and some other Stratified Deposits in the North of Scotland. 3\3 



connecting links with the oolites of the midland counties of England : and 

 without their intervention as terms of comparison, much obscurity might still 

 attach to the geological place of these northern deposits ; for the apparent 

 anomaly of the latter,, in having lost the oviform structure or usual type of 

 formation, is reconciled, when it is seen that in the beds of the district with 

 which they have been compared there are few or no traces of oolite. 



Red Conglomerate. 



The entire absence of the carboniferous series in the N. E. of Scotland, 

 renders it difficult to determine the age of the red conglomerate which in 

 those districts, is alone interposed between the lias and the primitive rocks ; 

 since it is now admitted that the new red sandstone cannot, in some situations, 

 be mineralogically distinguished from the old, when these two formations 

 are not separated from each other by the carboniferous or mountain limestone, 

 which being wanting, all inferences respecting the age of this conglomerate 

 must be deduced from its internal characters. The different appearances 

 which it assumes in Sutherland and in Ross-shire have already been de- 

 scribed. Near the North Sutor of Cromarty it has been stated to be uncon- 

 formable to the lias, to which it succeeds : but this fact can lead to no con- 

 clusion, because the strata there are much disturbed, the beds of lias being 

 much contorted, and the red sandstone, which is but slightly inclined through- 

 out the adjoining country, is in this place nearly vertical, owing to the proxi- 

 mity of the elevated granitic ridge. On the other hand, at Ethie Bay, where 

 the strata are less disturbed, the beds of lias are conformable to the general 

 range of the inferior sandstone. 



Although the latter deposit in Ross-shire and in Sutherland does not, as far 

 as my observation went, contain any substances sufficiently peculiar to mark 

 its date, still it should be stated, that in some parts of those counties there are 

 traces of carbonaceous matter; and the great fertility of the plains of Easter 

 Ross (see note, p. 308) affords also some slight ground for presuming- that this 

 great deposit may be referred to the age of the newer red sandstone. More 

 decided conclusions can, however, be drawn from certain remarkable organic 

 remains recently observed in the bituminous schists of Caithness, which appear 

 to be subordinate to, or contemporaneous with, the same conglomerate. 



The extensive plains of Caithness forming the N. Eastern extremity of 

 Scotland and succeeding in that direction to the E. coast of Sutherland de- 

 scribed in this memoir, are composed of bituminous schists ; in some places 

 accompanied by beds of compact lamellar sub-crystalline limestone ; in others 

 by a close-grained calciferous and micaceous grit ; whilst the promontories of 



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