﻿184 



DB. W. E. JONES ON THE SECOSDAKY 



[vol. lxxii* 



crushed and washed, yielded in one mine, the Menglembu Lode Mine, 

 for the year 1913 no .less than 4726 pkls. or 281 tons of tin-ore. 



At Krarnat Pulai a section was exposed, in which a kaolin -vein 

 was supposed to he intrusive into ' boulder-clay ' containing tin- 

 ore : this was regarded as proving definitely that the ' boulder-clay ' 

 was older than the kaolin-vein, and hence that the tin-ore in 

 the ' boulder-clay ' was older than the present granite. My own 

 recollection, combined with what I have subsequently seen at 

 numerous other mines, of the above section (which I examined 

 with Mr. Scrivenor), is that the variation in colour in different 

 parts of the deposit was due to the presence in some parts of much 

 oxide and hydroxide of iron and to its absence in other parts, and 

 that the so-called 'boulder-clay' and the ' kaolin -vein ' simply 

 represent different colours. 



Mr. Scrivenor describes a similar case at the Pusing Bharu mine 

 as follows : — 



'Once a vertical pipe of pale-coloured mottled clay was found in the darker 

 clays. This was not a kaolin vein, but probably marked the bleaching- action 

 of the slow current of water either from above or from a spring in the lime- 

 stone.' 1 



Kramat Pulai Mine supplies a very definite proof of the origin 

 of its tin-ore deposits, for recent developments have conclusively 

 shown the presence of beds of lignite and peat resting under the 

 supposed 'glacial clays' and directly upon the limestone. The de- 

 cayed wood is unquestionably recent, and the explanation advanced 

 in other cases that trees fell down long-forgotten excavations, 

 subsequently filled in by detritus, 3 cannot even be suggested for a 

 definite bed of lignite (see PI. XIII). 



At Siputeh boulders of quartz with tourmaline and cassiterite are 

 very frequently observed in the clays, and quartz-veins carrying 

 these minerals are occasionally found intrusive in the limestone bed- 

 rock. The localized presence of these boulders has, on three definite 

 occasions, enabled me to presume the proximity of a vein, which 

 has, with the help of the manager, been subsequently located. In 

 one case the vein carried tin-ore in situ. 



A feature of the ore from this mine is its coarseness and angu- 

 larity, and Mr. Scrivenor photographed some of it to illustrate 3 the 

 difference between this supposed case of angular ore from Glacial 

 Clays and the rounded ore from alluvial deposits. The fact, how- 

 ever, that a lode was worked on this very mine about ten years 

 ago, when under the management of Mr. F. E. Mair, A.R.S.M., 

 and that Mr. Scrivenor now agrees 4 that ore has been recently 



1 ' The Geology & Mining Industry of the Kinta District ' 1913, p. 65. 

 - J. B. Scrivenor, ' The Gopeng Beds of Kinta ' Q. J. G. S. vol. lxviii 

 (1912; p. 150. 



:i 'The Geology & Mining- Industry of the Kinta District' 1913, pi. iv,. 

 fig. 3. 



4 ' The Deposits of Tin-ore in Limestone, Ipoh ' Times of Malaya Press, 

 1914, p. 8. 



