GEOLOGY OF THE CAMPSIE HILLS. 



27 



two rivers rising nearly at the same point, and im- 

 mediately flowing in directions diametrically op- 

 posite to each other, sufficiently ascertains that 

 this hill of Meikle Ben forms the saddle of this 

 part of the country. 



I shall now proceed to describe the interior 

 structure and composition of this hilly district. 



As far as this tract of country has been dipped 

 jnto, the geological materials of which it is formed 

 are as follow : A surface of vegetable soil,— trap, — 

 sandstone, — limestone, — shale or slate-clay, — blue 

 clays of various tints and of various consistences, — 

 bituminous shales, — clay iron-ores, some of which 

 are thinly stratified, and others are imbedded in 

 the shale in lenticular forms, — coal, — and clay- 

 marl ; all of which materials, have been arranged 

 by nature in the order in which they are here 

 placed, from the ^urface-soil downwards. 



The vegetable surface-soil of this district, is 

 but thinly scattered over the face of its hills : it 

 consists mostly of an argillaceous matter of a light 

 brown colour, much mixed with the small debris 

 of the trap on which it generally rests, and from 

 the decomposition of which it has evidently ori» 

 ginated. The quantity of iron in this soil is con- 

 siderable, and it owes its colour to an oxide of that 

 metal. 



The rock which occurs immediately under the 

 surface-soil, is trap, which generally, in this dis- 

 trict, is of great thickness, and, in the broken 



