﻿192 



DR. W. R. JONES ON THE SECONDARY 



[vol. lxxii, 



Malaya are tentatively stated to be the 'equivalent of the Mahadeva 

 Group, or possibly the Pcinchet Group of the Indian Gondwanas,' 1 

 so that between the glacial elaj^s and the Younger Gondwana Rocks 

 of Malaya, the rocks of the Karharbari sub-stage and of the whole 

 of the Damuda Stage are entirely absent. This would mean that 

 a very important unconformity existed in Malaya, representing 

 well over 8000 feet of strata in India, and yet an unconformity so 

 obscure that in no section has it been possible to decide where it 

 exists ! 



Palffiontological evidence shows also that, even if the clays were 

 of glacial origin, they could not be correlated with the Talchir 

 Beds of India. As Mr. T. H. D. La Touche remarks, 3 it is difficult 

 to understand how glacial deposits lying above the Glossopteris 

 Beds can be equivalent to the Talchirs of India, which are older 

 than the Glossojyteris Beds. 



VIII. Summary and Conclusion. 



More than half of the Kinta district is occupied by granite 

 which has proved to be stanniferous in a very large number of 

 places, both in the Main Range and in the Kledang Range. 



The isolated limestone hills are the result, not essentially of 

 faulting, but of .unequal denudation on a strongly jointed lime- 

 stone ; hence the position on the valley-floor of the stanniferous 

 clays and ' boulder-clays ' (other than the clays formed from the 

 weathering of the schists and phyllites in situ) makes it impossible 

 to regard them as being of Talchir age, or indeed as anything 

 but alluvial deposits derived from the weathering-down of the 

 neighbouring rocks. 



The theory of the glacial origin of these deposits involves a 

 number of improbabilities, among which may be enumerated : — 



(a) Simultaneous faulting - , over an extensive area, with fault-planes in 

 various directions and throws of several hundreds of feet. 



(6) Magmatic stoping, on an enormous scale, over selected areas only. 



(c) The deposition of supposed Permo-Carboniferous glacial clays, contain- 

 ing different types of rock, in adjoining- areas, the dividing- line be- 

 tween them being coincident with the chief drainage-course of a 

 valley of post-Cretaceous age. 



(r7) The superposition of two important tin-fields, one of Permo-Carboni- 

 ferous age and the other of post- Cretaceous age, in one and the same 

 district ; and in the former case, in a very restricted part of that 

 district. 



(e) The absence of metamorphism in clays lying between highly meta- 

 morphosed beds and in contact, in places, with enormous masses of 

 granite. 



1 J. B. Scrivenor, ' The Geological History of the Malay Peninsula ' 

 J. G. S. vol. lxix (1913) p. 356. 



2 Ibid. pp. 370, 371. 



