Early Permian sequence from Sungai Itau quarry, Langkawi: its age, depositional environment and palaeoclimatic implication
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Geological Society of Malaysia Annual Geological Conference 2002
May 26 - 27, Kota Bharu, Kelantan, Malaysia
Early Permian sequence from Sungai Itau quarry, Langkawi: its age,
depositional environment and palaeoclimatic implication
MOHD SHAFEEA LEMAN & ASMANIZA Y OP
School of Environmental Sciences and Natural Resources
Faculty of Science 'and Technology
Universiti Kebangsaan Malaysia
43600 Bangi, Selangor Darul Ehsan
Abstract: A sequence of thickly bedded sandstone, massive mudstone, silty shale and massive sandstone exposed at
a quarry in Kampung Sungai !tau, Langkawi is described herein. In the lower part, sandstone with calcareous horizons
is rhythmically interbedded massive black pebbly mudstone or diamictite indicates sea level fluctuation influenced
by glaciation and deglaciation of the Gondwana supercontinent. The deposition took place in the outer shelf. The silty
shale yields an Early Permian (late Asselian-Sakmarian) brachiopod assemblage of strong Gondwanan affinity. The
massive sandstone on the top part of the section represents a storm deposit.
Abstrak: Makalah ini memperihalkan mengenai jujukan lapisan tebal batu pasir, batu lumpur masif, syal berlodak
dan batu pasir masif yang tersingkap di kuari Kampung Sungai Itau, Langkawi. Di bahagian bawah jujukan, batu pasir
dengan lapisan berkapur berselang berirama dengan batu lumpur masif hitam berpebel atau diamiktit menunjukkan
perubahan aras laut yang dipengaruhi pengglasieran dan pencairan glasier di superbenua Gondwanaland. Pengenapan
batu lumpur berpebel ini berlaku di pelantar luar. Syal berlodak mengandungi himpunan brakiopod berusia Perm
Awal (akhir Asselian-awal Sakmarian) yang banyak kesamaan dengan fauna Gondwana. Batu pasir masif di bahagian
atas jujukan Sungai Itau merupakan enapan ribut.
INTRODUCTION assemblage has a very strong affinity with the Early Permian
Gondwanan fauna. Mohd Shafeea Leman (1997), Mohd
Although the Singa Formation is largely exposed on Shafeea Leman & Shi (1998) and Shi et al. (1997) correlated
the Langkawi main island, very little is known about its the Kilim Quarry section as part of the Selang Member,
geological section and the depositional environment in based on the age and the presence of pebbly mudstone in
this area. This was mainly due to the lack of fresh rock the sequence.
outcrops in the Langkawi main island in the past. Gobbett An active e~rth quarry at Kampung Sungai Itau
(1973) and Jones (1981) described the Singa Formation exp,?sed an excellent lithological section, comprised of
based mainly on the coastal exposures of small islands in sandstone interbedded with mudstone, silty shale and
the southwestern part of Langkawi Islands. Ahmad Jantan limestone. Several sedimentary facies are recognised within
(1973, unpublished) subdivided the Singa Formation based this quarry section, the assemblage of which indicates an
on the natural outcrops at Pulau Rebak, Pulau Kentut, offshore marine depositional environment greatly
Pulau Ular and Pulau Selang. Stauffer & Lee (1986) also influenced by the fluctuation of sea level. This sea level
described the pebbly mudstone sequence of the Singa fluctuation could be closely related with the changes in
Formation from these natural exposures. On Langkawi palaeoclimatic condition of the Langkawi islands during
main island, valuable information on various aspects of the deposition. The age of the Sungai Itau section is Early
the Singa Formation were only. recently exposed at several Permian (late Asselian-early Sakmarian), based on the
road cuts, quarries and construction sites following recent brachiopod assemblage found in the middle part of the
rapid infra-structural development of the island. section. This paper will describe the sedimentary facies
The areas in the north and northeastern flank of and discuss their depositional environment as well as their
Gunung Raya has been marked by Gobbett (1973) and bearing on the palaeoclimatic changes in Langkawi Islands
Jones (1981) as part of the Singa Formation, but no detail during the Early Permian time.
