Geology of the Pengkalan Hulu-Betong Transect area along the Malaysia-Thailand border

103 Pages·2010·33.66 MB·English

GEOLOGY OF
THE PENGKALAN HULU-BETONG
TRANSECT AREA ALONG
THE MALAYSIA-THAILAND BORDER
By
The Malaysia-Thailand
Working Group
A joint project carried out by
Minerals and Geoscience Department Malaysia
and
Department of Mineral Resources, Thailand
The Malaysia-Thailand Border Joint Geological Survey Committee
(MT-JGSC)
2009
LIBRARY CLASSIFICATION:
Science
Geoscience
Geology
Mapping Geology

Published by and obtainable from:
MINERALS AND GEOSCIENCE DEPARTMENT MALAYSIA
(Jabatan Mineral dan Geosains Malaysia)
20th Floor, Tabung Haji Building
Tun Razak Road
50658 Kuala Lumpur
Malaysia

Also obtainable from:

TECHNICAL SERVICES DIVISION
(Bahagian Perkhidmatan Teknikal)
Minerals and Geoscience Department Malaysia
(Jabatan Mineral dan Geosains Malaysia)
Scrivenor Road off Sultan Azlan Shah Road
31400 Ipoh
Perak
Malaysia

Price: RM60.00

Printed by:

PERCETAKAN ZAINON KASSIM SDN. BHD.
No. 1 & 3, Tingkat Kilang
Kawasan Perindustrian Ringan Jelapang
30100 Ipoh, Perak Darul Ridzuan

2010
iii

PREFACE

This report together with the accompanying geological map on the scale 1:250,000 is
the result of close cooperation between the Minerals and Geoscience Department
Malaysia, and the Department of Mineral Resources Thailand in resolving problems
related to cross border geological correlation between Malaysia and Thailand. The
Transect area covers about 1,350 square kilometres along the common Malaysia-Thailand
border. Fieldwork was carried out separately (November 2002 – May 2003) in the
Pengkalan Hulu and Betong areas. A joint field check in Malaysia (25th to 28th April
2003) and Thailand (29th April to 1st May 2003) was carried out by the geoscientists from
both Malaysia and Thailand.
Problems on the discontinuity of time rock unit boundaries between the various rock
units found on both sides of the common border areas have been satisfactorily resolved.
Potential mineral deposits occur along the border areas but the present security situation,
as well as environmental issues does not encourage the exploitation of these mineral
deposits. Future increase in the price of minerals coupled with advances in mining
technology may facilitate joint exploitation of these mineral deposits.

Dato’ Yunus Abdul Razak Adisak Thongkaimook
Director General Director General
Minerals and Geoscience Department Department of Mineral Resources
Malaysia. Thailand.

September 2009 September 2009
iv

ACKNOWLEDGEMENT

The Malaysia-Thailand Working Group would like to thank the Minerals and
Geoscience Department, Malaysia (JMG) and the Department of Mineral Resources,
Thailand (DMR) for their support and funding of this project. Thanks are also due to the
Malaysia and Thailand military, provincial and border police officials for their help,
especially in security matters.
The Malaysian Working Group would like to thanks to Dr. Mohd Shafeea bin Leman,
Professor, Geology Programme, Universiti Kebangsaan Malaysia, who has helped us to
identify the trilobite and brachiopod samples collected on the Malaysian side of the
Transect area.
The Thai Working Group would like to extend their thanks to Dr. Thanis Wongwanich
the former Director of the Bureau of Geological Survey Division, Department of Mineral
Resources, Thailand, for his encouragements during the study.
Last but not least, thanks are also due to all JMG and DMR officers and staffs for their
support and assistance during the fieldwork and preparation of this report.
v
Geology of the Pengkalan Hulu-Betong Transect area
along the Malaysia-Thailand border

