72 On Hawick and its Neighbourhood. 



The strike of the strata here, as in Berwickshire's from north- 

 east to south-west nearly, and that also without any great 

 foldings, although often turned a little out of the general 

 direction. 



The summits of all our highest hills are of trap rock, 

 leading, in combination with the appearance of some of 

 them, to the idea that they have been centres of volcanic 

 action ; but a more probable theory is that the whole district 

 has been at one time overlaid, to some height, with trap 

 rock, which subsequently, by the action of glaciers and the 

 inroads of the sea, has been all swept away, except in a few 

 spots where superior compactness has preserved both the 

 trap itself and the rock below it from denudation. The only 

 argument against this is, that not a fragment of trap remains 

 in the upper valley of the Teviot. On the top of Wind- 

 burgh, and also on the Eildon Hills, the trap may be seen 

 in vertical and very regular basaltic columns. 



Besides these trap summits, there are some dykes of 

 greenstone, the principal one of these extending across the 

 whole island, in a direct but tacking course, and of a nearly 

 uniform width, from Acklington, in Northumberland, to the 

 mouth of the Clyde. 



The district is entirely devoid of coal, and shows only the 

 faintest traces of some of the commoner metals. Even the 

 dyke just mentioned, which appears to be auriferous in its 

 north-western course, shows no trace of gold here. 



The present condition of the district is undoubtedly due 

 to glacial action, but not demonstrably so, as in the High- 

 lands ; where we can measure the depth of every glacier. 

 The surface of the rock here is so uniformly covered with soil, 

 that grooved and polished surfaces are rarely visible. Our 

 numerous scaurs, however, composed of boulder clay, are 

 evidently deposits from glaciers, a great part of the stones 

 washed out from them being polished and striated, on one 

 surface at least. We have no ice-berg boulders. 



Until lately the district was believed to be entirely devoid 

 of organic fossils, of either animal or vegetable origin ; a 

 solitary specimen, supposed to be the footsteps of a crusta- 

 cean, having been found by Professor Harkness, at the 

 extreme limit of the district. But in 18G9, I sent some 

 good specimens to Sir R Murchison, at his request, and 

 subsequently exhibited some others to the Hawick Archaeo- 

 logical Society, and to the Geological Societies of Edinburgh 