information given. Later, Basir Jasin et al. (1992) described
the bryozoan limestone exposed at Kilim Quarry as part SUNGAI ITAU SECTION
of an undifferentiated Singa Formation, regarding them as
a transition bed from the Singa Formation to the overlying The Kampung Sungai Itau earth quarry is located in
Chuping Limestone. Mohd Shafeea Leman (1996), the southwest of Kampung Sungai Itau,about 500 m from
however, discovered that the Kilim brachiopod fauna is the Kampung Sungai Itau-Durian Perangin road junction
very closely related with pebbly mudstone of possible (see the insert map in Fig. 1). The Sungai Itau quarry
marine glacial origin, and that the brachiopod faunal operation cut almost the entire northwestern tip of the164 MOHO SHAFEEA LEMAN & ASMANIZA YoP
-+- 62srl
1
LEGEND
I~I Contour
I"';., 1Terrace
c:t;J Stream
B Mainroad Figure I. Locality map showing
B Track the position of Kampung Sungai
o 'Om 6 Electricity Cable Itau quarry and the measured
section.
NW -SE trending ridge connecting this quarry and the Kilim lithology, sedimentary structures and fossil contents this
quarry described earlier in Basir Jasin et al. (1992), Mohd lithological section can be divided into four major
Shafeea Leman (1996, 1997) and Shi et al. (1997). The sedimentary facies, namely the thin to moderately bedded
geology of the Kampung Sungai Itau quarry is dominantly sandstone, massive mudstone, silty and sandy shale and
made of thick to massive sandstone and mudstone with thickly bedded to massive sandstone facies. The first two
subordinate silty shale and limestone. The beds are generally facies are found inter!:>edded with one another (Fig. 2) in
moderate to gently dipping to the east-northeast. In the the lower half of the section, with total thickness exceeding
lower part of the section, several normal and lateral faults 35 m. The upper part of the section is made of silty and
repeatedly cut the rock sequence almost parallel to the sandy shale facies, succeeded by the thickly bedded to
bedding strike. These faults are usually marked by intense massive sandstone facies. The detail relationships between
shearing within the thick to massive mudstone, and rarely all these facies are shown in Figure 3.
cut across the more competent sandstone. A major lateral Thin to moderately bedded sandstone facies - This
fault with strike and dip of about 285°/80° can be seen at facies comprises fine- to medium-grained gray sandstone.
the western foot of the quarry. The sheared black mudstone The sandstone beds range in thickness from 2-30 cm but
in the south-southwestern fault block exhibits several drag occasionally reach 1.2 m thick. The thinner sandstone is
folds indicating left lateral movement. The black mudstone generally homogenous in texture. However, the thicker
is faulted against more resistent sandstone beds forming one sometime shows grading at the base where coarse-
the west-northwestern boundary of the Sungai Itau ridge. grained sandstone graded into medium-grained sandstone
Intense shearing of the faulted mudstone in places (Fig. 4) or at the top of the bed where the fine-grained
transformed this fine-grained sediment into mylonite. sandstone graded into siltstone or silty shale. Thin shale
A sedimentological section has been logged roughly laminae are found interbed~ed with the thinner sandstone.
across the strike along the line marked as A-B in Figure 1. The interbedded thin shale-sandstone often contains
The exact geographic position of point A (the base of the numerous trace fossils dominated by surface grazers. The
section) is at latitude 6°24.787'N; longitude 99°49.484'E bedding plane is planar in most cases, but irregular erosion
and altitude 46 m above m.s.l., while point B (the top of the base and broad lenticular sandstone bodies are occasionally
section) is at latitude 6°24.817'N; longitude 99°49.545'E present (see Fig. 3). Cross-laminated sandstone (Fig. 5)
and altitude 64m above m.s.l. The data were obtained from and laminated sandstone are also present. Other
a Magellan GPS Tracker instrument. sedimentary structures include small-scaled transverse
catenary ripples (Fig. 6) and transverse sinuous ripples
SUNGAIITAU SEDIMENTARY indicate palaeo-current directions towards N200E and
N65°E, respectively. Small assymetrical sandstone lenses
SEQUENCE found at the bottom of the Sungai Itau Section may
More than 55 meters of sedimentary rocks were represent climbing ripples formed by a stronger palaeo-
