﻿part 3] STANNIFEROUS DEPOSITS OE EI NT A DISTRICT. 



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Tin -ore has now been proved in situ in the Kinta district : — 



(1) In the stanniferous granite of the Main Range and the Kledang Range, 



which flank the Kinta Valley, and in several places are being ex- 

 ploited for tin-ore. 



(2) In other stanniferous granite outcrops, almost certainly connected with 



the granite ranges, outcrops which have yielded, and are still yield- 

 ing, tin- ore. 



(3) In the schists, phyllites, quartzites, and indurated shales towards the 



granite-junctions, which in numerous places are worked for the ore 

 occurring in them as stockworks, and in the granitic veins connected 

 with the granite. 



(4) In the large number of granitic intrusions traversing the limestone 



floor of the Kinta Valley, and forming an important source of ore. 



The angularity of the boulders and tin-ore in a clayey matrix in 

 the supposed glacial deposits is due in places : — ■ 



(a) To the weathering of phyllites, etc. into clay which sank gradually on 



the dissolving limestone underneath, resulting in the breaking-up of 

 the veins of quartz and pegmatite traversing the phyllites. 



(b) To soil- creep effecting the same result. 



(c) To the breaking-up of the much- weathered tin-bearing pebbles in the 



alluvium. 



Tin-ore has been found in situ either on the mine or on the 

 property immediately adjoining it in eighteen out of the twenty 

 largest tin-mines in the Kinta district. 



Over 90 per cent, of the ore worked in the district is obtained 

 from mines situated at less than a mile from granite or granitic 

 intrusions, and over 80 per cent, of the ore is won from mines 

 where granite or a granitic intrusion has actually been proved on 

 the properties. Yet it is contended by Mr. Scrivenor that the 

 tin-ore in these supposed glacial deposits was derived from another 

 and distant source outside the Malay Peninsula. 



It has now been shown that all the rocks and minerals 

 present in the ' Gondwana clays and boulder-clays ' of the Kinta 

 district must have been derived originally from a cassiterite- 

 bearing granite and from schists, phyllites, etc., metamorphosed by 

 such a granite : in other words, that the ' clays and boulder-clays ' 

 must have been derived originally from an area containing rocks 

 bearing striking and peculiar resemblance to those now in situ 

 near the granite-junctions in this district. 



At the same time, it has been shown that the acceptance of a 

 glacial origin for these ' clays ' implies that in a district in which 

 tin-ore is being worked in situ at more numerous localities than 

 in any other district in the world, the bulk of the ore in the 

 cla} r s in the lower part of the valley was brought by ice from 

 an ancient tin-field hundreds of miles away to the west of the 

 Maky Peninsula. 



An alluvial origin for the clays, or their formation by weather- 

 ing in situ, necessitates, on the other hand, only the postulate 

 that the processes of weathering now actively at work in the Kinta 

 district have continued over a long period. 



