336 GANGETIC MUD AND EUROPEAN LOESS. chap. xvi. 



bious mollusca might in this way accumulate to any extent, 

 so that the waters might overflow some of the heights ori- 

 ginally bounding the valley, and deposits of "platform mud," 

 as it has been termed in France, might be extensively formed. 

 At length, whenever a re-elevation of the Alps at the time 

 of the second extension of the glaciers took place, there 

 would be renewed denudation and removal of such loess ; and 

 if, as some geologists believe, there has been more than one 

 oscillation of level in the Alps since the commencement of 

 the glacial period, the changes would be proportionally more 

 complicated, and terraces of gravel covered with loess might 

 be formed at different heights, and at different periods. 



Himalayan Mud of the Ganges compared to European 



Loess. 



Some of the revolutions in physical geography above sug- 

 gested for the continent of Europe during the post-pliocene 

 epoch may have had their counterparts in India in the recent 

 period. The vast plains of Bengal are overspread with Hima- 

 la^^an mud, which, as we ascend the Ganges, extends inland 

 for 1200 miles from the sea, continuing very homogeneous on 

 the whole, though becoming more sandy as it nears the hills. 

 They who sail down the river during the season of inundation 

 see nothing but a sheet of water in every direction, except 

 here and there where the tops of trees emerge above its level. 

 To what depth the mud extends is not known, but it resem- 

 bles the loess in being generally devoid of stratification, and 

 of shells, though containing occasionally land-shells in abun- 

 dance, as well as calcareous concretions, called kunkur, which 

 may be compared to the nodules of carbonate of lime some- 

 times observed to form layers in the Ehenish loess. I am 

 told by Colonel Strachey and Dr. Hooker, that below Cal- 

 cutta, when the flood subsides, the Gangetic mud niay be seen 



