456 MR MILNE ON THE GEOLOGY OF ROXBURGHSHIRE. 



At Wooden Hill (Eckford parish) there is a considerable mass of basalt, full 

 of elongated crystals of dark glassy felspar. 



Beneath Maxton Manse, there is a fine-grained greenstone, approaching to 

 clinkstone, which does not appear to have affected the adjoining sedimentary 

 rocks. 



(2.) Greenstone and basaltic rocks, of a more recent epoch, occur in two 

 forms, viz. in dykes, and in hills, or aggregate masses. On the Carter, there is a 

 large mass of Greenstone lying at a considerable distance above the limestone 

 worked there, and which may be traced for about a mile along the top of the 

 hill. Windburgh Hill consists, on its west side, of fine-grained greenstone, 

 which has there formed itself into columns nearly vertical, and has affected the 

 adjoining coal strata and limestone. At Greena Hill, in Carby Hill and in 

 Tweeden Burn (all in Liddesdale), there are considerable masses of basaltic por- 

 phyry, which have upraised the coal-measures surrounding them. 



Below Maxton Schoolhouse there is a fine-grained greenstone, which has 

 hardened as well as tilted up the sandstone strata on all sides of it. About a 

 mile above this, on the south side of the Tweed, opposite to Merton House, there 

 is a mass of basaltic greenstone (called Craigoer), which has evidently hardened 

 the sandstone strata. I at one time considered this a dyke, running north-east 

 and south-west ; but as it is composed partly of vertical columns, I am now in- 

 clined to think that it is an overflow. The sandstone in its immediate neigh- 

 bourhood has lost its red colour, and become yellow, as near the Holm, before 

 referred to. There is a good deal of greenstone and clinkstone along the south 

 bank of the Tweed, between Craigoer and Maxton, which has hardened the sand- 

 stone strata near it. 



Dykes of basalt or greenstone are not numerous. There is one which I have 

 traced for about 26 miles, passing through Hawick at its north end, and a little 

 to the south of Edgerstone at its south end. It is, or has been, worked at the fol- 

 lowing places, beginning at its north end, viz. at a place 1^ miles north of Hawick, 

 Miller's Knowe (1| miles south of Hawick), Orchard, Ormiston, Kirkton, on muir 

 west of Ruberslaw, Hallrule Mill, Falside, Roughlie, Rink. It may be seen beyond 

 this last mentioned point crossing the Edgerstone Burn, and also the Kale Water 

 near Hindhope.* At this last point it enters the coal-measures of Northumber- 

 land ; so that even within this county, it intersects the greywacke, the porphyry, 

 the red sandstone, and the coal formations in its course. 



Its course is not very regular, especially when within the limits of the grey- 

 wacke formation. Its general direction towards the north, when viewed from the 

 Miller's Knowe, by the line of its bearing apparent on the surface, is north 63 

 west. On the muir west of Ruberslaw, its line may be traced pretty uniformly 



* The best maps of the county do not, with any sort of correctness, indicate the position of the 

 Cheviot Hills, or even the situation of the farm-houses existing among them. I found it, therefore, very 

 difficult to lay down the dyke in this part of its course. 



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