196 GEOLOGY OF ARRAN. 



place the beds approach it at an inclination, and there is a 

 mass of broken rock between them, a small cave being 

 formed in this at the bottom. Here, as shewn in the annexed 

 cut (fig. 35), the mass of claystone on the south side is 

 divided into great concentric curved bands, arranged round 

 a prismatic nucleus, and exhibiting on a large scale that 

 peculiar structure of the rock, often seen in the fracture of 

 hand-specimens, which it has in common with the other 

 felstones and the ordinary traps, and which comes most 

 strongly out in decomposition. The appearances here are 

 strongly illustrative of the eruptive character of the clay- 

 stone. 



The sands stretching hence to Drumadoon exhibit many 

 dikes, ranging in various directions, of various widths, and 

 consisting of basalts, greenstones, both common and of 

 porphyritic structure, and felstones. The botany of the 

 sands is rich; the surface has a thin carpeting with a pro- 

 fusion of beautiful wild flowers. On approaching the grand 

 facade of columns forming the precipice of Drumadoon, we 

 find at its south-west base on the shore a great bed, or per- 

 haps dike, of felspar porphyry tilting up the sandstone, at a 

 high angle, in no way connected, so far as can be seen, witli 

 the overlying porphyry above, but running out into the tide- 

 way, and forming a low cliff in the sands. This is Druma- 

 doon Point. It is intersected by basaltic dikes, one of 

 which has been hollowed out by the waves, and forms a 

 landing port for boats. It is probable that these beds, and 

 others on the south-east side, are connected, underneath the 

 sandstone, with the overlying masses. The beds below can- 

 not have been, at a former period, continuous with the 

 porphyry of the facade, as the sandstone rises high in front, 

 between them. Yet the cliff has obviously suffered consider- 

 able disintegration along the front; an isolated, nearly entire, 

 pillar stands out from the facade at the south-west corner, 

 and the sandstone below is strewed with great numbers of 

 fallen columns, forming a talus to the precipice. These 



