18 GEOLOGY OF THE LOTHIANS . 



coal-field. The strata are semicircular and have their con- 

 vexities uppermost, or form what is called a saddle ; they 

 are of a reddish-brown colour, and alternate with layers of 

 greyish-black coloured slate-clay, and reddish-brown colour- 

 ed clay-ironstone. On each extremity of the saddle rest 

 the more common rocks, viz. grey-coloured sandstone, glo- 

 bular clay-ironstone, &c. d. The rock on which Craigmillar 

 Castle is situated, belongs to the coal formation of Mid-Lo- 

 thian. It is composed of horizontal beds of greyish and red- 

 dish-coloured sandstone, that alternate with their beds of 

 reddish-coloured slate-clay and limestone conglomerate, e. 

 The hill of Salisbury Crags belongs to the coal formation, 

 and in it we observe repeated alternations of reddish-coloured 

 sandstone, clay-ironstone, slate-clay, and limestone conglo- 

 merate." 



In Fife, the coast between Dysart and Wemyss exhibits 

 four alternations of the red with the white sandstone; and 

 in the course of the Bevelaw Burn, a small stream which 

 runs for a few miles at the base of the Pentland range, 

 the white sandstone underlies the red. In other quarters 

 this arrangement is completely reversed ; as on the coast of 

 East Lothian, between the Cove and Dunglass Burn, where 

 the white coal-sandstone overlies the red. By following the 

 courses of the Dunglass, Bilsdean, and Thornton burns, 

 the transitions of the white sandstone series into the red, are 

 most satisfactorily displayed; the strata, as they recede 

 from the sea, gradually assuming a red colour, till, at last, 

 they pass into the red sandstone. In that part of the Esk 

 river which runs past Arniston and Kirkhill, there are nu- 

 merous alternations of the red with the white sandstone. 

 Much also of the country intervening between Drummore- 

 mill and Hawthornden, through which the Esk flows, is 

 formed of the same red sandstone : its relations, however, to 

 the white sandstone, are evident, and exhibit nothing fitted 



