GEOLOGY AND SUEFACE FEATUEES. 9 



extending northward to Montrose, is occupied by old red sandstone and marl, 

 and by the shales, sandstones, and limestones of the carboniferous series. Masses 

 of igneous rocks rise above its surface and diversify its scenery. By its fertility 

 this plain contrasts most strikingly with the Grampians, which, like a wall, bound 



Fig. 4. — CoTiDAL Lines. 

 According to Scott Russell. Scale 1 : 10,625,000. 



o-of P 



o'ofG. 



Depth 0-54 



Over 109TsLthoms 



it on the north. It is rich, moreover, in coal and iron, and has become a great 

 centre of population. 



The hills of Southern Scotland, sometimes called the Cheviot Region, after the 

 range of hills which almost severs Scotland from England, resemble the Grampians 

 in geological formation, consisting, like them, of Silurian rocks; but being less 

 rugged in their character, and penetrated by broader valleys of considerable 

 fertility, they are far more hospitable. Extensive tracts are covered with grass, 



