GEOLOGY OF THE BELUM – HALA TRANSECT AREA ALONG THE MALAYSIA–THAILAND BORDER

GEOLOGICAL PAPERS VOLUME 9

by

The Malaysian - Thai 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) 2012

GEOLOGY OF THE BELUM-HALA TRANSECT AREA ALONG THE MALAYSIA-THAILAND BORDER

by The Malaysian-Thai 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) 2012

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 2,020 square kilometres along the common Malaysia-Thailand border. Fieldwork was carried out in October 2005, January 2010 and March 2010 in the Belum area, Malaysia. A joint field check was carried out in the Belum area from 9th to 14th March 2010 by the geoscientists from both Malaysia and Thailand. There was no fieldwork carried out in the Hala area, Thailand due to security and accessibility reasons (very thick jungle). Thus, geological interpretation in the Hala area was based on the remote sensing interpretation and correlation of the photogeological units with the Belum area, Malaysia as well as previous works done in the Batu Melintang-Sungai Kolok and Pengkalan Hulu-Betong Transects areas. 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 Director General Minerals and Geoscience Department Malaysia March 2012

Mr. Nitat Pootanakul Director General Department of Mineral Resources Thailand March 2012

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ACKNOWLEDGEMENTS

The Malaysian - Thai Working Group would like to express their gratitude to the Director General, officers and staffs of the Minerals and Geoscience Department Malaysia (JMG) and the Director General, officers and staffs of the Department of Mineral Resources, Thailand (DMR) for their encouragement, support and funding of this project. Thanks are extended to Mr. Alexander Unya Ambun, Director of Technical Services Division, Minerals and Geoscience Department Malaysia and Dr. Tawsaporn Nuchanong, Director of Bureau of Geological Survey, Department of Mineral Resources, Thailand, for their encouragements during the study. Thanks also due to all staffs of the Minerals and Geoscience Department Malaysia and Department of Mineral Resources, Thailand for their involvement in this project either directly or indirectly. The Malaysian and Thai military, provincials and border police officials are duly thanked for their assistance in the security matters especially during the field trips in the Royal Belum State Park and Temengor Lake areas. Last but not least to all local residences for their support and assistance during the fieldworks.

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Geology of the Belum-Hala Transect along the Malaysia-Thailand Border by The Malaysian-Thai Working Group

EXECUTIVE SUMMARY According to the Sixth Meeting of the Malaysia-Thailand Border Joint Geological Survey Committee held in Kuala Lumpur on 11th June 2009, both parties have agreed to carry out the study on the Geology of the Belum-Hala Transect as proposed by the Malaysian-Thai Working Group. Since then, the project has been carried out by the geoscientists from the Minerals and Geoscience Department Malaysia and the Department of Mineral Resources Thailand in 2010 and 2011. On the Malaysian side, systematic geological mapping in the Belum, Gunung Hulu Merah and Kerunai areas where the Belum-Hala Transect is located was carried out by the Geological Survey Department during the year 1991-1993. During that time, the Malaysian side of the Transect area was mapped on the scale of 1:63,360. For the purpose of this joint geological mapping, the Malaysian Working Group has undertaken geological field checks on the scale 1:50,000 at selected localities in October 2005 and January 2010. In the areas where the ground data is not available, the remote sensing interpretation has been done. Then the geological map on the scale 1:250,000 was produced and attached to this report. On the Thai side, the geology mapping of the Belum-Hala Transect area was carried out based on the remote sensing interpretation and previous works on the Batu Melintang-Sungai Kolok and Pengkalan Hulu-Betong Transect areas. A geological map based on remote sensing data has been prepared since January 2010. A joint field check had been carried out on the Malaysian side of the Transect area close to the Malaysia-Thailand border in conjuction with the Malaysia-Thailand Working Group Meeting on the Belum-Hala Transect area that was held from 9th to 14th March, 2010 at the Belum Rainforest Resort, Malaysia. Then the photo-geological map has been improved by using the data and information collected from the joint field check. In addition, raw data from the field works in the Batu Melintang-Sungai Kolok and the Pengkalan Hulu-Betong Transect areas were also included in describing the characteristics of rock units. The Transect area is covered by the Silurian-Devonian Betong Formation (SDbt), Carboniferous Tiang schist (Cts), Carboniferous Kubang Pasu/Yaha Formation (Ckp/yh), Carboniferous-Permian Mangga formation (CPmg) and Permian Gerik formation (Pgk). The Betong Formation is only exposed on the Thai side, whereas the Mangga formation and the Gerik formation are only exposed on the Malaysian side. The photogeological ST1 unit is well exposed as the long, narrow roof pendant area in the vicinity of the granite/shear zones in the upper central and northwestern parts of the area. The unit

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is represented mainly by schist and phyllite, which can be correlated to the metamorphic rocks of the Silurian-Devonian Betong Formation (SDbt1). The photogeological ST2 unit forms a long, narrow-shaped roof pendant in the vicinity of the granite/shear zone in the northwestern part of the Transect area. The characteristic of this unit is similar to the ST1 unit but has more resistance. The unit is interpreted to be schist, phyllite and minor quartzite which can be correlated to the metamorphic rocks of the Silurian-Devonian Betong Formation (SDbt2).

The Tiang schist (Cts) comprises purplish grey to dark grey quartz-mica schist, quartz schist, quartz-mica-graphite schist and quartz-mica-garnet schist with minor hornfels. The schist is strongly schistosed, well foliated, consisting essentially of medium-grained elongated quartz and mica. On the Malaysian side, the Kubang Pasu/Yaha Formation (Ckp/yh) occupies the Sungai Kenerong valley in the western and central parts of the Transect area. The rocks in this area are metamorphosed to hornfels, phyllite, schist, metasandstone and metaconglomerate. On the Thai side, the Yaha Formation (Ckp/yh: S3) unit is distributed in the south-western part of the Transect area adjacent to the Malaysia-Thailand border. The unit shows a wide roof pendant on granite with prominent N-S bedding trace. The unit is characterized by well-bedded sandstone and shale which can be correlated to the arenaceous and argillaceous facies within the Carboniferous Kubang Pasu/Yaha Formation (Ckpar/yh1 and Ckpag/yh2). Only arenaceous facies of the Mangga formation (CPmg) is exposed in the southeastern part of the Transect area. The arenaceous facies consists of yellowish grey, light grey, thin- to medium-bedded, fine- to medium-grained metasandstone and metagreywacke interbedded with minor metasiltstone. The Gerik formation (Pgk) is distributed in the southwestern part of the Transect area. It comprises predominantly tuffs of rhyolitic to rhyodacitic composition. In addition, interbeds of tuffs, limestone, calcareous shale, tuffaceous sandstone and chert as well as siliceous shale also occur in places. Foliation can be seen in the groundmass of the tuffs as a result of regional metamorphism. On the Malaysian side, the igneous rock that is predominantly consists of granitic rock and distributed as N-S linear masses in the middle part of the Transect area known as the Main Range Granite. It comprises the Kabut granite (Trgrkt), Merah granite (Trgrmr) and Singor granite (Trgrsg). Based on remote sensing interpretation, four types of the granitic rocks are identified on the Thai side of the Transect area and can be described as follows: i.

The G1 unit that is correlatable with the Merah granite/Bu Do granite (Trgrmr/bd) is widely distributed as batholith in the eastern-central part of the Transect area and some stocks are located in the central and western parts. It is also extented to the eastern part of the Belum area in Malaysia

ii.

The G2 unit that is correlatable with the Kabut Granite (Trgrkt) unit is exposed as the N-S trending batholith in the western part of the Transect area. It is also extented to the Bang

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Lang reservoir in Thailand and the upper reaches of Sungai Perak in Malaysia. Many roof pendants are taken place in this granite type.

iii.

The G3 unit or Chantharat Granite (Trgrch) is characterized by its medium- to coarsegrained, sparsely megacrystic to good megacrystic, unfoliated to weakly foliated biotite granite. It can be traced along the western flank of the Belum-Hala Transect area.

iv.

The G4 unit that is correlatable with the Singor Granite/Hala granite (Trgrsg/hl) is light grey or leucocratic, fine- to medium-grained, equigranular to inequigranular biotitemuscovite granite. Tourmaline is also present in significant amount. The Singor Granite (Trgrsg) occurs as small isolated bodies within the Merah/Bu Do Granite (Trgrmr/bd) and Kabut Granite/La Sa granite (Trgrkb/ls).

On the Malaysian side, the structural geology is generally corresponds to the regional tectonic pattern of the Peninsular Malaysia with a slight variance as compared to the regional pattern in places. The active period of tectonic activity, especially related the Bentong-Raub Suture Zone during the Triassic might be responsible for the formation of major structures in the Transect area during which the igneous intrusion and uplifting also occurred. Structurally, the sedimentary and metamorphic successions of the Lower Paleozoic on the Thai side are characterised by generally N-S trending strongly, close fold especially in the Silurian-Devonian succession. The Upper Paleozoic rock sequence generally exhibits the N-S trend, close and tight folds with fault-bounded units. The strike-slip, normal, reverse, and thrust faults are trending in N-S, NW-SE and NE-SW directions.

On the Malaysian side, the Transect area was unknown for its economic deposits as there were no records of prospecting and mining in the past. However, based on regional geochemical survey carried out by the Minerals and Geoscience Department Malaysia during 1991 to 1993, seven multi-elements anomalous areas had been identified. Other than that, rock aggregates and dimension stone showing a good potential to be exploited. On the Thai side, mineral potential area in the Belum area has been studied by the Department of Mineral Resources Thailand using airborne geophysic and magnetic anomalies since 2003. The mineralization is found related to the contact metamorphism of granite intrusions and country rocks, and subsequent hydrothermal activities. The Pb-Zn sulphide mineral potential area, along the Hala stream, near the Malaysia-Thailand border and small Sn-W potential areas were observed.

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Contents PREFACE ................................................................................................................................... i ACKNOWLEDGEMENTS .......................................................................................................ii EXECUTIVE SUMMARY ..................................................................................................... iii 1.0

INTRODUCTION ........................................................................................................... 1

2.0 PREVIOUS WORKS AND GEOLOGIC SETTING ................................................... 12 2.1 Previous works ..................................................................................................... 12 2.2 Geologic setting .................................................................................................... 13 3.0 LITHOSTRATIGRAPHY............................................................................................. 17 3.1 Sedimentary and metamorphic rocks ................................................................... 17 3.1.1 The Betong Formation (SDbt1 and SDbt2).............................................................. 17 3.1.2 Tiang schist (Cts) .................................................................................................. 18 3.1.3 Kubang Pasu/Yaha Formation (Cyh)..................................................................... 22 3.1.4 Mangga formation (CPmg) .................................................................................... 27 3.1.5 Gerik formation (Pgk)............................................................................................ 29 3.2 Igneous Rocks ...................................................................................................... 35 3.2.1 Introduction .......................................................................................................... 35 3.2.2 Chantharat Granite (Trgrch) ................................................................................... 41 3.2.3 Kabut Granite/La Sa granite (Trgrkt/ls)................................................................... 41 3.2.4 Merah Granite/Bu Do granite (Trgrmr/bd) ............................................................... 42 3.2.5 Singor Granite/Hala granite (Trgrsg/hl) ................................................................... 44 3.2.6 Age and correlation .............................................................................................. 46 4.0 STRUCTURAL GEOLOGY ........................................................................................ 47 4.1 Introduction .......................................................................................................... 47 4.2 Bedding ................................................................................................................ 48 4.3 Foliation................................................................................................................ 48 4.4 Folding.................................................................................................................. 48 4.5 Faulting ................................................................................................................. 49 4.6 Jointing ................................................................................................................. 49 5.0 MINERALS AND OTHER NATURAL RESOURCES .............................................. 53 5.1 Introduction .......................................................................................................... 53 5.2 Geochemical Exploration ..................................................................................... 54 5.3 Other Geological Resources ................................................................................. 58 6.0

DISCUSSION AND CONCLUSION ........................................................................... 59

SELCTED BIBLIOGRAPHY ................................................................................................. 61 APPENDICES ......................................................................................................................... 64

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LIST OF FIGURES

Figure 1: Location map of the Belum-Hala Transect area .......................................................... 1 Figure 2: Location of the Pengkalan Hulu-Betong Transect as compared to the earlier Transcet areas............................................................................................................... 2 Figure 3: The Transect area on the Malaysian side covered by topographic map sheets scale 1:50,000 ....................................................................................................................... 2 Figure 4: The Transect area on the Thai side covered by on the topographic map sheets scale 1:50,000 .............................................................................................................. 3 Figure 5: Rafflesia azlanii ........................................................................................................... 4 Figure 6: Landsat TM satellite image of the Transect area. ........................................................ 5 Figure 7: Photogeological interpretation map of the Malaysian side of the Transect area ......... 7 Figure 8: Photogeological interpretation map of the Thai side of the Transect area .................. 9 Figure 9: Three dimensional surface view of Landsat 7 image of the Belum-Hala Transect area. ............................................................................................................................ 11 Figure 10: Elevation map of the Belum-Hala Transect area ....................................................... 11 Figure 11: The three “Belts” of the Peninsular Malaysia and the northwestern domain within the Western Belt. ........................................................................................................ 14 Figure 12: Generalised geologic sequence of the Belum-Hala Transect area (Malaysian side). 16 Figure 13: Schematic lithostratigraphic correlation for the Transect area. ................................. 17 Figure 14: Outcrop of the Tiang schist at Km 66.1 ..................................................................... 21 Figure 15: Close-up view of the Tiang schist. ............................................................................. 21 Figure 16: Exposures of quartz-mica-garnet schist at 5o 45‟ N, 101o 38‟ E, upper reaches of Sungai Machang......................................................................................................... 21 Figure 17: The metaconglomerate exposures are limited within the vicinity of river mouth of Sungai Tan Hain (05o 44.884‟ N, 101o23.389‟ E) ..................................................... 26 Figure 18: Various size of quartz clasts within the conglomerate............................................... 26 Figure 19: Dark grey mudstone clasts that is up to 5 cm in diameter. ........................................ 26 Figure 20: Cross-bedding observed on the top part of the sandstone beds grading from the conglomerate. ............................................................................................................. 26 Figure 21: Exposures of the psammitic unit of the Mangga formation near TM Communication Tower at Km 173.2 of the East-West Highway. ............................. 28 Figure 22: Close up view of the psammitic unit of the Mangga formation near TM Communication Tower at Km 173.2 of the East-West Highway. ............................. 28 Figure 23: Deformed metatuff of the Gerik Formation expose at river mouth of Sungai Kenarong. ................................................................................................................... 32 Figure 24: Deformed metatuff of the Gerik Formation expose at river mouth of Sungai Kenarong. ................................................................................................................... 32 Figure 25: Tuffaceous sandstone expose at Km 34 of the East-West Highway. ........................ 33 Figure 26: Close-up of the tuffaceous sandstone expose at Km 34 of the East-West Highway. 33 Figure 27: Bedded metasandstone at Sungai Ta Eng. ................................................................. 33 Figure 28: Cross-bedding in the metasandstone bed. .................................................................. 33 Figure 29: Calcareous facies expose at the river mouth of Sungai Gadong. ............................... 33 Figure 30: Calcareous facies expose at river mouth of Sungai Gadong...................................... 33 Figure 31: Subvertical to vertical strata of well-bedded light grey to grey radiolarian bearing chert and silliceous shale interbedded with thin beds of shale at Km 18.6 EastWest Highway (5o 31.655‟ N, 101o 14.790‟ E). ......................................................... 34 Figure 32: Thinly-bedded radiolarian bearing siliceous shale interbedded with thin beds of shale located at the old stretch of the East-West Highway (5o 31.633‟ N, 101o 17.633‟ E). ......................................................................................................... 34 vii

