BATE OP EEOSION OF THE SEA-COASTS OF ENGLAND AND WALES. 903 



At St. Donat's large rounded blocks are taken away from the beach, to be used as 

 building-stone and occasionally for lime-burning. 



West of St. Donat's there are fine level platforms of rock on the foreshore. Here 

 the cliflE follows the strike of the strata, but the ledges naturally vary much along 

 the line of coast, according to the inclination of the strata and the changes in the 

 direction of the coast. 



South-east of Nash Point, between the two lighthouses, the cliSs have suffered 

 noteworthy losses by slips and falls of rock. Here, for a short space, a wall has been 

 built to protect the higher lighthouse. 



South-east of Dunraven, the ledges and platforms of Lias rock, covered in places 

 by sand, may be seen stretching out rather more than a furlong seawards at low tide. 

 Considerable slips of rock have taken place, and accumulations of tumbled blocks 

 and boulders are to be seen here and tliere along the foot of the cliffs. 



At the Witches' Point, Dunraven, tbe lowest beds of the Lower Lias are unusually 

 hard and more or less conglomeratic, and they rest irregularly on the upturned edges 

 of the Carboniferous limestone. A prominent headland has been the result, and 

 there are three caverns on the south side of it in the Lias. To the north-west of this 

 headland there is a fine expanse of sand between tide-marks, while the coast is 

 bordered near the Lodge, Dunraven, by very coarse boulder-shingle. 



The cliffs in the north-eastern angle of the bay, under Dunraven Castle, show the 

 Lias strata much disturbed and faulted, and here considerable slips take place. I 

 was informed in 1887 that ten or twelve years ago there were caverns here, but no 

 trace of them remains. 



From Dunraven, past Southerndown, to Sutton, the cliffs are formed of the 

 ordinary Lias limestones and clays, dipping eastward, but undulating under Southern- 

 down. These beds rest on about 90 feet of hard blue conglomeratic Lias, and hard 

 white and conglomeratic rock, known as the Sutton stone. These lower strata here, as 

 well as south of Dunraven, stand out in massive beds, and offer greater resistance to 

 the breakers than do the ordinary beds of the Lower Lias. They rest irregularly on 

 the Carboniferous limestone ; and partly from this fact, and partly owing to great 

 joints and fissures in the rocks, numerous caverns have been excavated by the sea. 

 In one place below West an outlying stack of the Sutton stone, &c., stands out on 

 the foreshore. The cliffs rise rapidly from the beach south-east of Southerndown to 

 an elevation of about 1 50 feet near West, but decrease again further on to below 

 50 feet as far as the mouth of the Ogmore. Under Southerndown there are two or 

 three faults where the beds are slightly displaced, and the cliffs stand out in wall- 

 like buttresses. 



The Black Kocks, west of Southerndown, are formed of Carboniferous limestone, 

 much fissured, and worn into irregular shapes by the action of the breakers. Both in 

 this rock and in the harder beds of Lias, deep channels, basins, and tiny arches are 

 excavated by the waves dashing over the rocks and then draining off in lines of 

 jointage, &c. Curious honeycombed surfaces are produced in the rocks by the 

 combined action of the breakers and the spray. Here and there little sandy bays 

 occur among the rocks, while more sand and shingle are exposed at low tide near 

 Sutton, the shingle containing pebbles of red and brown Coal-measure grits, as well 

 as pebbles and boulders of Carboniferous limestone : no doubt deriving many stones 

 from the river, which brings material from the South Wales coal-district, while some 

 of the boulders are derived from the Dolomitic conglomerate. 



The low cliffs here consist of Carboniferous limestone, with thin and irregular 

 cappings of Lower Lias (white Sutton stone and conglomerate) near the Black 

 Kocks, and irregular masses of Dolomitic conglomerate further on. 



Near the mouth of the Ogmore, and on both sides of it, the Carboniferous lime- 

 stone and Dolomitic conglomerate are smothered up over considerable areas by 

 blown sand. This extends by Candleston Castle and forms the Newton Burrows, 

 which stretch towards Newton Nottage and Porth Cawl. Not far from the mouth of 

 the river is the Tusker Rock, an islet of Carboniferous limestone that is ordinarily 

 exposed at low tide. 



