Geognosy of' the Country, 137 



at another, it appears in grains dispersed through the felspar, so as to form 

 the appearance of porphyry, rather than of granite. Sometimes, again, it 

 runs through the rock as a large vein ; and, not very unfrequently, it is seen 

 in fine parallel layers. I remember it on one occasion, so minutely dispersed 

 through the stone, as to bear no faint similarity to the beautiful ramifica- 

 tions of calcareous spar often seen in newer rocks. In the rocks of the 

 tract described, mica also has much difference of character, b^ing, at one time,* 

 in scales of a large size, which, I think, happens mostly when the felspar 

 is in very small quantity ; and, at another, in scales of the smallest kind. 

 It is particularly towards the north side of Alford that the mica abounds ; the 

 rock in that quarter passing from granite into true mica slate, of which a 

 quarry is worked in the parish of Tullynesle. The felspar likewise varies 

 much in colour and quantity. In the form of small loose stones it is often 

 found pretty pure ; and in^the parish of Forbes, beds of that kind are to be met 

 with ; in which neighbourhodd, I understand that, a few years since, search 

 for felspar of a particular description was made, but without any satisfactory- 

 result, by persons connected with the manufacture of stone-ware in Stafford- 

 shire. In the neighbouring parish of Monymusk, a quarry of this sort was for 

 several years worked, and the felspar transmitted to England; but as this has 

 been given up, it may be presumed that the experiment has not answered ex- 

 pectation. 



In point of hardness, the granite at Alford differs greatly at different places ; 

 but, in general, it is to be considered of a kind tending to separate and crum- 

 ble down ; from which cause the hills usually have a rounded aspect, and are 

 without the bold abrupt summits to be seen in other parts of Aberdeenshire ; 

 and, indeed, usually forming a characteristic feature of granite districts. From 

 this remark we must except Bennochie. Around, and near the highest part of this 

 mountain, are strewed blocks of granite of every size and shape, placed in al- 

 most every possible position ; some rather soft, but many so hard, that on 

 these the humblest lichen has never been able to fix its habitation ; but, in 

 comparison with other hills in the neighbourhood, the chief peculiarity of 

 Bennochie is its bold peaks, that communicate to it, when viewed from certain 

 points at a distance, a remarkably grand and striking aspect. For building, 

 the best varieties of granite in Alford are two ; a stone characterised by a 

 blackish colour, derived from hornblende, being mixed with the other ingre- 

 dients; and another of a reddish colour, from the abundance of a flesh-colour- 

 ed felspar. These are the stones most esteemed; but the forms of granite, as 

 already stated, are without number. 



In connection with the present subject, a rocky ridge, conspicuous at a 

 great distance, situate on the south side of the Alford district, deserves to be 

 mentioned. It is from forty to fifty feet broad, and extends from north-east 

 to south-west for several miles ; but I only examined it near the division be- 

 tween the parishes of Tough and Lumphanan, where the outside is a beauti- 

 ful porphyritic felspar, similar to a few blocks found on Bennochie, and the in- 

 ner part is of the ordinary reddish granite. 



In Alfor^, limestone makes its appearance only in small quantity, and at a 

 few places, namely, at one spot in Tullynesle, at another in Tough, and at a 

 third in Cushnie. > 



