OLA.CIAL DEPOSITS OF THE TTNE VALLEY. 193 



Once this fact is recognised certain features in the section, 

 which it may at first seem difficult to explain, become, I think, 

 easy to understand. 



Thus towards the eastern extremity of the section the beds of 

 sand and gravel are seen dipping at a high angle towards breaches 

 in the continuity of the cliff ; in one case forming a high-pitched 

 anticlinal between two such breaches — an arrangement remind- 

 ing one strikingly of the typical arched structure of hames. An 

 examination of these dips shows them to be directed towards 

 the centre of funnel-shaped hollows, now intersected by the 

 river and forming the aforesaid cwm-like breaks in the section. 

 It is evident that the withdrawal of matter from within, if con- 

 centrated towards certain spots, would, by the gradual sinking 

 of the upper mass beref c of adequate support, and by subsequent 

 sHps of sides, produce such funnel-shaped hollows and such dips. 



On climbing to the surface of the undulating terrace above 

 the bluff, between the road and the river, there is to be found 

 abundant confirmation of the truth of this explanation. Here, 

 a few yards from the edge of the cliff, is to be seen at the present 

 time (March, 1893) a roughly circular depression many yards 

 in diameter and with an unbroken margin which has sunk within 

 the last few months. Its depth is from five to ten feet in dif- 

 ferent parts, and it has so recently been formed that the sides 

 are still vertical and vegetation has not yet had time to conceal 

 the gravel bared by the slip. "When the cliff is sufficiently worn 

 back (as in a short time it inevitably must be) this hollow will 

 be impinged upon by the river, and the action of surface denu- 

 dation will be added to that of the underground springs. A deep 

 funnel-shaped and breached cwm, towards the centre of which 

 the adjacent sand and gravel beds will be seen to dip, will in 

 due time be formed. 



More remote from the cliff-top are several other enclosed but 

 somewhat larger depressions. The sides of these are now gently 

 sloped and covered with grass, nevertheless one cannot but see 

 in them examples of the same kind of action, viz. : the abstrac- 

 tion of subjacent material by means of percolating rain-water 

 finding its way, laden with sediment, to the river. Some of 



