348 



SPECIAL GEOLOGY. 



were precipitated over the subjacent beds of lias. The 

 neighbouring coast of Devon presents 

 evidence of like action ; but, owing to 

 the firmer nature of the rocks of that 

 district, consisting largely of sand- 

 stones and limestones, appertaining to 

 the Devonian and carboniferous groups, 

 the action of the waves is less evi- 

 dent, and appears to have been less 

 rapid ; while on the adjacent shore of 

 Cornwall, the still harder and more 

 crystalline character of the plutonio 

 rocks, the granites, syenites, green- 

 stones, and the like, evince feebler 

 marks of the agency of the sea, and no 

 perceptible change, of any importance, 

 is recorded as having taken place in th<? 

 configuration of the coast during the 

 records of man. The general princi- 

 ples, which are remarked in other locali- 

 ties are observable here; the softer rocks 

 being gradually hollowed out into creeks 

 and bays, while the harder strata are 

 left to protrude as headlands ; the 

 results being proportionate to the 

 various causes arising from the un- 

 equal resistance of the rocks, the 

 power of currents, tides, waves, and 

 breakers, and the original form of the 

 coast line. Proceeding round the 

 Land's End, the same description ap- 

 plies to the northern shores of Devon, 

 Somerset, and the adjacent district of 

 Wales. On the Cheshire coast, the 

 cliffs, composed of the softer clays and 

 marls of the new red sandstone have 

 yielded immensely to the advance of 

 the ocean, and though in the estuary 

 of the Severn, land both in Somerset- 

 shire and Gloucestershire, has, to a 

 considerable extent, been formed, yet 



the loss on this part of the coast far exceeds the gain. 



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