THE EOCENE PERIOD. 215 



formable on the Eocene, and it was at the close of the Eocene (or per- 

 haps during the Oligocene) that an island, now included in the penin- 

 sula of Florida, was formed. In the Carolinas, and in the western 

 Gulf region, the .conformity between the Eocene formations and those 

 classed as Oligocene seems to preclude notable changes of geography 

 along the coast in the southeastern part of the United States, at the 

 close of the period. 



Foreign. 



Europe. — The Eocene beds of Europe may be grouped in three 

 principal areas, viz.: (1) The London-Franco-Belgian basin, including 

 the deposits of England, northern France, Belgium, etc.; (2) those 

 of south Europe west of Russia, and (3) those of south Russia. This 

 distribution, when compared with that of the late Cretaceous, shows 

 that there was a wide-spread withdrawal of the sea from northwestern 

 and central Europe at or near the close of the Cretaceous period. At 

 this time Great Britain probably became connected with the con- 

 tinent, though considerable lakes, estuaries, and perhaps other areas 

 of deposition remained over western Europe within the area from 

 which the sea withdrew. Later, but still early in the Eocene, sub- 

 mergence of the land set in, allowing the sea to again overspread con- 

 siderable areas from which it had been temporarily excluded. In 

 western and central Europe the maximum submergence of the Eocene 

 seems to have been accomplished by the middle of the period (Fig. 425). 

 Toward its close, the epicontinental waters of the northwestern part 

 of the continent were again restricted. It follows that in the earliest 

 stages of the period, the epicontinental deposits in the northern and 

 central parts of the continent were largely of fresh- and brackish-water 

 origin; that those of a later stage were more generally marine; while 

 those of still later stages were largely non-marine. The geographic 

 changes in southern and eastern Europe at the close of the Cretaceous 

 period seem to have been less considerable. 



The interval of rather general emergence in northwestern Europe, 

 following the close of the Cretaceous, must have been a somewhat 

 protracted one, for the next marine deposits (mid-Eocene) of this 

 region carry a fauna notably different from that of the Cretaceous 

 beds below. During this interval, the Mesozoic types of life (except 

 the lower forms) gave place to modern ones. In many places, too, 



