All jEolian Deposit at Clevedon. 415 



O.D., its relation to the 25 ft. raised-beach of Woodspring and 

 Weston is unknown. Sands as old as the Middle Pleistocene might 

 be expected to have undeigone some subaerial erosion (such as 

 sheets of boulder-clay invariably show here and there), but the 

 curving surfaces of these are wonderfully smooth and free from 

 channelling. Yet not only the general character of the fauna/ but 

 the abundant angular detritus, are suggestive, if not of a sub-arctic 

 climate, at any rate of severe winters. When the Welsh ice-sheets 

 were gradually receding, North Somerset, though habitable, would 

 have been extremely bleak in winter. Perhaps we may refer these 

 accumulations to some stage of the waning of the Glacial period. 



The Origin op the Deposits. 



To what agency are we to ascribe these accumulations ? It must, 

 in the first place, be one that operates upon a land-surface, for the 

 fauna leaves no doubt that they are wholly terrestrial. Running 

 water may be suggested by the generally stratiform arrangement 

 at Holly Lane, and the jumble of bones inside the cave may seem, 

 at first sight, to demand som.e such an agent to carry them in. But 

 the terrestrial fauna, the exclusively local derivation and remarkable 

 angularity of the blocks, with the absence of internal stratification 

 in each of the bands of deposit, are not aqueous phenomena. More- 

 over, whence could such a river have come, and whither did it flow ? 

 Consider the physiography (Fig. 1). The Vale of Gordano is as 

 open at East Clevedon Gap as it is at Portishead. At one end is the 

 Channel, just outside the Severn's mouth ; at the other are 

 150 square miles of alluvial plain. There is no possible 

 course for such a river. Further, these beds climb up to at least 

 120 feet (perhaps 180 feet) O.D., so that, if we invoke this agency, 

 we must drown the greater part of Somerset under more than 

 100 feet of water ; water, too, which cannot be admitted to be 

 marine ! Plainly some other agency has been at work. 



Now the breccias are manifestly of the nature of local talus. 

 The fauna points, if not to sub-Arctic, at any rate to cold conditions. 

 We may therefore look upon these brec«ias as ancient scree, such as 

 is detached from crags by frost. But how could scree find its way 

 into, and nearly fill up, the cave ? A fortunate circumstance points 

 out the way. At the door, the crag is vertical. Rubble from a 

 surviving patch of breccia near the cliff's brow is now falling just 

 at that spot, piling itself up, and slipping back into the cave, which 

 it has already partly refilled, and will easily refill up to the level of 

 the crown of the arch, thus plainly indicating for us the manner 

 in which the same result was achieved in Pleistocene times. But 

 special facilities existed then. In a severe climate, frost would 

 furnish abundant scree-material which, falling over the cliff, would 

 pile itself up in a bank, which, elsewhere sloping only outwards, 



^ Mr. Hinton urges that Microtus nivalis does not, in itself, imply any great 

 desrree of cold. 



