546 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [JuilC 13, 



almost vertical, dipping at 7^° to 85° to S. 18° W. by compass (va- 

 riation 27° W.). North of Stonehaven a vein of light reddish-brown 

 felspar-porphyry, with large macled crystals of orthoclase and grains 

 of quartz, intersects the beds. It is about 30 feet wide, and runs 

 N. and S. nearly in the dip of the strata. Beyond this dyke the 

 red sandstone continues dipping almost at the same angle, but with 

 more of a westerly direction. Soon after, a mass of claystone-tufa {t)y 

 of a grey or reddish-brown colour, but much weathered and decom- 

 posed, appears in the cliifs. Immediately beyond this mass, the 

 primary clayslate {b) of the Grampians is seen dipping at 35° to N. 18° 

 W., and thus in the opposite direction to the red sandstone. The 

 actual junction of the stratified rocks is not seen, as the trap-rock 

 occurs in the interval, having apparently burst up through a fault 

 along the line of junction. 



Further north the inclination of the clayslate becomes higher, but 

 the dip is still to the same point, and continues northerly in its 

 whole range along the coast. The clayslate is fine-grained, of a light 

 greenish-grey colour, with a kind of fibrous laminar structure, 

 formed, as it were, by the interlacing of minute acicular green crystals 

 with grains of a whitish colour. Further north it passes into a 

 hardened sandstone or greywacke, composed of grains of quartz, 

 agglutinated in a sparing basis of a reddish or greyish colour. This 

 rock is in layers of about half an inch thick, somewhat undulated, 

 and closely intersected by cross fractures. At Carron Point a great 

 dyke, 40 feet wide, of yellow quartz or hornstone (</), runs N. and S, 

 through the strata, which dip nearly conformably on both sides. 

 This dyke is well seen in the bay south of the Point, and also in the 

 Point itself. In the rocks near it, beds or veins of magnetite, and 

 in some places also of pyrites, run nearly parallel to the strata. 



The clayslate continues for about half a mile beyond the Point, 

 Avhen it gives place to mica-slate (c). The dip of the beds is still to the 

 north at 45° to 55°, the angle being variable from the constant con- 

 volutions of the beds. There is, however, no doubt, that the general 

 dip is to the north, and consequently that the mica-slate overlies 

 the clayslate. The mica-slate, where first seen, is fine-grained, light 

 greenish-grey, and composed -of quartz and fine scaly mica or chlorite. 

 In some places it contains a considerable number of small garnets. 



Further north the coast becomes so precipitous, with the sea close 

 to the base of the cliffs, that the section cannot be followed con- 

 tinuously. The dip of the strata, however, appears to become more 

 and more nearly vertical, with many convolutions, throwing the beds 

 for short distances sometimes into one position, sometimes into the 

 reverse, so that the same stratum appears in one part of the cliif 

 inclined to the north, in another part to the south. Following the 

 coast northward, it is soon evident that the general inclination of the 

 beds is now to the south, or the reverse of that observed in the clay- 

 slate. This southerly inclination, on the whole also at low angles, pre- 

 dominates in the gneiss {d) along the coast to Aberdeen, though with 

 many local deviations, such as may be looked for in a highly disturbed 

 and convoluted group of rocks . At Muchal' s Burn a bed of red felspar- 



