Ill 



about three feet wide, in other parts five or six feet. Seaward it is 

 placed conformably among the sandstone strata, and is irregular in 

 direction and breadth. A dike of greenstone here cuts it nearly at 

 right angles, but the appearances are noway remarkable. This vein, 

 or bed, has been overlooked by MacCulloch and succeeding observers. 

 The greater pitchstone vein is conspicuous, forming a broad band in 

 the front of the sandstone cliff farther S., and has been noticed by 

 every one. It occupies a slanting position in the cliff, parallel to the 

 sandstone strata, dipping with them towards the S.S.W. at nearly 

 30, and rising towards the N.W. In the opposite direction, or 

 towards the S.E., it seems to plunge beneath the sea ; but the debris 

 here obscures it, so that its course cannot be traced to the water's 

 edge. Climbing up the cliff to examine it more closely, we find it 

 to be 13 feet 5 inches in thickness ; of lamellar structure and 

 dark bottle-green colour. There is no remarkable change on the 

 sandstone a slight induration merely, but the lower portion of the 

 pitchstone is changed into a blue-coloured porous slag-like matter, 

 like a pumiceous lava : this, however, is probably the mere result of 

 decomposition. Its exact position among the sandstone strata is 

 not easily determined : if parallel to them we must call it a bed, if 

 intersecting them, a vein. Fallen masses of the pitchstone strew 

 the beach ; and among these, where the path comes close on the 

 water, there is a dike of red quartziferous porphyry, nearly perpendi- 

 cular to the shore, twelve or fourteen feet broad seawards, but nar- 

 rowing inland to five or six feet. 



A granite boulder, about one-third of the size of the one at Corrie- 

 gills farm-house, rests here in the tideway ; and great numbers strew 

 the shore all along. 



75. Between the two veins of pitchstone which we have just 

 described, there occurs upon the flat shore another large vein of 

 claystone remarkable for a peculiar structure. This is developed in 

 those parts only which are near the junction with the sandstone, along 

 the south side of the vein. The appearances are fully and accu- 

 rately described by Dr. MacCulloch (vol. ii., p. 405). The structure 

 referred to " is concretionary globular, or striated ; the latter being 

 either found separate, or united with the globular in the same spe- 

 cimen. The former puts on sometimes the appearance of spots, cir- 

 cular or elliptic, resembling Siberian jasper. The spots, as well as 

 the stripes, are attended with corresponding differences of hardness, 

 the former arising from the globular structure, the latter from a 

 schistose or laminar one. The spots being often elliptical, com- 

 pressed or elongated, occasionally become Iamina3 in the progress of 



