936 HISTORICAL GEOLOGY. 



Eadiolarian earths. The Barbados are outside of the outermost range of islands ; and 

 whatever changes of level they have experienced may not have affected the Caribbean Sea. 

 At present the bottom of this sea is made of Globigerina and not of Radiolarian earth. 

 Eadiolarian deposits occur also on Haiti, Jamaica, and Cuba ; but they have less extent 

 and are less decisive as to change of level. 



Whether the following changes of level were epeirogenic or not is undecided. 



Over Europe and Asia the same elevation of the land over extensive areas 

 was in progress, especially during the Pliocene. Europe was much changed 

 in elevation cotemporaneously with the disturbance in the Alps ; and " by 

 the close of the Pliocene all its main features had come into existence." The 

 Alps were carried up probably 12,000 feet or more, and the Pyrenees over 

 10,000 feet. 



The Himalayan chain, a region of upturning at the close of the Miocene 

 ■ (if not before, at the close of the marine, Xummulitic epoch), when 20,000 

 feet lower than now, began afterward, or simultaneously, its slow emergence 

 and attained its present level according to Blanf ord by the end of the Pliocene 

 or in the early Quaternary. The Tertiary beds of the Sub-Himalayas, or the 

 SiAvalik Hills, which are chiefly freshwater Pliocene and contain the remains 

 of the Fauna Antiqua Sivalensis, were laid down during the progress of the 

 uplift. During all this Himalayan elevation, peninsular India underwent 

 little change. 



Blanford derives additional evidence as to the remoteness of the time 

 of the uplift, from the existing Mammalian fauna of Tibet. Out of 43 species 

 of Mammals in Tibet, pertaining to 26 genera, 27 species and 4 genera are 

 not known out of Tibet. Out of 16 species of Eodents, only one is not 

 purely Tibetan. The various facts accord with the view that the elevation 

 of the Himalaya Eange commenced early in the Tertiary. 



During the early Eocene, as well as the Cretaceous period, the British Channel was 

 crossed by an Interior basin, perhaps having, as Jukes-Browne suggests (1892), a range 

 of land over the western part, uniting Brittany to Cornwall. Bat in the Miocene, on the 

 same authority, even the area of the Eocene Anglo- Parisian basin had become dry land ; 

 and in the Pliocene, ridges were formed crossing the Channel from northwest to southeast, 

 as the Weald Axis, the Portsdown, the Purbeck corresponding to the axis of Artois, 

 Bresle, and Bray to the south. Only in the Middle Quaternary, after a phase in which a 

 passage extended across from below Dover and Brighton on the north to the Province of 

 Calais in France, did the Channel secure its place through a general subsidence. 



"Thus, throughout the Tertiary era, the continents of Europe and Asia,, 

 as well as America, were making progress in their bolder surface features^ 

 as well as in the extent of dry land. The evidence is sufficient to show that, 

 wnen the period ended, the continents had in general their mountains raised 

 to their full height." The evidence is stronger now than it was, more than 

 30 years since, wher those words were written.' 



GeosyncUnal movements over the oceanic basin — the " Coral Island sub- 

 sidence.^^ — That there were profound geosynclines over the oceanic basins 

 during the later Tertiary and early Quaternary is put beyond question by 



