﻿1861.] 



MTJRCHISON: — HIGHLANDS. 



231 



placed between the quartz-rocks and limestones and the overlying 

 chloritic and somewhat gneissic schists. 



In referring to the conclnding pages of Professor Mcol's last 

 memoir, I must remind him, that, when he calls for more proofs of 

 the continuance of the ascending order through the central and more 

 easterly parts of Sutherland and Eoss than have as yet appeared, he 

 ignores what I have published on those very points. In 1858 I gave 

 a section from Loch Eriboll across the Moin to the Kyles of Tongue, 

 and in the following year I traced the ascending order with Professor 

 Bamsay from the inferior quartz-rock and limestone through over- 

 lying micaceous schist into gneissic rocks, the latter being invariably 

 most prevalent when in the neighbourhood of eruptive masses of 

 granite and syenite. It was on that occasion that we first ascertained 

 that Ben Stomino (which in Professor NieoFs map is represented as 

 Old Ked Sandstone) was a granite. We had therefore already 

 answered Professor Nicol's present query, and had shown that " the 

 huge syenitic domes of Ben Loaghal and Ben Stomino do not break 

 the series, and bring it under the lower and older gneiss*." Again, 

 Professor Nicol writes as if Strath Oikel had not been examined, 

 though that tract was specially cited by myself as proving an as- 

 cending order; and when he says that no one has been in the 

 fastnesses of Pannich Porest, I may refer him to my own descrip- 

 tion of a great north-westerly fold of the overlying strata on Loch 

 Pannich f . In fact, if geologists will only take the trouble to read 

 my memoirs of 1858 and 1859, as published in the Journal of the 

 Geological Society, they will find many other proofs of the conti- 

 nuity of the ascending series to the eastern parts of Eoss-shire, 

 and of their intense metamorphism and gneissic characters when in 

 contact with granitic rocks. 



As Professor Nicol has endeavoured to show that my sections are 

 inaccurate, I may be permitted to point to the great discrepancy 

 between his earlier sections, published the year after he accompanied 

 me (his first visit to Sutherland), and those on which he now 

 relies. Denying as I do the accuracy of the last, I affirm that some 

 of his first or original sections are quite correct ; indeed they entirely 

 agree with my own if. Pirst, in the west of Sutherland, he shows, 

 as I have done, a fundamental gneiss (a), a red sandstone (5), 

 quartz-rocks and limestones, and a conformably overlying "upper 

 gneiss" [sic] (/) above the House of Eriboll. Yet now he has 

 composed the very different diagram for the same spot, and on that 



I saw evidence so clear, I at once adopted your conclusions." Professor Harkness 

 thus concludes his letter: — "The observations which I have since made, both in 

 other parts of the Scotch Highlands, and in the north of Ireland, have still 

 further corroborated your conclusions ; and, with reference to the hypothetical 

 views you expressed, I am convinced that the whole arrangement of rocks from 

 the fundamental gneiss to the upper gneissic rocks, &c, as recorded in your 

 memoirs, is the true sequence of the strata which make up the older sedimentary 

 series of the Highlands of Scotland." 



* See Prof. Nicol's Memoir, Quart. Journ. Geol. Soc. vol. xvii. pp. 112, 113. 



t Quart. Journ. Geol. Soc. vol. xv. p. 387. 



| See Quart. Journ. Geol. Soc. vol. xiii. pp. 22, 23. 



E 2 



