Bentong-Raub Suture Zone Research Articles

The central Qiangtang Metamorphic Belt in northern Tibet is an in-situ Paleo-Tethys Ocean: Evidence from newly discovered Late Devonian radiolarians

The paleogeographic position of the North Qiangtang Block, as well as the origin of the Central Qiangtang Metamorphic Belt (CQMB) have subjected to considerable debate that hampers the understanding of the early evolution of the Paleo-Tethys Ocean. This study reports a new radiolarian fauna of a Famennian age (Late Devonian) from the ophiolitic mélange south of Gangtang Co, northern Tibet, including Callela parvispinosa Won, Entactinia foveolata Nazarov, and Plenoentactinia pinguis Won. The discovery of Devonian radiolarians in the CQMB strongly supports the model that the Longmu Co–Shuanghu suture zone represents the main branch of the Paleo-Tethys Ocean. A correlation of the Late Devonian radiolarian in Tethys realm reveals that the Longmu Co–Shuanghu suture zone was connected to the Changning–Menglian suture zone in western Yunnan, the Chiang Mai–Inthanon and Chanthaburi suture zones in Thailand, and the Bentong–Raub suture zone in Malay Peninsula. The synchronous advent of Late Devonian radiolarians suggests that the Paleo-Tethys Ocean may have opened during that time.

EVALUATION ON GEOHERITAGE POTENTIAL OF THE LOJING-GUA MUSANG ROAD, KELANTAN

The Lojing-Gua Musang road runs through outcrops that are home to various species of flora and fauna. The road also exposes several lithologies, including those from the Bentong-Raub Suture Zone and the Main Range granite. The area has significant geoheritage values that make it suitable to be geosites. The study aimed to evaluate the potential of the selected localities as geosites based on their educational/scientific, aesthetic/scenic, protection values and public safety. The geoheritage potential assessment was divided into two phases: (1) data gathering for the potential geosite and (2) evaluation using a scoring rubric of the Geosite Assessment Model (GAM). The sites assessed were GunungSwettenham, Sungai Ber Hot Spring, Pos Blau brecciated limestone, and Pos Blau bedded chert. The assessment results showed that Gunung Swettenham and Sungai Ber Hot Spring had higher scores due to their aesthetic values and better protection. Brecciated limestone and bedded chert in Pos Blau area had lower scores in most of the categories of this assessment. To improve the quality of these potential geotourism spots, the study recommends the construction of basic infrastructures, including parking lots, information boards, proper pavement to the interest points, electronic monitoring devices, lighting systems, and security boundaries. Overall, the study suggests that with proper development, these geosites have the potential to attract tourists and promote geotourism in the area.

Community structure of thermophilic photosynthetic microbial mats and flocs at Sembawang Hot Spring, Singapore.

The Sembawang Hot Spring in Singapore lies at the foot of a major regional geological feature called the Bentong-Raub Suture Zone. Amid an extensively managed surface geothermal park, an undisturbed hot spring emerges with source water at 61°C, pH 6.8, and 1 mg/L dissolved sulfide. A small main pool at the source supported orange-green benthic flocs, whereas the outflow channel with gradually less extreme environmental stress supported extensive vivid green microbial mats. Microscopy revealed that cyanobacterial morphotypes were distinct in flocs and mats at several intervals along the environmental gradient, and we describe a spiraling pattern in the oscillatorian cyanobacteria that may reflect response to poly-extreme stress. Estimation of diversity using 16S rRNA gene sequencing revealed assemblages that were dominated by phototrophic bacteria. The most abundant taxa in flocs at 61°C/1 mg/L sulfide were Roseiflexus sp. and Thermosynechococcus elongatus, whilst the mats at 45.7-55.3°C/0-0.5 mg/L sulfide were dominated by Oscillatoriales cyanobacterium MTP1 and Chloroflexus sp. Occurrence of diverse chemoautotrophs and heterotrophs reflected known thermal ranges for taxa, and of note was the high abundance of thermophilic cellulolytic bacteria that likely reflected the large allochthonous leaf input. A clear shift in ASV-defined putative ecotypes occurred along the environmental stress gradient of the hot spring and overall diversity was inversely correlated to environmental stress. Significant correlations for abiotic variables with observed biotic diversity were identified for temperature, sulfide, and carbonate. A network analysis revealed three putative modules of biotic interactions that also reflected the taxonomic composition at intervals along the environmental gradient. Overall, the data indicated that three distinct microbial communities were supported within a small spatial scale along the poly-extreme environmental gradient. The findings add to the growing inventory of hot spring microbiomes and address an important biogeographic knowledge gap for the region.