Figure 33: Geological setting of the granites in Peninsular Malaysia. ........................................ 37 Figure 34: Distribution of granitic rocks exposed in the Transect area ...................................... 40 Figure 35: Photographs of the Kabut Granit/La Sa granite (Trgrkb/ls) in Malaysia at Km 56.6 of the East-West Highway. ........................................................................................ 42 Figure 36: Photographs of the Kabut Granit/La Sa granite (Trgrkb/ls) in Sungai Singor area on the Malaysian side...................................................................................................... 42 Figure 37: Photographs of the Merah Granite/Bu Do granite (Trgrmr/bd) in Malaysia at Sungai Kejar area. .................................................................................................................. 43 Figure 38: Photographs of the Merah Granite/Bu Do granite (Trgrmr/bd) in Malaysia at Km 56.6 of the East-West Highway.. ............................................................................... 43 Figure 39: Photographs of the Singor Granite/Hala granite (Trgrsg/hl) in Malaysia at the Sungai Singor area. ................................................................................................................ 45 Figure 40: Photographs of the highly fractured Singor Granite/Hala granite (Trgrsg/hl) in Malaysia at the Sungai Kejar area. ............................................................................ 45 Figure 41: Microphotograph of Singor Granite/Hala granite (Trgrsg/hl) shows euhedral to subhedral tourmaline at Sungai Palai. ........................................................................ 46 Figure 42: Lineaments interpreted as the Ruok Fault Zone that almost parallel with the Temengor Lake orientation ........................................................................................ 50 Figure 43: Location of the Ruok Fault Zone ............................................................................... 51 Figure 44: The Ruok Fault Zone crosses the East-West Highway at km 184 towards Kota Baharu (208 km towards Ipoh) (05o 34.521‟ N, 101o 24.289‟ E). ............................. 52 Figure 45: Numerous sigmoidal quartzs within the schist in the Ruok Fault Zone at km 184 towards Kota Baharu (05o 34.521‟ N, 101o 24.289‟ E). ............................................ 52 Figure 46: Mining activities in the surrounding areas. ................................................................ 54 Figure 47: Anomaly map of the Transect area. ........................................................................... 56 Figure 48: Abandoned granite quarry at Km 61.6 of the East-West Highway. .......................... 58 Figure 49: Abandoned granite quarries at Km 63.3 of the East-West Highway. ........................ 58

LIST OF TABLES Table 1: Photo-geological units of the Malaysian side (Belum) of the Transect area .................. 6 Table 2: Photo-characteristic and correlation unit on the Thai side of the Transect area ........... 10 Table 3: Simplified geological sequence of igneous rocks on the Malaysian side of the Transect area. ............................................................................................................................... 38 Table 4: Correlation of igneous rocks on the Malaysian side of the Transect area .................... 38 Table 5: Summary of anomalies on the Malaysian side of the Transect area. ............................ 57

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1.0

INTRODUCTION

During the Sixth Meeting of the Malaysia-Thailand Border Joint Geological Survey Committee held in Kuala Lumpur on 11th June 2009, both parties have agreed to carry out the study on the Geology of the Belum-Hala Transect which was proposed by the Malaysian and Thai Working Groups of the Malaysia-Thailand Border Joint Geological Survey Committee (MT-JGSC) within the period 2010-2011. The Transect area is bounded by latitude 05o 30‟ N to 06o 00‟ N and; by longitude 101o 15‟ E to 101o 35‟ E covering an area of 2,020 square kilometers (Figure 1). It is located between the Pengkalan Hulu-Betong Transect on the west and the Batu Melintang-Sungai Kolok Transect on the east (Malaysian-Thai Working Group, 2006 & 2010). Figure shows location of the Transect area as compared to the earlier Transects.

Figure 1:

Location map of the Belum-Hala Transect area

On the Malaysian side, the Transect area covers approximately 1,770 square kilometers along the Malaysia-Thailand border. It is covered by four topographic map sheets on the 1

scale 1:50,000 i.e. nos. 3666 (Tasek Temengor), 3667 (Belum) as shown in Figure 3. The Transect area lies to the northeast of Gerik Township, in the district of Upper Perak. The access road to the Transect area is through the East-West Highway, the only road connecting Gerik in Upper Perak with Jeli in west Malaysia.

Figure 2: Location of the Pengkalan Hulu-Betong Transect as compared to the earlier Transcet areas

Figure 3: The Transect area on the Malaysian side covered by topographic map sheets scale 1:50,000

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On the Thai side, the Belum-Hala Transect area covers approximately 350 square kilometres along the border (Figure 4) and is geographically covered by two topographic map sheets (scale 1:50,000) of Khao Hun Kut (5220 I) and Ban To Mo (5320 IV) Quadrangles.

Figure 4: The Transect area on the Thai side covered by on the topographic map sheets scale 1:50,000

On the Malaysian side, the Transect area that stretches from the East-West Highway up to the Malaysia-Thailand Border in the north is located within the Royal Belum State Park. The state park is administered and managed by the Perak State Park Cooperation, an agency under the State Government of Perak. Previously, the entire forest of the Royal Belum State Park was considered as a „black area‟ and was placed under a state of emergency from 1948 until 1989 due to extremely active subversive of the Communist Party of Malaya (CPM). According to sources, when the highway was under construction, the stretch constructed crossing the Belum area was constantly under threat of being bombed and sabotaged by renegades. Most of the Transect area is mountainous terrain geomorphology covered by dense forest; The Royal Belum State Park, mostly grown by Dipterocarpus sp. One of the attractions to the Royal Belum State Park is the occurrence of Rafflesia, the biggest flower in the world. Previously there were two species of Rafflesia found in this area, namely Rafflesia cantleyi and R. hasselttii. In 2004, a new species of Rafflesia was discovered, known as R. azlanii, named after the Sultan of Perak, His Royal Highness Sultan Azlan Shah (Figure 5). On the Thai side, the Transect area is situated in the Hala-Bala Wildlife Sanctuary. Geomorphologically, the Belum-Hala Transect area on the Thai side covers mostly of mountainous terrain (so-called the Hala mountainous terrain) with dense forest (90%). Another 10% of the eastern part is covered by relatively undulating terrains with rubber and oil palm plantation. In the western part, the mountainous area shows the high elevation (750950 m above MSL) at the Malaysia-Thailand border and decreases northwardly in elevation 3

to 200-300 m MSL at Bang Lang reservoir. The central-eastern part of the Transect area on the Thai side is a plateau of high elevation mountainous terrain (1,000-1,400 m above MSL) showing drop valley morphology around the plateau. The highest elevation of this mountain is 1,490 m MSL. The eastern part of the Transect area consists of the N-S trending elongated mountain and low-lying areas. General elevation of these terrains is about 200-600 m above MSL. The main river of the Transect area on the Thai side is the Hala River originated from the Hun Kut-Bu Lo mountainous area.

Figure 5: Rafflesia azlanii

The climate is Tropical Rainforest type (Koppen`s: „Af‟ climate). The mean annual rainfall for 30 years (1951-1980) was 2,618.8 mm. The hottest month is May (28.4C in average) and the coldest month is December (25.9C). The geology of the Transect area on the Malaysian side was compiled based on the geological maps on the scale of 1:63,360 covered by topographic map sheet nos. 19 (Kerunai), 20 (Belum) and 11 (Gunung Ulu Merah). Detailed geology and mineral resources of those areas had been reported by Mohamad Hussein Jamaluddin et al. (in manuscript) and Mohd Badzran et al. (in manuscript). The areas had been mapped systematically in the early to middle nineties. Later, in early 2010, for the purpose of preparing this report, the Malaysian Working Group has re-studied geology of the area briefly on the scale of 1:50,000. Due to time and budget constrain, the Malaysian Working Group has only managed to recheck the geology of the Transect area along the East-West Highway and at the selected localities in the Temengor Lake area. Besides field data, aerial photograph and Landsat TM satellite imageries have been used in the interpretation of some of the geological boundaries and major geological structures in the Transect area especially on the Thai side, which no accesiblity. Enhanced false colour composites of satellite data were used. In Malaysia, the black-and-white aerial photographs covering the Belum area on the scale 1:25,000 taken in 1966-1967 were also used. The main objectives of the remote sensing study are to demarcate the regional geological structures which are lacking in existing maps as well as the extensions and correlation of existing rock units across the border. Digital image processing was carried out with Landsat TM scene 127/56 (18.01.96) on the ERDAS IMAGINE image processing system. The data covering the study area was

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extracted from the geo-coded (rectified to RSO projection) full scene. Image of the study area which is the subset of the full scene were generated for further processing (Figure 6 ).

Figure 6: Landsat TM satellite image of the Transect area.

The spectral bands corresponding to one visible red band (3) and two infrared bands (4 and 5) were chosen for analysis. False colour composite (RGB 453) generated from these bands was subjected to contrast stretches and selected filtering process to generate 1: 100,000 hard-copy imagery. On the Malaysian side, sixteen major broadly generalized photolithological units were identified to fall under four main categories: sediment/metasediment, volcanic/pyroclastic, plutonic/granitoid and alluvium as shown in Figure 7. List of the photo characteristics are given in Table 1. The rocks occur generally in almost parallel north-south aligned belts. The 5

photolithological units are described in the corresponding rock units which was interpreted and confirmed by ground truthing.

Table 1: Nos.

Photolithological Unit

Photo-geological units of the Malaysian side (Belum) of the Transect area Topography

Drainage Pattern And Texture

Erosional Feature

Photo Tone Of Colour Composite

Vegetation And Land Use

1.

Alluvium A1

Low and flat area

Principal stream flow

Principal stream

Bluish light green

Agriculture and settlement

2.

Tuffaceous shale V6

Moderate relief with a major ridge

Trellis drainage pattern with fine texture

Small gullies perpendicular to the ridge

Yellowish brown

Forest

3.

Metatuff V5

High relief with a major ridge

Trellis drainage pattern with coarse texture

Moderate gullies perpendicular to the ridge

Yellowish dark brown

Forest

4.

Tuffaceous sandstone V4

High relief with irregular hill ridge

Moderate gullies with irregular orientations

Brown

Forest

5.

Slaty tuff V3

Moderate relief with parallel ridges

Moderate gullies perpendicular to the ridge

Reddish moderate brown

and disturbed forest

6.

Phyllitic tuff V2

Moderate relief with parallel ridges

Dendritic and trellis drainage pattern with coarse texture Trellis drainage pattern with moderate texture Trellis drainage pattern with fine texture

Small gullies perpendicular to the ridge

Yellowish moderate brown

, disturbed forest and settlement

7.

Schistose tuff V1

Moderate to high relief with parallel ridges

Moderate gullies perpendicular to the ridge

Yellowish moderate brown

, disturbed forest and settlement

8.

Argillaceous rocks S6

Moderate relief with sharp irregular ridges

Trellis drainage pattern with moderate texture Dendritic drainage pattern with fine texture

Small gullies with irregular orientations

Dark brown

Forest and disturbed forest

6

Figure 7:

Photogeological interpretation map of the Malaysian side of the Transect area

In Thailand, the remote sensing work activities comprise image processing and geological data interpretation from Landsat 7 imagery band 4, 5 and 7 as well as aerial photograph. Geological interpretation including lineament mapping of the satellite data was exclusively carried out on hard copy plots of the digitally enhanced satellite data for visual interpretation. The visually extracted information can be annotated either onto a transparency sheet overlaying the plotted-image or it can be digitized directly on the computer screen using Geographic Information Systems (GIS). Accordingly, geological interpretation of the aerial photography was done by visual interpretation. Photogeological map interpretated from the Landsat 7 imagery is able to demarcate four units of sedimentary and metamorphic rocks, and five units of igneous rocks (Figure 8). The 7

photogeological map interpreted from aerial photograph is able identify six units of sedimentary and metamorphic rocks, and four units of igneous rocks, as shown in Table 2. The final task, the geological map of the Belum-Hala Transect area on the Thai side was compiled based on the remote sensing geological map and the geological data from fieldworks in the Batu Melintang-Sungai Kolok Transect area and the Pengkalan HuluBetong Transect area. Three dimensional surface view of Landsat 7 image and elevation map of the Belum-Hala Transect area are shown in Figures 9 and 10.

8

Figure 8:

Photogeological interpretation map of the Thai side of the Transect area

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Table 2: Photo-characteristic and correlation unit on the Thai side of the Transect area Unit

Photo-characteristic

Unit ST4

The S4 unit is interpreted as Schist, Phylite, Shale and sandstone. This unit is distributed in the north-eastern corner of the study area, low-relief. The unit has grey tone, granular texture, and mountainous landform with moderate resistance, dense vegetation and forest land use. Drainage pattern is persistent lines, moderate to high density, dendritic type. Several joint directions and inferred boundary are also remarked in this unit.

Tiang Schist (Cts)

Unit ST3

The unit has dark grey tone, granular texture, and mountainous landform with high resistance, dense vegetation and forest land use. Drainage pattern is persistent lines, moderate to high density, dendritic and trellis type. The good bedding trace, moderate attitude, several joint directions and inferred boundary are also remarked in this unit. This unit was interpreted as sandstone and shale.

Kubang Pasu/Yaha Formation (Ckb/yh)

Unit ST2

The Unit S2 show dark grey tone and moderate to high resistant. The unit has grey tone, granular texture, and mountainous landform with moderate resistance, dense vegetation and forest land use. The drainage pattern is persistent lines, moderate to high density, dendritic type. Several joint directions and inferred boundary are also remarked in this unit. This unit was interpreted as shale and sandstone.

Kroh/Betong Formation (SDkr/bt2)

Unit ST1

The unit has grey tone, granular texture, and mountainous landform with moderate resistance, dense vegetation and forest land use. Drainage pattern is persistent lines, moderate to high density, dendritic type. Several joint directions and inferred boundary are also remarked in this unit. This unit was interpreted as schist and phyllite.

Kroh/Betong Formation (SDkr/bt1)

Unit GT4

The unit has grey tone, granular texture, mountainous landform, circular feature with moderate resistance, moderate to dense vegetation and forest land use. This unit was interpreted as granite

Singor granite (Trgrsg)/ Hala granite (Trgrhl)

Unit GT3

The unit has grey to dark grey tone, granular texture, mountainous landform with high resistance, moderate to dense vegetation and forest land use. Drainage pattern is persistent lines, moderate density, and dendritic type. Several joint directions and sharp boundary are also remarked in this unit. This unit was interpreted as granite.

Chantrarat granite (Trgrch)

Unit GT2

The unit has dark grey tone, granular texture, and mountainous landform with moderate to high resistance, moderate to dense vegetation and forest land use. Drainage pattern is persistent lines, moderate density, and dendritic pattern. Several joint directions and sharp boundary are also remarked in this unit. This unit was interpreted as granite.

Kabut granite (Trgrkt)/ Lasa granite (Trgrls)

Unit GT1

The photo-characteristic of this unit is grey to dark grey tone, granular texture, mountainous landform with moderate resistance, moderate to dense vegetation and forest land use. Drainage pattern is persistent lines, moderate density, and dendritic pattern. Several joint directions and sharp boundary are also remarked in this unit. This unit was interpreted as shale and siltstone.

Merah granite/Bu Do granite (Trgrmr/bd)

10

Correlation unit

Figure 9:

Three dimensional surface view of Landsat 7 image of the Belum-Hala Transect area.

