362 CRETACEOUS. 



sand, and loam of a yellowish or white colour. In the neighbour- 

 hood of Hastings they consist of soft yellow and white sand, hard 

 ferruginous sandstone, and shale, having a thickness of 140 or 150 

 feet. The beds are exposed at Little Horsted, and in the railway- 

 cutting north of Worth. In the neighbourhood of Tunbridge 

 Wells their total thickness is about 180 feet. 



They contain Lcpidotiis Fiftoni, Unio, Cyretia, Pahtdina, Cypridea, 

 etc., and among Plants, Carpolithcs, Sphcnoptcris, Zamiostrobus, and 

 Clathraria Lyellii. 



Some hard beds of ferruginous sandstone are dug for road-metal. Lignite has 

 been found at Newick Old Park, near Cuckfield, and was known as the Newick 

 Coal ; it has very much the character of jet. 



Grinstead Clay. — The Tunbridge Wells Sands in the western part 

 of the Wealden district, are divided into an Upper and Lower Series 

 by a band of clay which has been mapped by the Geological Survey 

 under the name of Grinstead Clay. The name was suggested by 

 INIr. Drew, because on the north side of East Grinstead the clay 

 occupies a considerable area, and its relations with the Sands 

 beneath may be well seen. 



The Grinstead Clay attains a thickness of 50 feet or more in 

 places; at Rye and Fairlight it is only 10 feet in thickness. 



It is not quite certain, as Mr. Topley observes, whether this clay 

 as mapped on the south side of the Weald, is always on the same 

 horizon. He observes that the clay is generally loamy and nearly 

 always mottled ; sometimes it is stiff and shaly. The mottled 

 variety is usually known as ' catsbrains ' ; but there is no positive 

 character whereby to distinguish it from the Wadhurst Clay. It 

 sometimes occurs only thirty feet above the base of the Sands ; 

 it contains Paludma, Cyrena, etc. 



Prof. T. R. Jones has noticed sand-worn or polished pebbles in the Upper Tun- 

 bridge Wells Sandstone.^ 



Near Lindfield a bed of conglomerate occurs at the top of the 

 Lower Tunbridge Wells Sand ; here Mr. Topley found a fragment 

 of an Ammonite, and he would infer that although the pebbles are 

 apparently mostly derived from Palaeozoic rocks, yet the Wealden 

 rocks were also partly derived from the waste of Secondary strata.* 



In the neighbourhood of Cuckfield the Upper Tunbridge Wells 

 Sand contains a bed of clay called the Cuckfield Clay, about 15 

 feet in thickness, which is described by ]Mr. H. W. Bristow as a 

 sandy and mottled clay, sometimes shaly. In this district the beds 

 occur as follows : — 



Feet. 

 / Sand and sandstone with layers of Tilgate 



Upper Tunbridge ) stone at the top 115 



Wells Sand. Cuckfield Clay 15 



I Sand and Sandstone 7° 



Grinstead Clay 80 



Lower Tunbridge Wells Sand loo 



1 G. Mag. 1878, p. 287. 



2 Topley, Geol. Weald, p. 84. 



