STRUCTURAL GEOLOGY OF BRITISH MALAYA 



SSI 



1. Recent alluvium; particularly extensive on both the coasts of the Peninsula. 



2. High-level alluvium; in Singapore, Johore, and perhaps in the Kinta Dis- 

 trict of Perak; raised beaches in several localities may be tabulated in 

 this group. 



3. Tertiary bedded rocks, probably Miocene, with coal. Only three small 

 patches of these rocks are known. 



4. Dolerite, rhyolite, and quartz-porphyry; extensive outcrops on the coast 

 of Pahang and Johore. The dolerite, and in one case quartz-porphyry, 

 is certainly younger than the granite. There is some doubt about the age 

 of the rhyolite. 



5. Granite, hornblende-granite, syenite, and small exposures of gabbro and 

 norite. Small exposures of diorite may belong to this group also, 



6. Extensive quartzites and shales in which two " 

 definite horizons have been found. In Perak 

 and Kedah shales contain Triassic fossils; in 

 Pahang and Singapore fine-grained sandy beds 

 have yielded a Rhaetic fauna (Myophoria 

 Sandstone). In Singapore Upper Gondwana 

 plant-remains have been found wdth marine 

 moUusca first described as probably on the 

 horizon of the Inferior Oolite.^ In the Kinta 

 District of Perak, clays with boulders may be 

 tabulated here. Chert pebbles are common in 

 the coarser quartzites. 



7. Quartzite with interbedded radiolarian chert, 

 occurring in Negri Sembilan and believed to be 

 the lowest part of the quartzite and shale series. 



8. Chert and shales; extensive in Kedah and 

 Pahang, and occurring elsewhere. They mark 

 the beginning of the shallow water conditions 

 under which groups 6 and 7 were deposited. 

 In Perils poorly preserved Fusulinidae have 

 been found in chert, but this may be silicified 

 limestone not belonging to this group. 



9. Extensive calcareous shales and limestone with 

 ■some non-calcareous beds. The limestone 



has yielded a definite Visean fauna^ in the 

 Kuantan District of Pahang, and Carbonifer- 

 ous fossils elsewhere. 

 10. Quartzite and shale with limestone bands overlain comformably by 9 in 

 the Langkawi Islands. It is probable that rocks in Patalung (Lower 

 Siam) with fossils belong to this group. The fossils were first described 

 as Permo-carboniferous,3 but have been re-examined and determined as 

 probably Lower Carboniferous. i 



' The fossils found in Singapore have been described by Mr. R. B. Newton who is 

 now preparing a new paper on the subject. 



2 Described by Dr. Stanley Smith; his report has been published only in Malaya. 



3 Professor McKenny Hughes, Rep. Brit. Assoc, Glasgow, 1901, p. 414. 

 ^ F. R. Cowper Read, Geol. Mag., 1920, pp. 113-20 and 172-78. 



A contemporaneous series 

 of volcanic and hypabyssal 

 rocks called the Pahang 

 Volcanic Series. Expo- 

 sures are extensive in 

 , Pahang and Kelantan. 

 The series ranges from 

 rhyolites to dolerites. 

 Agglomerates and tuffs 

 are particularly wide- 

 spread. 



