﻿140 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 5» 



But, beset as we are with numerous difficulties, no reason exists 

 to prevent our elucidating those details which may serve to connect 

 the stratigraphical geology of Scotland with that of other regions. 

 By pointing out obstacles to be overcome, we enable others to gain 

 the vantage ground. It is in this sense, and in the conviction that 

 the time is arrived when some effort should be made to develope the 

 earliest epoch of Scottish primaeval life (the next sera of which, or the 

 Old Red Sandstone, has been rendered classic through the clear de- 

 scriptions and powerful reasoning of Mr. Hugh Miller), that this 

 memoir is written. 



Deriving as I have great benefit from the assistance of Professor 

 Nicol, he is not, however, to be held responsible for all the opinions 

 now published ; and in justice to him I shall indicate a point of de- 

 tail in which he entertains a hypothetical view differing slightly from 

 my own. 



Lastly, let me express the gratification I experienced, when, in 

 turning over the pages of Hector Boetius in the Chronicles of Hollin- 

 shed (let no rigid critic interfere with my belief), I found that the very 

 tract, in which there are strata undistinguishable in their aspect and 

 fossil contents from the sandstones I had named after Caradoc or Ca- 

 ractacus, had been also occupied by tribes of the Silures ! In short, it 



the map. In the South-western Highlands, a large portion of Cantire, coloured 

 as mica-slate, is sandstone and limestone, covered with trap, as recently shown 

 by Professor Nicol. The lias of MacCulloch in Cantire is partly coal, partly recent 

 tertiary, and partly a peat bog. Much of his primary limestone is a black basalt 

 (see Edin. Phil. Journ. vol. xlix. p. 385, and Professor J. Nicol's account of Can- 

 tire, given to the British Association for the Advancement of Science, 1850). 

 Further north the singular trap rocks on the coast (like those of Arran, &c), are 

 all passed over. 



On the north-east, a great deal of trap in the Red Sandstone of Forfarshire and 

 Kincardineshire is omitted. In the Grampians south of Aberdeen, there are trap 

 and granite, both of which are not noticed. In the country round Aberdeen the 

 boundaries of the granite and gneiss are incorrect, hills of the one rock being 

 coloured like those of the other. All the region in and around the Forest of Glen- 

 orchy is most inaccurately given, arid even in the easily accessible countries north 

 and south of Loch Fyne and Loch Tay, long and persistent bands of limestone, 

 so important in such tracts, are either omitted or occasionally marked as igneous 

 rocks ! In general, even where the map is tolerably correct, the formations are 

 not distinguished as could now be done. The map is, in truth, more mineralo- 

 gical than geological, but in the igneous rocks it has not even lithological merit. 

 The felspar-porphyries are not separated from the traps, nor from the horn- 

 blende-rocks. In the absence of a correct geographical survey, MacCulloch may 

 however be held excusable for the omission of many details and much inaccuracy 

 of outline. 



This national deficiency, through which all benefit of the application of the 

 " Geological Survey of Great Britain and Ireland " has also been lost, will I trust 

 be soon remedied by an adequate grant of money to produce a correct map on 

 the scale of an inch to a mile. Making a first remonstrance on this subject in 

 1834, and vigorously reviving it last year (on both occasions at my instance), the 

 British Association for the Advancement of Science, being supported by the pro- 

 prietary and public bodies, including the Wernerian Society and the Royal and 

 Highland Societies, has at length succeeded in directing the serious attention of 

 the Government and Parliament to the untoward condition of the geography of 

 Scotland. See Returns to the House of Commons. Trigonometric Survey of 

 Great Britain and Scotland, 1836, no. 106, and 1837, no. 525. 



