34 Journal of the F.M.S. Mitteums. [Vol. VII. 



radiolaria. The resemblance then, of the Pulau Pisang f^rey. 

 fine-grained rock, to the light-coloured rocks forming part of 

 "tourmaline-corundum rocks " and its association with chert, 

 is further evidence for the tourmaline-corundum rocks being in 

 part altered Chert Series rocks. 



But, assuming this to be correct, there is a great difference 

 between the alteration by granite on Pulau Pisang and by 

 granite in Kinta. In the former case the very fine grain makes 

 determination of constituent minerals difficult, but epidote, 

 fibrous amphibole, and brown mica seem to be the result of 

 metamorphism, while in the latter the alteration produced 

 large quantities of tourmaline and corundum, with rntile, 

 spinel, white mica, and fluorite. 



