1873.] 



JTJDD — THE SECONDARY ROCKS OF SCOTLAND. 



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clusively establish, as I believe, the Secondary- 

 age of the long-disputed beds (fig. 14). 



The beds referred to are seen at Dunrobin 

 to underlie conformably a considerable thick- 

 ness of strata, which I shall demonstrate by 

 most abundant palaeontological evidence to be 

 of the age of the Middle and Lower Lias. 

 With these Mesozoic strata the formation in 

 question agrees both in strike and dip, while 

 with the Old Red Sandstone strata, which are 

 exhibited in close proximity, it has no common 

 relations whatever. Indeed, the strata in 

 question appear to have been seen by Sir B. I. 

 Murchison, though probably not under favour- 

 able conditions, and were by him unhesitatingly 

 placed in the Secondary series. 



There are two objections which may pos- 

 sibly be urged against the view which I have 

 taken of the relations of this formation in 

 Sutherland. 



It may be said that the agreement in strike 

 and dip of the strata at Dunrobin may be ac- 

 cidental, and that the Lias strata, instead of 

 overlying the calcareous and cherty rock, may 

 be faulted against it. This objection may ap- 

 pear to receive some support from the facts 

 which I have already pointed out, indicating 

 the greatly faulted condition of these Suther- 

 land rocks. 



To this objection there is fortunately the 

 most complete answer. The lowest beds of 

 the Lias series, as is so often the case, consist 

 of a conglomerate ; and among the pebbles in 

 these beds are numerous fragments of the 

 peculiar calcareous and cherty rock so fre- 

 quently referred to. 



It may also be urged that possibly the con- 

 formity of the beds of the formation in ques- 

 tion with the overlying Lias strata may be 

 accidental, and that in spite of it they may be 

 of as early date as the Old Eed Sandstone. 



In reply to this objection I would point to 

 the fact that in Golspie Burn the Cherty Bock 

 of Stotfield is seen at only a very short distance 

 from beds of undoubted Old Bed Sandstone 

 strata, and that while the latter are greatly 

 disturbed and dip S.E., at an angle of 70°, the 

 former dips N.N.E. 12°, conformably to the 

 great mass of Secondary strata here. 



The facts now adduced with regard to the 

 stratigraphical relations of the " Cherty Bock 

 of Stotfield" and the underlying sandstone 

 (which we cannot hesitate to recognize as the 



