2 GEOLOGY OF PENINSULAR MALAYSIA 2.1 INTRODUCTION Peninsular Malaysia has traditionLlly been subdivided into NNW-SSE longitudinal belts on the basis of stratigraphy, mineralisation, geological structure, geological history and tectonic evolution . Scrivenor (19:;8) subdivided the Peninsula into three elongate belts on the basis of mineralisation: a western tin belt, a central gold belt and an eastern tin belt. Hutchison (1977) divided the Peni isula into four major tectonic subdivisions on the basis of different tectonic histories; the '1Vestern Stable Shelf, the Main Range Belt, the Central graben, and the Eastern Belt. Fo ) (1983) divided the Peninsula into four zones on the basis of differences in stratign phy. Khoo and Tan (1983) proposed a threefold subdivision; a Western Belt, Central Belt and an Eastern Belt on the basis of differences in stratigraphy and geological histoi y within Peninsular Malaysia. Within this threefold subdivision, Khoo and Tan (1983' further divided the Western Belt into two regions: a northwest sector and a Kinta-Ma acca sector. Tjia and Harun (1985) recognised four structural domains within the Peninsula. They defined Northwest, West, Central and Eastern structural domains. Within all the above subdivision schemes, the boundary between the eastern and central "belts" is taken as the Lebir Fault 2 one, and the boundary between the central and western "belts" is the Bentong-Raub line of Hutchison (1975). As previously stated (Chapter 1.5.2), Metcalfe (1988) proposed that Peninsular Malaysia consisted of two continental terra les, a western Gondwanan affinity continental terrane (Sibumasu) and an eastern Cathaysian affinity continental terrane (Indochina/East Malaya) Chapter 2: Geology of Peninsular Malaysia (Fig. 2.1). Sibumasu and Indochina/East Malaya are separated by the Bentong-Raub suture zone, a highly-deformed ac::retionary prism containing the remnants of the Palaeo- Tethys ocean which once divided them (Stauffer, 1974; Sengor, 1984; Hutchison, 1987; Metcalfe, 1988; Sengor et al., 1988) (Fig. 2.1). The Sibumasu terrane is characterised by a Palaeozoic passive margin sequence which includes a belt of Late Carboniferous - Early Permian glacial marine diamictite ; (Stauffer and Mantajit, 1981; Stauffer and Lee, 1986; Metcalfe, 1988). Early Permian faunas have a high-latitude, cold--water Gondwanan affinity. Carboniferous and Permian volcanic rocks are rare. In contrast, the Indochina/East Malaya continental terrane is distinguished by abundant Carboniferous - Permian volcanism and equatorial tower and Upper Permian Gigantopteris floras (Asama, 1984). No post Devonian Gondwanan faunas or floras are found on this terrane. The Malaysian part of the Sibun asu Terrane of Metcalfe (1988) corresponds with the Western Belt of Khoo and Tan (P)83). Tie Malaysian part of the Indochina/East Malaya Terrane of Metcalfe (1988) corresponds with the Central and Eastern Belts of Khoo and Tan (1983) (Fig. 2.1). The stratigraphy of Peninsular Malaysia is summarised below within the tectonic subdivision of Metcalfe (1988), but incorporating the threefold stratigra.phic subdivision of Khoo and Tan (1983). The rocks of the Bentong-Raub suture zone will be described separately. Chronostratigraphic columns for the Western, Central and Eastern Belts, as well as the Bentong-Raub suture z(me are provided in Fig. 2.2. 2.2 GENERAL GEOLOGY OF PENINSULAR MALAYSIA 2.2.1 Sibumasu Terra ne A belt of Lower Palaeozoic rocks extends from The Shan States of Burma (Myanmar), through South China, Thailand and Peninsular Malaysia. The southern extension of the belt is controversial. This belt has been referred to by several names, and the most commonly used are listed in the tal ,le below: 36 Chapter 2: Geology of Peninsular Malaysia 102E 0 50 100 150 km N ■ Alor Star - 5N 5N - Cameron Highlands Kuala ■ .t;t. Kangsar INDOCHINA/ EAST MALAYA ..?"1v••A Raub TERRANE SIBUMASU Jengka TERRANE Bentong ■ Kuala Lumpur Bahau Kuala Pilah 0 Malacca 0 Muar Bentong-Raub suture q zone (sensu stricto) Semanggol Formation 102E Figure 2.1 Map of Peninsular Malaysia illustrating the Sibumasu and Indochina/East Malaya terranes, the Bentong-Raub suture zone that divides them, and the Semanggol Formation of northwest Peninsular Malaysia. (Western, Central and Eastern Belt terminology after Khoo and Tan, 1983). 37 WESTERN BELT CENTRAL BELT EASTERN BELT .e71 Mélange 1 I Protcrozoic basement cp 1 2 3 4 5 0 F, LANGKAWI KUALA BENTONG-RAUB W.C. TRENGGANU/ ri 07iA Schist E AND LUMPUR SUTURE ZONE PAHANG E. PAHANG MALAYA NW (sensu stricto) I Sandstone vc) oo arc ? -••••-•....."...