434 MR MILNE ON THE GEOLOGY OF ROXBURGHSHIRE. 



I. Stratified or Aqueous Rocks. 



1. The first of these which I shall describe, and which is by far the most 

 abundant, is the Greywacke. Almost all those hills which occur in elongated 

 ridges, are composed of this rock. 



It has, in most places, the usual colour of bluish grey, though occasionally 

 the colour is red, as in the Leader near Carolside, in the Jed near Kersheugh, and in 

 the Kale near Oxnam. Its strata vary much in thickness ; some being almost as 

 thin as paper, and others several feet in thickness ; but its ordinary charac- 

 ter is slaty, a character for which it is indebted to the presence of mica. On this 

 account, the greywacke rocks very generally exfoliate by the varying influence of 

 the atmosphere, and produce a soil, wet but by no means ungenial. I am not 

 aware that the thin strata are found anywhere in this county so hard as to pro- 

 duce roofing-slate; but the thicker strata afford tolerably good building ma- 

 terials. 



The texture of the greywacke is, generally speaking, what is termed " fine 

 granular." A coarser variety (amounting almost to conglomerate) sometimes 

 occurs, as a few miles west of Galashiels, on the turnpike road, where it is 

 quarried. 



The greywacke strata are in this county, as in the rest of the British islands, 

 almost every where vertical. Any deviations from this rule observed by me, 

 were very rare. At the Miller's Knowe, near Hawick, they dip at an angle of 80 

 to the south ; at Kirkton, 80 to the south ; at Rinkfair, about 75 to north ; at 

 Southdean Manse and at Abbotrule, they dip south at an angle of about 50 ; above 

 Jedburgh, the dip is to south at an angle of 65 ; at Carolside Bridge, about 40 to 

 the north ; west of Edgerstone Rig, they make an angle of only 20 with the hori- 

 zon, dipping south. 



In several places, the foldings or contortions of the greywacke strata are well 

 exhibited. On Jed water, about a mile west of Edgerstone, there is a good example, 

 in consequence of the great height of the west bank. The greywacke strata are 

 there bent, forming a very acute angle, opening vertically downwards. The same 

 individual strata which, at the top of the bank, form this rapid curvature, may 

 be seen at a little distance, forming an opposite bending at the bottom of the 

 bank. On Oxnam water, a similar fracture of the greywacke strata may be seen, 

 and on a much larger scale ; but on that account it is not so obvious, as the whole 

 contortions cannot be easily taken into one view. Near Crailing house, they dip 

 north at an angle of 85., whilst near Upper Crailing mill (about two miles higher 

 up the river), they dip south at an angle of 80 ; and in the intervening parts of the 

 river, they present extraordinary bendings and twistings. Near South Dean and 



