WALES. 



51 



These variations of level are perhaps still going on. They must have singu- 

 larly increased the effects of erosion, as exercised upon the rocks and coasts of Wales. 

 The carboniferous formation of South Wales originally occupied an oval-shaped 

 basin of pretty regular contour, surrounded concentrically by beds of more ancient 

 age, but it has been visibly encroached upon by the floods of the Atlantic. The 

 peninsula of Gower, to the west of Swansea, is nothing but the remains of an 

 ancient jaromontory, formed of carboniferous and Devonian rocks. St. Bride's 



I'ia-. 24. — Effects of Erosion on the Coast of South Wales : the Huntsman's Leap. 



Bay, at the south-western angle of Wales, is the result of the continued erosive 

 action of the sea. The two promontories which bound it on the north and south 

 are composed in a large measure of hard rock, capable of resisting the onslaught of 

 the sea, but the softer intervening rocks of the carboniferous formation have been 

 washed away, and their place is occupied now by a bay of strikingly regular con- 

 tours.* The erosive action of rain and running water has completely changed the 



* Eamsay, " The Physical Geology and Geography of Great Britain." 



