BEACHES, ETC., OP THE SOUTH OF ENGLAND. ^91 



(20) MewslacU and RJios Sili. — These Beaches are amongst the 

 finest examples in the countr7, but they have not yet been described 

 except in a slight notice of the former that I gave to Dr. Palcouer.^ 

 The Mewslade Eeach extends for a distance of nearly half a mile 

 along the coast, and exhibits the old submerged cliff, the Beach, and 

 the Head in a manner analogous to the Brighton and Sangatte 

 sections (see PI. YII. fig. 6). 



The Beach, which maintains a thickness of from 2 to 4 feet 

 throughout, consists of well-rounded pebbles, chiefly of limestone, 

 with a few subangular chalk-flints in a matrix of sand and commi- 

 nuted shells, and is often concreted. Perfect shells are scarce. 

 The common species are : — Littorina Itttorea, L. rudis, Patella 

 vidgata, Purjpura lapillus, Cardium edule, Tellina haltJiica, and 

 Cyi^rinai^.)^ with Balanus. 



The red sand overlying the Beach is in places 4 feet thick, but is 

 very irregular. The Head, which consists of an unstratified mass 

 of angular limestone-fragments in a macrix of red clay and sand, 

 with some rolled fragments and pebbles of grey and red sandstone, 

 quartz-grit, white quartz, &c., is 27 feet thick at the eastern end, 

 becoming gradually thinner westward. The rubble is flush with 

 the top of the submerged cliff", which runs a short distance at the 

 back of the Beach, and behind it the limestone rises to the surface. 



Between Mewslade and the Worm's Head is another similar 

 section, but of less height. The only point to note is that there are 

 some large rounded blocks of limestone in the Beach, and that the 

 rubble is composed of larger fragments than at Mewslade. The 

 shells are the same. 



The cliff's on the southern coast of Gower range east and west. 

 At their western extremity they are only separated by the bold 

 promontory of the Worm's Head from the fine bay of Phos Sili, which 

 extends from south to north, or at right angles to Mewslade Bay, 

 for a distance of three miles. In the near background of this bay. 

 is a range of high grassy hills, or downs, running parallel with the 

 shore, from which they are separated by a narrow terrace, not 

 more than a furlong in width, sloping from the base of the hills 

 and ending in a line of low cliffs. 



The hills are formed of Old Bed Sandstone with a thin scattering 

 of Glacial drift spread over the surface, and the terrace is composed 

 of a vast mass of angular rubble or Head derived from these rocks 

 and the overlying drift. Under this Head is. a shell-bed resting on 

 a mass of rubble of Old Bed Sandstone, very similar in appearance 

 to the upper bed, 9,nd beneath which the Bed Sandstone shows in 

 places. 



The shell-bed may be a beach or a shallow sea-bed, and differs 

 from the littoral Beaches we have been examining. The whole 

 group has at first sight very much the look of a cliff' of ttje 

 Boulder Clay gravels. At the Phos Sili end the cliff is about 30 feet 

 high, the Head being 10 to 12 feet thick, the shell-bed !^ to 4 feet, 

 and the underlying mass of red rubble 8 feet. 



^ ' Palaeont. Memoirs,' vol. ii. p. 536. 