by

The Malaysia-Thailand Working Group

EXECUTIVE SUMMARY
Detailed systematic geological mapping in the Pengkalan Hulu-Betong Transect area
on the scales 1:100,000 and 1:250,000 (using the 1:50,000 base maps) was carried out by
the Malaysian Working Group (Appendix 1) during parts of November 2002, January,
February, March and May 2003. On the Thai side, detailed geological mapping on similar
scales was carried out independently by the Thailand Working Group (Appendix 2)
during February 2003 and re-checked during April 2003. Joint field checks at selected
localities along the Transect area by geoscientists from both Malaysia and Thailand were
conducted on the Malaysian side (25th to 28th April 2003) and on the Thai side (29th April
to 1st May 2003). Problems in discontinuity among time rock unit boundaries between the
Palaeozoic rocks to Quaternary deposits, and the extension of granitic rocks (including
the mineral association), have been satisfactorily resolved.
The oldest rock unit, the Silurian-Devonian succession of the Kroh formation/Betong
Formation (SD ) consists mainly of very thin- to thin-bedded carbonaceous shale (often
kr/bt
siliceous), mudstone, siltstone, sandstone with subordinate chert and argillaceous
limestone lenses in the middle to upper part of the rock sequence. These rocks are
commonly metamorphosed to hornfels, calc-silicate hornfels, metasandstone and marble.
The succession is well exposed along the road-cuts in the middle and southwestern parts
of the Transect area. The thickness of the Silurian-Devonian rocks from representative
section exeeds 100 m. Fossil assemblages such as Spirograptus, Tentaculites elegans,
Tentaculites sp. and Styliolina were found in the shale strata indicate that the age of the
rock sequence is Silurian-Devonian.
The undifferentiated Carboniferous clastic rocks of the Kubang Pasu/Yaha Formation
(C ) are largely exposed in the northwestern, middle and southeastern parts of the
kp/yh
Transect area. Some roof pendants of this rock unit are confined to the middle part of the
Rimba Telui/Si Nakhon granite (Tr ) belt. The rock sequence of the Kubang
grrt/sn
Pasu/Yaha Formation (C ) with total thickness of more than 800 m is characterized by
kp/yh
the presence of very thin- to medium-bedded sandstone, siltstone, shale and chert at the
lower part; and thick- to very thick-bedded sandstone, argillite, and minor ribbon chert
and limestone lenses at the upper part of the formation. In the central-eastern part of the
Transect area, the succession can be lithologically subdivided into two facies i.e. the
argillaceous and arenaceous facies. The former is well exposed and forms a low relief in
the middle part of the area, near the Chantharat granite (Thailand). It is usually affected
by local deformations and low grade metamorphism that had taken place in the shear and
contact zones, and progrades to thin- to medium-banded phyllite, phyllitic schist, mica
schist and quartz schist with minor quartzite and calc-silicate. The thickness of this facies
is inconclusive due to strong folding of the strata. The arenaceous facies is well exposed
along several road-cuts on high relief terrains. It is characterized by the presence of
medium- to very thick-bedded sandstone, quartzite and minor argillite with inconclusive
vi
thickness. The age of the Kubang Pasu/Yaha Formation (C ) is considered to be
kp/yh
Carboniferous as indicated by the presence of radiolarian and conodont Phatonothus in
the siliceous rocks.
The Permian Ratburi Group is well distributed in the northern part of the Transect
area. Some patches of the unit are locally distributed as small hills to the west of Betong
town, located in the middle part of the Transect area. The succession can be lithologically
subdivided into two formations; the lower clastic, Sri Paen formation (P ) and the upper
sp
carbonate, Tham Krachaeng (P ) formation. The Sri Paen formation (P ), 500 m thick,
tk sp
comprises predominantly very thin- to thin-bedded argillaceous limestone, shale, siltstone
and chert with minor sandstone in the upper part. Some successions are locally deformed
and metamorphosed to phyllitic shale, schist and calc-silicate rocks. The Tham
Krachaeng formation (P ), is mostly recrystallized, consisting of thick to massive
tk
recrystallized limestone to marble with chert nodules. Thickness of this rock unit is
inconclusive. The occurrence of fossil assemblages, i.e. bivalves and brachiopods in
siltstone strata, radiolarian assemblage in siliceous bed, and fusulinids and brachiopod
fragments in limestone layers, indicates that the age of the Ratburi Group in the Transect
area is Permian.
The term Gerik formation (P ) formerly designated as Grik tuff (Jones, 1970 &
gk
Burton, 1986) is introduced by the Malaysian Working Group in this report. It is fairly
well-developed around Gerik town (Malaysia), situated in the southern part of the
Transect area. The formation consists of rhyolitic to rhyodacitic tuffs and occasionally
metamorphosed. These tuffaceous rocks also contain variable amounts of clastic
sediments of limestone and lenses of calcareous shale. Interbeds of tuff, limestone and
calcareous shale are also present. The Gerik formation (P ) is overlying both the Kubang
gk
Pasu/Yaha Formation (C ) and the Kroh formation (SD ). The age of the Gerik
kp/yh kr
formation (P ) is expected to be Permian as indicated by the presence of Anisopyge sp.
gk
and Phillipsia sp. (trilobite) found in calcareous shale interbedded with tuff and sandstone
at Kampung Batu 2, Gerik. Chonetid (brachipod) is also observed within this rock unit.
The Berapit formation (K ) is a new rock formation introduced by the Malaysian
br
Working Group to explain the very well cemented conglomerate unit deposited in a
continental fluvial channel area, unconformably overlying the Kroh formation/Betong
Formation (SD ). Outcrops of this rock unit are well exposed at Km 2.2 along the
kr/bt
Malaysian side of the Malaysia-Thailand border security road. The earlier workers
considered this rock unit as the lowermost part of the Nenering beds (Q ). The presence
nn
of few Caronatispora telata and Spheripollertes scabratus (pollen) indicates that the age
of this formation is Mid Cretaceous (Aptian-Albian).
The unconsolidated sediments were deposited in non-marine environments and can be
subdivided into two formations in ascending order: the Nenering beds/Ai Yoe Boe Chang
Gravel beds (Q ) and Recent fluvial deposit (Q ). The Pleistocene gravel beds of the
nn/ay a
Nenering beds/Ai Yoe Boe Chang sediments are more than 25 m thick, and are well
exposed as small hills around Betong District. It is composed of gravel, sand, silt, and
laterite with abundant iron concretions. The size of various pebbles in gravel beds
decreases westwards, towards Betong town. The Holocene fluvial deposit is well
deposited as channel filled in the Khlong Ka Pae and Pattani rivers. It is mainly composed
of sand, silt and clay.
The Palaeozoic succession in the Transect area was intruded by the Triassic granite
which can be divided into six units: Rimba Telui/Si Nakhon granite (Tr ), Bintang
grrt/sn
granite (Tr ), Chantharat granite (Tr ), Damar granite (Tr ), Batu Puteh/Pa Ret Tu
grbt grch grdm