Geological heritage as a basis for geoscience development: A case study of Bentong-Raub Suture in Lojing District, Gua Musang District, Kelantan, Malaysia

The research area was completed in the Upper Triassic and is situated in the Bentong-Raub suture zone of the Upper Permian collision zone between the Sibumasu and Indochina plates. Geoheritage must be preserved for educational reasons in order to preserve the geological processes that create different lithologies as well as the geological structures that create distinctive geomorphology. Geological features can be utilized for geotourism and have geoheritage significance. The purpose of this study is to evaluate the geoheritage component in the Malaysian Kelantan region of Lojing Gua Musang. The classification of geoheritage is based on factors related to geodiversity, scope, and scale. A minor geodiversity of lithological changes in metamorphic rocks, sediments, and volcanic rocks (as members of chert lithology) represent the structure’s position. The minor geodiversity of lithological changes in metamorphic rocks, sediments, and volcanic rocks (as members of chert lithology), with a score of 4, represents the structure’s location (good). Scientific geosite values, such as the numerous lithologies that characterize the Bentong Raub Suture Lojing region, have a rich geological history that makes them appealing to tourists and researchers.

Petrography of The Main Range Granite Characterization in Titiwangsa Rest Stop, Perak, Malaysia

The area of research is located in between the Titiwangsa Rest Stop, Perak allocated along the Gerik-Jeli highway, approximately 25km in area. The objective of this research is to remodify a geological map with a scale of 1:25,000 and to determine the petrological aspects of the metamorphic mineral assemblages around the study area. One of the methods used during the initial of this research is primarily on previous research and literature review. The geological mapping technique such as traversing was applied to map the allocated study area and rock samples are collected from three different outcrops that are exposed around the area as well. Moreover, the samples are then sent to a lab to undergo microscopic and petrographic analysis of the rocks’ compositions by producing thin sections to determine the mineral assemblages which surround the area on Titiwangsa Rest Stop, Perak. The rocks that can be identified around the area include igneous and metamorphic rocks such as biotite granite, gneiss, and mica-schist. The area of research which extends from the Titiwangsa Rest Stop towards the Gerik-Jeli highway is located directly on the Bentong-Raub suture zone. The depositional setting hypothesized in the area is a marine depositional coastal environment which includes a transition of a lower grade metamorphic rock towards a higher-grade metamorphic rock.

Shear joints and its relations with subsurface structures in Batu Melintang, Jeli, Kelantan, Malaysia

Shear joint is the common rock deformation structures formed in Batu Melintang, Jeli due to its location within Bentong-Raub Suture zone. The structural analysis of shear joint can give information about the direction of maximum and minimum stress exerted on a rock while undergoing deformation as the effect of stress fields in the study area. The subsurface structural analysis is done by using the geophysical resistivity method. It displays the subsurface structure in the area for confirmation of the structure found on the surface whether it is highly fractured, moderately fractured or low fractured. The research area was divided into six grids for systematic field measurement. The shear joints orientation were taken while conducting geological mapping and recorded using rose diagram analysis; while the geophysical resistivity method was carried out with a varied length of survey lines set at 200/100m and 1.25/2.5/5m electrode spacing. The subsurface depth of penetration for each survey line is varied, ranging from 0m to 50m. The data is processed in RES2DINV software to obtain the pseudosection profile of the subsurface. The study area principal stress was identified; the maximum stress force ?1 was directed in NW-SE in direction of S107°E and N287°W, while minimum stress ?3 was directed in NE-SW in direction of N17°E and S197°W. The pseudosection subsurface image also displayed a correlation between surface shear joint structures and subsurface structures. The subsurface investigation; according to the pseudosection found that the study area consists of highly fractured structure displayed as several weak zones and fractures of bedrock.

