The Devonian–Lower Carboniferous succession in Northwest Peninsular Malaysia Hakif Hassan Meor * , Chai Peng Lee Geology Department, University of Malaya, Kuala Lumpur 50603, Malaysia Received 1 March 2003; accepted 18 September 2004 Abstract A new stratigraphic nomenclature is proposed for the approximately 600 m thick, mainly clastic transitional sequence between the underlying Mempelam Limestone and overlying Kubang Pasu/Singa Formation in northwest Peninsular Malaysia. This sequence represents shallow marine deposits of the continental margin of the Sibumasu Terrane during the Middle Palaeozoic (Devonian–Carboniferous). It is separated into several formations. The Timah Tasoh Formation is an approximately 76 m sequence consisting of 40 m of laminated tentaculitid shales at the base, containing Monograptus yukonensis Jackson and Lenz and Nowakia (Turkestanella) acuaria Alberti, giving an Early Devonian (Pragian–Emsian) age, and about 36 m of rhythmically interbedded, light coloured argillo-arenites. The Chepor Formation is about 90 m thick and consists mainly of thick red mudstone interbedded with sandstone beds, of Middle to Late Devonian age. A new limestone unit is recognized and named the Sanai Limestone, which contains conodonts of Famennian age. The Binjal Formation consists of red and white mudstone interbedded with sandstone beds showing Bouma sequences. The Telaga Jatoh Formation is 9 m thick and consists mainly of radiolarian chert. The Wang Kelian Formation is composed of thick red mudstone beds interbedded with silty sandstone, and contain fossils indicative of an Early Carboniferous (Visean) age. The succession was deposited on the outer shelf, with depositional environments vertically fluctuating from prodelta to basinal marine. The Devonian–Carboniferous boundary is exposed at Hutan Aji and Kampung Guar Jentik, and indicates a major regressive event during the latest Devonian. q 2004 Elsevier Ltd. All rights reserved. Keywords: Sibumasu; Continental margin sequence; Unconformities; Transgression/regression; Hangenberg event 1. Introduction Early work on the Devonian of Peninsular Malaysia focused mainly on well exposed coastal outcrops on the islands of Langkawi. However, these outcrops are structu- rally complex, and stratigraphic relationships between certain units confusing. Recently, several new outcrops of equivalent rocks exposed in the mainland state of Perlis have been discovered and reported (Lee and Azhar, 1991; Meor and Lee, 2002). The new findings are used here to propose a new stratigraphic nomenclature for the Devo- nian–Carboniferous succession of northwest Peninsular Malaysia, and to further resolve the Devonian–Carbonifer- ous history of the Sibumasu Terrane. 2. History of stratigraphic nomenclature Jones (1966) was the first to make a detailed map of the Palaeozoic rocks in the northwestern part of what was then called Malaya. He recognized four Palaeozoic formations exposed on the islands of Langkawi; the Cambrian Machinchang Formation, the Ordovician to Silurian Setul Formation, the Carbo-Permian Singa Formation (and its equivalent on the mainland, the Kubang Pasu Formation) and the Chuping Limestone. The scarcity of Devonian rocks was explained by a regional unconformity proposed between the Setul Formation and Singa Formation (Jones, 1981). The unconformity was said to be between the areno- argillites of the Upper Detrital Member of the Setul Formation, and the red pebbly mudstone of the Langgun Red Beds, considered as the base of the Singa Formation. This unconformity was never observed, but was inferred 1367-9120/$ - see front matter q 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jseaes.2004.09.005 Journal of Asian Earth Sciences 24 (2005) 719–738 www.elsevier.com/locate/jaes * Corresponding author. E-mail address: [email protected] (H.H. Meor).
