TERTIARY AGE. 525 



feet : for marine deposits of the Cretaceous era exist in the mouutains 

 at this elevation. 



Thus the North American Continent, which, since early time, had 

 been gradually expanding in each direction from the northern Azoic, 

 eastward, westward, and southward, and which, after the Paleozoic, 

 was finished in its rocky foundation, excepting on the borders of the 

 Atlantic and Pacific and the area of the Rocky Mountains, had 

 reached its full expansion at the close of the Tertiary period ; and 

 even these border regions received afterward but small additions. The 

 progress from the first was uniform and systematic : the land was at 

 all times simple in outline ; and its enlargement took place with almost 

 the regularity of an exogenous plant. 



In Europe, the elevation of the Pyrenees took place after the Middle 

 Eocene, or at the close of the formation of the Nummulitic beds ; and 

 the same was true of the Julian Alps, and of the Apennines, Carpa- 

 thians, and also other heights in eastern Europe. The Nummulitic 

 strata have now a height of ten thousand feet in the Alps, and nine 

 thousand in the Pyrenees. The elevation of the chain of Corsica, and 

 some minor disturbances, in Italy and other parts of Europe, are re- 

 ferred to the close of the Eocene. The western Alps, ranging N. 26° 

 E., which include Mount Blanc, Mount Rosa, etc., were raised, accord- 

 ing to Elie de Beaumont, after the deposition of part or all of the 

 Miocene ; for the Molasse of this region was raised or disturbed by 

 the uplift, and not the Pliocene. In Britain, there were great erup- 

 tions of igneous rocks during or at the close of the Miocene, according 

 to Geikie, the dolerytic rocks, from the south of Antrim through the 

 chain of the Inner Hebrides to the Faroe Islands, being part of tho 

 results. The igneous beds of the Hebrides are three thousand to 

 four thousand feet in thickness, and overlie beds containing leaves of 

 Miocene plants. The Antrim deposits cover eight hundred to twelve 

 hundred square miles, and have an average thickness of five hundred 

 and forty-five feet. The earlier volcanic eruptions of Auvergne and 

 Velay are referred to the same era. The larger part of the dolerytic 

 and trachytic eruptions of Europe are of Tertiary origin. 



The elevation of the eastern Alps, from Valais to St. Gothard, along 

 the Bernese Alps, and eastward to Austria, ranging N. 74° E., is 

 attributed by the same geologist to the close of the Pliocene, as it 

 lifted the Pliocene, but did not disturb the Quaternary. Even in the 

 later part of the Pliocene era, there was an elevation of three thousand 

 feet, in apart of the island of Sicily (p. 512). Thus, throughout the 

 Tertiary period, the continents of Europe and Asia, as well as Amer- 

 ica, were making progress in their bolder surface features, as well as in 

 the extent of dry land ; and the evidence is sufficient to show that. 



