244 Messrs. Von Oeynhausen and Von Dechen o?i the 



granite differing from the rest by containing more quartz and 

 being harder; these quartz veins therefore evidently appear 

 to be of the same kind as those of Cligga Point and Cai- 

 claze. 



X. Tol Pedn Peivwith. Cape Barrah. — Hitherto we have 

 given the description of granite veins in the killas and in the 

 serpentine, but these veins also occur in the granite itself; 

 Mr. Carne mentions them, page 53, loc. cit. The most south- 

 w^estern promontory of the Land's End district, Tol Pedn 

 Penwith and Cape Barrah, appears to exhibit the most ex- 

 traordinary facts. The granite in the neighbourhood is that 

 of the common kind, with porphyritic twin crystals of felspar, 

 with schorl and pinite, as may be seen going down from the 

 small village of Sawah to the cliffs. I'here, at the point (?) fig. 23. 

 appears fine-grained granite, quartz and felspai", of a very close 

 texture ; the latter being of a red colour, gives to the whole 

 rock a reddish hue ; mica is not abundant in it, but schorl is 

 more common. This granite is of the same kind as that which 

 forms the veins; but here its position is not that of a vein. It 

 appears in the cliffs for a considerable distance below the large- 

 grained granite ; the section, fig. 26. represents its position ; 

 the junction of both is very distinct, and dips to the east at 

 an angle of 10 degrees. In some places both rocks hang to- 

 gether; but an open interstice is left between them, broad 

 enough to admit the blade of a knife. Some large crystals of 

 felspar occur near to the junction in the fine-grained variety, 

 but are not found further off from this line than three or four 

 inches. A sort of terrace traces this junction along the cliffs ; 

 in the section (c d) fig. 25, the overlying large-grained granite 

 projects over the fine-grained, like the roof of a house; the in- 

 clination of the junction is here 30 degrees. To the north 

 the junction of both the rocks inclines to the sea, and in the 

 cove [l) fig. 23. the elevation of the fine-grained gi-anite above 

 the level of the sea is not very considerable ; the point where 

 the large-grained granite comes down to the sea was not ac- 

 cessible. On the other side the fine-grained granite may be 

 traced as far as the cove [rii) ; the junction of both sorts of 

 granite becomes steeper and steeper, and suddenly the under- 

 lying mass of fine-gi'ained granite is stopped by numberless 

 little quartz veins, which, for the breadth of thirty feet, intersect 

 the rock. The fine-grained granite may reach at the highest 

 points the height of 150 or 200 feet; and continues here as far 

 as the level of the sea ; it is intersected by a great many quartz 

 strings, which bear a striking resemblance to those at Cligga 

 Point. The mass of fine-grained granite is perfectly fine- 

 grained, from the junction with the large-grained to the distance 



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