A HISTORY OF SUSSEX 



coated flints and pieces of ironstone. Some of the unworn flints in it 

 undoubtedly are derived from the slow solution of the Chalk below, and 

 a small part of the clayey matrix also may come from this source. The 

 Upper Chalk of Sussex however is so pure that the removal of the 

 soluble carbonate of lime would leave merely a stony desert of flints, 

 without sufficient clay to fill the interstices. Such a stony waste is now 

 gradually forming on parts of the Downs where no Tertiary material 

 remains. 



The London Clay in Sussex is more sandy than the corresponding 

 deposit in the London basin, though not nearly so different as the local 

 name, 'Bognor Beds,' formerly used would imply. It is a dark-blue clay, 

 more or less sandy, containing beds of sand in the upper part, and in places 

 it has a mass of flint shingle at the base. Two of the sand-beds near 

 Bognor have been consolidated into hard sandstone ; and as these sand- 

 stones form conspicuous rocky ledges, the Bognor Rocks and the Barn 

 Rocks, projecting seaward from a coast otherwise flat and sandy, they 

 have been given more importance than their small thickness would 

 warrant. The Bognor Rock however is of considerable interest, for 

 the fossils contained in it, now difficult to obtain, are well preserved and 

 are not compressed like those ordinarily found in the London Clay. 

 The most common are Fectunculus brevirostris, P. decussatus, Cardita 

 brongniarti, Panopcea intermedia, Pholadomya margaritacea, Pimia affinis, 

 all common fossils of the London Clay elsewhere. There is also a 

 peculiar volute. Valuta nodosa, and the flat-coiled Vermetus bognoriensis . 

 The total thickness of the London Clay is about 320 feet. Like the 

 Reading Beds, much of it is hidden by newer deposits ; but where 

 exposed it forms heavy clay land principally covered by oak plantations. 

 Bricks are made from it ; but not to any great extent in Sussex, where 

 better and more easily worked brick-earth is to be found in the same 

 districts. 



It is still somewhat uncertain whether Sussex contains any repre- 

 sentative of the Lower Bagshot Beds. Sandy strata occur at the top of 

 the London Clay on each side of the Selsey peninsula ; but they are 

 difficult to examine, being hidden by gravel, and striking the coast just 

 where everything is obscured by the mud of Pagham Harbour and of 

 West Wittering. The sands cannot be thick, and no fossils have been 

 obtained from them ; it is possible however that some of the deposits 

 with driftwood occasionally to be seen on the foreshore near West 

 Wittering may be referred to this formation. 



The Bracklesham Beds form one of the most interesting deposits of 

 the county from a scientific point of view ; but as they are entirely 

 hidden by drift, except on the foreshore, and are confined to the Selsey 

 peninsula, they have little influence on the character of the scenery, 

 nature of the soil, or position of the settlements. The thickness of 

 these strata reaches however as much as 500 feet. From top to 

 bottom they consist of greenish, more or less carbonaceous clays and 

 marls, alternating with glauconitic sands. Fossils are abundant, in fact 



14 



