THE TERTIARY PERIOD 309 



were also upraised not earlier than in late Miocene, since Miocene 

 strata are there found about 7000 feet above sea-level. 



Considerable igneous activity accompanied the late Miocene 

 orogenic movements. 



Pliocene. — The Pliocene opened with comparatively little of 

 Europe under marine waters, only a little of southern England, 

 Belgium, the northwestern border of Germany, a little of southern 

 France, and much of Italy having been submerged (see map Fig. 

 189). Only in Italy are thick marine deposits known where the 

 sediments washed from the newly built Apennines accumulated 

 to a thickness of from 1000 to 3000 feet. Since some of these 

 deposits now lie at altitudes of 2000 to 3000 feet, it is evident that 

 the Apennines were again notably upraised after the deposition of 

 the Pliocene sediments. Volcanoes were active in the Mediter- 

 ranean region, especially in Italy and Sicily, where volcanoes like 

 Vesuvius and Etna began their eruptions. 



In southeastern Europe conditions were favorable for much 

 deposition of continental material — lake, river, and terrestrial 

 deposits. 



Marine Pliocene extends up the Nile Valley for many miles. 

 As a result of the erosion of the newly upraised Himalayas, a 

 deposit of sandstones, conglomerates, clays, etc., several thousand 

 feet thick, accumulated at the southern base of those mountains 

 during Pliocene time. 



In South America Pliocene deposition took place over much of 

 southern Argentina, deposits of this age being upturned on the 

 eastern flank of the southern Andes. 



Climate 



During the Eocene the existence of a subtropical climate well 

 toward the northern boundary of the United States, and in Europe 

 as far north as Germany and the British Isles, is abundantly proved 

 by the character of the fossil plants and animals. 



Over the Great Plains region of the United States the climate, 

 now semiarid, was distinctly moister during the earlier Tertiary, 

 because the great deposits of lignite prove the existence of prolific 

 plant life in swamps. Fossil Figs, Palms, and Magnolias in the 

 western interior indicate much warmer and moister climate than 

 now. This was in harmony with what we know of the physical 