Figure 10:

Elevation map of the Belum-Hala Transect area

11

2.0

PREVIOUS WORKS AND GEOLOGIC SETTING

2.1

Previous works

The Malaysian side of the Transect area had been systematically mapped on the scale 1:63,360 by the Geological Survey Department Malaysia in 1991-1993. Most of the middle part of the Transect area that covered by topographic map sheet no. 20 (Belum) and no. 11 (Gunung Ulu Merah) had been mapped by Mohamad Hussein et al. (in manuscript). The western part of the Transect area covered by topographic map sheet no. 19 (Kerunai) was mapped by Mohd Badzran et al. (in manuscript), and the eastern part that partly covered by topographic map sheet no. 21 (Batu Melintang) and no. 12 (Belum) was mapped by Mohamad Hussein et al. (in manuscript). Mohamad Sari et al. (in manuscript) mapped the sheet no. 32 (Temengor) covering the area south of Belum. The rock sequence consisting of quartz-muscovite schist, quartz-biotite schist, quartzbiotite-muscovite schist, quartz-sericite schist and quartz schist in the Belum and Temengor areas had been mapped as the Tiang schist by Mohamad Hussein et al. (in manuscript). Quartz-mica-garnet schist and silimanite gneiss occur locally. Mohamad Hussein et al. (in manuscript) introduced the term Mangga formation to describe the sequence of chert, siliceous shale, phillite, greywacke and sandstone with tuff lenses exposed on the eastern margin of Main Range Granite. Subsequently, Mohamad Sari et al. (in manuscript) includes the sequence of metagreywacke and metasandstone exposed in the vicinity of Temengor to the south of the Transect area as part of the Mangga formation. MacDonald (1953) mentioned in his field record about an exposure composed of lenses and bands of schist and hornfels occurred within the black limestone believed to be part of the olistostrome unit. Wong (1974) reported the occurrence of sequence of upper greenschist to lower amphibolites schist metamorphic grades in this area which are common in the suture zone. The rocks are schists and gneisses containing muscovite, biotite, andalusite and garnet. Hornblende amphibolite is conformable with the pellitic schist. Subsequently Tjia (1989a) and Tajul Anuar (1989) proposed the zone as the extension of the Bentong-Raub Suture Zone in the Transect area. In addition, Mohd Raji (1990) who studied in detail geology around Batu Melintang area, reported the occurrence of muscovite-quartz schist, garnet-muscovite schist, silimanite-muscovite schist, biotite-hornblend schist, hornblend-epidote schist and biotite-hornblende gneiss. Hutchison and Taylor (1978) proposed three geographical granite belts in the Malay peninsula based on lithology and petrochemistry of the granite. The Eastern belt granitoids are composed mostly of I-type, magnetite-series granitoids, which intruded the Palaeozoic host rocks during Permo-Triassic period. The Main Range granitoids (in the central belt area) are composed mainly of S-type, ilmenite-series granitoids with minor intrusions of I-type, magnetite-series granitoids. They also intruded the Palaeozoic country rocks in the Permo12

Triassic age. The western belt granitoids on the Thai side consist of both I-type, magnetiteseries granitoids and S-type, ilmenite-series granitoids of Cretaceous age. On the Thai side, the Belum-Hala Transect area was first mapped by the Geological Survey Division, Department of Mineral Resources Thailand (Muenlek et al., 1979) on scale 1:250,000 of sheet NB 47-12 (Betong District; reprinted in 1985). Muenlek et al. (1979) also introduced the Silurian-Devonian rocks as the Ban To and Betong Formations. The former consists of recrystallised limestones to marble, quartzite, phyllite, phyllitic schist and micaschist, and the latter comprises shales with Tentaculites elegans, cherts, siliceous shales, metatuff, carbonaceous shales, argillite, mudstones, sandstones, and bedded recrystallised limestones. Muenlek et al. (1982) published a regional geological map of the Narathiwat Sheet on the scale 1:250,000. The individual granite pluton was preliminarily studied petrographically and subsequently three granite phases were classified as gneissic granite, coarse-grained porphyritic biotite granite and tourmaline-muscovite granite. Cobbing et al. (1986) completed a Southeast Asian granite project including the geological map of individual granite plutons, petrography, geochemistry and Rb/Sr age determination studies. They suggested that the granites in the east coast of Malaysia-Thailand peninsula are mainly of Triassic age. Tonnayopas (1994) studied the geology and stratigraphy of the Bang Lang Dam area situated in the northeastern part of the Transect area. He suggested that the Bang Lang dam site could be mainly covered by the Kanchanaburi Formation which consists of sandstone, shale, argillite and schist, with igneous intrusion to the west of the Dam site. The formation could be separated into the Bang Lang Formation consisting mainly of clastic sedimentary rocks and underlying the Hala Formation comprising metamorphic rocks with an angular unconformity contact. Utha-aroon et al. (2000) reviewed the mineral resources near the Malaysia-Thailand border. They suggested that the mineralizations were related to granite intrusion and subsequent hydrothermal activities. Chanrungrot (2003) studied the economic geology and mineral potential on scale 1:250,000 of sheet NB 47-12. He proposed the potential of Pb-Zn and Sn-W in the BelumHala Transect area.

2.2

Geologic setting

Based on differences of stratigraphy, mineralisation and structure, Peninsular Malaysia had been divided into three north-south trending zones referred to as the Western, Central and Eastern “Belts”. Some authors have recognized a Northwestern Domain within the Western Belt that covers part of Kedah, Perlis and Langkawi Islands (Figure 11). The Transect area lies in the western margin of the Central Belt. The major structural geology features occurs in the Transect area is the Bentong-Raub Suture Zone that running accross the eastern part of the Transect area in the north-south direction. The Bentong-Raub 13

Suture Zone represents a segment of the main Devonian to Middle Triassic Palaeo-Tethys Ocean, and forms the boundary between the Gondwana-derived Sibumasu and Indochina terranes (Metcalfe, 2000). It extends from Thailand where it is known as the Sra Kaeo and Nan-Uttaradit Suture Zone, through the Transect area to Raub and Bentong, and then to the east of Melaka, Peninsular Malaysia. The suture is exposed as an approximately 20 km wide zone bordering the eastern limit of the Main Range granitoids and comprises melange, oceanic ribbon-bedded cherts, schist, and discontinuous, narrow, elongate bodies of serpentinised mafic-ultramafic rocks, interpreted as ophiolite (Hutchison, 1975, 1989; Tjia, 1987, 1989a,b). 7

O

O

O

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102 E

101 E

100 E

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103 E

104 E

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7

TH AI LA N

PERLIS

0

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D

NORTHWESTERN LANGKAWI DOMAIN ISLANDS

6O

KEDAH

SO H UT

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EA A S

BE

4O L

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RA

RN

NT

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CE

ES

K

T

NG

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A SEL

A PAH

BE

LT

S A

R NGO

R IT

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AN

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A PER

4O

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ER

RE

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P. Tioman

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2O

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103 E SINGAPORE

Figure 11: The three “Belts” of the Peninsular Malaysia and the northwestern domain within the Western Belt (after Lee, 2009).

14

The rock units on the Malaysian side of Transect area range from Carboniferous to Quaternary in age. Upper Palaeozoic rock is represented by the Carboniferous Kubang Pasu Formation (Ckp) and Middle Permian Gerik formation (Pgk). The oldest known rock unit is the Carboniferous Tiang schist that is believed to be contemporaneous in age with the Kubang Pasu Formation, which is widely exposed in southeastern part of the Transect area. It consists of purplish grey, medium- to thick-bedded, medium-grained quartz-mica schist, quartz-micachiastolite schist, amphibolites schist, silimanite gneiss and hornfels. The succession is strongly deformed and metamorphosed due to the Main Range Granite intrusion as well as tectonic activity along the Bentong-Raub Suture Zone that lies within this rock unit. The Kubang Pasu Formation (Ckp) comprises essentially thick interbeds of psammitic and subordinate pelitic rocks. The psammitic rock is composed of thick-bedded metasandstones i.e., quartzite with minor metagreywacke interbedded with subordinate metasiltstone. The pelitic rock consists of fine-grained quartz-mica schist, quartz-micachiastolite schist and hornfels. Lithologically, the Kubang Pasu Formation in the Transect area is slightly different from the succession exposed in the Pengkalan Hulu-Betong Transect area due to the differences in degree of metamorphism. Fossils have not yet been found in this rock unit in the Transect area. The rocks are commonly metamorphosed to metasandstone, hornfels and fine-grained schist due to the Main Range Granite intrusion. The Carboniferous-Permian Mangga formation (CPmg), located at the western margin of the Bentong-Raub Suture Zone, overlies conformably the Carboniferous Tiang schist. It comprises low- to medium-grade metamorphic sequences of psammitic, pelitic and pyroclastic as well as schistose rocks. Generally, the Permian Gerik formation (Pgk) overlies conformably the Carboniferous Kubang Pasu Formation. However, a fault contact can be seen in the Transect area as a result of uplifting of Carboniferous succession due to granite intrusion. The Gerik formation consists of pyroclastic rocks, mainly tuffs of rhyolitic to rhyodacitic composition with limestone and calcareous shale lenses, tuffaceous sandstone as well as chert and siliceous shale that occur sporadically. The age of the Gerik formation is not older than Permian as indicated by the presence of Phillipsia, Anisopyge (trilobite) and Chonetid (brachiopod) within the calcareous shale at Kampung Batu 2, Gerik (Malaysian-Thai Working Group, 2010). Radiolarian bearing pelagic sediments crops out at Km 18.6 of the East-West Highway and at an exposure (N 5o 31‟ 38”, E 101o 17‟38”) at the old stretch of the highway. The samples yield Follicucullus sp., Gustefana sp., Latentifistula sp., Triplanospongos sp. and Albaillella sp. Some radiolarian specimens resemble Follicucullus scholasticus and Albaillella levis which are important faunas. The age of these fauna is interpreted as Capitanian to Changhsingian stage of Middle to Late Permian (Saesaengseerung, pers. comm.). Quaternary alluvial deposits of appreciable extent and thickness are present along the valley of the Sungai Perak, Sungai Pergau and their larger tributaries. The Recent deposits have been accumulated through fluviatile accretion in the flood plains of the rivers. Generalised succession of the rock units on the Malaysian side of the Transect area is summarised in Figure 12. 15

Figure 12:

Generalised geologic sequence of the Belum-Hala Transect area (Malaysian side).

16

3.0

LITHOSTRATIGRAPHY

The Transect area is covered by the Silurian-Devonian Betong Formation (SDbt), Carboniferous Tiang schist (Cts), Carboniferous Kubang Pasu/Yaha Formation (Ckp/yh), Carboniferous-Permian Mangga formation (CPmg) and Permian Gerik formation (Pgk). The Betong Formation is only exposed on the Thai side, whereas the Mangga formation and the Gerik formation are only exposed on the Malaysian side. Schematic lithostratigraphic correlation for the Transect area is shown in Figure 13. Geological map of the Transect area is included in the back pocket.

SEDIMENTARY AND METASEDIMENTARY ROCKS AGE/COUNTRY PERIOD/EPOCH

CARBONIFEROUSPERMIAN

Gerik formation(Pgk)

MALAYSIA/THAILAND

Arenaceous facies(Pgkar) Pyroclastic facies(Pgkpy)

Tiang schist(Cts) Kubang Pasu Fm.(Ckpar)

SILURIAN-DEVONIAN

Arenaceous facies(Pgkar) Pyroclastic facies(Pgkpy)

Yaha Fm.(Cyh2) Tiang schist(Cts)

Kubang Pasu/Yaha Formation (Ckp/yh)

Tiang schist(Cts)

Yaha Fm.(Cyh1)

Betong Formation(SDbt2)

Betong Formation(SDbt1)

Betong Formation (SDbt)

Kubang Pasu Fm.(Ckpag)

Argillaceous facies(Pgkag)

Mangga formation(CPmgar)

Yaha Formation(Cyh)

Mangga formation(CPmgar)

Kubang Pasu Formation(Ckp)

CARBONIFEROUS

Argillaceous facies(Pgkag)

Betong Formation (SDbt)

PERMIAN

PALAEOZOIC

ROCK UNITS THAILAND

MALAYSIA Gerik formation(Pgk)

ERA

Betong Formation(SDbt2)

Betong Formation(SDbt1)

IGNEOUS ROCKS

MESOZOIC

Hala granite(Trgrhl)

TRIASSIC

Kabut granite (Trgrkt)

Kabut granite (Trgrkt)

Kabut granite (Trgrkt)

Merah Granite (Trgrmr)

Budo Granite (Trgrbd)

Merah Granite/Budo Granite (Trgrmr/bd)

Singor granite (Trgrsg)

Singor granite (Trgrsg) Chantarat (Trgrch)

Figure 13:

3.1

Hala granite(Trgrhl)

Chantarat Granite (Trgrch)

Schematic lithostratigraphic correlation for the Transect area.

Sedimentary and metamorphic rocks

3.1.1 The Betong Formation (SDbt1 and SDbt2) The rock unit, exposed only on the Thai side, is well distributed as N-S trending, long narrow, low relief terrain along the Hala River in the west-central part of the Transect area. The Betong Formation is in contact with the granite (units G3, G2, and G1) to the east, north, west and south. In some places, it forms the large roof pendant above the granite on the top of mountainous terrains. Bodies of small roof pendant are also exposed near the low-lying terrains in the western part of the Transect area near the Malaysia-Thailand border. Both units 17

can be correlated to the metamorphic rocks of the Silurian-Devonian Betong Formation (SDbt) and Kroh Formation (SDkr) on the Malaysian side in the Pengkalan Hulu-Betong Transect area. The term Betong Formation (SDbt) was proposed by Muenlek et al. (1979) to describe a sequence of fossiliferous sedimentary rocks of Silurian-Devonian age in the YalaBetong area. The formation is named after the Betong District, where good outcrops are well exposed on road-cuts. It is the oldest lithostratigraphic unit exposed in the Transect area (Malaysian-Thai Working Group, 2006). In the Pengkalan Hulu-Betong Transect area, fossil assemblages, i.e. Tentaculites elegans and Tentaculites sp. occur in light pink shale strata and limestone lenses. Conodont assemblage found in chert beds indicates the age of rock sequence is Devonian. However, the discovery of graptolite in light pink shale leads to the possible age of the succession is Silurian-Devonian. Therefore, the succession of the Betong Formation (SDbt) can be dated as Silurian-Devonian age. 3.1.2 Tiang schist (Cts) On the Malaysian side, the term Tiang schist had been introduced by Mohamad Hussein et al. (in manuscript) to describe a sequence of metamorphic rocks cropping out on the east of the Main Range Granite and to the west of the Bentong-Raub Suture Zone in the Belum and Batu Melintang areas. It is named after Sungai Tiang in the central part of the Transect area where good outcrops can be observed. On the Malaysian side, based on remote sensing interpretation, the Tiang schist is named as S4 Unit. S4 Unit This unit is interpreted as quartz-mica schist that could be correlated with the Tiang schist. The S4 unit is distributed in the eastern part of the Transect area from the north at Malaysia-Thailand border (Bt. Luat Lantai) to the south of the Transect area. The remote sensing characteristic of this unit is very high to high topography (mountain landform) with main ridges orientation in NS direction. The main ridges are curve, convex, round and branches irregularly. The branch ridges are angular to the main ridges. It has dendritic drainage pattern with coarse texture. V-shape valley/gully occurs between the ridges. It has dark grey photo tone, dense vegetation and forest cover. Part of the unit shows dome structure like granite intrusion. Based on the field observation, the lithology of the area is quartz-mica schist, amphibolite schist and silimanite gneiss. On the Thai side, the S1 unit referred to the S5 Unit from photo characteristic is interpreted as Schist, Phylite, Shale and sandstone. This unit is distributed as two N-S trending, low-relief elongated terrains on the Thai side and close to the Malaysia-Thailand border. The unit boundary can be correlated to the Cts unit on the Malaysian side. Some parts of this unit are intruded by Triassic granite showing the circular feature. The lithology is composed of quartz-mica schist, quartz-graphite schist, quartz-mica garnet schist, and quartz-

