660 



PROF. T. M'KEjS t jS t Y HUGHES ON THE ANCIEXT 



ately, so damp is the sand, while the yellow haze a few inches 

 deep tells us the surface is beginning to drift; away. Stick a slate 

 or a shell up to catch it, and you soon find how rapidly the work is 

 going on. So the sandhills are formed which protect the lower part 

 of the lowlands behind from the rush of the wind-driven tides. In 

 exceptionally high tides, however, the sea is carried far up the 

 incline formed by the dunes, and so marine deposits are intercalated 

 in the lower part of the blown sand. Thus we must have in all 

 such cases marine deposits at the base, then resting on them alter- 

 nations of iEolian and marine, all heaped up on solid rock or estua- 

 rine silt or whatever the floor may happen to have been. 



When we examine the upper part of the deposit, we find that the 

 sand is carried by the wind above the highest water-mark to form 

 the danes, and in like manner up the hill-sides that bound the 

 estuary or bay. 



Here another operation is at the same time going on. The talus 

 due to gravitation or pluvial action creeps down over the shifting 

 sand and covers or is covered by it. This may go on up to any level 

 if the slope be favourable and the supply of sand sufficient ; and if 



Fig. 2. — Diagram showing Succession of Deposits West of 



Saunton Court. 



3 4 



1. Talus. 3. Marine sand and shingle. 



2. Blown sand. 4. Pilton Beds. 



deposits thus formed are cut back and exposed in section, we see 

 alternations of blown sand and talus, but further from the hill the 

 blown sand only, as shown in the diagram (fig. 2). 



Where therefore only this last-described deposit of blown sand 

 and talus rises above highest water-mark, but the marine deposits 

 at the base are no higher than could now be reached by the waves, 

 there is no evidence of change of level such as would justify our 

 calling the deposit a raised beach. 



Along the coast from the north end of Braunton Burrows around 

 Croyde Bay, but especially under the south slope of Saunton Down 

 and west of Middle Borough, there is an almost continuous beach, 

 which I would refer to the agencies I have just been describing (see 

 fig. 3). The upper part consists of angular fragments of the rocks 

 which occur on the hill immediately above it imbedded in earth, the 

 result of the subaerial decomposition of those rocks. Where the 

 cliff has been cut back pretty close to the steeper slopes the thick- 



