20 



ture, varying from soft clays to the hardest rocks. Since the 

 ancient beaches are as a rule wonderfully horizontal in their 

 present position, it seems hardly conceivable that land masses of 

 such different structure could be so uniformly upraised. Suess 

 believes that in many cases the level of the water has been 

 lowered by earth movement or wrinkles affecting the ocean basins. 

 A kernel of truth probably exists in both views, and the raising 

 of the land and the lowering of the water level may at different 

 periods have produced the same results. 



We may see by a glance at a map showing the Raised Beaches 

 of the south of England, that they are almost invariably situated 

 on a foundation of some hard rock. Those which rested upon 

 soft rocks have been cut back and entirely lost, the hard founda- 

 tion of the others being their safeguard. We have already seen 

 that at Brighton the Raised Beach rests upon Chalk. At Wey- 

 mouth it has a foundation of Portland Limestone. The Raised 

 Beach at Saunton, in Devon, is worth a few passing remarks. 

 It is there found resting on the upturned edges of Upper 

 Devonian .Slates. At the base of the ancient beach, on the 

 old waveworn surface of the slates, there are here and there 

 along this part of the coast enormous boulders of granite. A 

 picture of one of these is here shown which probably weighs 

 about seventeen tons, and must have been carried by an iceberg 

 to its present position. Above this Raised Beach there is an 

 interesting deposit of false-bedded sands, rendered coherent by 

 calcareous material, with included marine and land shells. This 

 accumulation is of great thickness, often measuring 50ft., and 

 representing ancient sand-dunes formed above high water mark, 

 much in the same way that Braunlon Burrows are now being 

 formed. At Torquay and Baggy Point the Raised Beach is 

 found again upon Upper Devoni.Tn Rocks. At Weston-super- 

 Mare and at Gower, in South Wales, it is found on the 

 Carboniferous Limestone. 



Li conclusion we may note the many coastal areas affected 

 by recent upheaval or the reverse, in various parts of the world, 

 and for a case lately brought before our notice this may be 

 illustrated by the views taken by Mr. C. W. Andrews, of the 

 elevated beaches and reefs of Christmas Island. 



The Lecture iv as fully illustrated with a large nufuber 0/ Lantern 

 Slides. 



