276 PEOF. J. PRESTWICH OlS THE RAISED 



into two parts — an upper one composed essentially of ferruginous 

 sandy debris from the Lower Greensand, and a lower one consisting 

 of a clay similar in colour and substance to the Gault which crops 

 out just above. 



At Freshwater Gate there is a well-marked deposit of Head, 

 descending on both sides of the valley to the water-level. It is 

 possible, by drawing a vertical line at any part of the section, to 

 divide the deposit into beds, as was done by E. Forbes,^ but they 

 are rather lenticular masses than true beds, and such sections would 

 vary with the ever-varying face of the cliff. 



On the eastern side of the Bay the deposit is more chalky, with 

 more brick-earth and less gravel than on the western side, where 

 the Chalk hill behind rises higher and the drift goes higher up the 

 slopes — to a height of 60 ft. according to Mr. Codrington.^ The great 

 mass of the gravel on this side is very coarse and consists approxi- 

 mately of 



Per cent. 

 Angular flints, with some others stained light brown and more 



worn , 63 ' 



Pebbles of bard chalk and chalk-marl 6 



Subangular aiid worn fragments of iron-sandstone and ironstone 



(Lower Greensand and Wealden) 26 



Slightly subangular fragments of chert and ragstone 5 



Looking at the angle at which the Cretaceous strata lie, all this 

 debris may have come from high ground a few hundred feet south 

 of the Bay, now removed by the wear of the cliff, and not from any 

 distant point. It presents no appearance of river- action, and the 

 only shells found are land-shells. The few chalk-pebbles would 

 require but little wear to produce them, or they may have lost 

 their angles and become rounded merely by the percolation of water. 

 Most of the chalk-flints retain their sharp angles, and the beds on 

 either side of the Bay follow the steep slopes of the hills and not 

 the horizontal lines of a river-deposit. 



Allowing for the differences of the substrata, these drifts on the 

 south-western coast of the Isle of Wight have all the characters of 

 the Elephant Bed of the Brighton district, only on this coast the 

 encroachment of the sea has removed the Baised Beach and the 

 old cliff. In both cases the debris is local and unstratified, has 

 undergone comparatively no wear, and contains land-remains only. 



The second edition of the Survey Memoir on the Isle of Wight, ^ 

 which describes more fully the Pleistocene beds, contains several 

 notices of a drift which may possibly be referred to the Bubble- 

 drift, such, for example, as the gravel capping the cliffs between 

 Blackgang and Shepherd's Chine (pp. 230-234), including the 

 sections in Shippard's Chine, in which, besides wood and nutshells, 

 the remains of beetles are recorded (p. 232). The Chalk talus in 



1 ' Geology of the Isle of Wight ' (1856), pp. 2-5, 103. 



^ The manner in which this deposit follows the slope of the hill is shown 

 in E. Forbes's sketch of Freshwater Bay, op. cit. p. 5. 



^ Revised by Messrs, Clement Eeid and Aubrey Strahan, 1889. 



