84 GEOLOGY OP THE LOTHIANS. 



N. E. and S. W., and is traversed by two vertical dykes of 

 greenstone, the largest of which is about twenty feet wide ; 

 but neither the greenstone nor the slate exhibit any mark- 

 ed signs of alteration. 



Above the village of Currie, the hill of Warklaw rises 

 through the white sandstone series, which occurs abutting 

 against it in the bed of the Water of Leith ; it is partly 

 composed of a common greenstone, and partly of a porphy- 

 ritic clinkstone, and on its south side, strata of red sandstone, 

 in some places highly calcareous, are found reposing. On 

 the banks of a rivulet which takes its rise at the foot of Har- 

 bour Hill and joins the Braidsburn here, the white sand- 

 stone is found dipping N. N.E., being cut through by a 

 dyke of trap which dips N. at 80°. All the rocks are indurat- 

 ed, the sandstone passing almost into granular quartz, and 

 the argillaceous shale becoming compact. The greenstone 

 which occurs here is of the usual description, and is arranged 

 in perfect globular concretions. On the other side of the 

 greenstone dyke, the strata dip to the S. S.W., resting upon 

 the red sandstone, which reclines against a rock of com- 

 pact felspar. After leaving Bevelaw Quarry, and proceed- 

 ing along the Pentland range, the igneous rocks are found 

 to be replaced by the red sandstone, which constitutes, with 

 the exception of one or two veinous masses of trap, all the 

 remaining Mid-Lothian portion of the Pentlands. In East 

 Cairn Hill, the sandstone rises to the height of 1802 feet, 

 forming a well-marked table-shaped mountain, and on its 

 south side, the strata of sandstone crop out, and dip to the 

 north at about 25°. Concerning the immediate agents which 

 have caused the red sandstone of this quarter to rise into 

 mountain masses, we cannot speak with certainty, inasmuch 

 as they are all completely concealed. In the pcrphyry 

 hills of the range, however, there exist causes quite suffi- 



