﻿170 Revieivs — Belt — On the Loes of the Rhine and Danube. 



I. — On the Loess of the Ehine and Danube. By Thos. Belt, 

 F.G.S. (Quarterly Journal of Science, January, 1877.) 



THE Loess in the valleys of the Ehine and Danube has formed 

 the theme of many papers published both here and on the 

 Continent, and numerous theories have been advanced respecting; 

 its origin ; but probably no bolder hypothesis has been put forward 

 than that now propounded by Mr. Belt. 



The paper commences with a description of the character and 

 extent of this deposit, the position it occupies with respect to the 

 rivers and slopes of the valleys being illustrated by woodcuts (in 

 which the vertical scale is of course greatly exaggerated). The 

 greatest elevation to which it attains in the valley of the Khine is 

 800 feet above the sea-level, whilst in the basin of the Danube it has 

 been found at a height of 1300 feet above the sea. 



Mr. Belt thinks that he has been able to trace the gradual passage 

 of the Loess into the northern drift; and the animal -remains that 

 are found in it being of the Glacial type (see ante, p. 168), he is led 

 to class the Loess as the southern equivalent of the northern drift 

 (the Upper Boulder-clay of Searles V. Wood). 



Eespecting the origin of this wide-spread alluvium, the author 

 shows in the jSrst place that it must have been deposited subsequent 

 to the excavation of the valley system, and not during the course of 

 its formation ; and he complains that " the usual explanation of the 

 facts of the Glacial period is one continued appeal to the hypothesis 

 of great oscillations of the earth's surface at that time." " But is 

 there," he asks, " really no other way of getting water up to the 

 heights we require without resorting to this extreme hypothesis ? " 

 This " other," and simpler, way is to be found in the theory already 

 advanced by Mr. Belt on a former occasion when treating of the 

 deposition of the Northern drift, viz. " That the ice of the Glacial 

 period flowed princiiDally down the ocean depressions, and blocked 

 up the drainage of the continents as far as it extended, causing 

 immense lakes of fresh or brackish water." Mr. Belt then explains 

 how, according to his hypothesis, a glacier of fresh-water ice occujiied 

 the basin of the Atlantic, and reared its snowy crest some 1700ft. 

 above the now sea-level, damming back the drainage of Europe, and 

 converting the lowlands into a lake studded with icebergs. This 

 huge lake " was once completely drained ; at first gradually, but 

 from about 500ft. above the present level of the sea suddenly and 

 tumultuously by the breaking away of the icy barrier, and thus 

 was produced a great deluge or debacle that swept over the low- 

 lands, and covered them with a mantle of false-bedded sands and 



gravel After being thus broken, the icy barrier soon closed 



up again, and the great lake was reformed, and this time was much 

 more permanent." 



Such is the picture of the Physical Geography of the period given 

 us by Mr. Belt; but whether the land to the south is sufficiently 



