40 Mr. H. Holland on the Cheshire Rock-salt District. 



extremity. Another ridge of land, possessing a small and irregular 

 elevation above the adjoining plain, may be traced from the hills on 

 the eastern border of Cheshire, in a westerly or north-v^resterly direc- 

 tion to Halton and Runcorn. At this point, where it attains its 

 greatest height, it is separated from the northern extremity of the 

 former ridge, only by the intervention of the valley of the Weaver, 

 which valley is here about two miles in width. Towards the eastern 

 extremity of this range, we meet with a singular sandstone hill, 

 called Alderley Edge, in which have been found ores of lead, copper 

 and cobalt, and masses of sulphate of barytes. 



This distribution of the high grounds in the Cheshire plain is 

 traced out in the annexed map, and it will be seen, by a reference to 

 this, that they form three distinct divisions of its area : one to the 

 west of the higher sandstone range ; another to the east of this, and 

 south of the lower range ; and a third lying north of the latter, and 

 including the southern parts of Lancashire. With the exception of 

 a very few instances only, the existence of the rock-salt appears to 

 be exclusively confined to the southern or central plain. 



The marl beds form the most peculiar feature in the alluvial 

 strata of the Cheshire plain. These occur in great abundance in 

 every part of the district ; being found not only under the common 

 soil, but occasionally, as on the borders of Delamere Forest, interposed 

 between layers of sandstone rock. The Cheshire marls are also very 

 frequently met with in large detached masses, twenty or thirty feet in 

 thickness, in the working out of which, it is not unusual to find 

 large assemblages of fragments of the older rocks. Portions of 

 granite, often of large size, and shewing on their surface evident 

 marks of attrition, are among the most common appearances in these 

 collections : no granitic rocks are found within fifty or «ixty miles of 

 this district. 



