32 Journal of the F.M.S. Museums. [Vol. VII, 



Mining Industries of Ulu Pahang," p. 59, 60) which are 

 believed to be of the same age as the granite of that range and 

 possibly to owe their distinct composition to a mixture of a 

 basic magma with that of the granite. Some of these rocks, 

 however, contain pyroxene. There is none in the Pulau 

 Pisang pebble nor is there any reason to believe that the 

 hornblende is derived from pyroxene, and a rock of this nature 

 might consolidate at a shallow depth from a part of a 

 hornblende-granite magma poor in quartz. There is a quantity 

 of white opaque matter showing a trace of crystal outline 

 which is probably a decomposed titaniferous mineral. 



j. This is a dark pebble, shown by the thin section to be 

 altered volcanic ash rich in quartz and with orthoclase and 

 soda-plagioclase as felspars. Alteration is proved by the hard 

 compact nature of the rock and the presence of a secondary 

 mineral, in minute grains. It may be zoisite. 



4. Another altered ash similar to 3. The secondary 

 mineral is probably epidote. 



5. A finer grained ash, full of a granular mineral, probably 

 secondary epidote. 



6. A rock with much secondary epidote which obscures 

 its original nature. It may have been sandstone. 



7. A pale grey pebble of very fine but hard texture. It 

 is impossible to say anything with certainty about its mineral 

 composition even after examination under a 1/12" oil immersion 

 objective. It is probably altered shale with minute granules 

 of epidote. 



8. A pebble closely resembling black chert of the Chert 

 Series, the resemblance being confirmed by the section. The 

 secondary minerals are epidote, some forming minute veins, 

 and a very finely fibrous mineral of which nothing definite can 

 be said but which is probably an amphibole. There is no trace 

 of radiolaria. 



9. A banded pebble showing black and grey rock. Both 

 are very fine grained but the black rock is certainly altered 

 chert, while the grey is either shale or fine ash. 



ro. This is one of the two specimens mentioned by Mr. 

 Kloss and is like No. 7. It shows stratification. Thin sections 

 of the rock point to it being fine shale full of granular epidote. 



11. The other specimen mentioned by Mr. Kloss consists 

 of alternating bands of black and grey rock, the latter having a 

 slight buff tint. The grey bands resemble 7 and 10 and mav 

 be either altered shale or fine ash. The black bands are 

 altered chert and fine black shale. The secondary minerals 

 they contain are epidote, the fibrous mineral seen in No. 8, 

 which, in one slide, has a distinct greenish tint, and brown 

 mica. 



