RECENT INVESTIGATION OF COASTAL PLAIN FORMATIONS 653 



strata, both marine and non-marine, from New Jersey to the Mississippi basin, 

 since even the lowest known Upper Cretaceous deposits in this area (Raritan 

 formation) contain a few marine invertebrates of possibly identical species 

 with those of higher horizons. Those who hold this view necessarily consider 

 that the earlier Turonian and Cenomanian epochs are unrepresented, since 

 every one now agrees that the unconformably underlying deposits are Lower 

 Cretaceous. It is quite possible, however, that a more exhaustive study of 

 these faunas may show them to be in part of pre-Senonian age. 



It is essential, however, before passing final judgment on the basis of marine 

 invertebrates to examine the evidence furnished by the fossil plants which 

 occur in great variety in the lowest beds beneath those containing the marine 

 invertebrates, as well as in interbedded strata in the middle of the series. 

 Berry, who has been engaged in a comparative study of the Cretaceous floras of 

 the Atlantic and Gulf coasts, states that the Magothy-Black Creek flora is iden- 

 tical with that of the Tuscaloosa. Not only do they have the same floral char- 

 acteristics, but the species are in a large number of instances identical. Fur- 

 thermore, the same forms occur in the Woodbine formation in Texas and in the 

 Dakota beds of the West. The flora has been regarded as characteristically 

 Cenomanian, although it may represent the somewhat meager Turonian flora 

 which succeeds it, and therefore belong to that horizon. On the other hand, it 

 is distinctly older than the Montana flora of the West and its Senonian equiva- 

 lent in Europe. 



The evidence afforded, therefore, by the invertebrates and plants is appar- 

 ently in conflict, since the former present a Senonian facies throughout, accord- 

 ing to many invertebrate paleontologists, while the latter are regarded by 

 paleobotanists to be characteristicaly Cenomanian, or possibly Turonian, in age. 

 In this connection we find in the western Gulf that the Woodbine formation, 

 which is the representative of the Dakota sandstone farther west, and which 

 contains, as already pointed out, a Black Creek-Magothy-Tuscaloosa flora, is 

 succeeded by marine beds known as the Eagle Ford and Austin Chalk forma- 

 tions, which represent the Colorado group farther west, and that these are again 

 succeeded by deposits containing the Ripley fauna, the latter being regarded as 

 the equivalent of the Montana group of the Rocky Mountain district. Since 

 the Dakota has been generally regarded as containing a Cenomanian flora and 

 the Montana a Senonian fauna and flora, the Colorado and its equivalents have 

 been assigned to the Turonian. As the Montana flora is considered by paleo- 

 botanists as quite distinct from and much younger in its facies than the Da- 

 kota, it is difficult to see, if we are not to ignore the evidence of paleobotany, 

 how, as some have supposed, the entire series of Upper Cretaceous sediments 

 on the Atlantic and Eastern Gulf coasts can be assigned to the Senonian. Such 

 a conclusion is still further weakened by the fact that the Woodbine beds may 

 be stratigraphically continuous beneath the Mississippi embayment with the 

 Tuscaloosa deposits farther east in which the same flora occurs. A much more 

 exhaustive study of the stratigraphy of the Cretaceous deposits of the Central 

 and Western Gulf regions is clearly demanded, therefore, before these questions 

 can be finally settled. 



It is apparent, in any event, that we are still forced to consider the possibil- 

 ity of the Upper Cretaceous sediments of the Atlantic and Eastern Gulf coasts 

 representing horizons earlier than the Senonian. Since the Turonian has not 