recorded from the Sungai Itau quarry section. Based on its current at N45°E direction. The colour of the sandstone is
Geological Society of Malaysia Annual Geological Conference 2002EARLY PERMIAN SEQUENCE FROM SUNGAI ITAU QUARRY, LANG KAWI 165
CALCAREOUS
SANDSTONE Brachiopod
horizon
LEGEND
E2ill Sandstone
D Mudstone
~
--- Sandstone Inte!bedded with
shale and silty shale
Figure 2. Sungai Itau qualTy section viewed from so uth showing ~ Limestone
sandstone intebedded with massive mudstone. g Calcareous rocks
EJ Sandstone lenses
gray when fresh, but the weathered sandstone is brownish 0 Porallellqmination
to whitish in color. Petrographically, the sandstone can be ~ Cross lamination
classified as quartz arenite with angular to sub-rounded ~ 0 Pclleocurrent direction
quartz grains and rare sub-angular fresh feldspar grains. ~
~
~ Ripple marl<
At particular horizons , the sa ndstone gradually []]
"
Pebble
becomes calcareous, both vertically and laterally. The IT] Bioturbation
weathered calcareous horizon is often marked by its coarser
textures (Fig. 7), resulting from the weathering or
~
. rn Brachiopod
-166 M OHD SHAFEEA L EMAN & A SMANIZA YoP
Figure 4. Coarse-grai ned sa ndstone with erosive base grad ing into Figure 5. Thinl y bedded sa ndstone showing paralle l and cross-
med ium-grained sa ndstone. Note white recta ngul ar feldspar grains lamin at ion.
in the coarse-grained sa ndstone.
Figure 6. Transverse catenary ripples showing palaeo-curren!
directi on toward s N2ooE. Figure 7. Calcareo us sa ndsto ne bed (where the hammer is placed)
on top of a sequence of thin to moderately bedded sa ndsto ne.
sma ll le nses of light coloured sandstone (Fig. 9). In the THE AGE OF SUNGAI ITAU SEQUENCE
middle part of the seq uence, the massive silty shale (Fig.
10) yields a hi g hl y fossiliferous horizon of ma inl y The Sungai Itau sequence is very rich in fossi ls. Body
brachiopod and bryozoan fauna. The foss il hori zon ranges foss il s are fo und in severa l calcareous hori zons and the
in thi ckness from 10 cm to 30 cm, and ex tends latera ll y for silty shale, whil e trace foss il s are found in the thinly
more than 80 m. interbedded sandstone - sha le as well a in the silty shal e.
Thickly bedded to massive sandstone facies - a total Body foss il s are do minantl y made up of bryozoans and
of more than 15 m thickly bedded to mass ive li ght gray brachi opods with less common echinoderms. Bryozoa ns
med ium grained sandstone occur at the top of the sequence. and echin oderms (c rinoid stems) do min ated the calcareous
T he sandstone is generall y tructureless, except for the hori zons while brachi opods are more abundant in the s ilty
presence of parallel thin lamin ae of shale parting. The sha le. The brachiopod fa un a co ns is ts of Spire/ytha
shale partings are more closely spaced and more continuous pelalijormis Pavlova , Spire/yt/w buravasi (H amada),
in the lower part of the sandstone seq ue nce compared to Sulciplica thailandica (Waterh ouse), ?Lamnipiica sapa
the top of the sequence. Thi s give an impress ion th at there (Wa te rh o use), Sp iriferella sp., Rhy nchopora culta
is a general thickening upward in the success ion. In the (Wa te rh o use), Bandoproductus cf. monticulus
lowermost part, however, several thinning and f ining (Wate rh o use), Arclitre ta percostata Waterhouse,
upward sequences prevail. Taell.iolha erus sp. and Elasmata sp. Figure 11 shows
Geological Society of Malaysia Allnual Geological Conference 2002E ARLY P ERM IAN SEQUENCE FROM SUN GA I ITAU QUAR RY , L ANGKAWI 167
Figu re 8. Rare rounded sa ndstone pebbles set at random in the Figure 9. Bioturbated sil ty shal e showing numerous lenses of
massive black pebb ly mudston e. sandstone.
representative fossils found in the si lty shale horizon at
Sungai Itau quarry. The brachiopod assemblage is very
close to the Early Permian (late Asselian-earl y Sakmarian)
brachiopod assembl age of Ko Muk in Southern Thailand
described by Waterhouse (1982) and the Kili m fauna
described by Mohd Shafeea Leman (1996). Although Shi
ef al . (1997) generali sed the age of the Kilim brachiopod
fa una as of Sakmarian age, their close affi nity with the Ko
M uk fa una suggests a possib le late Asseli an - early
Sakmarian age to the Ki lim fauna too. Thus, the Sun gai
Itau brachiopod horizon may represent a northernmost
extension of the late Asselian - early Sakmarian Kilim -
Su ngai Itau brachiopod bed. Meanwhile, the bryozoan
dominated limestone fa una is stratigrap hically older than
the brachiopod domjnated silty shale discussed above.
