2[)0 



PROF. J. PEESTWICH ON THE RAISED 



the present shore are not given. I should judge them to be from 

 15 to 20 feet. 



Patches also of the concreted sand, and pebbles of an old beach, 

 are attached to the rocks about 12 to 15 feet above the present 

 beach, just outside Bosco's Den, Paviland Cave, and Long Hole 

 Cave; at the last-named place the deposit contained Littorina 

 littorea, L. rudis, and Puiyura lainllus. illlowing for the slope 

 outwards from the interior of the Caves, where Col. Wood's sections 

 were taken, this corresponds pretty accurately with the other levels 

 of the Raised Beach on this coast, which, between the Mumbles and 

 Mewslade Bay, may be taken at from 12 to 20 feet above sea-level. 

 The rise has not been uniform. 



Not only does this marine basement-bed of the Cave-deposits 

 correspond with the Eaised Beach, but the limestone-rubble which 

 overlies the Ca.ves, and in many cases has overspread them, likewise 

 corresponds in character with the Head of the South Coast Beaches. 

 The position of the ossiferous beds in the Caves is therefore inter- 

 mediate between the Beach and the Head. While, however, the 

 Beach has been in most places worn away b}' the encroachment of the 

 sea, the Head — being at a higher level — has remained attached to 

 the face of the cliff, wherever the slope has been sufficient to give it 

 support. At Bosco's Den, the rubble fills the fissures above the Cave, 

 masks the entrance to it, covers the Baised Beach, and extends 20 to 

 30 feet seaward. At Raven's Hole and Bacon Hole similar conditions 

 obtain. Dr. Palconer remarked, in speaking of Bacon Hole and 



Fig. 11. — Dlcujram-section of a Gower Coast Cave. 



S£E«7 



a. Rubble-drift or Head, made up of angular fragments of 

 and pebbles from the drift capping the hill. (This 

 carried rather lower down.) 



h. Cave-deposits, 



c. Raised Eeach. 



d. Plateau and glacial drift. 

 1. Carboniferous Limestone. 



limestone 

 should be 



Crow Hole, that this " breccia corresponds in the character of the 

 materials with the angular brecciated debris which overlies the 

 liaised B.each in the Mewslade section given hy Mr. Prestwich '" 

 (^op. cit. p. 518). The diagram, fig. 11, shows the position of these 

 severaldeposits and their relation to the Caves. 



