Middle Permian Brachiopods from Central Peninsular Malaysia Ð Faunal Af®Nities Between Malaysia and West Cambodia
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Journal of Asian Earth Sciences 19 (2001) 177±194 www.elsevier.nl/locate/jseaes Middle Permian brachiopods from central Peninsular Malaysia Ð faunal af®nities between Malaysia and west Cambodia Masatoshi Sonea,1,*, Mohd Shafeea Lemanb, Guang R. Shia aSchool of Ecology and Environment, Deakin University, Rusden Campus, Clayton, Vic. 3168, Australia bSchool of Environmental Sciences and Natural Resources, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia Accepted 27 April 2000 Abstract A moderately diverse Permian brachiopod fauna is described from a new rock unit, the Bera Formation, in the Bera District, central Pahang, Peninsular Malaysia. The fauna consists of 19 taxa, including 14 genera and 17 (both identi®ed and unidenti®ed) typically Tethyan species. The fauna appears to be correlative on the basis of brachiopods with the Neoschwagerina-Yabeina fusulinid Zones in Indochina and South China. In particular, it has strong linkage to Member C (Yabeina beds) of the Sisophon Limestone, west Cambodia. This is indicated by three of the Bera species Ð Urushtenoidea chaoi (Ching), Spyridiophora gubleri Termier and Termier, and Transennatia termierorum sp. nov., being shared with the Cambodian fauna. A possible early Capitanian (Middle Permian) age is proposed for the Bera brachiopod fauna. q 2001 Elsevier Science Ltd. All rights reserved. 1. Introduction and regional geology ¯anked on the east by ?Jurassic to Cretaceous continental sediments of the Bertangga Sandstone, but exposures to east This paper describes the largest known Permian brachio- and west are poor (Leman et al., in press). The northern and pod fauna from the so-called Central Basin (or the Central southern boundaries of the Bera Formation are also uncer- Belt) of Peninsular Malaysia, and reports on the southern- tain, but in the north it is associated with an andesitic vol- most occurrence of such a fauna in that region. Most of the canic unit thought to be of a Late Permian age (Cook and fossils examined in this study were collected by Sone and Suntharalingam, 1970). The occurrence of the fusulinid, Leman in the Bera District in February 1998. Additional Parafusulina sp., from a small limestone outcrop near material came from a collection in the palaeontology labora- Tasik Bera implies that the lower part of the Bera Formation tory of the National University of Malaysia (Universiti may extend down into the Kungurian (upper Early Permian) Kebangsaan Malaysia), collected originally by Leman. All (Cook and Suntharalingam, 1970). described specimens are registered in the same university with pre®x UKM-F. The regional geology of the Bera District is known from 2. Stratigraphy only two brief reports (Cook and Suntharalingam, 1970; MacDonald, 1970). The rock unit from which the current The fossils of this report come from the ªSungai Bera fossil horizon is studied has been named the Bera Formation sectionº (grid reference WF151446; the National Map (Leman et al., in press). The area where it occurs was Malaysia 1:50 000 Sheet 4157) exposed on the eastern previously considered to be part of the Triassic Semantan side of Bera Road, 17.3 km south of Felda Sebertak junction Formation Ð for example, on the most recent of®cial geolo- (Fig. 1). This section is equivalent to Locality BF2 of gical map of Peninsular Malaysia (Geological Survey of Leman et al. (in press). The outcrop was originally prepared Malaysia, 1985). The Semantan Formation, as revised, for construction of a resort. The exposed strata extend outcrops west of the Bera Formation, which in turn is approximately 90 m vertically and 300 m laterally, and appear to have undergone gentle but pervasive soft-sedi- * Corresponding author. ment deformation westwards. It is thus dif®cult to trace E-mail address: [email protected] (M. Sone). the sequence from one side to the other. The general strike 1 Present address: Institute for Environment and Development (LESTARI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, is N50±708W and dip 70±908SW. The lithology consists Malaysia. mainly of mudstone±siltstone interbedded with sandstone, 1367-9120/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved. PII: S1367-9120(00)00026-2 178 M. Sone et al. / Journal of Asian Earth Sciences 19 (2001) 177±194 Fig. 1. Possible extent of the Bera Formation and the location of the Sungai Bera section (modi®ed after Leman et al., in press). becoming dominantly tuffaceous in the upper part of the brachiopod faunas in the Neoschwagerina-Yabeina Zones section. The surface is bleached soft sediment. More of the Middle Permian, most likely to a lower Capitanian, outcrops occur along the road; these are much smaller This is based on the three brachiopod species shared with than the Sungai Bera section. Member C (Yabeina beds) of the Sisophon Limestone, west Three major fossiliferous stratigraphic intervals can be Cambodia. discriminated; these are referred to as Assemblages A±C The Permian strata