Figure 10 . Brach iopod fossi I horizon in the midd le of thi ck silty
Therefore, the bryozoa n limestone may represent the oldest
shale.
Permi an fauna ever recorded in Malaysia.
DEPOSITIONAL ENVIRONMENT Gondwanan derived terrane. Fossi l findin gs by Mohd
Shafeea Leman (1996, 1997) and S hi ef ai. (1997) not just
The presence of calcareous horizons in the Singa strongly confirmed the earlier presumptio n o n cold climate
Formation has been a very interesting topic of discuss ion , of Langkawi islands, but also dated some of the dropstone
late ly. Basir Jasin ef ai. (1992) described this phenomenon bearin g horizons.
as the evidence of climatic changes from cold polar to In this stud y, the pebble-bearing mass ive mud stone
wa rm e r clim a te as Sibumasu B lock drifted from fac ies in the lower part of the Sungai Itau section is we ll
Gondwanaland. However, the presence of drops tones above interbedded with the limestone-bearing sandstone facies
the Kilim bryozoa n limestone (S hi ef ai ., 1997) suggests (see Fig. 2) . The massive bl ack pebbl y mudstone matches
that the clim ate was still rather cold durin g the deposition tlle descripti on of marine glacial diamictite deposit described
of the li mestone, as dropstones normall y deposited during by Stauffer & Mantajit (1981), Stauffe r & Lee (1986) and
the warmer deglaciation period (Mohd Shafeea Leman , Mohd Shafeea Leman (2000) from oilier parts of the Singa
1997,2000). The presence of marine glacial diamictite in Formation. The rhythmic limestone - pebbly mud sto ne has
the Singa Format ion has been described and discussed by been well documented in the Early Permi an of Tasmani a,
Stauffe r & Mantaj it (1981), Stauffer & Lee (19 86) and which was positioned at a palaeo-latitude of 80 0 S by Rao
Mohd Shafeea Leman (2000) . These glacial di amictite (1981) . According to him, the carbonates (calcareous
were used by Gatinsky & Hutchi son (1986), Hutchison sandstone and argi Il aceous limestone, rich in bryozoan
(1987) and Metcalfe (1984, 1996) as the key ev ide nce for skeleton) were accumul ated during the terrigenously-starved
connecting La ngkaw i Island toge the r with Wes te rn glac ial phases of marine low-stand , and the dropstones
Sumatra, West Thai land and Shan State in Burma as were deposited from ice-bergs as warmer c li mate brought
May 26-27 2002, Kota Bharu, Kelanlan , Malaysia168 M OHO SHAFEEA LEMAN & A SMANIZA Y oP
excessive terrigenous material to dilute the carbonate. floor during th e glac ial period. I nde n & Moore (1983)
Henrich (1991) also described an almost si mil ar record of mentioned that the bryozoan - brachiopod - crino id lime
rhythmic diamicton - calcareous ooze fro m the present packstone normall y represents an offshore open marine
Norwegian seabed, where dark diamicton (unconsolid ated facies, wh ile the bryozoan - brachjopod lime wackestone
diamictite) is most common in the open shelf of around may indicate a restri cted marine facies. The presence of
200 m depth. In their model , Hambrey & Harland (19 81) small scale ripples, laminated and cross-laminated sandstone
also indicated that the marine glacial diami ctite normall y and horizo ntal trace fo ssil s also suggests a qui et and
deposited on an open shelf. re latively hall ow e nvironment. The mass ive pebbly
The Sungai ltau alternate seq uence of calcareous mudstone was deposited during the interglac ial period
sa nd ston e - pebbly mud stone close ly resembles the fo ll ow ing rapid increase in the sea level with hi gh input of
rh ythmi c limestone - pebbly mudstone sequence described terrigenou s material. T he percentage of pebb les is
by Rao (1981) and therefore can be interp reted as an open remarkably low compared to those reported by Stauffer &
shelf deposit where the calcareous sandston e intelfingered Lee (1986) and Mohd Shafeea Leman (2000) from the
with the bas i.nal massive mudstone. The bryozoans, crinoids so uthwest of Langkaw i Islands and those reported by
and brachi opods flouris hed on the very quiet shall ow ocean Tantiwanit et al. ( 1983) from southern T haj land. Th is may
Figure 11 . Representative brachi opods fro m Sungai Itau, Langkawi. A - Arctitreta percostata
Waterhouse (ventra l va lve); B - Spirelytha buravasi (Ha mada) (conjo in val ves); C , D - Sp irelytha
petaliformis Pavlova (C - interna l mould; D - ex te rn al mould) ; E -Sulciplica thailandica Waterhouse
(ventral in terna l mould); F - Taen iothaerus sp . (dorsa l internal mould ); bar scale is 10 mm.
