180 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



croinsr eastward not less remarkable than that observed in 

 the opposite direction in the strata of the same age in North 

 America. 



EUROPE AND ASIA IN THE GLACIAL PERIOD. 



Belt lias put forward a theory with regard to the glacial 

 period in Northern Europe. He supposes, with Croll, that 

 the North Sea between Scandinavia and Scotland was at one 

 time filled with ice, so that (Great Britain being then con- 

 tinuous with the continent) the German Ocean was blocked 

 up to the north, and formed a great lake, the waters of 

 which found an outlet to the southwest, and gradually cut 

 through the Straits of Dover. From the waters of this lake, 

 which gradually became fresh, were deposited the clays of 

 Southeastern England. The ice, as it advanced southward, 

 reached the coast of Norfolk, and not only denuded and dis- 

 turbed these clays, but, according to Belt, uplifted both the 

 Cretaceous and Neocomian, and even forced the boulder- 

 clay beneath their inclined strata. 



THE LOESS OF CENTRAL EUROPE. 



The alluvial deposit known as the loess, which attains a 

 height of 900 feet above the sea on the Rhine and 1300 feet 

 on the Danube, is, in the opinion of Belt, of glacial origin, 

 and, in fact, the equivalent of the northern glacial drift, which 

 passes gradually into the loess. The conditions which per- 

 mitted the deposition of these were, according to Belt, 

 brought about, not by a subsidence of the land, but by a 

 great glacier which occupied the bed of the Atlantic to a 

 height of about 1700 feet above the sea, damming back the 

 rivers which drain the continent, and converting this into a 

 vast lake, which was filled with icebergs. He has since ex- 

 tended this hypothesis, and supposes that another great gla- 

 cier extended down the North Pacific, arresting also the 

 drainage of Asia. 



After the Miocene age, the Aralo-Caspian area was cut off 

 from its connection with the Mediterranean, when the north- 

 ern basin grew fresh, and discharged its waters to the north, 

 until, by the accumulation of ice both in the Atlantic and 

 the Pacific, the drainage of this region was checked, and 

 there Mas formed a great lake, into which came the icebergs 



