THE UPPER CRETACEOUS DEPOSITS OF 

 MARYLAND 



BY 

 WM. BULLOCK CLARK 



INTRODUCTION 



The Upper Cretaceous deposits of Maryland can only be interpreted 

 through an understanding of the physiography and geology of the broad 

 province of which the State of Maryland forms a part. The physical 

 features which characterize this area may be traced for varying distances 

 into adjoining regions, some being recognized as far as the New England 

 coast on the north, and others as far as the Gulf Region on the south. 



The Physiography 



The region here considered forms a portion of the Atlantic slope, 

 which stretches from the crest of the Alleghanies to the sea, and which 

 is divided into three more or less sharply defined regions known as the 

 Coastal Plain, the Piedmont Plateau, and the Appalachian Region. 

 These three districts follow the Atlantic border of the United States 

 in three belts of varying width from New England southward to the 

 Gulf. Maryland is, therefore, closely related in its physiographic fea- 

 tures to the states which lie to the north and south of it, while its central 

 location on the Atlantic border renders it perhaps the most character- 

 istic in this broad tract. In crossing the three districts from the ocean 

 border the country rises at first gradually, and then more rapidly, until 

 it culminates in the highlands of the western portion of the state. 



The Coastal Plain is the name applied to the low and partially sub- 

 merged surface of varying width extending from Cape Cod southward 