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The Devonian–Lower Carboniferous succession
in Northwest Peninsular Malaysia
Hakif Hassan Meor*, Chai Peng Lee
Geology Department, University of Malaya, Kuala Lumpur 50603, Malaysia
Received 1 March 2003; accepted 18 September 2004
Abstract
A new stratigraphic nomenclature is proposed for the approximately 600 m thick, mainly clastic transitional sequence between the
underlying Mempelam Limestone and overlying Kubang Pasu/Singa Formation in northwest Peninsular Malaysia. This sequence represents
shallow marine deposits of the continental margin of the Sibumasu Terrane during the Middle Palaeozoic (Devonian–Carboniferous). It is
separated into several formations. The Timah Tasoh Formation is an approximately 76 m sequence consisting of 40 m of laminated
tentaculitid shales at the base, containing Monograptus yukonensis Jackson and Lenz and Nowakia (Turkestanella) acuaria Alberti, giving an
Early Devonian (Pragian–Emsian) age, and about 36 m of rhythmically interbedded, light coloured argillo-arenites. The Chepor Formation is
about 90 m thick and consists mainly of thick red mudstone interbedded with sandstone beds, of Middle to Late Devonian age. A new
limestone unit is recognized and named the Sanai Limestone, which contains conodonts of Famennian age. The Binjal Formation consists of
red and white mudstone interbedded with sandstone beds showing Bouma sequences. The Telaga Jatoh Formation is 9 m thick and consists
mainly of radiolarian chert. The Wang Kelian Formation is composed of thick red mudstone beds interbedded with silty sandstone, and
contain fossils indicative of an Early Carboniferous (Visean) age. The succession was deposited on the outer shelf, with depositional
environments vertically fluctuating from prodelta to basinal marine. The Devonian–Carboniferous boundary is exposed at Hutan Aji and
Kampung Guar Jentik, and indicates a major regressive event during the latest Devonian.
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738720
based on angular strike relations and the occurrence of red
pebbly mudstones interpreted as a basal conglomerate.
The presence of this unconformity was, however, later
refuted (Ahmad Jantan, 1973; Yancey, 1975). The contact
between the Upper Detrital Member and the Langgun Red
Beds was demonstrated to be conformable. The two once
separate Devonian units were now continuous, and this
led to suggestions by Yancey (1975) of a single Devonian
unit. Gobbett (1972) proposed the name Rebanggun Beds
(combination of the names Rebak and Langgun Island,
where outcrops of the unit were found) for the Langgun
Red Beds. The Upper Detrital Member was also clearly
different from the main Setul Formation, as the Setul
Formation was predominantly bedded limestone, while the
Upper Detrital Member was composed of siliciclastics.
Yancey (1975) was the first to propose the melding of the
Upper Detrital Member and the Langgun Red Beds into
one continuous Devonian unit, which, unfortunately, he
left unnamed. A new stratigraphic nomenclature has been
proposed by Cocks et al. (2005), in which separate
formations were erected for the Upper Setul Limestone
and Lower and Upper Detrital Members of the former
Setul Formation.
Recently, new exposures in the state of Perlis show the
presence of a sedimentary succession equivalent to the
Devonian and Carboniferous rocks of Langkawi, but
relatively less deformed, giving us a clearer view of the
middle Palaeozoic stratigraphy of northwest Peninsular
Malaysia.
Fig. 1. Locality map of outcrops of the Middle Palaeozoic succession in northwes
District, Perlis; (2) Hutan Aji, Kangar District, Perlis; (3) Teluk Mempelam, Pu
Kampung Jelutong, north Kedah.
3. Study area
The study focused on isolated outcrops throughout
Perlis and north Kedah, in northwest Peninsular Malaysia
(Fig. 1). Four main outcrops were recognized and studied
in detail:
1.
t Pe
lau
Kampung Guar Jentik
2.
Hutan Aji
3.
Kampung Wang Kelian
4.
Teluk Mempelam, Pulau Langgun.
