﻿E. J. Rehert — Reversed Faults in Slates. 441 



tins to the cliff, and it will project so far over the site of the 

 boulder-beds as quite to preclude the idea of their having fallen 

 from the cliff above. But drowning sceptics catch at straws. So 

 we have a further exhibition of intellectual contortion. It is now 

 asserted by the sceptical geologist that the boulder-bed has come 

 through a providential pot-hole or pipe, "of which," it is said, 

 "there are plenty in the limestone above." Memory, when sceptical, 

 is certainly creative. The limestone plateau above is singularly free 

 from pot-holes : there is not one of any great size within many a 

 mile, the nearest being Gingling Hole, more than three miles distant; 

 and I much doubt whether there are any worthy the name nearer. 

 But even had they been tolerably abundant, has the ingenious author 

 of this theory ever seriously asked himself what are the chances 

 of a pot-hole occurring just in so very convenient a situation, and 

 what the chance of the cliff having just weathered back far enough 

 to destroy this ]3rovidential pot and no further ? When he has got 

 an idea of the smallness of these chances separately, let him then 

 endeavour to estimate the probability of their both having occurred 

 together. I rather fancy the figures will somewhat astonish even 

 the sceptic. So much for the geological question, the chief points 

 of which have been insisted on over and over again by Mr. Tiddeman. 

 As regards the paleeontological question, Mr. Tiddeman's argument 

 is simply this : here we have a fauna which is elsewhere often 

 associated with the remains of man ; whatever be the age of this 

 fauna, is presumably also that of man ; in the Victoria Cave we have 

 evidence that this fauna existed before the close of the Glacial 

 period ; therefore, presumably, man existed in this country also 

 before the close of that period. The fact that the said fauna with 

 human remains is post-Glacial in the South of England is to be 

 explained by the consideration that the last glaciation of the country 

 did not extend over the South of England. This consideration too 

 explains the remarkable fact, that no Pleistocene fauna has been, 

 found in river-gravels in the North of England. Why should such 

 a fauna, when found in river-gravels, be confined to the south ? 

 Simply because the last glaciation has swept away all the river 

 deposits of that age from the north ; but as it did not extend to the 

 south, the old river-gravels of that district have escaped destruction, 

 and remain to-day to be seen with their included fauna. 



III. — Eeversed Faults in Bedded Slates. 



By E. J. Hebert, M.A., P.G.S., 

 of H.M. Geological Survey. 



IF it be an established rule, in coal-mining districts, that the hade 

 of a fault is to the doionthroio, it is an equally undeniable fact, 

 that the surfaces of bedded slates, as a rule, exhibit only faults 

 which hade to the upthrow. In suggesting a possible explanation of 

 this phenomenon, I shall allude to the latter as reversed, and the 

 former as direct faults. Let Fig. 1 represent a piece of wood six 

 inches square and one inch thick, lying upon a table, and let it be 



