360 CRETACEOUS. 



grit with freshwater shells, Cyclas, PaJudina and Ujiio, in the White 

 Rock Clift', where rocky ledges run out to sea. 



The old town of Hastings is built entirely on Ashdown Sand, whilst 

 St. Leonards is mainly built on Tunbridge Wells Sand, the two 

 series being brought together by the " White Rock Fault." (See 

 Fig. 5g.) The Ashdown Sand forms the fine clifts on which the 

 Castle is built ; here the beds consist of compact white rock-sand, 

 resting on beds somewhat more clayey in nature. The uppermost 

 beds are generally massive, and form a range of bare rocks around 

 the Hastings and Ecclesbourne valleys. The East Cliff is composed 

 almost entirely of sandstone like the Castle Cliff, but in going 

 eastwards the beds contain intercalated beds of clay ; hence the 

 cliffs at Hastings weather into vertical faces, whilst those nearer 

 Fairlight present a succession of steps. The top of the East Cliff 

 from Hastings to Fairlight is composed of Wadhurst Clay, and the 

 lower part of Fairlight Clays.' 



White pipe-clay occurs in the beds at East Cliff, Hastings. In 1801 a block of 

 jet or lignite was obtained between Heathfield and Waldron, east of Uckfield. 

 Lignite has also been found at Bexhill, west of Hastings, and the occurrence gave 

 rise to fruitless searches for coal. The Crowborough stone is dug in places in 

 Ashdown Forest. 



Wadhurst Clay. 



This deposit was named by ]\Ir. F. Drew from the village 

 of Wadhurst south-east of Tunbridge Wells. It consists of clay 

 and shale, with a bed of sand towards the base near Rye, and at 

 Icklesham, west of Winchelsea ; it also contains, near the bottom, 

 lignite and nodules and bands of clay-ironstone, which furnished 

 the chief supply of iron-ore to the old furnaces of the Weald. 

 The top of the clay is commonly of a bright red colour, as around 

 Tenterden, etc. 



The beds sometimes contain calcareous sandstone — the Tilgate 

 Stone of Dr. INIantell— which Mr. C. Gould has noticed at irregular 

 intervals throughout the series, either in large detached rounded 

 masses or in continuous layers. When unweathered and freshly 

 broken, it is of a bluish colour ; occasionally it passes into a con- 

 glomerate. As pointed out by Mr. Topley, the ' Tilgate Stone ' of 

 Dr. Mantell occurs at different horizons in different localities. 



Sections of Wadhurst Clay may seen in the cliffs on either side 

 of Ecclesbourne Glen, on Telham Hill, south-east of Battle, etc. 

 The thickness of the deposit at Pembury is about 160 feet, and near 

 Goudhurst about 180 feet ; at Rye and Fairlight it is about 120 feet. 



This formation is rich in fossil Plants, and freshwater Molluscs, 

 together with the Fishes Hybodiis, Lepidoiiis Mantdli, etc. 



The Tilgate Stone is noted for its Reptilian remains : it becomes 



1 W. Topley, Geol. Weald, p. 54 ; see also Webster, T. G. S. (2), ii. 31 ; 

 Fitton, Geology of Hastings (1833) ; T. G. S. (2), iv. 163, plate x^ ; and S. H. 

 Beckles, Q. J. xii. 2S8. 



