782 GEOLOGY 



allowing the sea to again overspread considerable areas from which 

 it had been temporarily excluded. In western and central Europe 

 the maximum submergence of the Eocene seems to have Urn 

 accomplished by the middle of the period. Toward its close, the 

 epicontinental waters of the northwestern part of the continent were 

 again restricted. These changes are inferred from the consider- 

 able development of fresh- and brackish-water beds in the lower 

 part of the system, of marine beds above them, and of non-marine 

 formations again at the top. Most of the system in central and 

 western Europe is clastic, and the beds are still unindurated, for 

 the most part, and not very thick. 



In the south, the Eocene sea spread much beyond the borders 

 of the present Mediterranean, covering much of southern Europe, 

 northern Africa, and part of southeastern Asia. The eastward 

 extension of this sea joined the Indian Ocean, cutting off the 

 southern peninsulas of Asia from the Mainland to the north. A 

 narrow sound east of the Urals probably connected the Arctic 

 Ocean with the expanded Eocene Mediterranean. Out of this 

 extended sea rose many islands, some of which correspcnded in 



position to the Alps, Carpathians, 

 Apennines, and Pyrenees. 



On the bottom of this great body 

 of water, which should perhaps be 

 thought of as a part of the ocean 

 rather than as a mediterranean sea, 

 limestone was deposited on an ex- 

 tensive scale. Much of it is made 

 ~lfmes t tone nUm: U P almost wholly of the shell 



nummulites (foraminifera, Fig. ~> 



and is found from one side of the Old World to the other. 

 Since it is often thick (locally several thousand feet), a 

 as wide-spread, the sea must have swarmed with fornmmifeni, 

 and the period must have been long. 1 la n 11 y anywhere else in the 

 rocks of the whole earth are there indications of such great numbers 

 of organisms of one kind. The Fusulina limestone of the Carbonif- 

 erous is perhaps most nearly comparable. Some idea of the 

 deformative movements since the Eocene may be gained from 



