1894-95-] Geological Notes from A rran. 119 



island, including Goat Fell, Ben Nuis, the Castles, and many- 

 others. 



South of the line mentioned, from Brodick Bay to Dougrie, 

 the country consists of hilly downs quite different in appear- 

 ance to the scenery in the north, and the rocks are made up 

 for the most part of Carboniferous strata with their associated 

 volcanic rocks. There are two districts in which a species of 

 granite occurs in these newer rocks which I shall notice later. 

 Between the Carboniferous rocks of the south of the island and 

 the slates of the northern district there runs a narrowish band 

 of strata, widening considerably to the west, which I believe 

 have been referred to the Lower Old Bed Sandstone. 



Having now got a sort of general idea of the geology of the 

 island, we will proceed to make a few scattered observations 

 here and there, not according to any definite plan. A walk 

 along the sea-shore, either from Brodick pier to Corrygills, or 

 from Brodick Castle to Corrie, exhibits a fine example of the 

 younger raised beaches : the amount of elevation is small, but 

 the shore generally consists of a low rocky platform above the 

 reach of high tide. This platform is bounded on the land side 

 by more or less elevated cliffs, in which may be seen, in many 

 places, the old sea-caves worn out by the waves at the time 

 when the sea extended to their base. The rocks of the shore 

 towards Corrie consist of red sandstone, and towards Corrygills 

 of more or less coarse conglomerates of lower carboniferous 

 age ; their general strike appears to be nearly N.E.-S.W., and 

 the dip 20°-23° to S.E. Many fine examples of false bedding- 

 are to be observed, in many instances to quite an exaggerated 

 degree. 



The most interesting feature to be observed on the Corrygills 

 shore is the curious way in which the sandstone and con- 

 glomerate rocks are intersected in all directions by intrusive 

 dykes of igneous rocks. These run for considerable dis- 

 tances, and are of all widths, from a couple of feet or so up 

 to at least 100. Their position has probably been deter- 

 mined, in the first instance, by cracks or fissures in the rocks. 

 It is hardly possible, at least in the case of the narrower dykes, 

 that they can have eaten their way through the strata in a 

 molten state, for if so they would have become so impregnated 

 with the material through which they passed that their com- 



