lOG PKOCEEDIXGS OF THE GEOLOGICAL SOCIETY. [Jan. II, 



As examples that may be easily examined, I may cite a section on 

 the Dufftown Railway, at the Popine meal- and saw-mill, near 

 Lower CraigeUachie, also the rock at Craigellachie Bridge, and 

 along the side of the Fiddich from Craigellachie Station to near 

 Kininvie Castle. The rock of the hill called Tipper Craigellachie 

 near Aviemore, is also of a similar nature^ so that in many places I 

 should be at a loss to say whether the granite or the gneiss prevails. 

 Along the Fiddich, from Craigellachie Station to near Kininvie 

 Castle, the rock exposed in the railway- cuttings is a hard quartz, so 

 full of veins that one is occasionally in doubt whether to pronounce 

 it a stratified rock or a granite. In many places, where the aggre- 

 gation of the mineral particles is granitic (rather small-grained and 

 i-eddish), traces of the undulating bedding may be observed ; in short, 

 the rock seems to me to consist of the beds of lower quartz-rock 

 merging into granite — that is to say, incipient granite, a stratified 

 rock far gone on its way to granite. 



In some places, near Craigellachie, there is a good deal of 

 greenish matter in the rock, as if it had consisted of alternations of 

 talcose schist or grit and quartz-rock, such as occur near the base 

 of the slate on the Mulben stream, and also near the Giant's Chair, 

 where the upper beds of slate meet the overlying quartz-rock. I 

 observed that the small granite veins occasionally form alternating 

 laminoe in the rock, and reddish streaks parallel to the bedding, the 

 greenish matter segregating into irregular branching plates. 



The hiU called Little Conval, near Dufftown, is of granite, which 

 at its south-eastern base I found to be large-grained and composed 

 of red felspar and whitish quartz, with little or no mica ; but higher 

 up the rock becomes finer-grained, and at the top consists of a 

 small-grained mixture of red felspar and quartz, much resembling 

 some varieties of quartzose gneiss, such as that at Red Hythe 

 Point, as if the metamorphism decreased in intensity as it passed 

 upwards. The felspar, however, is redder than is usual in gneiss, 

 and seems to bear a larger proportion to the quartz. There are 

 the remains of an old stone rampart or enclosure round the crest 

 of this hill. 



Theory of the Deeivation op the Sedimentary Strata and of 



THEIR PRESEIifT StRIKE. 



The general texture of the materials of which the gneiss, quartz- 

 I'ock, and clay-slate are composed is fine-grained, and I observed no 

 beds of conglomei'ate or large pebbles. The nearest approach to these 

 which I saw was in the coast-section between Gamrie Head and 

 Melrose, near a place called the Grey Mare's Point, where the anti- 

 clinal fold occurs that is shown in Prof. Harkness's section. Here 

 I observed a seam composed of water-worn pebbles of white quartz, 

 some of which were tAVO inches in length. This is near the base of 

 the slate, and is the nearest approach to a conglomerate that I 

 have observed. But in general there is nothing larger-grained 

 than what, in its original condition, would have been a coarse sand. 

 It is a curious circumstance that such a thick mass of sediment 



