A. M. Davies — Base of the Gault in E. England. 159 



III. — The Base of the Gault in Eastern England. 

 By A. M. Davies, A.B,.C.S., B.Sc, F.G.S. 



IN a paper published ia this Magazine in March, 1895,^ Dr. J. W. 

 Gregory, incidentally discussing the exact age of the base of the 

 Gault Clay, wrote: " HopHtes interruptus seems restricted in [Eastern] 

 England to the Folkestone area and the Red Chalk." Although some 

 of his conclusions on that point were modified later,- the general 

 statement quoted above, with the qualification indicated by the 

 bracketed word ' Eastern,' does not seem to have been challenged. 

 Having myself found H. interruptus at the base of the Gault at 

 several places in Eastern England, I have been led to look up 

 previous records, with the result that I am convinced that the zona 

 of H. interruptus is represented in the lowest beds of the Gault Clay 

 over a large part of that area. 



Taking first the Gault outcrop south of the North Downs, the 

 following table shows the localities from which this fossil has been 

 recorded, in order from east to west, and the distances between 

 them : — 



Locality. 



Authorities. 



Notes. 



Folkestone. 



Omnes passim. 





19 miles. 







Leacon Hill, 

 2 miles S. of Charing. 



17 miles. 



Aylesford and 

 Maidstone district. 



Fitton, Trans. Geol. Soc, 

 ser. II, vol. iv, p. 112. 



De Eance in Topley's 

 " Weald Memoir." 



'Afnm.dentatiis.'' For locality 

 see also T. E,. Jones, Geol. 

 Mag., DecII.Vol. Ill (1876), 

 p. 118. 



13 miles. 







St. John's Brickyard, 



between Sevenoaks 



and Otford. 



A. M. D. 



S. splendens also. 



4| miles. 







Westerham. 



9| miles. 



Battlebridge, near 

 Merstham. 



Fitton, loc. cit., p. 152. 



"Whitaker & Hinde, Proc. 

 Geol. Assoc, vol. XV, p. 114. 



' Amm. dentatus ' in Gault 



Clay. Specimen in Geol. Soc. 



Museum. 



9^ miles. 







"Westcott, near Dorking. 

 20 miles. 



Leighton, Proc. Geol. 

 Assoc, vol. xiii, p. 9. 



At base of Gault. 



"Wracclesham, 

 near Farnham. 



Monckton, ibid., p. 76. 



In sandy beds, four or five feet 

 below base of clay. 



4 (?) miles. 







Eailway cutting " near 

 Alton." 



Bristow & Whitaker, 

 ' ' Geology of parts of Berks 

 and Hants " : Mem. Geol. 



Surv., Sheet 12, p. 4. 



Acanthoeeras mammillatum, 



Soplites lautus, and H. tuber- 



ci^foi^ew recorded also. All from 



Gault ; no details. 



^ " Fossils from Lower Greensand of Great Chart" ; 

 Vol. II, p. 97. 2 Ibid., pp. 187-9. 



Geol. Mag., Dec. IV, 