18

mica-chiastolite schist. Amphibolite schist occurs locally. This unit can be correlated to Tiang Schist/Ban Sa formation. Ban Sa formation is correlate to Tiang Schist in Malaysia side. The term Tiang schist was introduced by Mohamad Hussein et al. (in manuscript) to describe a sequence of metamorphic rocks out cropping in the east of the Main Range Granite in the Belum area. It is named after the Sungai Tiang River where good outcrops can be observed. The term Ban Sa formation is proposed during the joint Malaysia-Thailand geological survey project to describe the high-grade metamorphic rocks on the Thai side of the Batu Melintang-Sungai Kolok Transect area (Malaysian-Thai Working Group, 2006). It is named after the Ban Sa village, near the Mae Nam Kolok (Kolok River) where good outcrops are exposed. Distribution The Tiang schist occupies a north-south trending belt whose western margin is in contact with the eastern margin of the Main Range Granite. It extends northeastwardly into the Batu Melintang-Sungai Kolok Transect area, northwardly into Thailand and southwardly into the Temengor area. The rock unit is highly faulted throughout the area; therefore it is difficult to estimate its thickness (Mohamad Hussein et al., in manuscript). In the Belum-Hala Transect area, this unit is distributed as two N-S trending, low-relief elongated terrains on the Thai side at the boundary pillar No. 60, Khlong Kue Sa, close to the Malaysia-Thailand border. The unit boundary can be correlated to the SDts unit on the Malaysian side. Some parts of this unit are intruded by Triassic granite showing the circular feature. Lithology The Tiang schist (Cts) consists of purplish grey to dark grey quartz-mica schist, quartz schist, quartz-mica-graphite schist and quartz-mica-garnet schist with minor hornfels. The quartz-mica schist is strongly schistosed, well foliated, consisting essentially of mediumgrained elongated quartz and mica, commonly muscovite with chlorite (Figures 14 & 15). Hornblende, calcite, diopsite and pyrite occur as accessory minerals. Although biotite is predominant, muscovite is fairly common. Lenses of amphibolite schist comprising quartzactinolite-tremolite schist and quartz-mica-hornblende schist occur at several localities along Sungai Tiang. Rohayu (1994) reported the occurrences of sillimanite gneiss at the higher terrain along the East-West Highway in the Transect area. The presence of quartz-micachiastolite schist at Sungai Palai and Sungai Dadek, and quartz-mica-garnet schist (Figure 15) at upper reaches of Sungai Machang indicates that it might be the result of both contact and regional metamorphisms. Although granite is not exposed in the surrounding area of quartzmica-chiastolite schist and quartz-mica-garnet schist, it is believed that granite is subcropping below the metamorphic rocks. Hornfels and hornfelsic rocks occur in the vicinity of the granite body. Tiang Schist (Cts) on the Malaysian side of the Transect area consists of quartz schist and quartz-mica schist. The quartz-mica schist is typically strongly schistosed, well-foliated, 19

consisting essentially of quartz and mica (most commonly muscovite). Chlorite, calcite and pyrite have also been recorded in the schist. Although muscovite is predominant, biotite is fairly common. Lenses of amphibolite schist comprising of quartz-actinolite-tremolite schist and quartz-hornblende schist occur at several localities along the Sungai Tiang. Rohayu (1994) reported that sillimanite gneiss has been found in the higher terrain along the EastWest Highway in the Belum area, 10 km southwest of the Transect area. The presence of quartz-mica-chiastolite schist indicates that it might be the result of both contact and regional metamorphisms. Although granite is not exposed in the surrounding area of quartz-micachiastolite schist, it is believed that the granite is sub-cropping below the metamorphic rocks. According to the geology of the Batu Melintang-Sungai Kolok Transect area on the Thai side, the Tiang schist/Ban Sa formation along the Mae Nam Kolok at Ban Sa and road-cut succession at Ban Ba La consists mainly of thin- to thick-bedded, light grey, biotite-augen gneiss (40-90%) intercalated with grey banded schistose biotite gneiss (10-60%). Augen biotite gneiss has well-developed gneissocity, 1 cm per band. It has 40-50% phenocrysts in volume. Phenocrysts are composed mainly of K-feldspar, porphyroblastic texture and are 0.51X 2-4 cm in size. Groundmass is medium- to coarse-grained and shows well-developed gneissic texture. Mineral composition consists of sheared quartz (30%), feldspar (40%) and platy biotite (40%). The schistose biotite-gneiss outcrop at Ban Sa has a similar lithology to the augen gneiss having fewer phenocryst than the former but has more mica. Quartzamphibolite schist has similar texture with the Ban Sa outcrop but has more silica and probably calcareous composition. Thinly banded, dark brown biotite, hornblende and actinolite are usually common. The succession is strongly deformed and metamorphosed as a result of the intrusion by the Main Range Granite as well as affected by the tectonic activity in the Betong-Raub Suture Zone along its eastern margin. The rocks trend N-S, with the foliation dip gently to steeply both eastwards and westwards, resulting from intensive folding and faulting. The rock displays well developed N-S and NNE-SSW trending cleavages.

20

Figure 14: Outcrop of the Tiang schist at Km 66.1 of the East-West Highway.

Figure 16:

Figure 15: Close-up view of the Tiang schist.

Exposures of quartz-mica-garnet schist at 5o 45‟ N, 101o 38‟ E, upper reaches of Sungai Machang.

Age and correlation No fossil assemblage is recorded and the thickness of the succession is indeterminable. Previously, this rock unit was interpretated as Silurian-Devonian in age. However, owing to the fact that the Tiang schist is conformably overlain by the Carboniferous-Permian Mangga formation, therefore it is interpreted that possibly Carboniferous age. In addition, Metcalfe (2000) discovered an Upper Devonian to Upper Permian radiolarian in some of collected chert samples along the Bentong-Raub Suture Zone to the south of the Transect area, which‟s also in contact with the eastern margin of the Main Range Granite. The Tiang schist is located at the same geological setting and geographical belt with the other Upper Palaeozoic rocks unit. Furthermore, the origin of the rock may be is same sequence with the Carboniferous Kubang Pasu that expose at the west side of the Transect area but just separated by the Main Range Granite intrusion, therefore it is believed that they are might be of the same age. The different of lithology is due to the degree of metamorphism. Lithologically, the schist interpreted as thick-bedded to massive arenaceous origin indicates very stable and consistent environment during the Carboniferous. Structurally, Tiang schist 21

shows gently dipping which can be observed at Km 66.1 of the East-West Highway (Figure 8), so that it might be younger than Silurian-Devonian that expected before. Hence, the succession of the Tiang schist can be dated as probably Carboniferous age. 3.1.3 Kubang Pasu/Yaha Formation (Cyh) The Kubang Pasu Formation is conformably overlain by the Permian Gerik formation. However, within the Transect area, it is interpreted as fault contact with strike NW-SE. Originally, the term Kubang Pasu Formation was introduced by Jones (1981) for a sequence of thick sandstone and thin shale in the Kedah and Perlis areas in northwest Peninsular Malaysia. The stratigraphic name was taken after the Kubang Pasu District, Kedah where the good outcrops of this rock unit can be observed. Lithologically, the Kubang Pasu Formation in the Transect area is different from that exposed in Kedah and Perlis due to metamorphism. The rocks in this area are locally metamorphosed to metasandstone, hornfels, phyllite and schist. On the Malaysian side, based on remote sensing interpretation, the Carboniferous Kubang Pasu/Yaha Formation can be divided into S1, S2 and S3 units as described below: S1 Unit The unit is interpreted to be schist and metasandstone which can be correlated to the arenaceous facies within the Carboniferous Kubang Pasu/Yaha Formation at Pengkalan HuluBetong Transect area. The S1 unit is distributed in the northwest of the Transect area at Malaysia-Thailand border in Ulu Titi Basah (5,030 m) and Gunung Angus (4,642 m) mountainous terrain. The remote sensing characteristic of this unit is very high topography (mountain landform) and NS orientation. The main ridges are curve and linear, concave, sharp and branches irregularly. The branch ridges are angular to the main ridge. It has dendritic drainage pattern with fine to coarse texture. V-shape valley and gully occurs between the ridges. It has grey to dark grey photo tone, dense vegetation and forest cover. Part of the unit shows bedding plane with N-S strike and dipping gently to the east. Based on the field observation, the lithology of the area are grey to greenish grey quartz-mica schist and yellowish grey massive metaquartzarenite and minor of reddish mudstone and siltstone. S2 Unit The unit is interpreted to be quartz-mica schist, metasandstone and metaconglomerate which can be correlated to the arenaceous facies within the Carboniferous Kubang Pasu/Yaha Formation at Pengkalan Hulu-Betong Transect area. The S2 unit is distributed in the northwest of the Transect area near Malaysia-Thailand border. The remote sensing characteristic of this unit is high topography having the N-S direction. The main ridge is curve, irregular, convex, sharp and has more ridges branches. 22

The branch ridges are perpendicular and angular to the main ridge. It exhibits dendritic and trellis drainage patterns with fine to coarse texture. More V-shape valley/gully occurs between the ridges. It has light grey to grey photo tone covered with dense forest. Based on field observation, the lithology of the area is grey to greenish grey quartz-mica schist, light grey to grey metasandstone grading up to metaconglomerate. This metaconglomerate was interpreted as the upper part of this unit.

S3 Unit This unit is interpreted to be arenaceous rock which can be correlated to the arenaceous facies within the Carboniferous Kubang Pasu/Yaha Formation at Pengkalan Hulu-Betong Transects area. The S3 unit is distributed in the central part of the Transect area. The remote sensing characteristic of this unit is moderate high relief topography having the N-S direction. The main ridge has curve, convex and sharp characteristics with irregular branches pattern. These branches are angular and perpendicular to the main ridge. It exhibits dendritic and trellis drainage pattern with fine texture. More V-shape gully occurs between the ridges. It has light grey photo tone covered with dense forest. Based on the field observation, the lithology of the area is quartz-mica schist. On the Thai side, the Yaha Formation (Cyh) is conformably underlain by the Betong Formation. The term Yaha was introduced by Nakapadungrat et al. (1988) to describe a sequence of thick Carboniferous clastic rocks in the Sadao-Yala area. It is named after Yaha District, where geological information was firstly studied and good outcrops are prevailed. This unit can be correlated with the Kubang Pasu/Yaha Formation.

Distribution In Malaysia, the Kubang Pasu Formation (Ckp) is well exposed in the western part of the Transect area, covering the Sungai Kenarong valley. The rock exposures can be observed along the streams of Sungai Kenarong which located in the remote and forested area. The only access to that area is by boat via Temengor Lake, and then proceeds to continue the traverse by foot. Metasandstone and metaconglomerate occurs in the river mouth of the Sungai Tan Hain in the northern part of the Temengor Lake. The succession also occurs as roof pendant within the Main Range Granite. The Yaha Formation (Cyh) is well distributed in the western part of the Belum-Hala Transect area. In the Transect area, the Yaha Formation can be subdivided into two facies, namely, the argillaceous facies (Cyh1) of the Yaha Formation (Cyh) or the lower part, and the arenaceous facies (Cyh2) of the Yaha Formation (Cyh) or the upper part of the complete sequence.

23

Lithology The whole succession of the Kubang Pasu Formation (Ckp) in the Transect area is metamorphosed. Granite intrusion in the country rocks can be observed along Sungai Terosak and its tributaries where the rocks are metamorphosed to phyllite, schist, hornfels, metasiltstone and metasandstone. In the Betong-Than To area, a complete sequence of the Yaha Formation (Cyh) is characterized by the presence of sandstone, siltstone, shale and ribbon chert with subordinate limestone lenses. The total thickness of this Carboniferous rock from the representative section exceeds 800 m. The succession consists of (in ascending order) thick sequence of pelitic rock comprising hornfels, phyllite and schist intercalated with light grey, thick-bedded to massive, finegrained, well-sorted and graded metasandstone or metaquartzarenite and minor metasiltstones overlain by metaconglomerate, grey, medium-grained grit and poorly sorted, graded and cross bedded metasandstones. The pelitic rocks consist of phyllite, schist, hornfels and a minor variety of thin-bedded, poorly sorted pelitic-psammitic rocks of metamudstone, metasiltstone and metagreywacke. The phyllite and schist consist of very fine- to fine-grained, elongated quartz grains with bands of sericite, chlorite, muscovite, biotite and iron oxide. Hornblende presents as accessory mineral. The phyllite is commonly laminated with the lamination parallel to the original bedding plane and occasionally shows wavy cleavage. Schistosity in the schist is made up of segregation of muscovite and biotite and other flaky and columnar minerals such as hornblende as well as secondary minerals such as sericite and chlorite. Metasiltstone and metagreywacke generally less than a few centimetres thick, occur commonly as interbeds and intercalations within the phyllite or schist sequences. The presence of quartz-mica-chiastolite schist at the right tributary of Sungai Kenarong indicates that it might be the result of both contact and regional metamorphisms. Although granite is not exposed in the surrounding area of quartz-mica-chiastolite schist, it is believed that granite is sub-cropping below the metamorphic rocks. On the Thai side, the S4 Unit referred to some parts of the S3 Unit, is interpreted to be well-bedded sandstone and shale which can be correlated to argillaceous facies (western part of S3) within the Carboniferous Kubang Pasu/Yaha Formation (Ckpag/yh) in the Pengkalan Hulu-Betong Transect area. The unit is distributed in the western part of the Belum-Hala Transect area (the Hun Kut mountainous terrain) close to the Malaysia-Thailand border. It shows the wide patches of roof pendants on granite with distinct N-S bedding traces. In the Transect area, the argillaceous facies of the Yaha Formation (Cyh) is well exposed in the low relief terrain, near the eastern granite pluton in the western part of the area and extends to the northwestern part of the Malaysian side. The argillaceous rocks in the lower part (Cyh1) of the Yaha Formation (Cyh) are affected by local deformation and low-grade metamorphism (or superimposed) in the shear and contact zones. The rocks are metamorphosed to be thin- to medium-banded phyllite, phyllitic

24

schist, mica schist and quartz-schist with minor quartzite and calc-silicate. The thickness of this unit is inconclusive due to strong folding. The psammitic rocks of the Kubang Pasu Formation are made up of thick sequence of thick-bedded to massive metasandstone, predominantly quartzite (metaquartzarenite) and minor pelitic rocks such as metasiltstone. At the Gunung Hulu Titi Basah, in the vicinity of Malaysia-Thailand border, the succession is composed predominantly of light grey- to yellowish grey, fine- to medium-grained metaquartzarenite containing more than 95% quartz grains. The rests are muscovite with minor tourmaline, feldspar and iron oxide. Thin interbeds of metasiltstone occasionally occur within the metasandstone. The Arenaceous facies (Cyh2) of the Yaha Formation (Cyh) are restricted as roof pendants on granite in the mountainous area close to the boundary pillar No. 56 B. The unit is distributed in the western part of the Belum-Hala Transect area (the Hun Kut mountainous terrain) close to the Malaysia-Thailand border. It shows the wide patches of roof pendant on granite with distinct N-S bedding traces. It is characterized by the presence of medium- to thick-bedded sandstone, quartzite and minor argillite with indeterminable thickness. The younger parts of the succession are composed of greywacke and subgreywacke. The grains are poorly sorted and more often grading up from pebbly sandstone or grit to conglomerate. The metaconglomerate exposures are limited within the vicinity of the river mouth of Sungai Tan Hain (05o 44.884‟ N, 101o23.389‟ E), in the northern part of the Temengor Lake area (Figure 17). The metaconglomerates, grey to yellowish grey when weathered, have medium- to thick-bedded (0.5-1.5 m thick) and coarsening upward sequence. Their texture comprises 20% - 30% clasts of subangular to angular, low sphericity and poorly sorted, various sizes from pebble to cobble; 1 to 5 cm in diameter of smoky, pinkish to white vein quartz (95%) (Figure 18), and the rest is light grey sandstones, dark grey siltstone and grey chert (5%) with occasional large mudstone clasts (Figure 19). Orientation of clasts commonly follows the current direction. Matrix of rocks is fine- to medium-grained poorly sorted grey dirty sandstones exhibiting well-developed graded and cross bedding. In places, cross-bedding can be observed on the top part of the sandstone beds that graded to the conglomerate (Figure 20). The rocks cleavage strikes N-S and NNW-SSE, generally dipping both eastward and westward. The total thickness of the Carboniferous rocks from the representative section is more than 800 m.

