156 



GEOLOGY OF PULO PINANG, 



1. — Pulo Beedan, or JBidan, is about a mile in length and three-fourths 

 of a mile in breath, of an elliptical shape, with a bay on its southern side. 

 It is thickly wooded, the trees, as usual, coming in most places down to 

 the water's edge. It may be noticed here once for all, that this circum- 

 stance offers an obstacle to the complete investigation of the geological 

 structure of the island round Pinang, as it does of Pinang itself in some 

 measure. The interior cannot be penetrated, and were it even possible to 

 do so, the closeness of vegetation would shut out all view of the rocks. 

 The observations are thus necessarily limited in most instances to the coast. 

 The beach, on Ptdo JSidan, near the south-east point, is composed of 

 an argillaceous rock, resembling grey wacke, both lamellar and conglo- 

 merate, irregularly intermixed, (Nos. 41 and 42). This seems to dip at a 

 considerable angle to the west ; it is entirely covered at high water by the 

 sea, and the outgoings or crop of the strata form sharp ridges, more or 

 less elevated. Rolled masses of ironstone, (No. 43,) are found on it, of 

 various sizes. On the argillaceous rock, rests a mass of limestone strati- 

 fied, the strata dipping to the south-west at an angle of 45°. It is 

 of a bluish grey colour, (No. 40,) and at first sight seems to have 

 a slaty texture. The colour of some of the strata is nearly black. 

 They are every where traversed by veins of quartz and calcareous spar, 

 irregularly intermingled. The whole island seems to be composed of the 

 same material. 



2. — P'ulo Pangkil is a small rather elevated island, about two miles 

 to the northward of the preceding, and celebrated for its turtles, which 

 lay their eggs in the sandy points and bays. The coast is covered 

 with smooth round stones of argillaceous matter, probably rolled over 

 from P^do Sonsong ; but the body of the island is composed of the same 

 kind of limestone as Pido Bidan, (No. 45). In Turtle-bay, at the dis- 

 tance of ten or twelve yards from the main body of the island, some 