3.1. Kampung Guar Jentik
The first locality is Kampung Guar Jentik (Kam-
pungZvillage), in the Beseri District of Perlis (68
33.129 0N; 100812.524 0E). Middle Palaeozoic rocks are
exposed as a hilly ridge trending roughly north–south
along the R121 road linking Kangar and Kaki Bukit, just
south of the Timah-Tasoh Dam. The ridge is locally
called Guar Sanai, and is separated into three small hills,
here referred to as Hills A, B and C from south to north
(Fig. 2). The outcrop is completely isolated as a faulted
block, and is surrounded by lowland developed into
paddy fields. It is bounded by the Setul Boundary Range
on the west, and karstic hills of the Chuping Limestone
far towards the east. The rocks were exposed due to
quarrying.
ninsular Malaysia. (1) Guar Sanai ridge, Kampung Guar Jentik, Beseri
Langgun, Langkawi; (4) Kampung Wang Kelian, north Perlis; and (5)
Fig. 2. Geological outcrop map of the Kampung Guar Jentik, Perlis, exposure. Location of the map in Fig. 1.
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738 721
3.2. Hutan Aji
There is a quarry site, called the Bumita Quarry, at
Kampung Binjal, Hutan Aji (68 33.2 0N; 100812.4 0E), just
5 km south of Kangar, the capital of Perlis state. The quarry
is situated around a hill, encompassing an area of roughly
300 km square, at Kampung Binjal and adjacent Kampung
Behor Chepor (Fig. 3). Similar to Kampung Guar Jentik, the
exposure is also a large, isolated, faulted block, this time
surrounded by villages. This area was studied by Kobayashi
and Hamada (1973) and Jones (1981).
3.3. Kampung Wang Kelian
The Kampung Wang Kelian outcrop was briefly
described by Lee and Azhar (1991). It is located south of
Kampung Wang Kelian (6840 0N; 100812.1 0E) on hilly
terrain, at an elevation of roughly 200–300 m above sea-
level. The exposures are in the form of roadcuts along the
road connecting Kaki Bukit and Kampung Wang Kelian.
3.4. Teluk Mempelam, Pulau Langgun
The most famous exposure of Devonian rocks in
Peninsular Malaysia, Teluk Mempelam is on the north-
western coast of Langgun Island (PulauZIsland), offshore
of the west coast, and just northeast of Langkawi Island (68
26 0N; 99853 0E). The type section for the Upper Detrital
Member is located here. The exposure on Pulau Langgun is
in the form of low cliffs, promontories and boulders along
the northwest coast. The rocks are not well exposed farther
inland due to thick vegetation.
4. Stratigraphic nomenclature
A preliminary description of newly exposed Devonian–
Carboniferous rocks in Perlis state was published in Meor
and Lee (2002), in which the authors proposed a single
stratigraphic unit for rocks of the transitional sequence
Fig. 3. Geological outcrop map of the Hutan Aji, Perlis, exposure. Location of the map in Fig. 1.
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738722
between the Upper Setul Limestone and the Singa/Kubang
Pasu Formation, called the Jentik Formation.
The Jentik Formation was defined as a mainly siliciclas-
tic unit consisting predominantly of pure, massive, grey,
red, yellow or brown coloured mudstone and shale, clean
quartz sandstone, with minor black laminated shales, cherts
and bedded limestone. An unconformity was inferred to be
present between the Jentik Formation and Kubang Pasu
Formation. The Jentik Formation was divided into six
separate subunits at that time. However, continuing work
has shown that the subunits are sufficiently distinct
lithologically to form separate formations. A major para-
conformity has also been identified lower in the Jentik
Formation type section, increasing the complexity. The
authors here discard the stratigraphic nomenclature pro-
posed in Meor and Lee (2002), and reject the notion of
a single, Jentik Formation, due to the influx of new data. A
new nomenclature is erected, with the subunits of the former
Jentik Formation upgraded to formation status.
Six formations are recognized from oldest to youngest:
the Timah Tasoh, the Chepor, the Binjal, the Sanai
Limestone, the Telaga Jatoh and the Wang Kelian
formations (Fig. 4).
4.1. Timah Tasoh Formation
The name Timah Tasoh Formation is proposed by Cocks
et al. (2005) for the siliciclastic sequence formerly known as
the Upper Detrital Member of the Setul Formation (Jones,
1981). The name is derived from the Timah Tasoh
Reservoir, just north of the type section, in north Perlis.
