An ^'Eolian Deposit at Clevedon. 417 



the cave. This hardly seems to be accoutited for by its having been 

 a den of occupation. But if it, and also the cliff's foot, were a 

 place to which both carnivores and herbivores crowded for 

 shelter from furious northerly storms of dust and snow, all becomes 

 intelligible. Cowed by the tempest, pursuer and pursued would 

 scarcely (as is well-known under such circumstances) be aware of 

 each other's presence, and all would be overwhelmed in a common 

 destruction by the drifts. They would crowd about the cave's door, 

 where the best shelter would be obtained. No vertebrate remains 

 have been found in the unsheltered places. Their bones would be 

 jumbled up as we have seen, and wind could easily whirl a little 

 vole-jaw into the neural canal of a horse's vertebra. Man niay 

 never have visited the spot at this time, but have come there during 

 the accumulation of the upper talus, by which time both the cave 

 and the remains of the larger vertebrates Avould have been completely 

 buried. 



In short, we may look upon the breccias as frost-shattered local 

 talus, and the alien loams and loamy sands as dusts transported by 

 northerly storms, while the same snow-storms and the accompanying 

 climatic conditions generally can account for the filling up of the 

 cave and for the peculiar distribution of the vertebrate and mollascan 

 remains. 



The Loess : A Comparison. 



Let us now turn to a consideration of the Loess. That remarkable 

 accumulation is described as a sandy loam, with occasional beds of 

 sand ; and the Clevedon drifts are loan)s and loamy sands. The 

 principal differences in composition seem to be that at Clevedon there 

 is too much sand and too little white mica for complete corre- 

 spondence. But here the petrological contrasts end.^ 



The loams, in both cases, are feebly plastic, siliceous, calcareous, 

 and ferruginous, and there is the same angularity in their minute 

 quartz. As in the foreign deposit, the finer quaitz of the sands is 

 angular, while its larger grains are often rounded, with the 

 characteristic dull surface of aeoiian transport.^ Loess, as the hill- 

 sides are approached, begins to contain angular blocks of rock, 

 and passes gradually into coarse talus with a matrix of loamy sand, 

 to which we have a precise parallel at Clevedon. In both cases, the 

 angular blocks are of exclusively local derivation, whereas the fine 

 materials are alien, and of constant composition, quite independent 

 of locality. The structural parallels are interesting. There is the 

 same plentiful lack of stratification, the same singular vertical 

 cleavage, the same calcareous concretions, and even the same 

 capillary tubes with remnants of carbonaceous matter. 



^ I have not yet seen any account of the lieavy minerals of the Loess. 



^ I do not remember any reference to this last feature in Richthofeu's and 

 Tietze's descriptions. But it may not have been recognized on the Continent 

 at that time as a 2:)roduct of aeoiian action. 



VOL. LIX. — NO. IX. 27 