Geological Society of Malaysia Annual Geological Conference 2002EARLY PERMIAN SEQUENCE FROM SUNGAI !TAU QUARRY, LANGKAWI 169
indicate that the depositional setting is very far away from ACKNOWLEDGEMENT
the source of glacier as is shown in models drawn by
Hambrey & Harland (1981) and Hendrich (1991). This research was funded by the Malaysian Ministry
The succeeding fossiliferous and bioturbated silty shale of Science, Technology and Environment's IRPA Research
represent another quiet environment. This is followed by Grant no 02-02-02-0015.
thickening upward sequences of sandstone indicating a
continuous prograding of the submarine fan as a result of REFERENCES
another sea level fall. Meanwhile, the massive sandstone at
the topmost part of Sungai Itau section may be deposited AHMAD JANTAN, 1973. Stratigraphy ofthe Singa Formation (Upper
by the storm current. Paleozoic) in the southwestern part ofLangkawi Island Group,
West Malaysia. MSc. Thesis, University of Malaya
(unpublished).
PALEOCLIMATIC IMPLICATION BASIR JASIN, WAN FUAD WAN HASSAN & MOHO SHAFEEA LEMAN,
1992. The occurrence of bryozoan bed in the Singa Formation,
The alternating sequence of massive pebbly mudstone Bukit Durian Perangin, Langkawi. Warta Geologi 18(2),29-35.
and bedded sandstone with calcareous horizons in the GOBBEIT, D.J., 1973. Palaeozoic. In: Gobbett,DJ. & Hutchison,
lower part of the Sungai Itau section represents several C.S. (Eds.), Geology of the Malay Peninsular. John Wiley
cycles of high and low stands, respectively. This sea-level Interscience, New York, 61-95.
fluctuation corresponds closely with the climatic changes GATINSKY, Y.G. & HUTCHISON, C.S. 1986. Cathaysia, Gondwanaland,
related to the glaciation and deglaciation of the nearby and the Paleotethys in the evolution of continental Southeast
Asia Geological Society Malaysia Bulletin 20, 179-199.
continent, which supplies sediments to the Langkawi basin.
HAMBREY, MJ. & HARLANd, W.B., 1981. Earth's Pre-Pleistocene
During the extreme glacial period, sediment supply to the Glacial Records, Cambridge University Press, Cambridge,
sea is almost entirely stopped due to the extensively 1004p.
frozen continent. This will create a clear and quiet sea- HENDRICH, R., 1991. Cycles, rhythm, and events on high input and
floor condition, suitable for the cold water bryozoa, low input glaciated continental margin. In: Einsele, G., Ricken,
brachiopod and crinoid to thrive. As a result, calcareous W. & Seilacher, A. (Eds.), Cycles and event stratigraphy.
horizons are developed together with reworked sandstone. Springer-Verlag, Berlin Heidelberg, 751-772.
The sea level drops gradually as a result of a prolonged HUTCHISON, C.S., 1987. Geological evolution of South-east Asia.