The exposure on Pulau Langgun, Langkawi, reaches 170 m
Fig. 4. Proposed stratigraphic nomenclature for the Middle Palaeozoic succession in northwest Peninsular Malaysia.
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738 723
in thickness, but mainland outcrops show a thickness of
about 76 m. The Timah Tasoh Formation is further divided
into two separate members.
4.1.1. Lalang Member
This subunit is exposed in Kampung Guar Jentik and
Hutan Aji, and Pulau Langgun, and overlies the Upper Setul
Limestone (renamed as the Mempelam Limestone For-
mation in Cocks et al., 2005—their nomenclature is used
here). The name Lalang Member is derived from the village
of Kampung Behor Lalang, which is just southwest of
Kampung Binjal, Hutan Aji area, and is closer to the outcrop
of the unit. The Lalang Member encompasses the basal beds
of the former Upper Detrital Member of Jones (1981), and is
the name proposed for Unit 1 of the former Jentik Formation
(sensu Meor and Lee, 2002). The unit is observed to be
conformably underlain by the Mempelam Limestone at
Teluk Mempelam, Pulau Langgun, while the contact is
faulted at Kampung Guar Jentik and Hutan Aji. The Lalang
Member is overlain by areno-argillites of the Bukit Raja
Member (Fig. 5a). The exposed thickness in Hutan Aji is
estimated to be about 40 m (Fig. 6). The unit is almost
wholly argillaceous, made up mainly of black, grey and
brown, laminated, tentaculitid shale and siltstone.
The lower boundary of the Lalang Member is earliest
Devonian (Lochkovian) in age, based on the occurrence of
Lochkovian aged conodonts in the uppermost beds of the
Mempelam Limestone on Pulau Langgun (Igo and Koike,
1973) and scyphocrinoid loboliths (Lee, 2001). But the
upper parts of the unit range into the Pragian and earliest
Emsian. The shales are highly fossiliferous, with abundant
dacryoconarid remains, including Nowakia (Turkestanella)
Fig. 5. Representative lithologies of the Middle Palaeozoic succession in northwest Peninsular Malaysia. (a) Black shales of the Lalang Member (at bottom)
underlying sandstone and mudstone of the Bukit Raja Member, Timah Tasoh Formation. Hill C, Kampung Guar Jentik, Perlis. (b) Distal turbidites with
scoured bottoms of the Chepor Formation, at Hill C, Kampung Guar Jentik, Perlis. (c) Devonian–Carboniferous boundary section at Hill B, Kampung Guar
Jentik. The Sanai Limestone is paraconformably overlain by cherts of the Telaga Jatoh Formation. Paraconformity marked by stippled line. (d) Turbidite
man, Metastyliolina sp. and Styliolina sp. (Fig. 7). Also
present in lesser numbers are the brachiopods Plectodonta
(Plectodonta) forteyi Boucot and Cocks, Lissatrypa? sp.
Boucot, Cocks and Racheboeuf and Orbiculoidea sp.
(Fig. 7), and unidentified pelecypods. Some horizons
contain monograptid fossils. Several specimens of Mono-
graptus langgunensis Jones and Monograptus yukonensis
fangensis Jaeger, Stein and Wolfart were found in the
exposure at Hutan Aji (Fig. 7), and remains of Monograptus
aequabilis? associated with a fragmentary rhabdosome
probably belonging to M. yukonensis fangensis Jaeger, Stein
and Wolfart were collected from the exposure at Hill C,
Kampung Guar Jentik. Monograptus langgunensis Jones
was first reported from the black tentaculitid shales of Teluk
Mempelam, Pulau Langgun, by Jones (1973a). The
occurrence of M. yukonensis is indicative of the M.
yukonensis Zone (Jaeger, 1988), which gives an Early
Devonian (Early Emsian) age. The tentaculitids Nowakia
(Turkestanella) acuaria posterior Alberti and Nowakia
(Alaina) matlockiensis Chapman are also characteristic of
the Early Emsian (Alberti, 1997). The abundance of pelagic
tentaculitids are indicative of Boucot’s (1975) Benthic
Assemblages 4–5, which suggest relatively deep waters,
between 50 and 200 m in depth (Brett et al., 1993).
