F. Rutley — Ironstone near Dover. 227 



period known as " Inter-Glacial " the melting of the ice produced 

 strong currents of water which washed away most of the argillaceous 

 matter of this early Boulder-clay, leaving only the coarser material, 

 such as sand and gravel, and even baring and disturbing the under- 

 lying rock, and re-depositing its material. It is not impossible for 

 the shells we are considering to have been preserved during all this 

 time, if surrounded by a matrix of clay, for beautifully preserved 

 fossils (derived) are often found in the Boulder-clay, and I have 

 even found them in the gravels below, though rarely. 



The disturbance and re-deposition of the Lincolnshire Oolite 

 present no difficulties, for there are other instances of re-deposited 

 beds. A considerable area, not far from Northampton, is covered 

 by re-deposited and finely-washed Northampton sand, and this has 

 Boulder-clay above it, and so is older than the latter. 



I have carefully examined a very similar section to the one 

 referred to in this paper, situated at Little Oakley (see Judd's 

 " Geology of Rutland," p. 191), and so has Mr. Wallis, but there was 

 no evidence of re-deposition, and no shells could be found. At this 

 place a stream enters the pit from below the Oolitic Beds and passes 

 out under the same, and no doubt discharges into the Harper Brook 

 not far away. 



I may say, in conclusion, that a fluviatile origin for the shells was 

 considered, and regarded as untenable. 



VIII. — On a Sandy Ironstone occurring above the Chalk at 



Capel, near Dover. 



By Frank Eutley, F.G.S. ; 



Lecturer on Mineralogy at the Eoyal College of Science, London. 



BETWEEN Dover and Folkestone there are certain deposits of 

 ferruginous sandstone or sandy ironstone, well known to 

 geologists, and somewhat doubtfully referred to some portion of the 

 crag. They may be the equivalents of the Lenham Beds, which 

 are assumed to be the lower part of the Coralline crag, and which 

 have been correlated with the Diestian Beds of Belgium. This 

 view is entertained by Prof. Prestwich, Mr. Clement Keid, and 

 others, and is based upon paleeontological evidence (chiefly from 

 Lenham, near Maidstone), from which locality Mr. Reid procured 

 casts of the following fossils : ^ 



Ficula [Pyrula) reticulata 

 Ringiciila ventricosa 

 Turritella incrassata 



Fectunculus glycimeris 

 Uiplodonta rotundata 

 Terebratula grandis, etc. 



On the other hand, some geologists, including the late Mr. H. W. 

 Bristow, Mr. W. Whitaker, and the late Mr. W. Topley, have been 

 inclined to regard these deposits as coeval with the Lower London 

 Tertiary and possibly as equivalents of the Oldhaven or Woolwich 

 Beds. 



Be this as it may, no one yet appears to have inqiiired into the 

 microscopic character of these highly ferruginous deposits. 



A section made from a specimen of sandy ironstone, which I 

 1 The Pliocene Deposits of Britain, 1890, p. 42. 



