168 T. H. Withers — Shell-fragments 



One reason against regarding these bedded deposits as recent 

 alluvium is their position. They form part of a watershed. They 

 rise to a considerable height above sea-level ; they are as high as 

 much of the land formed of shale and quartzite" in the centre of the 

 Kiuta Yalley ; and they differ from the recent alluvium in containing 

 much less vegetable matter, the few buried trees being the only 

 material of this nature. Their position, however, does not preclude 

 their being the remnant of deep alluvial deposits that filled a valley 

 when the Peninsula and the Archipelago were united, but the 

 difficulty is to reconcile with this possibility the evidence of the 

 kaolin-veins, which must in that case have been intruded into surface 

 deposits. 



The same objection applies to their being formed in the sea when 

 the Peninsula was a group of islands, and there is the further objection 

 that the deposits at Gopeng do not resemble the familiar coast deposits 

 of to-day. If they are considered to be of marine origin we have to 

 face the absence of marine organization and mangrove mud. 



Both in the case of unbedded and bedded deposits there is still the 

 question of the origin of the tin-ore to be noticed. Its most striking 

 feature is its angularity, which was shown in plate iv of the earlier 

 edition. On the west of the Kinta River there is no doubt that some 

 of the ore was brought by media that came through the limestone 

 from the granite of the Kledang Range or direct from granitic intru- 

 sions such as that at Pusing Lama. But this is not sufficient to account 

 for all the ore, and I think the only satisfactory solution is that 

 detrital ore derived from an older granite was added to by a younger 

 granite. It must be remembered that large areas of limestone bed- 

 rock have been exposed showing no veins by which tin might have 

 come to the rocks above. 



At Tekka and Gopeng the angularity of the detrital ore is against 

 its being alluvial, and on the Kinta Tin Mines Ltd. property and 

 elsewhere evidence has been found of enrichment from the kaolin-veins 

 and the granite of the Main llange. The detrital ore must be older 

 than the kaolin-veins, and therefore, we must conclude, older than 

 the granite of the Main Range, and it should be kept in mind that 

 the granite fragments in the altered volcanic ash of Pulau Nanas, 

 near Singapore, show that a granite mass older than the granite of 

 the Main Range once existed (QJ.G.S., Ixvi, p. 428, 1910). 



On pp. 39 and 40 of the 1913 publication I gave some objections 

 to these Kinta tin-deposits being held to be of glacial origin. The 

 Siputeh section is certainly a further objection, but, seeing that 

 extensive glaciation is known to have existed on Gondwanaland about 

 the time when these beds were laid down, a glacial origin appears to 

 meet more of the facts than anj' other explanation. 



III. — Some Pelecypod Shell-fkagments described as Cirkipedes. 

 By Thomas H. Withers, F.G.S. 



AMOjSTG a number of Cirripede plates from the Chalk Marl and 

 Cambridge Greensand of Cambridge submitted to me some time 

 ago, were certain fossils which at first puzzled me considerably. 



