608 H. L. FAIRCHILD POST-GLACIAL UPLIFT OF XEW ENGLAND 



The brilliant clays at Gay Head are capped by Pleistocene sands. The 

 wave-smoothed plateau on which stands the lighthouse, restaurant, and 

 wireless station has an altitude by the map of 130 to 135 feet. By the 

 map of isobases the marine summit is about 155 feet and overtops the 

 highest knoll. The higher hills of the island exhibit effects of wave- 

 action, but the moraine is so stony that the limit of wave-work is not 

 clear. 



In discussion of a paper by David White (35), F. J. H. Merrill said: 



"The opiDion of the writer, that the Gay Head strata were Post-Pliocene, 

 was chiefly based on the evidence of a stratum of Post-Pliocene sand, which 

 is the uppermost member throughout the section, being repeated frequently 

 by faults, and at one point containing fragments of Venus mercenaria and 

 other Quaternary shells*' (37, page 556). 



In 1892 P. E. Uhler also made record of the surficial sands (43, pages 

 176-177). 



At Sankatay Head, east end of Xantucket, the bedded sands carry 

 fossils to at least 50 feet above tide. Papers 3, 4' 16, 17, 18, 31, 38, and 

 48 refer to this occurrence. In paper 38, pages 10-16, Merrill said that 

 he measured the stratified sand to 83 feet above sealevel. 



Another critical locality is the north end of Manomet Hill, some five 

 miles southeast of Plymouth. This hill is crossed by the road to 

 Manomet village at about a mile from the sea. The altitude of the road 

 summit is 240 to 250 feet. Up to about 230 feet the evidence of stand- 

 ing water is conspicuous and abundant, in horizontal sands and gravel. 

 On the west side of the hill a broad gTavel plain lies at about 230 feet. 

 On the east slope water-laid deposits are well exposed in the new road 

 cutting at 230 feet, where the surface deposit is 3 to 5 feet of fine sand, 

 inclosing numerous boulders, evidently the product of ice-rafting. 



The stratified saftds by the Highland Light, North Truro, on Cape 

 Cod, are well known. The altitude of the top of the cliff of bedded sand 

 is about 120 feet, but the wave-smoothed plain on which the lighthouse 

 stands is 140 feet. Looking southward, the work of standing water is 

 apparent in the perfect horizontality of the land surfaces and the sky- 

 line. The theoretic uplift here is 185 to 190 feet, which gives 45 to 50 

 feet of submergence. The presence of huge boulders in the gravels, seen 

 by the road near the Highland House, one being 10 feet in diameter, is 

 evidence of sufficient depth of water to permit the 'rafting of heavy 

 boulders. There is no suggestion here of surficial drift. Standing 

 water was positively the last occupant of the region. 



In his paper on changes of level at Cape Ann, Massachusetts (71), 