Carbonaceous, laminated shale and sparse benthic fauna
suggests a dysoxic environment. Lack of coarse grained
siliciclastics and current structures show a low energy
setting. The overall interpretation is that of a basin starved
of sediment with sluggish circulation.
4.1.2. Bukit Raja Member
This represents the remainder of the Upper Detrital
Member, also known as Unit 2 of the former Jentik
Formation. The unit is about 18 m thick at Kampung Guar
Jentik (Fig. 5a) and Hutan Aji, but the exposures are
tectonically controlled. The name is derived from the local
name of a small hill being actively quarried at Hutan Aji,
where the thickest section is exposed. The observed
thickness of the unit on Pulau Langgun is 130 m, but there
are repetition and deletion of beds due to the complex
folding and faulting. The unit is predominantly made up of
light coloured sandstone beds interbedded with shales. The
unit is barren of body fossils, but contains abundant trace
fossils in the form of short, vertical to oblique burrows,
identified as Psilonichnus? and Macanopsis (Fig. 8).
The predominance of arenaceous deposits and vertical
burrows indicate a shallower, moderate to high energy
environment compared to the underlying Lalang Member.
The trace fossils are characteristic of the Psilonichnus
ichnofacies, indicative of a supralittoral, moderate to high
Fig. 8. Trace fossils in the Bukit Raja Member, Timah Tasoh Formation (Emsian-Eifielian?) of Kampung Guar Jentik, Perlis. (a) Macanopsis. GSCU2001. (b)
and (c) Psilonichnus?. (b) Top view of bedding surface showing paired burrows. GSCU2002. (c) Side view of single burrow. GSCU2001. Scale barZ1 cm.
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738726
energy environment (e.g. beach-backshore, dune areas and
supratidal flats on the coast). Exposures of this unit in Pulau
Langgun are highly folded, but also show a predominance of
quartzites, and limonitisation.
4.2. Chepor Formation
The name Chepor Formation is used for the red beds
exposed in the Bumita Quarry of Hutan Aji and at Hill A
and C, Kampung Guar Jentik. The most complete section,
at Bumita Quarry, shows a maximum thickness reaching
90 m (Fig. 3). The name is derived from Kampung Behor
Chepor, which is located just east of the Bumita Quarry.
Fig. 9. Representative sections of the Chepor Formation. Location of the lo
The lithology is mainly thick, red and grey coloured
fossiliferous mudstone interbedded with quartz sandstone
(Fig. 9). The Chepor Formation can be divided further into
two smaller subunits, i.e. member CF-1 and member CF-2.
