400 



existence of tlie new-red-sandstone formation in this county, Mr 

 Milne, whilst not wishing to affirm absolutely the non-existence of 

 any strata whatever belonging to this epoch, I'eferred to the older for- 

 mation the great mass of the red sandstones abounding in the dis- 

 trict, adding that he had himself seen none which necessarily be- 

 longed to a later epoch. 



It was stated that no fossils had been found in the greywacke strata, 

 but that in the old red sandstone formation, scales and bones of the 

 Holoptichius had been found embedded both in the red and the white 

 coloured strata. 



The igneous rocks consist of all the varieties of felspars, basalts 

 and greenstones, known in other parts of Scotland, the first men- 

 tioned of these being the oldest. All these rocks occur in the form 

 of dykes, as well as hills, of which the Eildons and Cheviots are the 

 highest and most extensive. 



The superficial deposits consist, beginning with the oldest, of the 

 boulder clay, well known in the Lothians, — of sand and gravels, — and 

 of great blocks or rounded fragments of rocks, all strewed over the sur- 

 face. It was mentioned, that, whilst the boulder clay was deposited 

 in tumultuous waters (presenting no signs of stratification), the sands 

 and gravels being for the most part stratified, have been deposited by 

 waters not in violent action. The greater number of boulders in 

 Liddesdale consist of grey granite, very similar to that of CrifFel, 

 situated between thirty and forty miles to the westward. 



In part 2d, the author observed, that the greywacke formation, 

 presenting as they do enormous foldings, in consequence of which the 

 formation is traversed by ridges and valleys, all running east and 

 west by compass, must have been acted on here, as throughout the 

 rest of this part of the island, by a force or system of forces, which 

 acted in a particular direction ; and that as hardly any igneous rocks 

 whatever occur, within the limits of this formation, it seemed that 

 the greywacke strata had not been elevated and folded together by 

 igneous action, but more probably in consequence of changes in the 

 form of the Earth's nucleus, as suggested by Elie de Beaumont. 



The elevation of the greywacke ranges was followed by eruptions of 

 felspathic and a few greenstone rocks, which took place chiefly on the 

 outskirts of that formation ; and from the sediment aff'orded by the 

 wearing down of these rocks, still at the bottom of a sea, the stratified 

 rocks surrounding and partly covering these older rocks were formed. 

 As the heaviest sediment would be deposited first, the sandstones 

 filled with oxide of iron, and now constituting the principal beds of 

 the old red sandstone formation, would girdle the hills of greywacke 

 and older felspathic rocks, whilst the strata of white sandstone, shales, 