- 00 CRETACEOUS Shaleimudstone a•••-,- - , ,,,, Saiong Beds Gagau Gp. _ , , (Continental) '6* - Tel-libeling I "‘„,_,,- ,1' -1 Conglomerate S-type Main • 0 JURASSIC 0',.." - - Raub - Fm. Z" 0 Range Granite ' Redbeds (Continental) v, • ' Limestone r, - -- - - - - (7--7778-;;;;777 (Continental) ..............,,-_,- . Minaimis•••••• •-• OCIII411EEM I. III. Kodiang --------- - --- i i-ly TRIASSIC LW • (turbidites) 4""-- _ (turbidtes) Easterntern Province Volcaniclastic Lst. Linial 11 I 111 L-2...,..,fA GraniteG Belt sandstone 00 0 'a, 1"Lower Chen C.„,___2502. Member" II I I Glacial marine Chuping 2"-.111 a =g1 Gua Musang BOUM (a PEPMTAN ---•• - • ..... ,-„ 7., diamictite Lst. ., '''7 0,.. ......7,,_ ._ - ,r, - ,.. c:-.) • _. Stratigraphic Bedded _ 11 1 111 break Singa Fm. - Kuhang Pasu chert and 7 L7 .-7, Sagor Fm. (glacial marine) - Fm • — Serpentinite CA CO CARBONIFEROUS - - _" t Panching Lst. n27,,,, . Cheri ct• - I CI Z.,- L-,7- 17. Charu Fm. 1 c 1 ---- I I 1 1 mead Upper Detrital — 104111(11.! C. • • . 7> Granitic intrusions 11) IIIIIMIIMIN Member DEVONIA MIIM■111•1 - Kenny Hill ▪t") ;ATM (marine redbeds) Formation 152E ass■••on■imoi 11) IIIIIIMMIl (age uncartain- may be ......, Carbo-Permian) 0 i • NMI= 6.1.111.11.• •1 N=M".1" ii■ Bemuse. EMMIllIM CD ...... Kuala Lumpur SILURIAN •...."11■1111•11 (Subtidal) NIM■111. 1 INDOCIeNA/ t-t 111111•11■111111 r 111■111MI -.1"...2 Limestone EAST MALAYA 0 IIIIIMIIIIM••,........ TERRANE sN _ Cr ORDOVICIAN Islcrtsthortiden CD siormireM SIBUMASU =Nu Lower Sctul Isl. Schists TTRRANE EINE Machinchang - - r Z 2 binding. - - - :;:; .: Fm. CAMBRIAN 7 r1 \ \ 0 Proterozoic Proterozoic ■ 0 /.•-.,,,,,, continental basement M, continental basement in Bentong-Raub suture PRECAMBRIAN 7.0f1C ./\ (not exposed) /.\.//.\/ (not exposed) Ma ,/\/-\.",./,„„..,,s-,-" 1100-1400 Ma 0 Semanggol Formationti ■.o --,/,/,),/,,\ \ A.:./\%\\. ..•,. 15 00- /700 1\---"-/-, 00 t.A)• Chapter 2: Geology of Peninsular Malaysia Yunnan-Malaya Geosyncline Burton, 1967 West Malaya Block Stauffer, 1974 Thai-Malay Peninsular Block R.idd, 1980 Shan-Thai craton Bunopas and Vella, 1978 Sibumasu Block Metcalfe, 1986 Sinoburmalaya Gatinsky and Hutchison, 1986 Sibumasu terrane Metcalfe, 1988 Burton (1967a) referred to the b( it of Lower Palaeozoic rocks in the Malay Peninsula which continues northward into China as the Yunnan-Malaya Geosyncline. Stauffer (1974) renamed the Yunnan-Ma aya Geosyncline as the West Malaya Block and he tentatively included the whole of Sumatra within the block. Ridd (1980) identified a crustal block in west Malaya and Peninsular and west Thailand, and named it the Thai- Malay Peninsular Block. The nor =hern and southern extensions into Burma and Sumatra were not well defined. Gatinsky and Hutchison (1986) defined a narrow, elongate continental block of predominantly Palaeozoic shelf sequence rocks that extends southwards from SW China, through the Shan States of Burma, western Thailand, into the western Malay Peninsula and the northern part of Sumatra. The) named this block Sinoburmalaya. Metcalfe (1986) defined the Sibu -nasu Block as comprising the Shan States of Burma, north-west Thailand, Peninsular Burma and Thailand, Western Malaya, and north-west Sumatra, and possibly extending northwards into western China and Tibet. It was said to be composed of continental shelf sequences of Cambrian to Permian age and a 2000 km elongate belt of Carboniferous-Pet mian glacial marine diamictites (Stauffer and Mantaj it, 1981; Stauffer and Lee, 1986; Metcalfe, 1988). Early Permian faunas have an affinity with Gondwanaland (Archbold et al., 1982; Shi and Waterhouse, 1991). There is also a general absence of Carboniferous - Permiat volcanism on Sibumasu. 2.2.1.1 Stratigraphy Proterozoic Basement Proven Precambrian basement is not exposed in Peninsular Malaysia (Hutchison, 1989). The age of the underlying, but une,:posed Proterozoic crust indicated by Nd, Sr, and zircon 39 Chapter 2: Geology of Peninsular Malaysia U-Pb isotopic data from granitoics of the Sibumasu terrane is 1500-1700 Ma (Liew and McCulloch, 1985). The age of the underlying basement of the Indochina/East Malaya terrane is 1100-1400 Ma (Liew and McCulloch, 1985). In north-west Peninsular Malaysia, fault-bounded blocks of amphibo ite facies granitic gneiss, mica schist and calc-silicate known as the Kupang Gneiss, havo been uplifted along the Bok Bak Fault. Burton (1972) proposed that these rocks represer t the Precambrian, but Hutchison (1989) suggested that metamorphic grade may not be co •relative with age and therefore the Kupang Gneiss may not be of Precambrian age. WESTERN BELT (Khoo and Tan 1983) Northwest sector of the Western Belt (Figs. 2.1 and 2.2) The northwestern sector of the We ;tern Belt of Khoo and Tan (1983) includes the areas of the states of Kedah, Langkawi-Perlis and north Perak. Geographic subdivision and location names within Peninsular Malaysia referred to in this thesis are found