Maryland Geological Subvey 107 



apparent, however, that the Upper Cretaceous formations of Maryland 

 are continued to the southward beneath the Tertiary formations into 

 southern Virginia, a region which must have been much more extensively 

 depressed during Tertiary time than Maryland and the district to the 

 north of it to have buried the Upper Cretaceous so deeply beneath the 

 later deposits. Whether more of the section penetrated by the well 

 borings should be assigned to the Upper Cretaceous or whether the strata 

 of this age have materially thinned along the dip cannot be determined 

 from present knowledge. The facts in any event are far too meager to 

 determine the location of the coast line in Virginia during this period. 

 It seems equally probable that the Virginia strata were likewise con- 

 nected on the south with those of North Carolina where deposits repre- 

 senting the Magothy-Matawan-Monmouth series are represented in the 

 Black Creek-Peedee series. There is no definite evidence of the existence 

 of the Baritan formation in the Virginia well borings, and it is quite 

 certainly absent in North Carolina, together with the Patapsco and 

 Arundel formations of Lower Cretaceous age. A much greater interval is 

 therefore represented between the Lower and Upper Cretaceous strata in 

 North Carolina than in Maryland, although the formations absent in this 

 district may have been overlapped and actually exist farther seaward. 

 The Black Creek formation, as already pointed out, contains both the 

 flora of the Magothy and the fauna of the Matawan in interbedded layers 

 and lacks the single change from non-marine to marine deposits shown in 

 the northerly area in passing from the Magothy to the Matawan. Although 

 the physical conditions existing in North Carolina must therefore have 

 been somewhat different from those farther north, there is little doubt 

 that these deposits must be linked through Virginia with those of 

 the northern Atlantic Coastal Plain in the same general province of 

 deposition. The Peedee formation presents so many characteristics in 

 common with those of the Monmouth formation that although they are 

 separated by wide areas of overlapping Tertiary formations these deposits 

 must be considered as probably forming a continuous belt of sedimenta- 

 tion with the more northern areas. 



