334 PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [May 21, 



the Burn of Boyne, is very indistinct in its stratification, and greatly 

 jointed. It seems to have a very persistent character, and can be 

 traced, on its strike, for a long way into the interior of Banffshire, 

 and always exhibits the same aspect as regards the indistinct nature 

 of its stratification. In the interior of the county, it is worked 

 about three miles S.E. of Keith, at Black Hillock, where its imper- 

 fect stratification is well seen. 



The limestone of the Burn of Boyne is the site of another anti- 

 clinal, which is pushed over to the N. W. ; and consequently the 

 overlying gneiss seems to come from beneath it. Very soon, how- 

 ever, N.W. dips occur ; and these continue in the gneiss, which is 

 much intersected by granite-veins to Portsoy, where, at the Downie, 

 a mass of fine-grained syenite makes its appearance. This syenite, 

 at the Downie of Portsoy, seems to manifest itself in a synclinal axis. 

 Immediately west of the Downie, the celebrated Portsoy serpentine 

 is seen. This possesses nothing like bedding in its aspect ; but it 

 reposes upon a mass of black schist, thin-bedded, and dipping S.E. 

 at 70° — a dip the reverse of that of the strata which occur E. of 

 Portsoy. This black schist, which forms the highest strata seen 

 in the neighbourhood of Portsoy, is probably the equivalent of the 

 drab shales before alluded to as forming the highest strata seen 

 between Macduff and Gamrie. Westwards from the black schist 

 of Portsoy, S.E. dips continue for about a mile, when an axis 

 of quartz -rock presents itself. This is an extension northwards 

 of the mass of quartz-rock which is so amply developed in the Hill 

 of Durn. 



A short distance west from this quartz-rock axis, N.W. dips 

 occur; but almost immediately S.E. inclinations again obtain; and 

 these continue to Eed Harbour, where a singular isolated mass of Old 

 Eed Sandstone is seen. In this axis of quartz-rock another instance 

 of a roll pushed over to the JST.W. occurs. 



At Sandend or Dunidich, on the west side of Red Harbour, lime- 

 stone again makes its appearance. Although much contorted, it 

 is very distinctly bedded, and has a prevailing S.E. dip. This lime- 

 stone, on its strike, is well seen in the interior, and is also worked 

 at several localities. At Eordyce it possesses the same character as to 

 regularity of bedding, dipping here S.E., at 45°. S.S.W. from this 

 it is exhibited at Keith in the cutting of the Dufftown Railway, 

 and extends in a S.S.W. direction to Dufftown. At the railway 

 cutting at Keith, and a little southward, this limestone appears to 

 dip under quartz-rock, and to lie upon gneiss, the result of a com- 

 plete reversal of the strata. 



This limestone contrasts strongly in the perfection of its bedding 

 all along its strike with that of the Burn of Boyne and the Black 

 Hillock already referred to. 



Although these two areas of limestone differ so much in their 

 stratigraphical aspect, I have little doubt that they occupy the same 

 horizon, and that their different appearance is the result of difierent 

 degrees of mechanical forces, which have operated in modifying these 

 beds of limestone at the period when Ihe great flexures and con- 



