1. Bowman — Atlantic Preglacial Deposits. 323 



Tertiary sands (p. 200) is noted. Were lithe-logic identity 

 alone a determinant in correlation, we should be completely 

 justified in calling these beds Upper Cretaceous. The irreg- 

 ularity of the New England shoreline, and the considerable 

 distance (52 miles) between Third Cliff and Gay Head, make 

 it probable that the physical conditions under which sedi- 

 mentation took place were not persistent throughout the 

 entire district, and it is, therefore, not surprising that at 

 Third Cliff there should be present a layer of red sand cross- 

 bedded throughout on a large pattern which does not appear 

 in the Gay Head section. With this exception the beds over- 

 lying the first unconformity at Third Cliff are again similar to 

 those at Gay Head, except for the osseous conglomerate which 

 is not present at Third Cliff, but the glauconitic sands are 

 present bearing the white well-rounded quartz pebbles. More- 

 over, these beds are at precisely the same altitude as those 

 definitely known to be Miocene (p. 321) at Marshfield, seven 

 miles south. The Marshfield beds rest upon granite, the dark 

 sands and clays of Third Cliff upon white sands. On the 

 whole, the relatively close agreement of unconformities and 

 lithologic characters seems very striking. While this resem- 

 blance, as was noted on the preceding page, may have slight 

 value on account of marginal redeposition without the destruc- 

 tion of characteristic features, it is in a measure significant on 

 account of the distinctness of the separating planes in the 

 deposits and the strongly marked individual character of each 

 bed. It is the more convincing to one who has seen the 

 Atlantic Cretaceous and Tertiary farther south and has noted 

 the persistent and distinctive character of these deposits. 



It would be quite unsafe to base a correlation of the Third 

 Cliff deposits with those of New Jersey entirely on the evi- 

 dence presented here, but it is not without interest to note 

 that with a single exception the Red Bank sands occur exclu- 

 sively in the Monmouth formation, Upper Cretaceous, u except 

 in certain marginal phases of the Rancocas formation,"'* 

 which latter is itself of Upper Cretaceous age. Glauconite 

 occurs in great abundance in the Upper Cretaceous of New 

 Jersey, and but sparingly at Gay Head, and certain yellow 

 sands are found alike in the Miocene and Upper Cretaceous. 



Paleontolocjic Evidence. — A fourth probability is suggested 

 by the studies of T. C. Brown of Columbiaf on the Chappa- 

 quiddic fauna from Martha's Vineyard. A comparison of 

 this fauna with the Eocene faunas of the Atlantic and Gulf 

 provinces indicates that the species closely resemble those 



* Upper Cretaceous Formations of New Jersey, W. B. Clark ; B. G. S. A. 

 viii 313-358, 1896-97. 



f A New Lower Tertiary Fauna from Chappaquiddick Island, Martha's 

 Vinej T ard, Science, New Series, vol. xxi, No. 548, pp. 990-991, 1905. 