Member CF-1 represents the bottom half of the Chepor
Formation, and is exposed at Kampung Guar Jentik (65 m
thick) and Hutan Aji (40 m thick). The lithology is
and Late Devonian-Early Carboniferous red beds in north-
west Peninsular Malaysia was suggested by Jones (1973b),
which was interpreted as an uplifting event (Hutchison,
1996, p. 236). Again this interpretation has proved to be
erroneous (Ahmad Jantan, 1973; Yancey, 1975; Meor and
Lee, 2002). The interpretation of the red beds in this paper
as deeper water, outer shelf, prodelta deposits further
weakens the Mid-Palaeozoic orogeny hypothesis. But the
idea persists, due to the scanty distribution of Devonian
aged sedimentary rocks. Wongwanich (in preparation, cited
in Boucot, 2002) reports the occurrence of a possible major
disconformity between Early Devonian tentaculitid shales
and Namurian aged shales. Meanwhile, Bunopas (1981) and
Metcalfe (1999) suggested that the regional unconformity at
the Devonian–Carboniferous boundary detected in the
Southeast Asian terranes was caused by Devonian rifting
of South China, Indochina, East Malaya and Southwest
Borneo from Gondwanaland. The paraconformity near the
Devonian–Carboniferous boundary at the Kampung Guar
Jentik and Hutan Aji sequences represents the depositional
hiatus on the Sibumasu/Shan-Thai terrane during the Mid-
Palaeozoic, previously suggested by Baum et al. (1970) and
Metcalfe (2002). There are no observed structural differ-
ences between the sections underlying the paraconformity
and the sections overlying it, implying that the depositional
hiatus was not associated with tectonic movement. The
possible correlation of the black mudstone facies of the
Chepor Formation, which lies just below the paraconformity
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738734
surface, with the global Hangenberg Anoxic Event indicates
that the cause of the depositional hiatus is most probably
the global regression occurring near the end of the
Famennian, just after the transgressive episode which
marked the Hangenberg Anoxic Event (Schonlaub, 1986;
Xu et al., 1986; Bai and Ning, 1988; Chlupac, 1988; Krstic
et al., 1988; Ulmishek, 1988; Feist, 1990; Klemme and
Ulmishek, 1991; Paproth et al., 1991; Wang et al., 1993).
7. Sea level fluctuations
A generalized sea-level curve for the Middle Palaeozoic
succession in northwest Peninsular Malaysia is recon-
structed using sedimentological and palaeontological data
presented here (Fig. 16). Several trends are observed.
Comparisons are made with sea-level curves for Euramerica
(Johnson et al., 1985) and Australia (Talent, 1989).
7.1. Pragian–Emsian transgression
A major transgression occurred on the Sibumasu Terrane
during the Late Pragian–Early Emsian, marked by gradual
vertical transition from pelagic limestone of the Mempelam
Limestone to Lalang Member, deeper water tentaculitid
shales. Water depth is estimated to be between 150 and
200 m. No transgressive episode during this period has been
observed in Euramerica (Johnson et al., 1985). A major
regressive episode was taking place in Euramerica, and sea-
levels remained low up to the Late Emsian. Mid-Palaeozoic
sea-level records for Australia are sketchy, but a regression
is recorded during the Pragian (Fig. 17), followed by a
transgression from the Late Pragian to the Early Emsian
(Buchan Caves Limestone transgression). A marine trans-
Fig. 16. Reconstructed sea level curves for the Middle Pala
gression occurred in the southern part of the South China
Block, starting in the Lochkovian and persisting into the
Pragian (Zhao et al., 1996). The Palaeo–Tethys Ocean was
forming during the Devonian, due to rifting of several
terranes (Indochina, Tarim, South China Block and North
China Block) from north Gondwana (Metcalfe, 1999). The
Early Devonian transgressive event of the Sibumasu
Terrane (marked by the Lalang Member) can be correlated
to the contemporaneous transgression occurring on the
southern part of the South China Block. The South China
transgression is interpreted as marking the initial rifting of
the terrane from Gondwana (Zhao et al., 1996), which led to
opening of the Palaeo–Tethys Ocean (Wu et al., 1994;
Metcalfe, 1999). The Lalang Member transgression also
marks this rifting, but on the side of Gondwanaland, as the
Sibumasu Terrane was probably still attached to Gondwana-
land during the Early Devonian (Bunopas, 1981; Sengor et
al., 1988; Metcalfe, 1988, 1999, 2000).
7.2. Late Famennian transgressive episode
A major flooding event is marked by an abrupt transition
from relatively shallow water red mudstone to a thin band of
black, pyritic mudstone in the Chepor Formation. As has
been discussed earlier, this probably marks the Hangenberg
Event, a transgressive episode recorded worldwide, and was
contemporaneous with a major extinction event (Fig. 17).
7.3. Latest Famennian paraconformity
A major paraconformity marks the boundary between the
Mid-Famennian aged Sanai Limestone and Early Carbon-
iferous cherts of the Telaga Jatoh Formation, exposed at
Kampung Guar Jentik. The Late Famennian record is absent
eozoic succession in northwest Peninsular Malaysia.
