GEOLOGY 



Of similar character is the broad flat of Romney Marsh, which Hke 

 the marshes of the Thames lies below the level of high spring tides. It 

 is fringed along the greater part of its seaward margin by an accumula- 

 tion of recent shingle, arranged in ' fulls ' or ' storm beaches,' and by sand 

 dunes ; and where these are wanting the marsh is protected from the sea 

 by artificial embankments. Within the marsh, marine sand and shingle 

 is generally found at a depth of from lo to 20 feet, but this is overlain 

 by clay and peat with trunks of trees. Great changes have taken place 

 within the recent period in this tract both in the shape of the coast line 

 and in the course of the river Rother across the marsh, but as these will 

 be dealt with by the historian, passing reference to them will here 

 suffice.' The great shingle spit at Dunge Ness, where the accumulated 

 ' storm beach ' is two or three miles wide, is known to be growing out 

 eastward at a rate estimated at about six yards annually, through the 

 steady transference of the shingle in that direction. Meanwhile on the 

 coast of the marsh to the westward the sea is encroaching, so that the 

 position and shape of the Ness is constantly undergoing modification, 

 and is known to have been quite diffisrent a few centuries ago. 



Being concentrated upon a narrow shore-line, the effisct of the sea 

 upon the land is always more obvious than the subtle all-pervading 

 influence of the atmospheric agencies. It seems scarcely necessary to 

 mention that every part of the Kentish coast, except where artificially 

 protected, is undergoing change, though nowhere so rapidly as at 

 Dunge Ness. Its cliffs are being sapped and torn away piecemeal — 

 rapidly where composed of soft material, as at Sheppey and Reculvers ; 

 and more slowly, but still not very slowly, where of firmer build, 

 as in Thanet and the South Foreland ; while its shallow estuaries 

 are being gradually silted up and its salt marshes converted into firm 

 land. 



DEEP-SEATED ROCKS 



Having deciphered the later portion of the geological history of 

 the county, from the records contained in the structure of the present 

 surface, and having thereby incidentally made easier the reading of such 

 evidence as we may possess regarding the rocks which do not appear at 

 the surface, we will now turn back to the earlier chapters of the 

 history and consider the deep foundation of the county. 



As mentioned at the beginning of this article, very important 

 additions have been recently made to our knowledge on this subject 

 by the numerous deep borings which have been sunk in search of 

 coal. Though the information as yet published regarding these borings 

 is somewhat limited, it enables us to add very considerably to the list of 

 formations recognized in Kent, and to prove the existence of a down- 

 ward succession reaching to the base of the Secondary or Mesozoic rocks 

 and even including part of the Palaeozoics. 



* Consult Mem. Geo/. Survey, 'Geology of the Weald,' chap. xvii. p. 302, for geological account 

 of these changes. 



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