DISTRIBUTION OF THE ROCKS OF THE LOTHIANS. 121 



The northern boundary of the red sandstone formation 

 in East Lothian, after this, becomes more obscure, from the 

 circumstance of a transition taking place into the white 

 sandstone series : the line of gradation appears to run S. W. 

 near Salton, Keith village, and Costerton, till at last in 

 Mid-Lothian it is terminated by a very ill defined boundary, 

 running more or less south from Crichton Dean to the 

 base of the greywacke hills. On the sea coast, extending 

 from Whitberry Point to Weaklaw, several minute masses 

 of red sandstone appear, all of which are generally associated 

 with rocks of igneous formation. 



In Edinburghshire and Lanarkshire, red sandstone forms 

 a considerable portion of the western division of the Pentland 

 range. As in East Lothian, the northern boundary cannot 

 be recognised, but the most natural line of distinction ap- 

 pears to be that, where the transition of the one formation 

 into the other has been completed ; and this line seems to 

 run more or less in the neighbourhood of Wark Hill, Har- 

 law, Upper Buteland, Harper Rig, Easter Cairns, Wester 

 Colzium, and Cross wood. The westerly part of the red 

 sandstone may be said to be bounded by the felspar rocks 

 of Black Hill, West Kip Hill, and Spittal Hill, while on 

 the south it runs parallel with the new line of road from 

 Nine Mile Burn to West Linton. Mountain limestone oc- 

 curs in numerous points in the Lothians,formingbands which 

 cross the country in different directions, and of these the 

 most extensive is that which in Mid-Lothian skirts the base 

 of the Moorfoot range. The most western point in Edin- 

 burghshire where this formation is exposed, is in the Hie- 

 flat quarry near Howgate ; to the west of this, however, it 

 is worked extensively at Rutherford and the Bents in Peebles- 

 shire. Crossing the country in a north-easterly direction, 

 mountain limestone forms much of high ground, running 