Fig. 17. Comparison of reconstructed sea level curve for the Middle Palaeozoic succession of northwest Peninsular Malaysia with eustatic sea level curves for
Euramerica (Johnson et al., 1985; Ross and Ross, 1988) and Australia (Talent, 1989).
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738 735
here. This same regressive episode is marked by the abrupt
transition from deep water black mudstones at the top of the
Chepor Formation, to shallower prodelta to delta front
deposits of the Binjal Formation. The paraconformity may
have been caused by the global regression occurring during
the End Famennian, just below the D–C boundary
(praesulcata Zone), and just after the Hangenberg Event
(Fig. 17).
7.4. Late Tournaisian transgression
Bedded chert and black shale deposition during the Late
Tournaisian marks a major transgressive episode, where
Late Devonian shallow water mudstone is replaced by
deepwater radiolarian chert. This event correlates well with
the global Burlington Cycle transgressive event (Ross and
Ross, 1988)
8. Geological history
The geological history of northwest Peninsular Malaysia
during the Middle Palaeozoic (Silurian-Early Carbonifer-
ous) is summarized here.
8.1. Early Devonian
Black shale deposition (Lalang Member) gradually
replaced the pelagic limestone deposits of The Mempelam
Limestone during the Lochkovian. This transition marks a
transgressive stage during the Late Silurian to Early
Devonian. The basin was already gradually deepening in
the Silurian, with deepwater pelagic limestone slowly being
replaced by siliciclastics. The basin was deep during the
Emsian, as indicated by fauna of Benthic Assemblage 4–5
(Boucot et al., 1999), which would give a water depth of
about 150–200 m. Sluggish circulation (probably a result of
a tropical climate) resulted in dysoxic and periodically
anoxic waters. But the basin was still connected to the open
sea, as evidenced by abundant pelagic dacryoconarid
tentaculitids and monograptids. This deepening of the
present day eastern margin of Sibumasu was tectonically
controlled, indicating subsidence probably due to block
faulting caused by rifting of the Indochina, Tarim, South
China Block and North China Block, which initiated the
formation of the Palaeo–Tethys Ocean (Metcalfe, 1999).
Later, possibly in the Eifelian, the basin started to be
filled with thick coarse grained siliciclastics, and benthic
fauna thrived, as evidenced by trace fossils in the Bukit Raja
Member. This marks a regressive phase, as the Bukit Raja
Member has the characteristics of a shallow water deposit.
8.2. Mid-Late Devonian
The start of a regressive event during the Mid-Devonian
is indicated by transition from basinal black shale to
prodelta siliciclastic deposition during the Mid-Late Devo-
nian. Thick mud of the Chepor Formation was being
deposited on the prodelta of an offshore delta fan. The water
depth of modern day prodeltas ranges from 10 to 30 m
(Sutton et al., 1970), and the Devonian basin prodelta was
probably similar in depth. Occasional turbidity currents
transported coarser grained material onto the prodelta. The
sea bottom was teeming with benthic life. The basin was
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738736
remotely connected with shelf areas in western peri-
Gondwana, explaining similarities with faunae from
southern Europe. Red coloured sediments do not indicate
an oxidizing depositional environmental, but is the colour of
the source rock of the sediments on the continent. The red
sediments of the Chepor Formation show a coarsening
and thickening upward sequence from the Mid-Devonian to
the Late Devonian. This is a shallowing upward, prograda-
tional sequence. A regression occurred in the Frasnian.
8.3. Late Devonian–Famennian
Red mudstone sedimentation continued in the area of
south Perlis. Coarse grained deposits became more
abundant during the Famennian, indicating progradation
of the Chepor Formation sequence. The siliciclastics did
not persist to the present day north during the Famennian.
