J. B. Scrivenor — Kaolin Veins, Federated Malay States. 79 



subject to more modification, may provide more certain ground for 

 distinp;uishing the various groups of related species. 



On these grounds it has been clearljr proved that tlie Chalk species 

 {T. carnea, etc.) are not to be referred to Liothyr'ina, but probably 

 belong to a separate group entirely ; and that the Crag and other 

 Tertiary Terehratulce form another distinct series. If we accept the 

 evidence as trustworthy in these cases, we seem compelled to 

 acknowledge the new ^qums, Liothyrella, recently created by Thomson, 

 subject to the emendations dealt with in this paper. 



V. — The Kaolin Yeins. 

 By Lieutenant J. B. Scrivenor, M.A., F.G.S. 



KAOLIN occurs abundantly in the Federated Malay States in 

 connexion with granite, and is certainly formed on a large 

 scale by w^eathering. The purest kaolin in large quantity, however, 

 is found as veins in clay above limestone at Gopeng and elsewhere in 

 Kinta, and in quartzite and shales near Tanjong iJalim and Kerling. 

 The purity of these veins and the information obtained about tliose 

 in Kinta when traced down to limestone, lead to interesting 

 considerations about their origin, and the nature of the material in 

 the limestone is a matter of importance in connexion with the 

 possibility of establishing a kaolin industry. 



The form of the Gopeng veins has been described elsewhere, and 

 in the early edition of the Kinta publication, illustrations were given 

 showing the junction of the kaolin and clay. In A HandbooJc to the 

 Collection of Kaolin, China-clay , and China-stone in the Museum of 

 Practical Geology, 1914, by Mr. J. A. Howe, some notes were 

 contributed and a vein at Kramat Pulai figured (p. 102). In these 

 notes I stated, " No fresh felspar or partially decomposed felspar has 

 been detected as yet in these veins. This might be taken as evidence 

 of the kaolin having been kaolin ah origine and not an alteration 

 product, but it is not conclusive evidence against a pneuniatolytic 

 origin." Since writing this, residues from many samples of kaolins 

 treated Avith acid have been examined, and among them some from 

 the Gopeng veins. The minerals unattacked are mica, quartz, 

 tourmaline, and small grains, not abundant, that may be partially 

 decomposed felspar. Fi-om kaolin near Kerling (Selangor) sand 

 lighter than 2'8 sp.g. was separated, and in it are a few grains that 

 may be partially decomposed felspar. In the field I have not seen 

 any felspar in these veins, but in places where quartz is abundant 

 I have noticed a trace of graphic structure, as though quartz and 

 felspar had once been intergrown. 



A pink mica is present in these veins and has been described as 

 lepidolite. A specimen of similar mica from Chanderiang gave 

 a strong lithia reaction with the spectroscope, but one specimen from 

 Gopeng proves on analysis by Mr. C. Salter, to be muscovite with 

 •86 per cent of manganese. It is possible, therefore, that much 

 of the pink mica may be a manganese mica. 



Tin-ore is believed to occur in the Gopeng veins, and is known 

 to occur in tlie Kerling veins, in fact they are worked for tin. 



