198 W. Whitaker—On the Plialk of the Cliffs 



I cannot conclude these brief and somewhat desultory remarks 

 without expressing my deep indebtedness to MM. A. de Borre, 

 Dupont, and Nyst, for the very kind attention they showed me when 

 in Brussels, and the hope that it may soon be my good fortune again 

 to visit their most attractive and hospitable capital. 



II. — On the Chalk ^f the Cliffs from Seaford to Eastbourne, 



Sussex. 



By William "Whitaker, B.A. (Lond.), of the Geological Survey of England. 

 (A Paper read before the Geological Society of London, December 1, 1870.) 



JUST out of Seaford the Chalk rises sharply from beneath the sand 

 of the Woolwich Beds, on an outlier of which the small town 

 is built. The dip however soon lessens, until the Chalk is flat, with 

 slight waves. Some of the layers of flint are continuous, and some 

 nearly so, but most are not continuous, and they are rather closer 

 together in the l^wer part of the clifi". There are a few thin beds of 

 hard chalk, and at the top a capping of " clay-with-flints." 



This thick mass of " Chalk- with-flints" (1 of the figure) occurs 

 again on the other side of Cuckmere Haven, and thence forms the 

 whole of the cliff (except for the flinty soil at top and for the rubble 

 in the hollows) almost to Beachy Head. The beds are flat as far as 

 the Lighthouse, when they rise slightly eastward ; and just before 

 getting to the Head this uppermost division passes downwards into 

 chalk, with layers of flints, and with cream-coloured nodular layers 

 that weather to a rough surface (2). 



Then, from the increase of the westwardly dip, still lower beds, 

 without flints, crop up eastwards ; firstly a bed with nodular layers, 

 as in the division above, which weather rough and give the whole a 

 darker colour (3) ; and then thick-bedded massive chalk (4). All 

 of the above four divisions occur at Beachy Head. 



After rounding the first point of the Head, there are, above the 

 Chalk- with-flints, at the highest parts (south-west of the " signal " 

 on the map) pipes of clay-with-flints and a little red sand, which 

 last may perhaj)s be the same as the Iron-sands of the North Downs 

 referred to the Crag by Mr. Prestwich.^ At -the bottom of the cliff 

 there rises up a mass of bedded chalk (5), in which there is a bed of 

 pale bluish-grey marl, here indeed divided into two, and altogether 

 fifteen feet thick ; but which at Holywell House, on the north-east, 

 is undivided and only three or four feet thick ; whilst just above there 

 are other marly beds, giving the whole a darker colour ,(at the lime- 

 kiln at the foot of the cliff). 



At the second point of the Head (south-east of the word " signal " 

 on the Ordnance Map) the Chalk Marl (6) crops up from below ; 

 and on rounding the point is succeeded by the green-grey sandstone 

 of the Upper Greensand, which is but little shown however, as there 

 is a small undeir-cliff, and as the dip changes and the beds fall 

 northwards for some way, until the Chalk Marl also is hidden (about 

 ^ Quart Journ. GeoL Soc. vol. xiv- p. 322. 



