 feet to the mile. It stands behind the sites of the outlying ice blocks 

 that gave rise to Snake Pond, at Forest Dale, and the chain of waterless kettle 

 holes that lie at the east base of Pine Hill. This fan appears to have been the 

 last part of the sloping plain to have been deposited at the ice front. From 

 Snake Pond southward the slope is gentler but somewhat difficult to generalize 

 upon because tracts of lower ground appear to have been held open by remnants 

 of the Nantucket ice. South of the belt of ponds in the latitude of Hatchville, 

 in Falmouth, the surface is channeled by stream creases, which are found along 

 the southern border of the fan between Falmouth and the vicinity of Waquoit 

 Bay. The bottoms of the widened-out lower courses of these creases lie below sea 

 level and form a series of beach-barred lagoons whose longer axes are perpendic- 

 ular to the coast line, like those bordering the outwash plains of Marthas Vine- 

 yard and Nantucket. 



North of the Falmouth moraine, along the shore of Cape Cod Bay, there 

 are a few till-covered morainal tracts, such as Town Neck and Scorton Neck, 

 in Sandwich, and Nobscusset Point and Quivet Neck, which rise nearly to a 

 height of 80 feet, in Dennis. Sections in cliffs or artificial cuts show that these 

 moraines are composed of beds of stratified gravel and sand. Precisely similar 

 low-lying areas lie inside of the moraine skirting Buzzards Bay and forming 

 so-called "necks," or even islands, at North Pocasset, near Cataumet, and 

 between North Falmouth and West Falmouth. Near North Falmouth there 

 are no boulders on the surface, which has the form of a terrace of stratified 

 sand that stands 60 feet above sea level. The associated boulder-strewn tracts, 

 some of which are higher, are obviously older than the moraine, yet this terrace 

 shows a good ice contact at Cedar Pond and just north of it, along the inner 

 part of Cataumet harbor, and is probably a late outwash of sand from the 

 retreating ice front. This terrace was made above sea level. 



THE INTERLOBATE MORAINAL AREA 



The Eastham Plain 

 North of the town of Orleans there are deposits of drift which have been 

 regarded by some as more recent than the Falmouth moraine. Chief among 



