OF WESTERN EUROPE AND THE MEDITERRANEAN COASTS. 
921 
the waters would still have been heaped up whilst wide valleys remained open with 
rivers offering ready channels of escape, is not easy to understand. Other objections 
to this view are urged by Professor J. Geikie. 
The other suggestion is that the great rivers of Europe had been dammed back 
for a time by the advance* of the great northern ice sheet, or, as others have 
suggested, by the block caused by great masses of ice carried down by these rivers 
at the break up of the ice in spring, as now of frequent occurrence in Arctic 
regions. The former suggestion is inadmissible, because, whatever the cause was, it 
v/as one that affected the whole central area, whereas a northern ice sheet would 
only have blocked the rivers flowing north, and not those flowing south. The other 
suggestion of ice-dams in the rivers might answer to some of the conditions, but 
would scarcely meet the case where the areas covered are so vast and high. We 
should have expected also to find greater traces of destructive and transporting , 
action. If the Loess had been confined to narrower valleys this cause might have 
been available, but the extensive plains and high hills over which it extends 
renders it difficult to imagine that river floods alone could have spread such a mantle 
over large portions of Europe. For these reasons, amongst others, I do not think 
that any land-flood hypothesis will satisfactorily account for all the phenomena. 
[More lately the Eolian theory, proposed by the'Baron F. von BiCHTHOFENt to account 
for the origin of the loamy deposit which covers large surfaces in China and some 
adjacent districts, has been thought applicable to the European area. This deposit is 
described by the Baron as perfectly similar to the Loess of Europe in composition, 
structure, and mode of occurrence. It extends from the alluvial plains, only a few feet 
above the sea-level, to heights of 8000 feet and more ; and, while thin in some places, 
it attains in others a vertical thickness of 500 to 1500 feet. It abounds in land shells, 
and contains also the bones of animals of the same genera, and mostly of the same 
species, as those that now live in steppes or on grassy plains. He ascribes this remark¬ 
able deposit to the action of the high winds that sweep over these parts of Asia and 
drive before them clouds of fine dust which in a few hours form thick dust-drifts, 
burying In them the land shells of the district and the bones of the animals left on 
the grassy surface. From this, I infer that the bones of the skeletons should be found 
not far apart, and sometimes in close relation to the skeleton, but whether or not this 
is the case, or whether any of them belong to extinct species, I cannot gather. 
Of the power of these winds and the height of the country devastated by them, 
there is ample confirmatory evidence. A recent traveller in these regions j says that 
on the high plateaux of Thibet and North-Western China, the winds are often fearful, 
* T. Belt, ‘Quart. Journ. Geol. Soc.,’ vol. 30, p. 490, 1874; ‘Quart. Journ. of Science’ for January, 
1877. 
t ‘Brit. Assoc. Rep.,’ 1873, Sect. p. 86; ‘ CEina,’ vol. 7, p. 97, 1877; ‘ Geological Magazine’ for 1882, 
p. 293. See also R. Pujipellt in ‘ Amer. Jonrn. Science and Arts,’ 3rd series, vol. 17, p. 183, 1879. 
+ ‘Across Thibet,’ by M. BoNYALOT, English translation, 1891. 
MDCCCXCIII.—A. 6 B 
