.BEACH AND BOULDERS NEAR BRA UNION AND CROYDE. 



659 



level to produce it. It would be brought about by the uniform 

 waste of an irregular coast-line, where the destruction of headlands 

 and the shifting of sandbanks and currents determine which part 

 of the rocky coast shall have a protecting mantle of sand for a time 

 thrown over it, and which shall be stripped to bear the ceaseless 

 lash of the waves. 



deferring to the diagram (fig. 1), let L, M represent high- and 



Fig. 1. — Diagram Section showing the Mode of Formation of some 

 of the High-level Beaches of Devonshire. 



2 4 



1. Talus. 3. Ancient shore-deposits. 



2. Modern shore-deposits. 4. Rock. 



low-water mark, the level of ordinary high and low water respec- 

 tively, and E ¥ the surface of the existing sand-slope ; then the 

 waves in storm may break against the foot of the cliff G H, but 

 never get as high as K, the base of what is called a raised beach. 



But when A B or CD was the surface of the sand-slope, the sea 

 in storm, especially if it was in a bay or creek or corner, would rush 

 up the incline along A B or C D to a level far above K. Then when 

 the gradual changes of the coast, shifting the sandbanks, eating 

 away the promontory, and so on, had removed the sand marked (3) 

 and cut back the cliff to G H, the portion above K would look like 

 a raised beach, and, in fact, would be practically out of reach of 

 the waves. 



If any change of level has taken place in this case it seems to me 

 to be quite as likely to have been a downward as an upward move- 

 ment. At any rate it is probable that if the sea were thrown more 

 strongly on to the sand-dunes in Barnstaple Bay by a small depres- 

 sion, the tendency would be to drive them back to the east, leaving 

 just such patches of consolidated sand and talus in cliffs near Saun- 

 ton Court as are now seen along the cliff further west. And the 

 height to which the, properly speaking, marine deposits occur is so 

 little above ordinary high tide that there is plenty of margin left for 

 storm-waves to carry them up to where they are now found. 



When a long sweep of shore such as Woolacombe sands or Bide- 

 ford Bay leaves a wide expanse of sand exposed between every tide 

 to the sun and wind, it is curious to notice how soon after the sea 

 has left it the surface of the sand begins to move under the influ- 

 ence of a dry wind. One might almost think sometimes that the 

 sun and wind dried one grain at a time and started it off immedi- 