Red mudstone deposition was replaced by pelagic lime-
stone (Sanai Limestone) here. This was probably because
of migration of the delta complex southwards, which
distanced the northern part of the basin from the sediment
source. This channel migration was coupled with tectonic
subsidence of the northern part of the basin (block
faulting), resulting in the localized deepening of the
northern part, leading to deposition of pelagic limestone
of Benthic Assemblage 4–5.
8.4. End Devonian: Hangenberg event
An abrupt transgressive event occurred near the end of
the Fammenian, represented in the Chepor Formation by a
thin black mudstone containing only Posidonia and
ammonoids. An anoxic–dysoxic pulse coincided with the
transgression. This black mudstone layer can be roughly
correlated to the global Hangenberg Event, an extinction
event marked worldwide by sudden black shale deposition,
just below the Famennian-Tournaisian boundary. The
stratigraphic record for the D/C boundary has been
completely eroded away in north Perlis, due to an erosive
hiatus marked by a paraconformity atop the Sanai Lime-
stone. This marks the global regression which occurred after
the Hangenberg Anoxic Event.
8.5. Early Carboniferous (Tournaisian)
Red prodelta mud deposition still continued in south
Perlis. Progradation of the Chepor Formation led to a facies
transition from prodelta to delta front deposits in the south
Perlis area. This represents another regression, which led to
redevelopment of the delta complex. The Earliest Carbon-
iferous in north Perlis is marked by a non-depositional
unconformity at the top of the Sanai Limestone. Both the
Chepor Formation regression and Guar Jentik paraconfor-
mity represents a global regressive episode which occurred
just after the Hangenberg Event. Prodelta to delta front
deposition was later replaced by deep water ribbon cherts.
Deep water, continental margin cherts of the Telaga Jatoh
Formation mark the global transgression event in the Early
Carboniferous (Burlington Cycle). Deposition of bedded
chert was widespread, and covered the areas of north Perlis
and north Kedah.
8.6. Early Carboniferous (Late Tournaisian–Visean?)
Prodelta to delta front deposition resumed again in the
Visean. The benthic fauna recovered after the Hangenberg
Event, but the diversity decreased. New genera of trilobites
and brachiopods, but from similar families as the Famen-
nian fauna, occupied ecological niches left open by extinct
taxa.
9. Concluding remarks
The Devonian–Carboniferous succession in northwest
Peninsular Malaysia is represented by a varied assem-
blage of depositional facies, ranging from black tentacu-
litid shales to pelagic limestone, all forming part of the
continental margin deposits of the Sibumasu Terrane.
The dramatic facies changes and the occurrence of
several unconformities in such a relatively thin sequence
is explained by rapid sea-level fluctuations during the
Middle Palaeozoic. The Early Devonian (Emsian)
transgression, represented by the Lalang Member black
shales, marks the initial rifting of the Palaeo–Tethys
Ocean. Also of particular interest is the structural
geology of the Perlis outcrops. The reverse and thrust
fault sets (Figs. 2 and 3) which affect the continental
margin sequence are reminiscent of a westward directed
foreland fold and thrust belt developed due to the
collision of the Sibumasu Terrane with the Indochina
Terrane in the Triassic (Metcalfe, 1999).
Acknowledgements
This paper presents work undertaken for Meor Hakif’s
MSc Thesis, supervised by Assoc. Prof. Dr Lee Chai
Peng at the University of Malaya, Kuala Lumpur, and
was supported financially by University of Malaya short
term research grants. We are grateful to Prof. Bernd
Erdtmann, Dr Doris Heidelberger, Dr Robert Blodgett,
Prof. Arthur Boucot, Prof. Ian Metcalfe, Dr Robin Cocks
and Dr Anthony Barber for stimulating discussion and
advice. Thanks to Dr Christian Neumann for access to
the Jaeger Collection at the Museum fur Naturkunde,
Berlin. Thanks also to Anuar Ismail, Ahmad Tarmizi,
Tam Chie Fatt and Mr Drasman for their assistance in
the field.
H.H. Meor, C.P. Lee / Journal of Asian Earth Sciences 24 (2005) 719–738 737
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