25

Figure 17: The metaconglomerate exposures are limited within the vicinity of river mouth of Sungai Tan Hain (05o 44.884‟ N, 101o23.389‟ E)

Figure 18: Various size of quartz clasts within the conglomerate.

Figure 19: Dark grey mudstone clasts that is up to 5 cm in diameter.

Figure 20: Cross-bedding observed on the top part of the sandstone beds grading from the conglomerate.

Age and Correlation No fossil assemblage is recorded within the rocks unit in the Transect area. The psammitic rock shows similar characteristics where thick-bedded to massive sandstone or metasandstone indicates very stable and consistent environment during the Carboniferous. It is correlatable with the Kubang Pasu Formation exposed in the Kubang Pasu area. The difference is just due to the degree of metamorphism; however they are expected to be of the same genesis. Furthermore, this rock unit is exposed at the upper reaches of Sungai Kenarong, in the vicinity of Malaysia-Thailand border, just 6 km to the southeast of Ban Tai Tong in Yala Province, Thailand where Carboniferous microfossils were found.

26

Depositional Environment The sandstone is intercalated with the thick to very thick sequence of pelitic rocks, followed by very thick sequence of thick-bedded to massive, well-sorted quartzitic metasandstone with graded bedding and cross lamination. The rocks are interpreted to represent a near shore environment of deposition, probably in either intertidal or upper subtidal zones. The poorly sorted metaconglomerate is interpreted as reworked conglomerate previously deposited in the shelf environment and then redeposited in the deeper environment together with the arenaceous and argillaceous materials.

3.1.4 Mangga formation (CPmg) The term Mangga formation was introduced by Mohamad Hussein et al. (in manuscript) to describe the low- to medium-grade metamorphic sequences of psammitic, pellitic, pyroclastic, hornfels and marble as well as schistose rocks in the eastern part of the Transect area. It is named after the Sungai Mangga where this rock unit was first mapped and good outcrops had been recorded. The formation exposed only on the Malaysian side. The Mangga formation (CPmg), which is strongly deformed and metamorphosed, trends N-S and dips moderately to steeply either westward or eastwardly. On the Thai side, the unit S5 is pointed to some parts of the S5 unit which interpreted from photo characteristics as shale and sandstone. The unit can be correlated with the arenaceous facies of the Carboniferous-Permain Mangga formation/Ka Lu Bi formation (CPmgkl) which comprises metasandstone, metagreywacke, tuffaceous sandstone, quartzite and conglomerate. This unit extends as elongated N-S trending ridge in the eastern part of the Transect area. The S6 unit is referred to some parts of the S5 unit. From the photo characteristics this unit is interpreted as shale and sandstone (S5 Unit). It is correlatable with the CarboniferousPermian Mangga formation/Ka Lu Bi formation (CPmgkl) on the Malaysian side. The Unit S6 is well exposed continuously along the elongated N-S trending ridge in the eastern part of the Transect area. Some parts of this unit are intruded by the Cretaceous To Mo granite (Kgrtm) and exhibit the aureole complex and circular feature. The eastern margin of the Mangga formation is situated within the Bentong-Raub Suture Zone. Structurally, the rocks within the suture zone are highly deformed due to the tectonic activities during the collision of the Sibumasu and Indochina terranes. Distribution The Mangga formation (CPmg) is confined to the Sungai Mangga, located in the southeastern part of the Transect area. It extends eastwardly into the Batu Melintang-Sungai Kolok Transect area where the equivalent Ai Ka Po formation (CPak) and Ka Lu Bi formation (CPkl) can be observed. The thickness of the succession is indeterminable due to its strongly deformed nature.

27

Lithology According to the Malaysian-Thai Working Group (2006), the Mangga formation/Ai Ka Po formation/Ka Lu Bi formation (CPmg/ak and CPmg/kl) in the Batu Melintang-Sungai Kolok Transect area, on the Malaysian side is represented by a low grade metamorphic sequence that can be subdivided into four facies, namely, argillaceous (CPmgag), arenaceous (CPmgar), pyroclastic (CPmgpy), and calcareous (CPmgcl) rocks. The argillaceous unit consists mainly of metamorphosed siliceous shale, slate, phyllite, metasiltstone and hornfels. There are two strata of argilliceous facies representative of the lower and upper parts of this formation. The upper part consists of hornfelsic rocks such as calc-silicate hornfels. The best outcrop of hornfels is located near the junction to Felda Tumbi Rapat. The rocks are light grey in colour, very fine-grained, slightly foliated and recrystallized with both quartz and calcite veinlets. Petrographically, the main minerals are quartz with minor muscovite, biotite, diopsite and iron oxide. The chert is light grey to grey with some impure cherts forming ribbon cherts. Only arenaceous facies is exposed in the Transect area. The arenaceous facies consists of yellowish grey, light grey, thin- to medium-bedded, fine- to medium-grained metasandstone and metagreywacke interbedded with minor metasiltstone. Due to deep weathering, no suitable photograph of the outcrops exposed in the Transect area can be shown in this report. Photographs of the arenaceous facies which is exposed in the Batu Melintang-Sungai Kolok Transect area at Km 173.2 of the East-West Highway, about 2 km to the east of the Transect area are selected as examples shown in Figures 21 and 22.

Figure 21: Exposures of the psammitic unit of the Mangga formation near TM Communication Tower at Km 173.2 of the East-West Highway.

Figure 22:

Close up view of the psammitic unit of the Mangga formation near TM Communication Tower at Km 173.2 of the East-West Highway.

Age and correlation MacDonald (1955) reported on the occurrences of the poorly preserved fossils of Palaeojera sp., brachiopod of Costiferina sp. and gastropod in the Mangga formation at Kampung Belimbing, in the Batu Melintang area indicative of Permian age. 28

During the Malaysia-Thailand Working Group joint field check in March 2010, several chert and siliceous shale samples were collected near the TM telecomunication tower at Km 173.2 of the East-West Highway (N 05o 35.883‟, E 101o 36.002‟), 2 km to the east of the Transect area. Radiolarians extracted from the chert and siliceous shale were poorly preserved. However, the radiolarian can be identified as Follicuculus sp. and others, quite similar with that found in the Gerik Formation at Km 18.6 of the East-West Highway, Upper Perak. These fossils suggest that the age of the rock unit is possibly of Capitanian to Wuchiapingian (Middle to Late Permian). However, based on lithological and stratigraphical correlations, the age of the succession was assigned as Carboniferous-Permian (Malaysian and Thailand Working Groups, 2010).

3.1.5 Gerik formation (Pgk) The term Gerik formation was informally proposed to replace the term Grik tuff introduced by Burton (1970, 1972, 1986) for the pyroclastic rocks consisting mainly of tuffs of rhyolitic to rhyodacitic composition (The Malaysia-Thailand Working Group, 2010). Limestone and calcareous shale lenses occur sporadically. The name of this formation is taken after the Gerik town situated 10 km to the southwest of the Transect‟s area boundary. The occurrence of interbedded tuff, limestone and fossiliferous calcareous shale on a roadcut at Kampung Batu 2, Gerik indicates a Permian age for the formation. The tuffs of the Gerik formation are occasionally metamorphosed (The Malaysia-Thailand Working Group, 2010). In the Transect area, the tuff is underlain by the thick beds of fine-grained tuffaceous sandstone. There are several small lenses of marble in the tuff at the river mouth of Sungai Gadong (05o 36.759‟ N, 101o 18.997‟ E) in northwestern part of the Temengor Lake. It is also well exposed at Bukit Tali Kail, Temengor Lake, just 1 km outside of Transect‟s south boundary. Lithologically, the sandstone resembles the Carboniferous Kubang Pasu Formation‟s sandstone, but structurally, the sandstone lies on top of the tuff beds. Therefore it is interpreted as belonging to the Permian Gerik formation. On the Malaysian side, based on remote sensing interpretation, the Gerik Formation can be divided into six units, named as V1 to V6 as described below: V1 Unit The unit is interpreted to be schistose tuff of the Gerik Formation. The V1 unit is distributed in the south central part of the Transect area which is in contact with the Main Range Granite. The remote sensing characteristic of this unit is moderate high relief topography; parallel ridges and unit orientation are in nearly NS direction. Main ridge has sharp characteristic, curve, convex and branches parallel/irregularly. The ridges branch not too sharp and perpendicular/angular to the main ridge. The unit has trellis and dendritic drainage pattern with moderate texture and many V-shape gullies. It has grey photo tone, dense vegetation and forest/disturbed forest landuse. The rock is of greenish grey to dark grey of quartz-mica schist. 29

V2 Unit The unit is interpreted to be phyllitic tuff of the Gerik Formation. The V2 unit is distributed in the south central part of the Transect area. The remote sensing characteristic of this unit is low relief topography (hilly landform). Main ridges, oriented nearly N-S direction, have not too sharp characteristic, curve, concave and many parallel branches. The branches are perpendicular to the main ridge. The unit has trellis drainage pattern with fine texture and V-shape gully. It has grey photo tone and dense forest. The rock is laminated to thin beds of grey to greenish grey metatuff of rhyolitic composition. V3 Unit The unit is interpreted to be slaty tuff of the Gerik Formation. The V3 unit is distributed in the southwestern part of the Transect area. The remote sensing characteristic of this unit is moderate high relief topography (hilly landform Main ridges, oriented nearly N-S direction, have not too sharp characteristic, curve, concave and many parallel branches. The branches are pendicular to the main ridge. The unit has trellis drainage pattern with moderate texture and V-shape gully. It has grey photo tone and dense forest. The rock is laminated to thin beds of grey to greenish grey metatuff of rhyolitic composition. V4 Unit The unit is interpreted to be tuffaceous sandstone of the Gerik Formation. The V4 unit is distributed in the southwestern part of the Transect area to the west of Temengor Lake. This rock unit forms the Gunung Pilong (2344 m) and Gunung Tenok (1970 m). The remote sensing characteristic of this unit is high to moderately high relief topography with many main ridges in various, especially in the N-S direction, concave, not too sharp, and curved. The branch ridges are angular to the main ridge. The unit has dendritic and trellis drainage pattern with fine to moderate texture and V-shape gully between branch ridges. It exhibits grey photo tone of dense vegetation. Part of the unit shows circular features like volcanic cone. The rock is high grey to high yellowish grey of thin to thick beds of fined grained tuffaceous sandstone. V5 Unit The unit is interpreted to be metatuf of Gerik Formation. The V1 unit is distributed in the west of the Transect area near Malaysia-Thailand border in Gunung Guak Rimau (3713) and Gunung Daungsang (3598) mountainous terrain. The remote sensing characteristic of this unit is high relief topography (mountain landform). Main ridge and unit orientation are in NS direction. Main ridge has sharp characteristic, curve, convex and branches irregularly. The ridges branch angular to the main ridge. The unit has dendritic drainage pattern with coarse/ moderate texture and V-shape gully. It has light grey photo tone, dense vegetation and forest landuse. Part of the unit shows circular features like volcanic cone. Based on the field observation, the lithology of the area is metatuff.

30

V6 Unit The unit is interpreted to be tuffaceous shale and minor chert of the Gerik Formation. The V6 unit is distributed in the southwestern part of the Transect area near the MalaysiaThailand border. The remote sensing characteristic of this unit is low relief topography (narrow hilly landform). It has a N-S main ridge with sharp characteristic, curve, concave. The branches are perpendicular to the main ridge. The unit has trellis drainage pattern with fine/moderate texture and V-shape gully between the branches. It has light grey photo tone and dense vegetation. Based on field observation, the lithology of the area is tuffaceous shale and minor chert. Distribution The Gerik formation is widely exposed in the western part of the Transect area on the Malaysian side but not exposed on the Thai side. It is fairly well exposed in the vicinity of the Gerik town and Lawin area. This rock unit also crops out in the Temengor Dam site‟s area. In the Transect area, the rock exposures can be observed along the East-West Highway especially around the Banding Island area. The Gerik formation is also exposed in the Kerunai area to the southwest of the Transect area. The eastern margin trends northward from Temengor Dam area passing the East-West Highway and then Sungai Chachor to the Main Range Granite mass at river mouth of Sungai Kejar in the central part of the Transect area. Some good metasandstone outcrops can be observed at the river mouth of Sungai Ta Eng. Lithology The Gerik formation consists of pyroclastic, calcareous, arenaceous and argillaceous facieses. The pyroclastic facies consists mainly of tuffs of rhyolitic to rhyodacitic composition. Interbeds of tuffs, limestone and calcareous shale also occur. These tuffaceous rocks also contain variable amounts of clastic sediments of sandstone, limestone and lenses of calcareous shale. In places, foliation can be seen in the groundmass of the tuffs as a result of regional metamorphism. The most altered rocks show clearer schistose texture (Figures 23 & 24). Burton (1986) reported that no lava flows were recognised when he studied the Gerk tuff. However a weak flow structure shown by the alignment of prismatic K-feldspar phenocrysts was observed at a road-cut near the Kuala Rui Police station, to the west of Gerik township in the Pengkalan Hulu-Betong Transect area. The flow direction is towards 330o (The Malaysia-Thailand Working Group, 2010). The arenaceous facies comprises of tuffaceous sandstone and sandstone. The rock is fine-grained and light grey to grey in colour. The tuffaceous sandstone can be observed along the East-West Highway (Figures 25 & 26). This N-S trending formation which dips steeply eastwards and westwards consists of greenish grey to light grey, thick-bedded to massive, fine- to medium-grained tuffaceous sandstones. The rocks are generally metamorphosed to metasandstones. The good outcrops of fine-grained grey sandstone can be observed at river mouth of Sungai Ta Eng (Figure 27). Cross bedding structure can be observed in parts (Figure 28). 31

Figure 23: Deformed metatuff of the Gerik Formation expose at river mouth of Sungai Kenarong.

Figure 24: Deformed metatuff of the Gerik Formation expose at river mouth of Sungai Kenarong.

The N-S trending ridge from the river mouth of Sungai Semilian at northern part of the Temengor Lake to Sungai Banun is represented by deformed sedimentary rocks of the Gerik formation. Quartz-mica schist occupies an N-S trending belt whose eastern margin is in contact with the western margin of the Main Range Granite. The rock is grey to dark grey and greenish grey in colour which consists of elongated quartz, biotite and muscovite. Some biotite altered to chlorite due to weathering process. In the Transect area, the unmappable calcareous facies of the Gerik formation is well exposed in the Temengor Lake as small lenses between arenaceous facies and pyroclastic facies. One of the good outcrops can be observed at the river mouth of Sungai Gadong i.e at 5o 36.759‟ N, 101o 18.977‟ E (Figures 29 and 30). Generally, limestone in the calcareous facies is metamorphosed to light grey to grey marble. The argillaceous facies of Gerik formation comprises of tuffaceous shale, shale, carbonaceous shale, siliceous shale and ribbon chert. The N-S trending ridge from the upper reach of Sungai Chinchong at westhern part of the Transect area to river mouth of Sungai Kedah and road cut of East-West Highway. Radiolarian bearing pelagic sediments comprises pelagic chert and siliceous shale occurred at several localities along the East-West Highway. One of the good outcrop can be observed at Km 18.6 East-West Highway (5o 31.655‟ N, 101o 14.790‟ E) which comprises subvertical to vertical strata of well-bedded light grey to grey chert and silliceous shale interbedded with thin beds of shale (Figure 31). At this locality the bedding thickness ranges from 5 cm to 10 cm. The shale beds become prominent and thicker towards the east. Another outcrop is at a locality along the old stretch of the highway (5o 31.633‟ N, 101o 17.633‟ E) where the rock sequence is made up of thinlybedded siliceous shale interbedded with thin beds of shale with bedding thickness of 2 cm to 10 cm; and strike and dip, 140o/30o (Figure 32).

