Boulder-clays, Federated Malay States. 163 



of brown tourmaline. I have not seen anything like it in the rich 

 tin-bearing ground. 



Again, in the Fusing neighbourhood veins have been found and 

 worked in clay just as soft as the Tronoh pay-dirt. They were 

 probably connected with the granite by fissures through the lime- 

 stone. In one case the vein was at a contact of granitic rock and 

 clay. But these veins preserved their identity as veins. There was 

 no mistaking them for anything else. At Tronoh, on the other 

 hand, the tin-bearing ground strongly resembles, if it is not, 

 a detrital deposit. If it were a broken-down lode we would expect 

 to find at least some trace of an "iron-hat" containing tin-ore, 

 lumps of hardened shale, with tourmaline, and large masses of tin- 

 ore. I have already mentioned the only section that I can remember 

 as even suggesting a lode. A hard mass with quartz seen lately in 

 the Tronoh Ltd. main lumbong also looked as though it might be 

 evidence of a lode, but the tin-ore was stated to be all to the east of 

 it, and it was only a weathered quartz-vein at the edge of the shales. 



At the North Tambun mine one could see, early in 1916, soft 

 shales showing distinct bedding lying on the limestone and unbedded 

 clay rich in tin-ore hard by. 



In Towkay Leong Fee's mine at Tambun highly inclined bedded 

 rocks lie side by side with clay very rich in tin-ore. The latter 

 sometimes shows a trace of lamination, but I have not seen any 

 section where bedded can be traced into unbedded rocks. They, 

 appear to be distinct, but one of the Perak mining community who 

 has had a long experience of the mine holds the view that the clays 

 are the-bedded rocks very much weathered, and tells me that in the 

 latter good tin-values have been found. In the North Tambun 

 mines the shales retain their bedding immediately above the lime- 

 stone, and it is difficult to understand why in this and in Towkay 

 Leong Fee's mine the bedded rocks have retained their bedding if 

 the others have lost it, seeing that both are equally soft and the 

 position of the limestone is sucli that one cannot help expecting it to 

 extend under the bedded rocks. 



At New Tarabun also the bedded rocks occurred in juxtaposition 

 to the clays. The former were traversed by numerous small kaolin 

 veins. They yielded a little tin-ore throughout, whereas the clay 

 was comparatively rich. No limestone was met with below the 

 bedded rocks. 



In the Tronoh and Tambun mines, and also elsewhere, it might be 

 argued that in addition to the disturbing effect of the limestone 

 surface being lowered, the bedding of shales and schists has been 

 destroyed by the media that brought the tin-ore; in fact, this view 

 was put forward during a discussion on a paper read in Ipoh some 

 years ago. This would account for the greater quantity of tin-ore 

 in the clays, but it is difficult to reconcile the theory with observa- 

 tions elsewhere. 



In Intan, in Upper Perak ; at the Ulu Gopeng mine; at Bruseh, 

 in Batang Padang ; at Jeher, and near Tanjong Malim ; and at 

 Pantai, near Kuala Lumpur, bedded shale and quartzite have been 

 invaded by tin-bearing media on a large scale, but I do not remember 



