29G William Stevenson. By Professor Duns. 



my mind as to some of these, I wrote a note of two or three lines 

 to Stevenson, looking for one quite as brief in return. But the 

 answer was as follows : — 



Dimse, 7th, Octr., 185S. 



My Dear Sir, 



You are quite right in your impression regarding the strata 

 below Langton Bridge. — They are Lower Carboniferous and their place is at 

 or near the very base of the System. Besides' the vegetable remains you 

 mention, I have found at the scaur below the bridge, or more correctly in the 

 same beds a little farther down (in the plantation) teeth, scales, and spines 

 of a large species of Gyracanthus. Similar fish remains have been found by 

 me in strata occupying the same geological position at Broomhouse and 

 Allanton. The Sandstones of Puttonmili and Kimmerghame are also very 

 near the same position, and likewise contain fish remains. 



There is an extensive series of beds in Berwickshire, intervening between 

 these and the Encrinal Limestone which crops out south of the Tweed. The 

 equivalents of these beds may be seen in Balagan Glen near Campsie, 

 Auchenreoch Glen near Dumbarton, &c. On the shore between the Pease burn 

 and Dunglass there is a splendid section where strata occur, which I consider 

 the representatives of the Langton beds (also fossiliferous near the south-east 

 end of the section, a little above the Old Red strata) . Sluch higher up in 

 the same section (just below the fi-hers' houses at Cockburnspath Oove) are 

 fossiliferous beds, which I consider the equivalents of the Burdiehouse strata. 

 The Encrinal Limestone is still a long way above these beds. The inter- 

 vening strata may be seen along the coast, where, however, they are not so 

 well developed as in the Merse. 



In the course of Langton burn, between the bridge and Langton wood, a 

 series of grey and reddish brown shales are seen associated with Sandstones 

 and beds of a sort of Cornstone or impure concretionary calcareous rock. 

 These strata contain no'fossils, but from their position and mineral character, 

 are evidently the connecting links between the Carboniferous and Devonian 

 Systems. The true Old Red (upper part) appears farther up the bum. 



A fault or faults of small extent probably existed near Langton bridge, 

 and a fault of great extent has produced a ' boulversement ' of the Old Red 

 above Langton wood. This fault runs along the east side of the Hardens by 

 Raecleugh, and along the course of the burn to Choicelee, etc. Nevertheless 

 I think the whole series of strata between the true Old Red, and the beds 

 below Langton Bridge may be made out with tolerable completeness by com- 

 paring other sections within a range of a few miles fiom Dunse. 

 Believe me, Yours very sincerely, 



WM. STEVEN-SON. 

 But the most important of Mr Stevenson's studies in geology is a 

 series of MS notes, consisting of more than two hundred and 

 thirty closely written folio pages, begun in 1841 and continued 

 till 1855 under the title " Materials for the Geology of Berwick- 

 shire. " They are of great value, and bear the fullest and most 

 satisfactory evidence of his rare accomplishments as a geologist. 



