316 Correlation of the Upper Cretaceous Formations 



described doubtless represent intervals of deposition that may be repre- 

 sented by deposits now buried beneath the Tertiary mantle, but so far as 

 known are not represented in their entirety in the surface outcrops of the 

 existing land. As already pointed out the most complete sequence of 

 Upper Cretaceous formations along the Atlantic border is to be found in 

 New Jersey, where the strata have been much more minutely subdivided 

 into stratigraphic units than is elsewhere possible. The major divisions, 

 however, may be traced over wide areas and are clearly recognizable 

 throughout the northern part of the Coastal Plain. Farther south, 

 although presenting many points in common with the northern districts, 

 the Upper Cretaceous has been somewhat differently subdivided and is 

 described under different formational names. At the same time the gen- 

 eral continuity of the series as a whole without doubt exists, notwith- 

 standing the necessity for the present of the existing local designations. 



The paleontologic characteristics afford ample evidence in the great 

 number of identical species of plant and animal remains, for the correla- 

 tion of the formations not only throughout the northern area but with 

 the Upper Cretaceous strata of the south Atlantic and Gulf regions. At 

 the same time the floras and faunas afford many forms that make possible 

 the correlation of the deposits with more distant areas and even permit 

 the reference of the formations to the standard Cretaceous section of 

 Europe. The significance of the faunas and floras from the standpoint 

 both of local and of more extended correlation will be discussed in the 

 subsequent pages. 



Correlation Within the Northern Atlantic Coastal Plain 

 The correlation of the Maryland Cretaceous formations with those of 

 Delaware, New Jersey, and the islands off the New York and New Eng- 

 land coasts is readily made on the basis of the continuity of the deposits. 

 the similarity of the materials, and the stratigraphic relations of the 

 several formations, as well as upon the basis of the identity in species of 

 a large number of plant and animal remains. 



During the past twenty years the senior author and his associates have 

 mapped in great detail the Upper Cretaceous formations throughout 



