1859.] MURcnisoN- — north highlands. 22'A 



dipping slightly to the north of east, as in Ben More of Assynt and 

 adjacent mountains, or E. and E.S.E. in a more southerly district, 

 are invariably surmounted by younger micaceous and gneissose 

 strata. In my communication of last year I stated that the quartz- 

 rocks were also overlain by a second zone of limestone in the country 

 to the east of Assynt ; and the fact has this year been corroborated 

 by Professors Ramsay and Harkness. "With the addition of some 

 material data, I am now enabled to reaffirm, not only that this 

 second limestone is superior to all the quartzo-calcareous strata, but 

 is, as I showed, conformably surmounted by those upper micaceous, 

 chloritic, gneissose, flaggy strata, the overlying position of which is 

 thus completely established. Professor Ramsay* not merely ob- 

 served this upper limestone where I had previously noticed it, but 

 rendered the case conclusive by tracing the rock from Cnoc-chaorie, 

 on the high road to Loch Ailsh, to the north, until he saw it follow- 

 ing the sinuous outline of the subjacent quartz-rocks. In this form 

 it is always seen dipping away conformably to the east or south and 

 north of east, according to the folds of the inferior strata which rise 

 into the lofty mountains of Bon More f . From Kinloch- Ailsh this upper 

 Limestone sweeps round to the cast and north of the mountain of 

 Ben More, and extends up the valley of the Cashly to the east side 

 of the Stack of Glencoul. Lithologically this limestone differs from 

 that of Assynt in being of a lighter colour and having somewhat of 

 a magnesian character ; and though no fossils have as yet been 

 found in it, I do not despair that such may still be detected. 



The position of this upper limestone is further important, in 

 showing that, whilst it is conformable for many miles to the sub- 

 jacent quartz-rock, it is overlain in like conformity by those dark- 

 coloured micaceous and chloritic schists and flagstones to which I 

 called attention last year as dipping to the E.S.E. upon the banks of 

 the River Oykel. These strata, becoming more gneissose in pints, 

 and particularly in their higher members towards Oykel Bridge, are 

 those which Prof. Nicol does not yet admit to be younger than the 

 quartzo-calcareous series. Strengthened, however, in my opinion by 

 the examination of Prof. Ramsay, and also by Prof. Ilarkncss's + 

 subsequent examination, I again assert that in this line of section, 



Fig. 5. — Section East of Jit EUag. 



N.W. s.K. I. Quartz-rook. 5. Gneissose quarts- 



2. Limestone, rook. 



.'{. Hornstone- •*>. Quartz-rook. 



porphyry. 7- < taeissoee lime- 

 t. Limestone. stone. 



\<> S. rpporllai^'v i,'iii-i.<s. Dip. l."> S K. 



* Being unwell on tbisoocasion, I begged Prof. Ramsay t" make tin'* exami- 

 Datum by himself ; and as Prof, darkness has since arrived si a similar conclusion, 

 1 1 iv former inferences are thus supported bj t«<> independent observers. 



t So- the east end of Bg. '•'<- 



j Prof Earkness minutely describes the junction <>f the upper quartz-rook 

 ami limestone with the so-called "superior gneiss;" and I thank him for the 

 pains he has taken t<> demonstrate the true order <>( the rooks t" die • uri "f alt 

 Ellag (as shown in Bg. 5) : 



