312 PROCEEDINGS. OF THE GEOLOGICAL SOCIETY. [Jan. 18, 



2. On the Association of the Lower Members of the Old Red Sandstone 

 and the Metamorphic Rocks on the Southern Margin of the 

 Grampians. By Prof. R. Harkness, E.R.S., E.G.S. 



[Abstract.] 



The area to which this paper referred is the tract lying between 

 Stonehaven and Strathearn, including the south-eastern flanks of 

 the Grampians for about two-thirds of their course. Metamorphic 

 rocks, trap-rocks, the Lower and Middle members of the Old Red 

 series (the former being sandstone, and the latter conglomerate), 

 are the constituent rock-masses of tbe district, and give it its pecu- 

 liar physical features. The mode in which these rocks are associated 

 is well exhibited in the section on the coast (at Stonehaven), and in 

 the several sections in the interior where streams lay bare the rocks. 

 Sections at Stonehaven, Glenburnie, Strathfinlass, North Esk, West 

 Water of Lethnot, Cruick Water, South Esk and Prosen, Blairgowrie, 

 Dunkeld, Strathearn, and Glenartney, were described in detail. 



Against the north-westerly dipping metamorphic schists (which 

 sometimes include conformable limestones) come purple flagstones, 

 but usually separated from them by trap-rocks, having the same 

 strike. These flagstones pitch to the south-east, but retain a high 

 angle away from the schists, and, in many places, are intercalated 

 with beds of trap. The lower purple flagstones are unfossiliferous ; 

 but higher up tracks of Crustaceans (Protichnites) have been dis- 

 covered by the Rev. H. Mitchell. The grey fossiliferous flagstones 

 of Eorfarshire succeed, still with a steep dip. Conglomerates succeed, 

 in beds having a less inclination, gradually becoming more and more 

 horizontal as they reach the low country. 



The axis of the elevation of the Grampians thus appears to be 

 along their southern margin, and to be marked by the trap-rocks 

 separating the metamorphic schists and the purple flagstones of the 

 Old Red series, and giving the latter their general south-easterly 

 dip. As the metamorphic rocks of the Grampians have not yielded 

 any fossils, their relation to the other old rocks of Scotland is diffi- 

 cult to determine. 



3. On the Old Red Sandstone of the South of Scotland. By 

 Archibald Geieie, Esq., F.G.S., of the Geological Survey of 

 Great Britain. 



[Plate XVIII.] 



Contents. 



Introduction. 

 Lesinahago : 



Silurian. 



Lower Old Red Sandstone. 



Carboniferous. 

 "Unconformity of Carboniferous and 

 Lower Old Red Sandstone. 



Pentland Hills. 



East Lothian and Berwickshire. 



Physical Geography of South Scotland 

 during the Old Red and Carbonife- 

 rous periods. 



Introduction. — During the last summer, while carrying on the 

 Geological survey of the Lammcrmuir Hills, I was particularly 