Clarendon Press, Oxford, 368p.
glacial period. During the interglacial period, the glacial
INOEN, R.F. & MOORE, C.H., 1983. Beach environment. In: Scholle,
melt water usually carries a high amount of suspended
P.A., Bebour, D.G. & Moore, C.H. (Eds.), Carbonate
particles to the sea, while large iceberg carries larger depositional environment. AAPG Memoir 33,212-265.
particles. The fine-grained sediment was deposited together METCALFE, I., 1984. Stratigraphy, paleontology and paleogeography
with drops tones from melted iceberg to form the marine of the Carboniferous of Southeast Asia. Memoire de la Societe
glacial diamictite. The melting of the continental glacier Geologique de France 147, 107-118.
resulted in the rapid rises in sea level. The climatically METCALFE,I., 1996. Gondwanaland dispersion, Asian accretion and
controlled sea levels, clearly show that the deposition of evolution of Eastern Tethys. Australian Journal of Earth
the Sungai Itau sequence is strongly influenced by the Sciences 43, 605-623.
MOHO SHAFEEA LEMAN, 1996. The occurrence of brachiopods from
Early Permian major glaciation of the Gondwana
pebbly mudstone near Kilim, Langkawi: Their age,
supercontinent.
paleobiogeography and paleoclimatic implication. Warta
Geologi 22(2), 100-102 (abstract).
CONCLUSION MOHO SHAFEEA LEMAN, 1997. Batuan Formasi Singa di Pulau
Langkawi. In: Ibrahim Komoo & others (Eds.) Geological
The Sungai Itau sequence is made up of massive Heritage of Malaysia: Conservation geology for ecotourism.
pebbly mudstone interbedded with calcareous sandstone, LESTARI UKM, 185-207.
succeeded by silty shale and then by massive sandstone. MOHO SHAFEEA LEMAN, 2000. Langkawi dropstones: outstanding
The massive pebbly mudstone is a marine glacial glaciogenic sedimentological features in Malaysia. In: Ibrahim
Komoo & Tjia, H.D. (Eds.), Geological Heritage ofMalaysia:
diamictite. The sandstone contains several calcareous
Resource development for conservation and nature tourism.
horizons rich in bryozoan and crinoid skeletons. The
LESTARI UKM, 59-82.
rhythmically interbedded pebbly mudstone - calcareous MOHO SHAFEEA LEMAN & SHI, G.R., 1998. The Permian ofLangkawi
sandstone indicates sea level fluctuations highly influenced Islands and the northwest Peninsular Malaysia with comments
by climatic changes. The silty shale contains Early Perrillan on the significance of the Kisap Thrust. Proceedings of the
(late Asselian - early Sakmarian) brachiopod fauna of Royal Society of Victoria 1/0(1/2),405-418.
strong Gondwanan affinity. The sedimentary sequence RAo, c.P., 1981. Criteria for recognition of cold-water carbonate
and fauna of Sungai Itau strongly suggest that Langkawi sedimentation: Berriedale Limestone (Lower Permian),
Island was located on the periphery of the Gondwana Tasmania, Australia. Journal of Sedimentary Petrology 51,
491-506.
supercontinent during the Early Permian.
May 26-27 2002, Kota Bharu, Kelantan, Malaysia170 MOHO SHAFEEA LEMAN & ASMANIZA YoP
SHI, G.R., MOHO SHAFEEA LEMAN & TAN, B.K., 1997. Early Permian Malaya, Thailand and Burma. In: M. J. Hambrey & W. B.
brachiopods of Gondwanan affinity from the SingaFormation, Harland (Eds.) Earth's Pre-Pleistocene Glacial Records,
Langkawi Island, northwestern Peninsular Malaysia. In Phisit Cambridge University Press, Cambridge, 331-337.
Dheeradilok& 8 others (Eds.) Proceedings ofthe International TANTIWANIT, W., RAKSASKULWONG, L. & MANTAJIT, N., 1983. The
Conference on Stratigraphy and Tectonic Evolution of Upper Palaeozoic pebbly rocks in southern Thailand.
Southeast Asia and the South Pacific and the Associated Proceedings of the workshop on stratigraphic correlation of
Meetings of IGCP 359 and IGCP 383, Bangkok, 62-72. Thailand and Malaysia, 8-10 September 1983, Haad Yai,
STAUFFER, P.H. & LEE, C.P., 1986. Late Paleozoic glacial marine Thailand, 96-104.
facies in Southeast Asia. Geological Society of Malaysia WATERHOUSE, J.B., 1982. An Early Permian cool-water fauna from
Bulletin 20, 363-397. pebbly mudstones in South Thailand. Geological Magazine
STAUFFER, P.H. & MANTAJIT, N., 1981. Late Palaeozoic tilloid of 119(4),337-354.
Geological Society of Malaysia Annual Geological Conference 2002You can also read
