140 THE GOPEK'a BEDS OF KINTA. [JuDG I9I2. 



8. The GoPENG Beds of Kiis^ta (Federated Malay States). By 

 John Beooke Scritexok, M.A., P.G.S., Geologist to the 

 F.M.S. Government. (Read jN'ovember 8th, 1911.) 



Iisr a former paper * describing the remarkable tourmaline-corundum 

 rocks found on the western side of the Kinta Valley in Perak, I 

 mentioned the fact that on the eastern side of the same valley, 

 near Gopeng, sandy schists occurred, but no tourmaline-corundum 

 rocks — although tourmaline alone was found, as also pieces of pure 

 corundum (at Pulai). Since that paper was written, I have been 

 chiefly engaged in detailed work in the neighbourhood of Gopeng, 

 and have also carried out some prospecting work in the same 

 locality by means of bores : with the result that, while the 

 western side of the valley had afforded an interesting study in 

 petrology, it was found that on the eastern side the geology was 

 such as to throw into the shade all the information previously 

 gained in the Federated Malay States, as regards both economic 

 iniportance and scientific interest. 



It is my object in the present paper to show that, in the neigh- 

 bourhood of Gopeng, there are remains of an ancient Gondwana- 

 land tin-field, older than the granite of the main range of the 

 Peninsula, altered by it, and further enriched in tin-ore by it near 

 the contact and in the vicinity of certain veins ; that the beds 

 composing this Gondwanaland tin -field were deposited under 

 conditions that were connected with the action of glaciers or of 

 masses of floating ice ; and that these Gopeng Beds are probably on 

 the same horizon as the Talchir Beds of Orissa, and therefore the 

 probable equivalents of the Bacchus-Marsh and Murree marine 

 beds of xiustralia and the Ecca Group of South Africa. 



Gopeng is a tin-mining centre of long standing and great 

 prosperity, lying close under the granite hills of the main range, 

 and situated on the trunk-road from Penang to Kuala Lumpur. 

 To a miner the Gopeng tin-field is worthy of attention on account 

 of the variety of methods that are employed to win the ore, ranging 

 from the most primitive Chinese work to large hydraulic plants and 

 a suction-gas dredge ; to one, however, who finds an interest not 

 only in the mining methods but also in the geology of the ground 

 worked, it is a striking fact that with the exception of a few mines 

 only, these various methods and installations of machinery are all 

 employed in the same beds, which, as regards problems of treatment, 

 do not vary to any great extent. 



The physical geography of Gopeng and its neighbourhood is 

 simple, but, as will be seen later, of great significance when con- 

 sidered in connexion with the geology. The accompanying sketch- 

 map ffig. 1, p. 141) shows on the east the flank of the great main 



1 Q. J. G. S. vol. IxYi (1910) p. 43S. 



