﻿part 3] STANNIFEROUS DEPOSITS OE KINTA DISTRICT. 



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latitude of Great Britain might explain some phenomena hitherto 

 unexplained in this country. 



Prof. W. G-. Fearnsides further congratulated the Author on 

 the good case that he had made, and commented upon the Kinta 

 district as an important source for the supply of those tungsten- 

 ores that are now so much in demand for the manufacture of 

 * high-speed ' steel. He enquired whether the Author had found 

 it possible to draw any sharp chemical distinction between the 

 clay-like residues which he attributes to the weathering in situ 

 of felspathic rocks in a tropical climate, and the true china-clays 

 or kaolins which, like the tin-lodes, are generally attributed to 

 the pneumatolytic action of the granite. 



Mr. T. Crook expressed appreciation of the paper, and agreed 

 with previous speakers that the interpretation of the Kinta Valley 

 seqiience given by the Author was simpler, and, judging the evi- 

 dence as a whole, more acceptable than that given by Mr. Scrivenor. 

 However, as that writer was not present to defend his view 

 with reference to the age of the boulder-beds, and as the dis- 

 cussion had revealed an overwhelming opposition to him on this 

 question, it might be worth while to call attention to one or two 

 observations to which Mr. Scrivenor had apparently attached some 

 importance. 



With regard to the origin of the alluvial tin-ore in the Kinta 

 Valley, Mr. Scrivenor himself admitted that it had been derived in 

 part from the Kinta granite-intrusions and from the disintegration 

 of the limestone and other rocks that had been veined and impreg- 

 nated as a result of this intrusion. But he also claimed that the 

 boulder-beds containing detrital tinstone were in existence at the 

 time of the intrusion. In support of this view, Mr. Scrivenor had 

 definitely stated that the Kinta granite exists in intrusive relation 

 with the boulder-beds. He stated further that the intrusive 

 granite was a factor in the impregnation of these beds with tinstone, 

 and that these later impregnations were of a type that could be 

 •clearly distinguished from the detrital tin already existing in the 

 beds. These observations by Mr. Scrivenor had an important 

 bearing on the question of age, and they apparently had largely 

 contributed towards leading him to the conclusion that the boulder- 

 beds were older than the granite intrusion. 



Mr. A. E. Kitson remarked that, from the evidence adduced, 

 the view advanced by the Author regarding the origin and age 

 of the deposits appeared to be the correct one, and he con- 

 gratulated him on his paper. He said that Mr. Scrivenor's 

 description of the locality was published some time ago, and it 

 seemed probable that since then local mining operations had disclosed 

 evidence disproving his view of the glacial origin of the deposits. 

 Among others, the absence of strise on the pebbles was a strong 

 reason for doubting such an origin. The photographs of the 

 limestone cliffs and isolated blocks appeared to indicate that they 

 were due to denudation and slipping of masses along master-joint 