32

Figure 25: Tuffaceous sandstone expose at Km 34 of the East-West Highway.

Figure 26: Close-up of the tuffaceous sandstone expose at Km 34 of the East-West Highway.

Figure 27: Bedded metasandstone at Sungai Ta Eng.

Figure 28: Cross-bedding in the metasandstone bed.

Figure 29: Calcareous facies expose at the river mouth of Sungai Gadong.

Figure 30: Calcareous facies expose at river mouth of Sungai Gadong.

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Figure 31:

Subvertical to vertical strata of wellbedded light grey to grey radiolarian bearing chert and silliceous shale interbedded with thin beds of shale at Km 18.6 East-West Highway (5o 31.655‟ N, 101o 14.790‟ E).

Figure 32: Thinly-bedded radiolarian bearing siliceous shale interbedded with thin beds of shale located at the old stretch of the East-West Highway (5o 31.633‟ N, 101o 17.633‟ E).

Age and Correlation Jones (1970) suggested that the age of Grik tuff (now Gerik formation) might be Late Ordovician. Burton (1986) interpreted the age of the Grik tuff as Middle Ordovician. However, Middle Ordovician to Early Silurian age was thought to be more possibility for this pyroclastic rock. The presence of Anisopyge sp. and Phillipsia sp. (trilobite) in the calcareous shale interbeded with tuff and dark grey impure limestone at Batu 2, Gerik in the Pengkalan Hulu-Betong Transect area strongly indicates Middle Permian age of the clastic sediments (The Malaysia-Thailand Working Group, 2010). During the joint field check of the Malaysia-Thailand Working Group along the EastWest Highway, Northeastern Perak in March 2010, several radiolarian bearing chert and siliceous shale samples had been collected from two localities along the highway. The first locality was at Km 18.6 East-West Highway (5o 31.655‟ N, 101o 14.790‟ E); and the second locality was at a locality along the old stretch of the highway (5o 31.633‟ N, 101o 17.633‟ E). The radiolarians yield from the samples had been examined by Dr. Duongrutai Saesaengseerung of DMR, Thailand. Based on diagnostic features observed under the microscope, the radiolarian specimens discovered from both localities were identified as Follicucullus sp., Gustefana sp., Latentifistula sp., Triplanospongos sp. and Albaillella sp. Some specimens resemble Follicucullus scholasticus and Albaillella levis which are important fauna. The age of these fauna are estimated as Capitanian to Changhsingian of Middle to Late Permian.

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Depositional Environment Based on the well-bedded characteristic of the tuff, together with the presence of epiclastic materials as well as the fact that the tuff is interbedded with argillaceous, siliceous and calcareous materials at some places, this formation is interpreted as pyroclastic origin. The volcanism might occur subaerially but the deposition of the erupted materials was in marine environment (Jones, 1970). Sia (1989) reported that the occurrence of fossil algae within the calcareous rocks in the tuff might indicate that the deposition was probably occurred in the shallow marine environment. The presence of sandstone with cross bedding, grit and conglomerate indicate that this sequent was deposited as the submarine fan. The fine-grained pelagic sediments comprised of chert and siliceous shale was deposited in the deeper part i.e. at the outer (distal) submarine fan.

3.1.6 Surficial Deposits Recent surficial deposits comprise unconsolidated gravel, sand, silt and clay of fluviatile and colluvial origin deposited in the non-marine environment overlying the major river valleys and low lying areas. On the Malaysian side, based on remote sensing interpretation, the surficial deposit is named as A1 Unit and described below: A1 Unit The unit is interpreted to be alluvium. The A1 unit is distributed in the east part of the Transect area from Malaysia-Thailand border in the north and along Kalai and Pergau river to the southwest. The remote sensing characteristic of this unit is low flat topography with principal stream in U shape valley. The principal stream branches irregularly. It has light grey poto tone, agriculture vegetation and settlement landuse. The unit occur along Kalai and Pergau Kalai River contains gravel, sand and silt, underlying the floodplain even the limestone from karst topography in Kg. Batu area.

3.2

Igneous Rocks

3.2.1 Introduction The igneous rock in study area consists predominantly of granitic rock. The Indosinian Orogeny is presumed to have been evolved by the subduction of a continental crustal plate (the western part) and an oceanic crustal plate (the eastern part) which is accompanied by the granite emplacements (Metcalfe, 2000). Geologically, the granitic rocks in Peninsular Malaysia are distributed as linear masses parallel to the Bentong-Raub Suture Zone. Malayan orogeny is presumed by the subduction of a continental crustal plate (the western part) and an oceanic crustal plate (the eastern part) which is accompanied by the granite emplacements.

35

In Malaysia, the granites can be divided into three belts based on lithology and petrochemistry of the granite, namely, the Main Range Belt, the Central Belt and the Eastern Belt. The Main Range granite which consists of S-type, ilmenite series granitoids, intruded into the Paleozoic host rocks during the Permo-Triassic period. The Central Belt granite consists mainly of S-type, ilmenite series granitoids of Triassic age with minor intrusion of Cretaceous I-type, magnetite series granitoids. The Eastern Belt granite consists mainly of Itype, magnetite series granitoids and intruded into Palaeozoic host rocks during the PermoTriassic period. The country rocks of the Main Range Province are separated from those of the Eastern Province by a structure designated the Raub-Bentong line (Hutchison, 1977). Later, Cobbing et al. (1986) divided the granites into two provinces Main Range granite and Eastern granite comprises of the Central belt plutons, the Eastern belt plutons and the Cretaceous plutons. The Main Range granite has been regarded to be constituted exclusively of S-type granites of mainly Triassic age (Bignell and Snelling, 1977 and Liew and Page, 1985; Hutchison, 1977; Cobbing et al., 1986; Hutchison, 1996). In contrast, the Eastern province granite is dominated by I-type with subordinate compositional overlap S-type granites of Permo-Triassic age (Bignell &Snelling, 1977; Hutchison, 1977). Small I-type plutons of Cretaceous age are present in the central part of the Peninsular Malaysia (Bignell & Snelling, 1977). Muenlek et al. (1982) recorded three granite phases which were classified as gneissic granite, coarse-grained porphyritic biotite granite and tourmaline-muscovite granite in published a regional geological map of Narathiwat sheet on scale 1:250,000. Finally, Cobbing et al. (1992) completed the Southeast Asian granite project including geological map of individual granite plutons, petrography, geochemistry classification and Rb/Sr age determination, and classified the granite in Southeast Asia into three granite provinces. The eastern granite province is composed mainly of Triassic I-type, magnetite series granitoids with minor compositional overlapping with S-type granitoids. The minor intrusion of isolated Cretaceous I-type, magnetite series is also present in this province. The western granite province consists of a mixture of S-type and I-type granites of Cretaceous age. The Main Range granite province and Northern Thai migmatite province composed mainly of Triassic S-type, ilmenite series granitoids. However, minor intrusions of isolated Cretaceous I-type, magnetite series granite plutons can be found in the northern Thai magmatite granite province. In term of age, the Main Range Batholith had been radiometrically dated at 198-220 Ma (Late Triassic to Early Jurassic) ages (Hutchison, 2007). The summary of the geological setting of the granites in Peninsular Malaysia is shown in Figure 33.

36

O

l

O

100 00

l

O

102 00

l

104 00

SCALE

T HA ILAN D

Km 50

0

50 Km

O

06 00 l

O

So

06 00 l

ut h C

66

hi

67

na Se

GON BET

ra

a

St s

E LIN UB RA

it of M al

O

O

04 00 l

ac

04 00 l

ca

LEGEND Western province granite Eastern province granite Cretaceous granite

O

02 00 l

66. 67. 68. 69. 70.

68 69 O

02 00 l

Noring granite Kenerong granite Batang Melaka granite Gunung Ledang granite Pulai granite

70

SINGAPORE O

l

100 00 East of Greewich

O

l

102 00

O

l

104 00

Figure 33: Geological setting of the granites in Peninsular Malaysia (modified after, Bignell & Snelling, 1977; Hutchison, 1977; Cobbing et al., 1986; Cobbing et al., 1992).

On the Malaysian side, the granitic rocks cover approximately 903 square km (42%) of the Transect area. The description of the granitic rocks in this report is mainly based on the works of Mohamad Hussein et al., (in manuscript). During the present work in January 2010, an attempt had been made to describe the selected outcrops and the surrounding geology in the Transect area. Granitic rocks that are part of the Main Range Granite exposed in the central part of the Transect area. The Main Range Granite comprises the Kabut granite (Trgrkb), the Merah granite (Trgrmr) and Singor granite (Trgrsg). In this report, the granite in the

37

study area is classified into different salient sub-zones based on field geological setting, structural and petrography supported by petrochemistry and petrogenesis analysis. The simplified geological sequence of igneous rocks in the Transect area is shown in Table 3. The distribution of granites in the Transect area is shown in Figure 34. Correlation of the granites in the Transect area is summarised in Table 4. Table 3:

Simplified geological sequence of igneous rocks on the Malaysian side of the Transect area.

Granite body

Description

Singor Granite

Leucocratic, fine- to medium-grained biotit-muscivittourmaline granite.

Merah Granite

Grey, fine- to medium-grained foliated bioite granite

Kabut Granite

Grey, fine- to medium-grained porphyrytic biotite granite.

Table 4: Correlation of igneous rocks on the Malaysian side of the Transect area

Malaysian side

Thai side

Malaysian/Thai side

Singor Granite (Trgrsg)

Hala granite(Trgrhl)

Singor Granite/Hala granite (Trgrsghl)

Merah Granite (Trgrmr)

Budo Granite (Trgrbd)

Merah/Budo Granite (Trgrmr/bd)

Kabut Granite (Trgrkt)

La Sa granite (Trgrls)

Kabut Granite/La Sa granite (Trgrkt)

Chantarat Granite (Trgrch)

Chantarat Granite (Trgrch)

TRIASSIC

The N-S and NE-SW trending quartz dykes and some small igneous stocks or dykes such as microgranite, aplite, pegmatite and lamprophyre usually intruded into the main granite body and also into the country rocks, especially the Carboniferous-Permian metasediments at the central and eastern parts of the Transect area. Contact metamorphism and the associated late stage mineralization may be observed in the country rocks. The Main Range Granite batholith is the main component of the Main Range Province of Peninsular Malaysia (Cobbing et al., 1986). It is the most widely spread granite mass, stretches from Melaka in the south to the Thailand frontier in the north. It forms the mountainous country generally regarded as the backbone of Peninsular Malaysia and emplaced mainly into the Silurian-Devonian and Carboniferous-Permian successions. This granite is considered as the S-type granite (Bignell and Snelling, 1977; Liew and 38

Page, 1985). It composed mainly of ilmenite series with S-type affinity granitoids and is typically related to cassiterite mineralisation. Late stage leucocratic granites are common including aplite dykes, pegmatite dykes, and quartz-feldspar veins. In the Transect area, the Main range granite can be classified into three textural types: medium to coarse-grained porphyritic biotite granite, named as Kabut Granite, fine to medium-grained foliated biotite granite, named as Merah granite and late phase fine to medium-grained leucocratic biotite-muscovite granite, named as Singor Granite. On its western margin, the Main Range Granite intruded the Upper Palaeozoic rocks represented by the Carboniferous Kubang Pasu Formation (Ckp) and the Permian Gerik formation (Pgk). On its eastern margin, the granite intruded the Carboniferous Tiang schist (Cts). On the Thai side, the study of granite geology in the Transect area was very limited due to security reasons. However, there was an effort by the local DMR workers who were assigned to carry out a geological mapping program in the southern part of the country.

39

Figure 34:

Distribution of granitic rocks exposed in the Transect area

40

3.2.2 Chantharat Granite (Trgrch) Distribution The Chantharat Granite (Trgrch) is only exposed on the Thai side. It can be traced along the western flank of the Belum-Hala Transect area. In the Pengkalan Hulu-Betong Transect area, this unit covers approximately 20% of the Transect area that can be observed on the road-cuts along the local road from Ban Chantharat to Ban Ai Yoe Quin, and Ban Chantharat to Ban Chulaporn 10. Petrography The vast majority of the Chantharat Granite (Trgrch) is characterized by its medium- to coarse-grained, sparsely megacrystic to good megacrystic, unfoliated to weakly foliated biotite granite. K-feldspar can be seen as large megacrysts of light grey to chalky white colour with elongate to tabular and euhedral to subhedral habits. Plagioclase presents in groundmass as chalky white colour, euhedral to subhedral crystals with tabular habit. Quartz can be observed as anhedral to subhedral crystals, single and clusters. Cognate and accidental xenoliths are also present in these rock. Dykes and veins are locally found along the intrusive margins.

3.2.3 Kabut Granite/La Sa granite (Trgrkt/ls) On the Malaysian side, the Kabut Granite (Trgrkt) is named after Bukit Kabut (Mohamad Hussein et al., in manuscript), which is located at the southern part of topographic map sheet no. 20 (Belum). On the Thai side, the La Sa granite (Trgrls) is named after Khao La Sa which is located in the central part of topographic map sheet no. 52201 Khao Han Kut Quadrangle. Distribution The Kabut Granite/La Sa granite (Trgrkt/ls) is distributed on the northwestern and southeastern part of the Transect area. In the northwestern part, the granite is in contact with the Merah/Budo Granite (Trgrmr/bd), Chantarat Granite (Trgrch), Kubang Pasu/Yaha Formation (Ckp/yh) and Betong Formation (SDbt). Whilst in the southeastern part, it is in contact with the Merah/Budo Granite (Trgrmr/bd) and Tiang schist (Cts). Petrography The granite is grey in colour, medium- to coarse-grained and contains K-feldspar megacrysts of up to 15-30% of the rock composition (Figures 35 & 36). The K-feldspar megacrysts is grey in coloured, euhedral in shapes, particularly of prismatic, stubby and an equant in shape. Their size mostly ranges from 1 cm up to 3 cm, but in several localities they can reach up to 5 cm long. In places, the granite exhibits foliated texture formed by the arrangement of K-feldspar megacrysts especially in the area closed to the minor late-phase magma such as dyke or veins of quartz or lamprophyre. The equigranular variety exposed in the contact zone with the Merah granite (Trgrmr) body.

41

Microscopically, the rock is granite in composition. It exhibits holocrystalline texture and its grains are hypidiomorphic granular in shape. The major mineral constituents consist of quartz (25-45%), K-feldspar (25-45%), plagioclase (35-50%) and biotite (5% to 15%). Apatite, zircon, sphene, allanite and opaque minerals present as accessory minerals.

Figure 35:

Photographs of the Kabut Granit/La Sa granite (Trgrkb/ls) in Malaysia at Km 56.6 of the East-West Highway.

Figure 36: Photographs of the Kabut Granit/La Sa granite (Trgrkb/ls) in Sungai Singor area on the Malaysian side.

3.2.4 Merah Granite/Bu Do granite (Trgrmr/bd) The Merah Granite (Trgrmr) is named after Gunung Hulu Merah, Upper Perak, Malaysia whereas the Bu Do granite (Trgrbd) is named after Khao Bu Do located at Narathiwat Province, Thailand.

