160 



GEOLOGY OF PULO PINANG, 



places the veins appear to be of quartz, mica, and chlorite blended together, 

 (No. 9). The body of the rock on this side, above the red material, is an 

 amorphous grey-wacke looking substance, resembling old sand-stone, 

 (No. 7). Above this again is the more slaty -looking rock, (No. 12,) 

 resembling clay-slate. On the south-east side, it seems entirely composed 

 of the red argillaceous rock above mentioned, (Nos. 10. and 11). On the 

 south-west and west sides of the island, from the precipitous nature of 

 the coast, the structure is easily noticed. The rock is entirely like 

 clay slate, (No. 12,) presenting more or less of the laminar structure, 

 slaty in some places, as marked in No. 15. In some parts there is a 

 bending in the strata, similar to that sometimes observed in gneiss ; thus 



The rock is traversed by veins of quartz of about 

 three inches in breadth, (No. 13,) and of a sub- 

 stance like iron-stone, (No. 14,) which also runs 

 in thin laminar beds through the slate. In the rolled masses, near the 

 beach on the east side, are observed portions of indurated clay, tinged 

 with chlorite, 



V. Pulo Rimau is situated at the south-east corner of Pinang, from 

 which it is distant about three-quarters of a mile. It is of an oblong shape, 

 about a mile in length, and one-third of a mile in breadth ; bold and rocky 

 except on the north side ; covered as usual with wood, and composed 

 entirely of grey granite of a fine grain, (No. 20). On the south side, the 

 rocks are rather fantastically shaped. One at a distance exactly resem- 

 bles the gable of a house. They were all exceedingly hard ; and with a 

 good sized hammer, I could v/ith difficulty break off specimens of proper 

 size. Near the centre of the south side of the island, a curious appearance 

 presents itself. Veins offrom one and a half to two feet in breadth, of quartz 

 rock (Nos. 22 and 23,) traverse the granite in different directions. The 

 walls of the veins are of a red colour, and finely crystallized, (No. 24). 



