?ix<^j^^^^5S^ 



successive stages in evoiution of Dungeness 



Dungeness Foreland Profile 



Dungeness, England, is a large 

 cuspate foreland which has been 

 built out to sea ten nniles to the 

 east from the former coast line. 

 The tip of the foreland is formed 

 by shingle storm ridges. The waves 

 that helped form Dungeness come 

 from the southwest in the English 

 Channel and from the east in the 

 Strait of Dover. The accretion of 

 Dungeness began possibly in Neo- 

 lithic times. It started, probably, 

 as a spit forming across a bay, 

 from Fairlight to Hythe, then 

 the spit gradually turned and built 

 eastward to its present position. 

 Today ridges on the southern side of 

 the foreland are being eroded, and 

 material is being redeposited on the 

 eastern shore of the foreland. 



S FEtl «»IK>1 INTEIVAtS 



SOUTH END 



--SOUTH END 

 300 FEET 



Marsden Bay Profiles 



On sandy beaches storm waves a^e 

 nearly always destructive, removing 

 sand from the foreshore - e\Aen from 

 the backshore zone in severe storms - 

 into deep water. Profiles at left 

 illustrate the effect of destructive 

 waves at Marsden Bay, County Durham. 

 Recorded by C. A. M. King, they show 

 that from December 2-12, 1950, about 

 three feet of sand was removed from 

 the north end of the bay; and that 

 during an earlier period - October 

 18-28 - enough sand was removed 

 above the high-water level of spring 

 tides to leave a small vertical face. 

 The profiles at far left illustrate the 

 effects of constructive wave action 

 at Marsden Bay at the end of 1949 

 and in 1950, showing the formation 

 of berms. 



^^ Erosion 



Accretion 



bedding-plarres dipping 

 towards ttie see 



Erosion of Cliffs 



A cliff formed of stratified and 

 jointed rock is easily undercut by 

 waves. It breaks along the bedding 

 planes and weak lines called "joints. 



When the beds of rock dip seaward 

 (and the joints landward) under- 

 cutting is more rapid. Large blocks 

 may fall outward onto the beach, 

 leaving an overhanging cliff. 



When the beds dip landward (and the 

 joints seaward) the rock is less 

 likely to fall onto the beach 

 below. The result is that the 

 cliff slopes toward the sea. 



265 