Distribution On the Malaysian side, the Merah Granite/Bu Do granite (Trgrmr/bd) is widely distributed in the central part of the Transect area as a north-south trending mountainous belt. The Merah Granite/Bu Do granite (Trgrmr/bd) was intruded into the Kabut granite (Trgrkb) in the northern part of the Transect area indicating that the Merah Granite/Bu Do granite (Trgrmr/bd) is younger than the Kabut Granite/La Sa granite (Trgrkb/ls). The contact of this granite can be observed near Kg Belum Lama at the upper reaches of the Sg Perak. Photographs of the Merah Granite/Bu Do granite (Trgrmr/bd) on the Malaysian side are shown in Figures 37 & 38. On the Thai side, based on data from the Batu Melintang Sungai Kolok Transect area, granite outcrops are widely exposed along the Ai So stream and the adjacent area. It forms a N-S trending batholith from the Malaysia-Thailand border to Sisakhon District (Bu Do mountain range), in the middle part of Sisakhon Quadrangle, northeast of the Transect area. The Bu Do granite exposed northern part of the Transect area. The southern part of this unit covers high terrain in the north of the Sungai Perak in Malaysia. 42

Petrography The granite is characterised by grey, fine- to medium-grained showing a distinct preferred orientation of biotite. It is moderate to strongly foliated striking from NNW to NNE and dipping almost 60 to 80 degrees from the ENE to ESE. In places, the K-feldspar phenocrysts are also observed as minor constituents.

Figure 37:

Photographs of the Merah Granite/Bu Do granite (Trgrmr/bd) in Malaysia at Sungai Kejar area. The foliation is formed by a distinct preferred orientation of biotite.

Figure 38:

Photographs of the Merah Granite/Bu Do granite (Trgrmr/bd) in Malaysia at Km 56.6 of the East-West Highway. Cognag xenoliths made up of mafic minerals enrichment particularly biotite can be seen at the EastWest Highway outcrop.

Microscopically, the rock shows holocrystalline texture and the grains are hypidiomorphic granular. This rock consists of quartz (30-35%), K-feldspar (20-30%) and oligoclase (20-30%). The mafic mineral is made up of biotite (5-10%). The accessory minerals are sphene, apatite, zircon, and epidote. Flakes of biotite are mostly oriented, kinked, deformed and interspaced between other minerals. According to The Malaysian and Thai Working Groups (2006), on the Thai side, the Bu Do granite (Trgrbd) forms an elongated north–south trending mountain range, starting from Pattani Province in the east coast, extending southward to Yala and Narathiwat Provinces north of the Malaysia–Thailand border. It is composed mainly of ilmenite series with S-type affinity granitoids and is typically related to cassiterite mineralization. The major rock forming minerals are quartz, K-feldspar, oligoclase and biotite, whereas subordinate muscovite and tourmaline are locally present as accessory minerals. Late stage leucocratic granites are abundant including aplite, pegmatite dykes, and quartz-feldspar veins. It is 43

noteworthy that the major granitic rocks in the Bu Do granite batholith are generally nonfoliated to slightly foliated. However, these rocks have been locally foliated along the margin and are called the marginal facies.

Age Bignell (1972) has done geochronological study for the Malaysian granites using both K/Ar and Rb/Sr methods. He concluded that the Main Range Granite is 200 – 230 Ma in age and the granite emplacement took place during the Triassic. Later on, Cobbing et al. (1992) reported the Rb/Sr isochron age of 207 Ma for Songkhla granitoid and 221 Ma for Satun granitoid. According to the field observation mentioned earlier by Cobbing et al. (1992), the Bu Do granite batholith (in Thailand) is geographically located within the Main Range granite province (in Thailand), which is represented by the Songkhla pluton. Therefore, the age of the intrusion of the Bu Do granite is also Triassic. The Merah/Bu Do granite (Trgrmr/bd) is, therefore, assigned by the Malaysia-Thailand Working Group to be of Triassic S-Type granite. 3.2.5 Singor Granite/Hala granite (Trgrsg/hl) The Singor granite (Trgrsg) is named after Sungai Singor a tributary of Sungai Perak that is located in the south of the East-West Highway in the Temengor area (Mohamad Hussein et al., in manuscript). Hala granite (Trgrhl) is named after Hala Forest Reserve located in Yala and Narathiwat Provinces, Thailand. Distribution The Singor Granite (Trgrsg) occurs as small isolated bodies within the Merah/Bu Do Granite (Trgrmr/bd) and Kabut Granite/La Sa granite (Trgrkb/ls) in the Sungai Perak area. This granite also intruded into the country rocks, especially the Carboniferous Tiang schist (Cts), within the fault zone and present as minor stocks in a few localities. However, this rock has been locally foliated along its margin and is called the marginal facies. Figure 39 & 40 show photographs of the Singor Granite (Trgrsg) on the Malaysian side.

44

Figure 39: Photographs of the Singor Granite/Hala granite (Trgrsg/hl) in Malaysia at the Sungai Singor area. Photograph shows the contact of the Singor Granite/Hala granite (Trgrsg/hl) with the Kabut Granite/La Sa granite (Trgrkb/ls) (dark in colour).

Figure 40:

Photographs of the highly fractured Singor Granite/Hala granite (Trgrsg/hl) in Malaysia at the Sungai Kejar area.

Petrography Singor Granite/Hala granite (Trgrsg/hl) is light grey or leucocratic, fine- to mediumgrained, equigranular to inequigranular biotite-muscovite granite. Tourmaline is also present in significant amount. Microscopically, it exhibits holocrystalline and alotriomorphic equigranular and hypidiomorphic granular textures. The major mineral constituents consist of quartz (50%), K-feldspar (30%) and plagioclase (15%). The mafic minerals (5% to 15%) are made up of biotite and muscovite with occasional tourmaline (Figure 41). Apatite, zircon and opaque minerals are present as accessory minerals. Tourmaline and muscovite are characterised as detritus and deuteric minerals respectively. These minerals indicate that the rock was formed at the late phase of the magmatic differentiation. This granite also shows the characteristics and relics of the Merah /Bu Do Granite (Trgrmr/bd) and Kabut Granite/La Sa granite (Trgrkb/ls) in parts, which suggests that the Singor Granite/Hala granite (Trgrsg/hl) pluton was formed at the late stage of the granitoid intrusion.

45

Figure 41: Microphotograph of Singor Granite/Hala granite (Trgrsg/hl) shows euhedral to subhedral tourmaline at Sungai Palai.

3.2.6 Age and correlation Bignell (1972) has conducted a geochronological study for the Malaysian granites using both K/Ar and Rb/Sr methods. He concluded that the Main Range Granite is 200-230 Ma in age and granite emplacement took place during the Triassic. Bignell and Snelling (1977) also concluded that the age of the granite is Triassic. Liew and Page (1985), reported that the age of the granite is 198 to 220 Ma (Late Triassic to Early Jurassic) based on U-Pb zircon dating method.

46

4.0

STRUCTURAL GEOLOGY

4.1

Introduction

Based on remote sensing study, linear features are well developed in the all rock units terrains. Bedding trends are well expressed in the sedimentary, volcanic and metamorphic rock units but dips magnitudes are difficult to elucidate. The regional structural trend is roughly N-S as expressed by the alignment of strike ridges and lithological boundaries. Fracture lineaments are prominent and abundant in this area, particularly in the granitoid, volcanic and metamorphic terrains with at least three main sets trending NE-SW, NNW-SSE and E-W (see Figure 7). The major lineaments trending NE-SW are Selantan Fault, Laho Fault, Cheng Fault, Jakal Fault and Belang Fault, whilst the NNW-SSW trends are Ruok Fault and Makar Fault. The E-W trend is represented by Belum Fault, Tiang Fault, Mendelum Fault and Banun Fault. Some circular features are also apparent in the volcanic unit (crater?) and the granitoid unit (minor intrusion). Pre-orogeny sedimentary successions in the Transect area are generally folded into a series of synclines and anticlines. Folding is characterised by tight, asymmetric and open folds, resulting in the repeated and overturn sequences in the older sedimentary rocks. The NE-SW and N-S trending fold axes are sub-parallel to the long axis of the Malay Peninsula. Historically, Malay Peninsula was formed as a result of the marine sedimentation took place continuously throughout the Silurian-Devonian and Carboniferous-Permian periods, then collision between Sinoburmalaya (Sibumasu/Shan Thai) block in the west and EastmalIndosinia block in the east. The collision zone is represented by the Bentong-Raub Suture which can be traced northward into Thailand and southward into the Banka and Biliton Islands. This collision accompanied by the major tectonic event during Middle to Late Triassic has resulted in rock deformation in the Malay-Thai Peninsula especially along and adjacent to the suture zone. Tectonic activities have affected most of the rock units that form various structures such as folding, faulting, jointing and fracturing. It was followed by major igneous intrusion that forms the Main Range granite to the west of the suture zone. The large breaks of sedimentation can be observed due to the uplift of granitic rocks during the Triassic. The continent-continent collision has caused uplifting and faulting along an N-S direction. Uplifting resulted in the formation of N-S trending of the granite mountainous range in the area. Pre-collisional rocks are fractured along the N-S direction as can be observed in the Tiang schist and Mangga formation as well as in the Gerik Formation. However, some major structures especially in the eastern part of the Transect area may have been affected by the younger Cretaceous Noring granite intrusion and multi direction fractures. Tectonically, the Transect area was formed by the collision of two tectonic terranes: the Sibumasu terrane in the west and Indochina terrane in the east which is separated by the N-S trending former subduction zone known recently as the Bentong-Raub Suture Zone. 47

On the Malaysian side, the structural geology of the Transect area generally corresponds to the regional tectonic pattern of the Peninsular Malaysia. However, detailed mapping has revealed that, in some places, the local structures appear to have a slight variance as compared to the regional pattern. It is believed that the active period of tectonic activity during the Triassic. For example the Bentong-Raub Suture Zone was responsible for the formation of major structures in the Transect area. The igneous intrusion and uplifting also occurred during this time. In Thailand, Khositanont (2004) have concluded that the Ka Toh-Buyong fault zone in the Batu Melintang-Sungai Kolok Transect area is the northward extension of the BentongRaub Suture Zone and represents a continent-continent suture on the Thai-Malay Peninsula. The younger NE-SW and NW-SE fractures, which can be prominently observed in both igneous and sedimentary host rocks, may have been resulted from the movement of the major fault along the Malaysia–Thailand border.

4.2

Bedding

Bedding trends that roughly parallel with the foliation still can be observed in the metasediments. Graded bedding and cross bedding can be observed in some of the arenite beds especially in the Kubang Pasu/Yaha Formation. No other sedimentary structures observed. This might be due to the regional metamorphism that accompanying the folding and faulting acted on the rock and destroyed all the sedimentary structures.

4.3

Foliation

The foliation is formed by subparallel to parallel alignment of the light and dark coloured minerals in the rocks. This can be observed in the metasediments. In the Transect area, foliation also can be observed in the granitic rock especially in the Merah/Bu Do Granite (Trgrmr/bd). Foliation in the granite is believed to be formed as a result of crystalplastic process during the crystallization of the rock. 4.4

Folding

Pre-orogeny sedimentary successions in the Transect area are generally folded into a series of synclines and anticlines that can be interpreted from the bedding‟s strike analysis. Folding is characterised by tight, asymmetric and open folds, which cause the repeated and overturn sequence in the older sedimentary rock. Generally folds are trending in the NE-SW to N-S direction and the fold axes are sub-parallel to the long axis of the Malay Peninsula. The synclinal and anticlinal axes can be recognised in the western side of the Transect area. Other minor folds are present with small magnitude. Most of the bedding planes dip towards the east with various dip angles.

48

4.5

Faulting

Faulting is widespread throughout the Transect area. Faults generally vary in width, characterised by fractured, sheared or mylonitised rocks with the presence of slickensided surfaces. However, in most cases it is very hard to observe traces of fault zones in the field due to the thick soil cover and deep tropical weathering. Aerial photographs interpretation and field evidences indicate that there are two prominent fault directions in the Transect area i.e. NW and NE trending sets (see Figure 7). There are several faults, which are mainly of strike-slip and normal faults, trending, NW-SE, NNW-SSE and NE-SW. Of these, the NWSE trending faults are the main fault of the Transect area. Among the major faults are Ruok Fault (NNW-SSE), Jakal Fault (NNE-SSW), Laho Fault (NE-SW), Belang Fault (NE-SW), Belum Fault, Tiang Fault, Mendelum Fault and Banun Fault (E-W). Syed Sheikh Almashoor and Tjia (1987) reported the prominent fault in the Transect area is named as the Ruok Fault. Based on Landsat image interpretation, the fault zone that trends in the NNW-SSE direction covers a 4 km wide zone of tonal and topographic lineaments that extend from Mae Nam Pattani in the north, in 165o direction, trends parallel with Sungai Kenerong and than probably ends at Sungai Sara in the south (Figures 42 & 43). The fault crosses the East-West Highway at Km 184 towards Kota Baharu (208 km towards Ipoh, 05o 34.521‟ N, 101o 24.289‟ E), where it can be observed within the quartz-mica schist and phyllitic rocks with northerly strike and steeply dip foliation (Figure 44). Numerous sigmoidal quartzs (Figure 45) within the schist and phyllite indicates left-lateral strike-slip movement (Syed Sheikh Almashoor and Tjia, 1987). In some places, faults formed the lithological contact between the granites and the metasedimentary rocks. These can be observed along parts of the Laho Fault, Sungai Dadek and Jakal Fault in the Transect area. Major faults might have been formed during the Late Triassic because they cut the earlier Triassic igneous rocks.

4.6

Jointing

Joints can be observed in all rock types. Most of the joints are steeply dipping. There are also minor subhorizontal joints. Joints system analysis on the granite around Sungai Singor revealed the main deformation (P) in the 126o - 306o direction. Whereas the joints in the granite body in the central part of the Transect area lies in the 015o-195o direction, the joints in the metasedimentary rocks around the Sungai Tiang area is 023o - 203o.

49

No rth

Zone

LINEAMENT Fracture

Khlong The Pho

Ridge Strike valley and indistinct lineament 10

0

20

Fault

No rt h

Kilometres

TEMENGGOR RESERVOIR

a S. Ti

ng

Banding East - West hig hway

ak

Ruok

S. Pe r

or

No rt h

S. Sin g

Landsat 3 10 Jan 1979

Figure 42:

Lineaments interpreted as the Ruok Fault Zone that almost parallel with the Temengor Lake orientation (after Syed Sheikh Almashoor and Tjia, 1987).

50

INDEX MAP

LEGEND Ban Nang Sata

F

Fault Road

River

F

International boundary State boundary

KEDAH 0

KILOMETERS 10

20

S. Patt ani

T HA ILA N D erak

S. P

Betong S. Ke

S.

ng Tia

g

ron

ne

Keroh

S. Pergau

erak

S. Sa

KE

ra

P E R AK

TA

F

N

S. P

LA

Gerik

N

S. Singor

Figure 43:

Location of the Ruok Fault Zone (after Syed Sheikh Almashoor and Tjia, 1987)

51

Figure 44:

The Ruok Fault Zone crosses the EastWest Highway at km 184 towards Kota Baharu (208 km towards Ipoh) (05o 34.521‟ N, 101o 24.289‟ E), where it can be observed within the quartz-mica schist with northerly strike and steeply dip foliation.

52

Figure 45:

Numerous sigmoidal quartzs within the schist in the Ruok Fault Zone at km 184 towards Kota Baharu (05o 34.521‟ N, 101o 24.289‟ E).

5.0

MINERALS AND OTHER NATURAL RESOURCES

5.1

Introduction

The Transect area is not known for its economic deposits as there are no records of prospecting and mining in the past. However, prospecting and mining activities have been carried out in the Batu Melintang-Sungai Kolok and Pengkalan HuluBetong Transect areas in the Kalai, Berusong and Kelian Intan in Malaysia, and Tham Thalu and To Mo areas in Thailand (The Malaysian-Thai Working Group, 2006 & 2010). On the Thai side, mineral potential area in the Belum-Hala Transect area has been studied by DMR using airborne geophysic and magnetic anomaly since 2003. The mineralization is related to the contact metamorphism of granite intrusions and country rocks, and subsequent hydrothermal activities. The Pb-Zn sulphide mineral potential area, along the Hala stream, near the Malaysia-Thailand border is observed. Mineralization was interpreted to occur in the contact zone between the granite and country rocks. High magnetic anomaly similar to those of the Pb-Zn sulphide model of the Tham Ta Lu area in Bannang Sata District was identified. The other Sn-W mineral potential area was proven in Ban Ai Yoe Quin, at the edge of the eastern part of the Belum-Hala Transect area. Mining activities in the surrounding of the Transect area is shown in Figure 46.

