734 HISTORICAL GEOLOGY. 



Carboniferous and lowest Permian, and this is true also in Lancashire and 

 Yorkshire. The ''Hercynian system" of Bertrand includes a long range of 

 dislocated Devonian and Carboniferous rocks extending from Brittany to 

 the Vosges and Ardennes, and beyond along the Black Porest, the Harz 

 to Bohemia. The line corresponds nearly with the *' System of the 

 Rhine" of de Beaumont, which was upturned, as he showed, before the 

 Triassic period. 



The " great fault " in the Alps raising the crystalline schists in the zone 

 of Mont Blanc, between the Bernese Alps on the east and the maritime Alps 

 on the southwest, was made between the Carboniferous and Triassic (or the 

 Lias, where the Trias is absent). The coal-formation, which is extensively 

 distributed in the Swiss Alps, is in part semi-crystalline. 



In Russia, strata are generally horizontal or nearly so, and lie above the 

 Carboniferous without unconformability. In the closing part of Paleozoic 

 time, either after the Carboniferous or after the Permian, a belt of rocks 

 along the Urals was folded and crystallized ; for Carboniferous rocks are 

 flexed and altered in the same manner as in the Alleghany region. But the 

 backbone of the Urals is Archaean. 



NORTH AMERICAN GEOGRAPHY AFTER THE REVOLUTION. 



The various movements over North America closing Paleozoic time ended, 

 as announced on page 714, in making dry land of the eastern half of the 

 continent. The western coast within the United States extended along a 

 north-and-south line near the meridian of 95° W.. and farther north trended 

 northwestward through British America, as delineated on the accompanying 

 map (Fig. 1155). The dry land had its Appalachian Mountain chain, and 

 was for the most part finished in its rock foundation, its mountains, and its 

 store of coal-beds. 



The positions of the rivers and lakes are doubtful. There were, beyond ques- 

 tion, a St. Lawrence River and other streams flowing off from Archeean lands. 

 The Hudson River had been a small stream from the Adirondack s, merely the 

 head of the present Hudson River, emptying into the waters of the eastern 

 Continental Interior below Albany. But what course it took after the mak- 

 ing of the Appalachians, remains to be learned from later records. The east- 

 ern coast-line of the continent, south of 'New York, which was still outside of 

 the existing position of the sea border, is placed on the map near that of the 

 100-fathom line — the true margin of the Atlantic basin. For not only are 

 all Paleozoic formations later than the Lower Silurian unknown on this part 

 of the border, but also all marine formations of the Early and Middle Mesozoic. 

 This was probably true, likewise, of the Gulf border. Whatever marine beds 

 were formed are now deeply submerged. The burial of the shore region by 

 Cretaceous and Tertiary strata prevents direct observation except through 

 borings, and these have not yet been carried to a sufficient depth to decide 

 the question. 



