538 PROCEEDINGS OF NEW YORK MEETING. 



Exogyra costata. Starting with this horizon, which forms the base of the series in 

 the lower Cape Fear river region and is the most extensively represented <>t' any of 

 the fossiliferous deposits, we find that in several localities it is overlain by a light- 

 colored calcareous marl, that in the neighborhood of Wilmington occurs as a compact, 

 fine-grained limestone or as a firmly cemented calcareous conglomerate. A.n exami- 

 nation of the region shows that this marl occupies wide basins or hollows within the 

 Cretaceous. It may be considered as Eocene. It- paleontologicul characteristics will 

 be referred to later. Widely extended over Eocene and Cretaceous alike is an inco- 

 herent >hell marl that may be referred to the Miocene. This, in brief, is the order of 

 Buperpositi >f the several formations with which we have to deal. 



These pediments probably represent a succession of events somewhat a« follows : At 

 the close of the Cretaceous period, the deposits that had been accumulated were ele- 

 vated above the sea for a sufficient length of time to allow the meandering streams 

 from the mountainous regions to the west, together with local tributaries, to excavate 

 -hallow basins. It is, moreover, evident that this process could not have been con- 

 tinued sufficient!}' long to plane off or base-level the region, else the depressions 

 themselves would have disappeared. When this land surface became depressed below 

 the sea, the deposits of the Eocene, formed largely from the remains of marine animal-. 

 were strewn over an uneven sea-floor. When elevation had brought them above the 

 level of the sea, denudation again began, bearing away the materials accumulated. 

 The elevation could not have been great, hut erosion on the other hand was long con- 

 tinued, until the surface of the region was approximately base-leveled. In this plan- 

 ing down of the land, the higher ridges of the Cretaceous were likewise removed, so 

 that an almost level sea-floor was this time presented for the reception of the sands 

 and shells of marine organisms which form the next formation, recognized as Miocene. 



A geological map of the Cape Fear river basin would exhibit the Eocene in numer- 

 ous detached areas, while the Miocene would be found in long hand- along the water- 

 courses, an arrangement of the deposits that would be anticipated after they had passed 

 through the various cycles of change above recorded. 



That these various formation- present pal itological peculiarities was early per- 

 ceived. From the fact that the limestone afforded fossils which were recognized as 

 in part of Cretaceous age, it was referred to the upper Cretaceous, or by others held 

 e transitional in character between the Cretaceous and Eocene. 



Lyell * stated in a communication to the Geological Society of London, made in 

 1842, that one of his chief reasons for examining the geology of the southern Atlantic 

 states was "to a -certain whether any rocks containing fossils of a character interme- 

 diate between those of the Cretaceous and Eocene really exist." The result was that 



he found •• n condary fossils in those beds which have been called upper Secondary 



and supposed to constitute a link between the Cretaceous and Tertiary formations." 

 Lyell collected from the lime-tone at Wilmington and Rocky Point, the localities 

 most carefully examined by the writer. Although the facts presented may not affect 

 I, veil- general conclusions, yet the occurrence of characteristic Cretaceous fossils at 

 the same horizon with Eocene i- beyond dispute. 



Tuomey stated before the American Association for the Advancement of Science 



in l-i- that " well characterized Cretai us forms " occur at Wilmington in the 



.-a me beds with ■ .it are "considered characteristic of i he Eocene of the United 



• Pi ..f i ondon, rol. ::. 1842, p 7 



'roe, \ne-i a- \i . s,-i , v.t i, im- 



