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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



[Feb. 20, 



On the Bocks of Portions of the Highlands of Scotland South 

 of the Caledonian Canal ; and on their Equivalents in the North 

 of Ireland. By B. Harkness, P.B.S., F.G.S., Professor of 

 Geology in Queen's College, Cork. 



Contents. 



§ 1. Introduction. 



§ 2. Section from Callender to Loch 

 Earn. 



§ 3. Section from Loch Earn to Loch 

 Tay. 



§ 4. Section from Loch Tay to Glen 

 Lyon. 



§ 5. Section from Dunkeld to Blair 

 Athol. 



§ 6. Sections from the south side of 

 Ben-y-Gloe Mountains and 

 Strath Ardle. 



| 7. Sections N.W. of the great zone 

 of quartz-rocks and limestones. 

 Section from Glen Lyon to Loch 

 Treig. 



§ 8. Section from King's House 

 through Glencoe to Baliahu- 

 lish. 



§ 9. Section across the peninsula of 



Ardsheal from Benivair. 

 § 10. Metamorphic rocks of the County 

 of Donegal, and section of the 

 east side of Lough Foyle. 



§ 1. Introduction. — The recent labours of Sir Boderick Murchison 

 in the N.W. Highlands of Scotland have so greatly increased our 

 knowledge of this portion of Great Britain, as to place the age and 

 arrangement of the rocks in this country in an entirely new aspect. 

 The result of these investigations has been made known so lately * 

 that it must be visibly impressed on the mind of every geologist, 

 and consequently will require no special reference to be made 

 thereto. In the memoirs in which these labotu's have been de- 

 tailed, there is a " hypothetical view " expressed concerning the 

 mass of metamorphic rocks which constitute the great bulk of the 

 Scottish Highlands ; and in this hypothetical view these rocks are 

 looked upon as the equivalents of the " upper gneiss " found re- 

 posing upon the quartz-rocks and limestones of Assynt and Dur- 

 ness, and which occupies so large a portion of the north of Scot- 

 land. 



Having had an opportunity of examining the deposits of Suther- 

 land so amply described by Sir Boderick Murchison, and cor- 

 roborating the results of his labours in the N.W. Highlands, I have 

 felt myself in a position which has enabled me to extend to a more 

 southern parallel investigations concerning the great area of Scot- 

 tish metamorphic rocks, and, as will be seen in the sequel, from 

 observations made last summer in many parts of the Highlands, 

 and also in the north of Ireland, have arrived at the same con- 

 clusions as are expressed in the hypothetical views already re- 

 ferred to. 



Before proceeding to detail the results of these observations, it is 

 necessary to say something concerning the nature of the rocky 

 masses which abound in the more southern part of the Highlands, 

 more especially as these are laid down in the geological maps of 

 this district. Certain rocks, to which the term metamorphic is 

 usually applied, have had assigned to them somewhat definite areas 



* See Quart. Journ. Geol. Soc, vol. xvii. p. 232 &c. as well as other previously 

 published memoirs. 



