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Sect. YI.] 



GEOLOGY, 



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accoTiipanying earthn^uakes, will be treated of by 

 Mallet, bat a few remarks on the nature of the evidence 

 to be Bought, on change^' of level not actually witnessed 

 by man, may be here mserted. Many appearances, such 

 as hnes of inland cHffs, of sand-hillocks, eroded rocks, and 

 banks of shingle, often indicate the former effects of the 

 sea on the land when the latter stood at a lower leveL 

 But the best evidence, and the only kind by which the 

 period can be ascertained (for the appearances above 

 enumerated, though well preserved, may sometimes be of 

 considerable antiquity), is the presence of upraised recent 

 marine remains. On land which has been elevated within 

 a geologically recent time, sea shells are often found, 

 either embedded in thin layers of sand and mould, or scat 

 tered on the bare surface. In these cases, and especially 



in the latter case, great caution is requisite in testing the 



evidence ; for man, birds, and herm^it-crabs often trans- 

 port, in the cour >. of agos, an extraordinary number ox 



shells. In the case of man, the shells generally occur in 



heaps, and there is reason to believe that this character is 

 long preserved^ To distinguish the shells transported by 

 animals from those uplifted by the movement of the earth, 

 the following characters may be used ;— Whether the 

 shells had long lain dead under water, as indicated by 

 barnacles, serpula?, corallines adhering to their insides t 

 whether the sheik, either from not being full grown or 

 from their kind, are too small for food ; remembcHng that 

 certain shells, as mus^ols, nu.^ be unintentionally trans- 



ported 



man or other animals in their young state 



adhering to larger shells ; and lastly, w hether all the spe- 

 cimens have the same appearance of antiquity. Some 



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