53

Figure 46: Mining activities in the surrounding areas.

5.2

Geochemical Exploration

On the Malaysian side, regional geochemical survey had been carried out by a group of geologists of Minerals and Geoscience Department in 1991 to 1993 covering Topographical Map Sheets 11 (Gunung Ulu Merah), 19 (Kerunai) and 20 (Belum) areas. Stream sediment and rock samples were collected for geochemical study. As a result, several multi-elements anomalous areas were identified; of which seven of them are situated in the Belum-Hala Transect area (Figure 47). Pertinent information on these anomalies including element associations, area extent, underlying geology, the number of anomalous samples and the range of values is summarized in Table 5. Anomalies are ranked from one to four in descending order of follow-up priority. 54

Follow-up work is not recommended for anomalies with a rating of four. Descriptions of first-, second- and third-order anomalies are given below. Anomaly 1901 [Sn, W, U (As, Ag, Zn, Pb)] Anomaly 1901 is situated in the upper reaches of Sungai Kenarong, close to the Malaysia-Thailand border. The area covers approximately 20 square km and is underlain by arenaceous rocks of the Carboniferous Kubang Pasu Formation, intruded by small granitic stock. Anomalous elements are Sn, W and U as well as As, Ag, Pb and Zn. Sn value ranging from 40 ppm to 160 ppm whereas W ranging from 3 to 20 ppm and U ranges from 2 to 19.8 ppm. This anomaly is rated as Priority 3 which requires possible follow-up for Sn, W and U. Anomaly 1903 [Au, Cu, Co (Mn, Ni, Hg)] Anomaly 1903 is situated on the western part of the Transect area. It covers approximately 27 square km in the headwaters of Sungai Kedah and Sungai Cermin. The area is underlain by arenaceous and argillaceous rocks of the Permian Gerik formation, intruded by small dolerite dyke. This is essentially an Au-Cu-Co anomaly with less extensive anomalies for Mn, Ni and Hg. Gold value in stream sediment is 0.05 to 10.049 ppm whereas in heavy mineral concentrate it gives maximum tenor value 3.2 mg/m3. Anomalous Cu and Co are found in Sungai Cermin. Their values in stream sediment are ranging from 60 to 300 ppm and 22 to 103 ppm respectively. This anomaly was rated as Priority 2 that requires eventual follow-up for Au, Cu and Co. Anomaly 2001 [Sn, As, W (Zn, Au)] This is predominantly Sn-As-W anomaly, located in the Sungai Palai drainage. It covers an area of at least 43 square km. The rocks underlying this anomaly are predominantly quartz-mica schist of the Tiang Schist that intruded by small stocks of Singor Granite. The area is cut by NE-SW fault that runs parallel to the Laho Fault. Tin and tungsten show high anomalous geochemical values in the stream sediment where anomalous Sn values range from 20 to 40 ppm and W from 4 to 12 ppm. Anomalous Sn values are randomly distributed over the area whereas As and W show good association. This anomaly is given Priority 3 which requires possible follow-up. Anomaly 2002 [Sn, Ag, W, As (Pb, Ni, U)] This multi-element anomaly, located in the upper reaches of Sungai Dadek and tributaries of Sungai Mangga with an areal extent of 51 square km. High geochemical values are centred over the NE-SW Jakal Fault and unnamed NW-SE fault which demarcates the contact between the Triassic Kabut Granite and the Carboniferous Tiang schist. This anomaly is highlighted by Sn associated with Ag, W and As. It is defined by thirteen anomalous stream sediment samples containing Sn values ranging from 20 to 30 ppm and also anomalous values of Ag (39 samples), W (15 samples) 55

and As (19 samples). Anomalous values of Pb, Ni and U also occur. This anomaly is given a Priority 2 and should be followed up to assess the tin and tungsten potential.

Figure 47:

Anomaly map of the Transect area.

56

Table 5: Summary of anomalies on the Malaysian side of the Transect area. Anomaly No. 1901

Element(s) Sn, W, U (As, Ag, Zn, Pb)

Area (km2) 20

1903

Au, Cu, Co (Mn, Ni, Hg)

27

2001

Sn, As, W (Zn, Au)

43

2002

Sn, Ag, W, As (Pb, Ni, U)

51

Range in ppm (No. of anomalous samples) Sn 40-160 (11) W 3-20 (10) U 2-19 (10) As 8-120 (4) Ag 0.08-0.4 (12) Zn 110-260 (10) Pb 6-60 (4) Au 0.015-10.049 (9) Cu 60-300 (5) Co 22-103 (5) Mn 5,000-6130 (2) Ni 16-83 (3) Hg 0.05-0.16 (2) *Gold tenor: 3.2 mg/m3 Sn 20-40 (31) As 10-200 (22) W 4-12 (8) Zn 127-142 (2) Au 0.083-0.324 (2) Sn 20-30 (13) Ag 0.6-1.0 (39) W 8-40 (15) As 10-60 (19) Pb 51-96 (5) Ni 49-55 (3) U 6.2-14.2 (8)

Note: Priority 1 indicates high priority rating - warrants immediate follow-up Priority 2 indicates moderate priority - requires follow-up Priority 3 indicates low priority - possible follow-up

57

Geology Arenaceous rocks of Carboniferous Kubang Pasu Formation, intruded by small granitic stock

Priority Rating 3

Arenaceous and argillaceous rocks of Permian Gerik formation, intruded by small dolerite dyke

2

Predominantly quartz-mica schist of the Tiang schist intruded by small stocks of Singor Granite, microgranite, lamprophyre as well as quartz veins.

3

Contact aureole between the Kabut Granite and Tiang schist. Fault zone striking NE-SW and NW-SE

2

5.3

Other Geological Resources

Other potential geological resources in the Transect area are rock aggregates and dimension stone. The reserves are sufficient enough to be quarried for construction materials. The granite supplies are available mainly from the Merah and Kabut Granites. There are three abandoned quarries, which previously supplied rocks aggregate for the construction of the East-West Highway, such as at Km 61.6 (05o 36.057‟ N, 101o 30.532‟ E) and at Km 63.3 (05o 36.345‟ N, 101o 31.181‟ E) as shown in Figures 48 and 49 respectively.

Figure 48:

Abandoned granite quarry at Km 61.6 of the East-West Highway.

Figure 49: Abandoned granite quarries at Km 63.3 of the East-West Highway.

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6.0

DISCUSSION AND CONCLUSION

6.1

Discussion i.

Lithostratigraphically, the Betong Formation (SDbt) is the oldest rock unit exposed in the Transect area. However this rock unit is not exposed on the Malaysian side within the Transect area.

ii.

Structurally, the Tiang schist (Cts) was affected by the tectonic activity along the Bentong-Raub Suture Zone that can be observed along the eastern margin of the rock unit and the intrusion of the Main Range Granite in its western margin.

iii.

The Carboniferous Kubang Pasu/Yaha Formation (Ckp/yh) is distributed in the central and western parts of the Transect area. The rocks are metamorphosed to metasandstone, hornfels, phyllite and schist due to the Main Range Granite intrusion. The Kubang Pasu/Yaha Formation (Ckp/yh) is conformably overlain by the Permian Gerik formation.

iv.

The Carboniferous-Permian Mangga formation (CPmg) was affected by the tectonic activity along the Bentong-Raub Suture Zone. Pelagic sediments within the Bentong Raub Suture Zone contain the radiolarian Follicuculus sp. suggesting a Permian age.

v.

The Permian rock unit in the Transect area is represented by the Gerik formation (Pgk) comprising predominantly tuffaceous sediments. Radiolarian fauna discovered in the siliceous sediments within this rock unit were identified as Follicucullus sp., Gustefana sp., Latentifistula sp., Triplanospongos sp. and Albaillella sp. Some specimens resemble the important fauna of Follicucullus scholasticus and Albaillella levis. The age of these fauna are estimated as Capitanian to Changhsingian of Middle to Late Permian (Saesaengseerung, pers. comm., 2011).

vi.

Surficial deposits comprise unconsolidated gravel, sand, silt and clay of fluviatile and colluvial origin deposited in the non-marine environment overlying the major river valleys and low lying areas.

vii.

The granite in the Transect area can be divided into four units; namely, in ascending order: a. the Chantarat Granite (Trgrch) – medium- to coarse-grained, sparsely megacrystic to good megacrystic, unfoliated to weakly foliated biotite granite. b. the Kabut Granite/La Sa granite (Trgrkb/ls) – grey, fine- to medium-grained, porphyrytic biotite granite c. the Merah/Bu Do Granite (Trgrmr/bd) – grey, fine- to medium-grained, foliated biotite granite

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d. the Singor Granite/Hala granite (Trgrsghl) – Leucocratic, fine- to mediumgrained biotite-muscovite granite with occasional tourmaline. viii The main structural feature in the Transect area is Ruok Fault. The fault zone trends NNW-SSE extending from Mae Nam Pattani in the north, in 165o direction, parallel with Sungai Kenerong and than probably ends at Sungai Sara in the south.

6.2 Conclusion

i.

The marine sedimentation in the Transect area took place continuously throughout the Paleozoic Eras. Nevertheless, the large breaks can be observed due to the uplift of granitic rocks during the Triassic.

ii. On the Thai side of the Transect area, the photogeological interpretation which have been correlated with the previous geological data and information revealed the rock units in the Transect area are as follows in ascending order: a. ST1 and ST2 units correlatable with the Silurian-Devonian Kroh/Betong Formation (SDkr/bt), b. ST3 unit correlatable with the Carboniferous Kubang Pasu/Yaha Formation (Ckp/yh), c. ST4 unit correlatable with the Tiang schist iii. The Silurian-Devonian Betong Formation (SDbt), Tiang schist (Cts), the Kubang Pasu/Yaha Formation (Ckp/yh), the Mangga formation (CPmg) and the Gerik formation (Pgk) were deposited on the Sibumasu terrane. All these Palaeozoic rocks in the Transect area were subsequently intruded, faulted against, and metamorphosed by the Triassic Main Range Granite. iv. Based on regional geochemical survey carried out by the Minerals and Geoscience Department Malaysia during 1991 to 1993, seven multi-elements anomalous areas had been identified on the Malaysian side of the Transect area. v. Rock aggregates and dimension stone have the potential to be exploited in the Transect area.

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Nakapadunrat S. Jeenkool A. and Boonkanpai N. (1988). Geology of Amphoe Khok Pho (5222 III) Quadrangle scale 1:50,000 Geological Survey report of Investigation No T-06-2-0109 (3)-88/GEOL 57 P. (in Thai) Muenlek, S., Meesook, A. and Thongchit, P., 1982. Geology and mineral resources of Sheet Narathiwas and Betong, southern Thailand. Geol. Surv. Div. Rept., DMR, Bangkok, Thailand, 1-56: (in Thai). Rohayu bt. Che Omar, 1994. Petrochemistry of the Palaeozoic rocks along the East-West Highway, Gerik-Jeli, Perak/Kelantan. National University of Malaysia MSc. thesis, 381 p. (in Malay). Rookewell, J., 1923. Kelantan Gold-Report of the consulting Engineer. Straits Times, February 12, 1923. Safeen b. Baharudin, 1987. Gold Investigation in Batu Melintang area, Kelantan. Geological Survey Malaysia. (in Malay). Scrivenor, J.B., 1915. Geologist‟s Annual Report for 1914. Federated Malay States and Straits Settlements. Sia, S.G., 1989. Geology of the Grik-Lawin area. University of Malaya B.Sc. (Hons.) thesis (unpublished). Singh, D.S., Chu, L.H., Loganathan, P., Teoh, L.H., Cobbing, E.J. and Mallick, D.I.J., 1984. The Stong Complex: A reassessment. Bull. Geol. Soc. Malaysia, 17, pp. 61-77. Syed Sheikh Almashoor and Tjia, H.D., 1987. A prominent fault across the Malaysia-Thai Boundary. A Preliminary Report. Warta Geologi, vol.13, No. 2, March-April 1987, pp 35-37. Tajul Anuar b. Jamaluddin, 1989. Engineering Geology East-West Highway, Peninsular Malaysia – with emphasise on rock slope failure. National University of Malaysia B.Sc (Hons.) thesis. The Malaysia and Thailand Working Groups, 2006. Geology of the Batu Melintang-Sungai Kolok Area along the Malaysia-Thailand Border Area. Minerals and Geoscience Department Malaysia. The Malaysia-Thailand Working Group, 2010. Geology of the Pengkalan Hulu-Betong Transect Area along the Malaysia-Thailand Border Area. The Malaysia-Thailand Border Joint Geological Survey Committee (MT-JGSC). Tjia, H.D., 1969. Regional implication of the Lebir fault zone. Geol. Soc. Of Malaysia Newsletter no. 19, p. 6-7. Tjia, H.D., 1987. Olistostrome in the Bentong area, Pahang. Warta Geologi 13, 105–111. Tjia, H.D., 1989a. Tectonic history of the Bentong–Bengkalis Suture. Geologi Indonesia 12 (1), 89–111. Tjia, H.D., 1989b. The Bentong Suture. In: Situmorang, B. (ed.), Proceedings of the Regional Conference on Mineral and Hydrocarbon Resources of SE Asia, pp. 73–85. Tjia, H.D., 1993. The Bentong Suture in Ulu Kelantan, Peninsular Malaysia. IGCP Project 321 Gondwana dispersion and Asian accretion, Third International Symposium and Field Excursion, Abstracts of papers, pp. 70–71. Tjia, H.D. and Syed Sheikh Almashoor, 1996. The Bentong Suture in Southwest Kelantan, Peninsular Malaysia. Geological Society of Malaysia Bulletin, 39, pp. 195-211. Tonnayopas, D., 1994. Geology and Stratigraphy of Bang Lang Dam area. Proceeding of the international symposium on: Stratigraphic Correlation of Southeast Asia, Bangkok, Thailand. Utha-aroon, C., Khuenkong, P., and Saisuttichai, D., 2000. Review on Mineral Resources near the Thai-Malay Border, Economic Geology Division, Department of Mineral Resources, Bangkok, Thailand, 14 p. Wong, L.C., 1974. Geology of the Batu Melintang area, northwest Kelantan, West Malaysia. Unpublished B.Sc. (Hons.) thesis, Dept. of Geology, University of Malaya.

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- 64 -

APPENDICES

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- 65 APPENDIX 1 List of the Malaysian-Thai Working Group Member Malaysian Working Group Member

Thai Working Group Member

Name 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Mr. Alexander Unya Ambun Mr. Ibrahim bin Amnan Mr. Noor Bakri bin Endut Mr. Mohd Badzran bin Mat Taib Mr. Mohamad Hussein bin Jamaluddin Mr. Mohamad Sari bin Hasan Mr. Mat Niza bin Abdul Rahman Mr. Muhammad Mustadza bin Mazni Mr. Mohd Anuar bin Ishak Mr. Amir Mizwan bin Mohd Akhir Mr. Azizan anak Juhin

1. 2. 3. 4. 5. 6. 7. 8. 9. 10 11

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Name Dr. Tawsaporn Nuchanong Dr Assanee Meesook Mr. Naramase Teerarungsigul Dr. Suree Teerarungsigul Mr. Terapon Wongprayon Mr.Suvapak Imsamut Ms. Piya-orn Assavapatchara Mr. Kitti Khaowiset Mr. Sutee Jongautchariyakul Ms. Pachara Sangoen Dr. Doungrutai Saesaengseerung