:Nbv 
■'ll 
salt minks or Cheshire. 
309 
Such ar.i 
“^position from the waters of the sea. 
much probability from the situation ill 
if usually occur ; occupying the vallies and 
the plains which are so surrounded by hills 
■>rmation, as to leave only a narrow egress 
The structure of 
^ Waitj'* ^*j^T^'^£cted °u their surface. 
iy.'t!h constitutes the salt district of Chcsliire, 
S®'’®tal character, leads strongly to the con- 
iif’ ^'5ve ^ waters of the sea must, ai some former 
-5i'r''‘bed lower parts at least of the basin 
auH '''^'ch at that time had a level lower by two 
or three hundred feet than the one now 
j) 7 -° account for the great depositions of salt in 
;vi’ this basin, it is necessary to suppose that 
''■'"'o been afterwards interposed to pre- 
, 4iis p .^“inmiinication of die waters of the sea with 
'k, ’'Oti i and the general course of the streams, 
'4,' t’allg y’ of rock-salt, and the contractions 
■’ll '^tid the Weaver, which appear below Nortli- 
‘^'“css and Frodsham, point out with some- 
111 place where these obstructions may pro- 
■ 
objection to this theor}’’ undoubtedly is,, 
a/ the uiarinc exiivite, either in the rock- 
w't-'ct v^r'iy ^^Jao'ont strata of clay; a fiict very difficult 
, 1 - j.; Oil) * aloa of a deposition from the waters ot 
, ,|j^’'°bjection3, though perhaps of less moment, 
appearance of the earthy salts in smaller 
'■ p.aru^'f rock-salt than in sea water ; from the 
■'ar . of , . tloposition of the beds ; and from the 
\y|P ‘''thng the formation of certain figured 
' occur in the substance of the rock. 
■*f'* ijf tho^'^'^*’ however, by no means authori-ze the 
mi idea which has been given of the 
^frengthened as it is by the situation 
'‘•'k'l Pf "P^orved in tRc' foreign salt mines, where 
'd It, rlepositioii are sLill stronger tlian lliose 
Cheshire district. 
