A HISTORY OF SUSSEX 



but it was only during the later researches of the Geological Survey, 

 when the superficial deposits were mapped, that the relation of these to 

 each other was clearly made out. A series of storms in the autumn and 

 winter of 1892 combined to cut back, the cliff, scour away the beach 

 and lay bare sections unlike any that had previously been noted. Nearly 

 opposite Medmerry farm in Bracklesham Bay the foreshore thus bared 

 exhibited the junction of the Glacial deposits with the Bracklesham Beds 

 over a considerable area. The surface of the Bracklesham strata was 

 neither smooth nor channelled, as in an ordinary shore ; but showed 

 clear evidence of the action of floating ice, probably of ' ice-foot ' such 

 as forms every winter in the arctic regions on the shore beneath the 

 cliffs. The ancient foreshore, which lay only a few feet above the level 

 of the present tidal flats, was full of basins or pits from 2 to 6 feet 

 across. Most of these pits contained nothing but loose gravel, with a 

 few valves of Balanus and rare fragments of marine mollusca ; the others 

 each contained a far-transported, erratic block, which had not merely been 

 dropped, but showed signs of having been forcibly squeezed or screwed 

 into the clay, until its upper surface was flush with the general level. 

 The pits filled with finer material probably mark the spots where large 



Fig. I. — Diagram-section to show the Relation of the Erratic 

 Blocks to the Floor of Bracklesham Beds.' 



erratics were formerly deposited, though, becoming again frozen into the 

 ice, they were lifted out and transported to fresh sites. Among the 

 erratics found on this coast were blocks of Bembridge Limestone, large 

 Chalk flints and Upper Greensand from the Isle of Wight ; many large 

 masses of Bognor Rock from the ledge a few miles to the east ; and 

 numerous more rounded blocks of harder rocks, such as peculiar granite, 

 diorite, felsite, porphyry and hard sandstone. Most of these igneous and 

 Palaeozoic rocks seem to have come from the Channel Islands and the 

 Brittany coast ; one granite with large crystals of white orthoclase felspar 

 is more probably of Cornish origin. A large block of fossiliferous Bog- 

 nor Rock, measuring 5 feet by 4, was beautifully striated. This is 50 

 miles south of the nearest glacial deposits of the Thames valley, and 

 is the only glacially striated rock yet observed south of the Thames. 

 Large granitic boulders of character similar to those of Selsey are scat- 

 tered over the plain as far as Worthing, where two or three are preserved 

 in the park ; other smaller pieces occur in the raised beach of Brighton, 

 in which deposit however they were not originally dropped. 



For the continuation of the Selsey record we must examine the 

 coast nearly a mile to the south-east and nearer to the Bill, for there the 

 series is more complete, though the glacial deposit just described has been 



1 Figs. 1-4 have been reproduced, by kind permission of the Council, from the Quarterly Journal 



of the Geological Society. 



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