MR MILNE ON THE GEOLOGY OF ROXBURGHSHIRE. 435 



near Abbotrule, the strata may be seen dipping in opposite directions, not far 

 from each other, affording indications of contortions on a still more gigantic scale. 



It is an interesting fact, as tending to indicate the direction of the forces 

 which produced these contortions, that the greywacke strata in Roxburghshire, 

 as elsewhere, crop out in lines which run nearly due east and west by compass. 



One place where I observed the greywacke strata cropping out in a different 

 direction was in Liddesdale, above Hermitage Castle, at a place called the Grains. 

 Its strike there is north-east by east; but this was a mere local aberration, 

 which was the more obvious, from the strata there dipping at the small angle of 

 40 to the horizon. In the burn behind Melrose, which flows from the Eildons, 

 the greywacke strata run north-west by west, and rise to these hills. This is the 

 strike of the beds also on the Jed, ^ mile from Cleslipeel, and on the Carter burn 

 at Sykehead. 



It is a consequence of these gigantic foldings of the greywacke strata, in an 

 east and west direction, that all the principal valleys in that formation run in 

 the same direction, as is well shewn by the course of the rivers Ewes, Teviot, 

 Ale, and Borthwick, which are the principal rivers in the district. 



No fossils, except some morsels of black vegetable matter, have been dis- 

 covered in the greywacke strata of Roxburghshire. Sometimes they exhibit on 

 their surface a curious concretionary structure, which has been by some, though 

 I think quite erroneously, attributed to organic causes. 



The only metallic veins I have observed in this formation consist of hematite 

 or red oxide of iron. They are in some places very abundant, as below Cowden- 

 knows (on the Leader river), where they may be seen in the channel, from half an 

 inch to an inch in thickness, filling up the natural joints of the rocks. In some 

 places, these hematitic veins form, at their out-cropping on the surface of the 

 greywacke strata, fantastic figures, as on the Jed at Cleslipeel. There is no doubt 

 that this red oxide is largely distributed through the greywacke rocks. 



I understand that small portions of galena were formerly found in the grey- 

 wacke strata, at Langholm Bridge. 



2. The next class of rocks to be described is the Old Red Sandstone formation, 

 though I am unwilling to assert, that they form a class independent of, and dis- 

 tinct from, the one which I am next to describe, viz., the Coal Measures. On the 

 contrary, there are strong reasons for believing, that both these sets of rocks, 

 though their outward and visible characters are very different, belong to the same 

 epoch, and have only been made to assume distinct appearances by local causes, 

 to be afterwards alluded to. At all events, there is no grand line of demarcation 

 between them, such as, in other cases, is indicated by the interposition of beds of 

 conglomerate, or by strik ing differences of dip. 



For the sake of distinctness, I will here treat of these two sets of rocks sepa- 

 rately, and in the order generally followed. 