of west Cambodia are exposed mainly in ascending order (Fig. 2). Assemblage A is predominantly in the Sisophon and Battambang regions (Fig. 4), as lime- a coquina of shell debris in grey mudstone; it often contains stone hills with intercalations of tuff, shale and mudstone fossiliferous calcareous concretions. This assemblage holds strata, collectively called the Sisophon Limestone (Ishii et the richest brachiopod deposit in this report. Assemblage B has less common brachiopods in nearly white, ®ne- to Table 1 medium-grained sandstone. Assemblage C consists princi- Brachiopod species from each assemblage of the Sungai Bera section pally of abundant lyttoniids in purple to black tuffaceous Species Assemblages mudstone and siltstone. The brachiopods are listed in Table 1. The genus Trans- ABC ennatia is the most abundant, although most specimens are Derbyia sp. X too poorly preserved for satisfactory illustration. The three Urushtenoidea chaoi (Ching, 1963) X X assemblages share few taxa, and may appear to represent Urushtenoidea sp. X distinct faunules, but sampling was not exhaustive. The Transennatia termierorum sp. nov. X three assemblages are considered as a single fauna in the Transennatia sp. indet. X following discussion. Spinomarginifera sp. X Echinauris sp. X Spyridiophora gubleri Termier and Termier, 1970a X Kozlowskia sp. X 3. Correlation and age Phricodothyris sp. X Orthotetes aff. picta Fang, 1983 X At present, there is no globally accepted Permian chron- Strophalosiina sp. X Linoproductus sp. X ological standard. The time-scale compiled by the Interna- Rhynchonellid family indet. X tional Subcommision on Permian Stratigraphy (Jin et al., Orthothetina cf. iljinae Sokol'skaya, 1965 X 1997) is applied in this study, with slight modi®cation to Gubleria aff. ninglangensis Fang and Jiang, 1992 X fusulinid biozonation for more appropriate correlation Gubleria sp. X within South-East Asia (Fig. 3). The brachiopod fauna of Eolyttonia? sp. X Spiriferinid family indet. X the Sungai Bera section appears to correlate with the other M. Sone et al. / Journal of Asian Earth Sciences 19 (2001) 177±194 179 species from their collections gained from that unit; Naka- mura (1979a) later revised the list. Based on lithology, Ishii et al. (1969) divided the limestone into four members, A±D in ascending order (Fig. 3). This division is supported by fusulinid faunas, supplemented by coral and brachiopod data. Because the four members are de®ned on lithologies and because a few key fusulinid species range through more than one member, the boundaries of each member cannot be precisely assigned chronologically. The most likely biostra- tigraphic ranges of the four members are indicated in Fig. 3, based on studies of Ishii et al. (1969) and Waterhouse (1976). Member C consists of shale and calcareous mudstone with calcareous nodules, sandwiched by the limestone facies of Members B and D (Ishii et al., 1969). It contains abundant brachiopods, and is characterised by fusulinid species such as Yabeina asiatica, Lepidolina multiseptata, Sumatrina longissima and Verbeekina verbeeki. Y. asiatica is the primitive form of the genus, suggesting the lowest part of the Yabeina Zone (Ishii, 1966). L. multiseptata and S. longissima are typical species of the middle Midian (the Y. globosa Zone) of the eastern Tethys (Leven, 1992, 1993). Species of Sumatrina and Verbeekina are not known to extend up to the upper Midian (see Kobayashi, 1997). The Midian Stage is approximately equivalent to the Capitanian Stage (Jin et al., 1997), although the lower boundary of the former is probably slightly older than that of the latter, as pointed out by Leven and Grant-Mackie (1997). Therefore, an early Capitanian age is the most de®n- able for Member C of the Sisophon Limestone. The most important species in the Bera fauna is Urushte- noidea chaoi (Ching) whose many reported occurrences are con®ned to the Kuhfengian Stage (Wordian) of South China and Member C of the Sisophon Limestone. It is one of the index fossils for the lower Maokouan Sub-series in the Nanjing Hills, southeastern China (He and Shi, 1996). An equally important form is Spyridiophora gubleri Termier and Termier. It has previously been found only in the Yabeina beds of the Sisophon Limestone (Mansuy, 1913; Chi-Thuan, 1961; Termier and Termier, 1970a). Nakamura (1979a) also listed its occurrence in Member C. Transenna- tia termierorum sp. nov. is elsewhere known only in the Yabeina horizon of the Sisophon Limestone (Termier and Termier, 1970a). These three species indicate strong linkage between the Bera fauna and that in Member C (the Yabeina Zone) of the Sisophon Limestone. Species of Orthotetes, Gubleria, Phricodothyris and Orthothetina in the Bera fauna closely resemble those recorded in the Gnishik-Khachik beds of the Trans-Cauca- sus and in the Maokou horizons of South China. In particu- Fig. 2. Stratigraphic log of the Sungai Bera section with indications of each Assemblage A to C (modi®ed after Leman et al., in press). lar, the species of Orthotetes and Gubleria are alike to those in west Yunnan, southwestern China.