468 Q. Dowker — On the Chalk of Kent. 



and Pegwell Bay, where, from the presence of numerous small faults 

 with a dip towards the south, the lower beds are rather suddenly- 

 brought to the sea -level, and beyond this, to Cliffs End, the upper or 

 Margate Chalk again appears. The Isle of Thanet being in fact an 

 elevated arch of Chalk, and the valley of the Stour, between it 

 and the rest of Kent, a synclinal filled with Tertiary deposits. At 

 Cliffs End, a junction of the Chalk and Tertiaries may be observed 

 by the green-coated flints : I have elsewhere described these junctions.' 

 Mr. Whitaker'^ considers the Thanet Beds to rest conformably on 

 the Chalk and if so we should expect to find the highest beds of 

 Chalk immediately beneath them. 



In the Diagram illustrating this paper I have ventured to adopt a 

 new nomenclature for the divisions of the Kentish Chalk. The 

 divisions of Mr. Phillips occurring as they do at Dover, St. Mar- 

 garet's, and at Eamsgate, I have preferred naming from the 

 towns where they may be most advantageously studied. Com- 

 mencing at Folkestone, the Grey Chalk (6) is easily recognised and is 

 a term universally admitted. Next, the Flintless Chalk ; (5) these two 

 constituting the Lower Chalk. Next, the Chalk with few flints I 

 have named Dover Chalk (4) (large Ammonites occur in it). The 

 next division (3) of Mr. Phillips, which he calls a bed of organic 

 remains with " interspersed flints," I call St, Margaret's Chalk (this 

 bed is of a greyish appearance). The next bed, (2) that with "nume- 

 rous flints in layers," Mr. Phillips has subdivided; I have classed it 

 altogether as Eamsgate Chalk ; this bed, which dips at Kingsdown, 

 rises again in the Isle of Thanet, and is well developed at Eamsgate, 

 where it constitutes the entire cliff; above this we have (1) the Margate 

 Chalk. These divisions hold good as far as East Kent is concerned. 

 Mr. C. Evans, in a paper lately read before this Society,^ divided the 

 Chalks near Croydon and Oxtead into Purley. Eiddlesdown, Kenley, 

 Whiteleaf, Warlingham, Morden, etc., beds, but without a knowledge 

 of those cuttings I am unable to class them with the East Kent 

 Chalk, nor do I believe much in the evidence of fossil zones, which 

 he lays much stress upon. As far as paleeontological evidence is 

 concerned, it depends much on the lithological character of the 

 Chalk in which fossils occur ; for instance, large Ammonites, I will 

 not say they are identical, occur in the Margate and Dover Chalks, 

 separated by great thicknesses of Chalk, in which they do not occur, 

 and over an extended area certain fossils are common or scarce in the 

 same bed of Chalk. At various parts of the Chalk of the upper 

 beds in the Isle of Thanet different fossils occur, and I have not 

 attempted to draw any particular inferences from the fossil evidence 

 until I have collected over a more extended area. But the fossils that 

 occur in the Margate Chalk are most of them identical with those of 

 the Norwich Chalk. I append a list at the end of this paper. 



Mr. Prestwich has suggested that the highest Chalk under the 

 Tertiaries of London belongs to the middle, rather than the upper 



1 Geological Magazine, Vol. III., No. 22, May, 1866. 



2 Quarterly Journal of Geological Society, 1865, p. 397. 

 ^ Proceedings of Geologists' Association, J'an. 7, 1870. 



