Abstracts. 



upper Cretaceous of the Northern AtltDitic Coastal Plain. 15\- \\'m. B. 

 Clark. 

 This paper was prepared in cooperation with Messrs. R. M. Bagg 

 and Geo. B. Shattuck who have been Professor Clark's geological assist- 

 ants for several years. The authors divide the upper Cretaceous into 

 (i) the Matawan formation (including the Crosswicks clays and Hazle, 

 sands), (2) the Monmouth formation (including the Mount Laurel 

 sands, the Navesink marls, and the Redbank sands), (3) the Rancocas 

 formation (including the Sewell marls and Vincentown lime sands), 

 (4) the Manasquan formation. Conformably overlying the last and 

 probably of Eocene Age is the Shark River formation. The areal 

 distribution of these five formations was represented upon a large map 

 on the scale of one mile to the inch, which embraced the area between 

 New York Bay and the Potomac River. The variations in distribu- 

 tion and structural relations presented throughout this distance of over 

 200 miles were discussed as well as the faunal characters of the several 

 formations. The unconformity existing between the lowest of the Cre- 

 taceous formations and the Potomac formation below was pointed out 

 as well as the clearly defined unconformity of the Miocene upon the 

 uppermost member of the green sand series ; at the same time the evi- 

 dence for and against unconformity between the Monmouth and Ran- 

 cocas formations was discussed without a final decision being rendered 

 upon this point, the evidence being somewhat conflicting in this matter. 

 The Matawan-Monmouth formation was held to be equivalent to the 

 Eutaw, Rotten Limestone and Ripley groups of Alabama and the 

 Pamunkey formation equivalent in all probability to all or the greater 

 part of the Lignitic, Buhrstone and Claiborne of the same area, so that 

 the Rancocas, Manasquan and Shark River formations must represent 

 the interval between the Ripley and Lignitic of the Gulf. The first 

 two are regarded as of Cretaceous, the last of Eocene Age. The differ- 

 ent Cretaceous formations of the Atlantic coastal plain were shown to 

 be approximately equivalent to the Senonian and Danian of Europe. 



