630 



NEW YORK 8TATK MrSEUM 



admits a different interpretation, one favoring the dislocation of the 

 section before the deposition of the till but on a scale quite admis- 

 sible as the work of a I'lacier. The 

 dislociited beds dip at high angles 

 to thesoutli. The underlying blue 

 clays weather whitish, carry quartz 

 l)el)bles and slight traces of black 

 carbonized plant remains and are 



FlK.4 DeUUlofsecUonJustwestofpre- P'-e^^^"^^^ PotoUiaC or Crcta- 



cediug section. A, sands and prraveis; ccous. Tlicy are unconformablv 



B. till; C, loeasllke sands inclosing i . .4.1 xi " ^ 



boulders beneath the sands. 



Another dislocated section affect- 

 ing sands underlain by clays occurs at the southern end of Center 



-—J — ___ — _ island (lig. Tj. The clays are 



here dark blue, well laminated. 



'<^d^^1^./^^^^. ^"^ P^ss by gradations into the 



Fte. 5 Local section at Rocky point showing ^^^rlying sauds, recalling many 



deformetl blue clays and banded sands, uncon- SCCtioUS OU Cape Cod bay in 



formably overlain by till with boulders up to 2 > r 1 , , m 



feet in diameter, passing laterally into strati- ^iassacUUSCttS. 1 iie Upper ])art 



^'^^™^^* of the sands carries boulders; 



the whole may well be a basal 

 portin,, of the Columbia. At one point a small fold overturned 



southward has passed into a reverse 

 fold-fault. Viewed as an over- 

 thrust, the movement has been 

 northward. To accord with the 

 hypothesis of glacial thrust acting 

 from the north, it is necessary to 

 suppose that underthrusting has 

 taken j^lacc. 



The railroad from Oyster Bay to 

 Koslyn passes through three deep 

 cuts in an eastwest valley in Mill 

 Neck. In the cut nearest Ovster 



with boulders; C, J^^,.^ .^l^i^j^j^ ^^ ^j^^j^j^j^ ^^^^^^^ ^;^^^_ 



ably Cretaceous, appear at the bot- 

 tom, succeeded bv about 30 feet of coarse gravels, ill stratified and 



FUC. Section at headland on south- 

 'f «« of I nt. A, clay: ». yel- 



lowiHh >- . 

 earthy Kravel 