Alluvium Assessment of Gold-Bearing Layer in Buried Old River Channel by using Electrical Resistivity Method at Batu Melintang, Jeli, Kelantan

The electrical resistivity imaging (ERI) survey was conducted to delineate the distribution of sediment in the gold-bearing layer and the nature of bedrock within the study area at Batu Melintang. The study area is known as a highly potential zone of gold mineralization due to its location within the Bentong-Raub suture zone. Miners are having difficulties to have a proper mining activities plan as the alluvium distribution is not well understood. The objectives of this study are to identify the sediment in the subsurface of the mining area and to locate the high potential deposit containing gold. ERI survey concerns with resistivity (ohm.m) value of rocks in the subsurface. This research was conducted by using the Schlumberger array with the total number of survey lines are four. All the survey line were done in 200m with 2.5m electrode spacing except for survey line 3 which was done at 100m with 1.5m electrode spacing. All the data obtained is processed in RES2DINV software. The results show variable resistivity ranging from 1-4000ohm.m with a depth of investigation is approximately 35m for 200m length of survey line and depth of 16m for 100m length of survey line. Low resistivity zones of 10-800ohm.m show the values for alluvium present in the area while high resistivity zones of 2000-4000ohm.m indicate values for bedrock. Alluvium layer is identified located around 15m depth, whereas the depth of bedrock is about 20m. This survey gives the general idea of the alluvium distribution, old river channel and the depth of bedrock that can be used for volume estimation and facilitates to create a proper sustainable mining plan in the future

Crustal thickness and velocity structure of Malay Peninsula inferred from joint inversion of receiver functions and surface waves dispersion

The Malay Peninsula is located within the Sunda shelf that is subdivided geologically into three distinctive tectonic belts; western, central and eastern belts. The north-south orientation of these belts was formed during the Paleo-Tethys subduction process in the Late Paleozoic. Bentong-Raub suture zone separates the central and western belts. While extensive studies have been conducted at the surface and near surface scale, the subsurface model of the Earth’s crust and upper mantle layers within this region are relatively few. Crustal structure model is crucial in investigating the cause of local earthquakes, which shocked Peninsular Malaysia between 2007 and 2009. The present study is conducted adopting the joint inversion of the P-wave receiver functions and surface wave dispersions techniques using the data collected from eight Seismological stations in the Malay Peninsula. The receiver function for each station was computed using over a thousand tele-seismic earthquake waveforms, recorded by the three-component broadband seismometers. For each station, the H-k was used to determine the Vp/Vs ratio and the depth to the Moho. This step was conducted to have an initial constraint for the crustal thickness. For the surface wave dispersion calculations, on the other hand, two hundred local and regional earthquakes with focal depth less than 30 km and with magnitudes mb 6.0 and above that occurred along South-East Asia’s ring of fire were analyzed. The analyses obtained from these two techniques were jointly inverted through a two-phases of velocity inversion to determine the 1-D velocity profile for each station. The results of inversion indicate that the Moho boundary is getting shallower towards the north of Malay Peninsula, as a 26 km depth of crust-mantle boundary were determined in station SKLT south Thailand. Furthermore, the subsurface profile of the western belt of Malay Peninsula was also found to be highly complicated, with complex receiver function responses being computed beneath the IPM and KUM stations where slow velocity zones are identified within the 10–20 km crustal depth. The region in southern Thailand might also have originated from Indochina/East Malaya block, due to similar crustal velocity characteristics found beneath the region compared to the area beneath KOM, JRM and BTDF stations in the southern part of Malay Peninsula and Singapore. The Vp/Vs ratios for the crust indicate that the crust is generally undisturbed except for station SKLT south Thailand. This may indicate that the occurrence of a large earthquake in the region is not likely.

Application of Landsat-8 and ALOS-2 data for structural and landslide hazard mapping in Kelantan, Malaysia

Abstract. Identification of high potential risk and susceptible zones for natural hazards of geological origin is one of the most important applications of advanced remote sensing technology. Yearly, several landslides occur during heavy monsoon rainfall in Kelantan River basin, Peninsular Malaysia. Flooding and subsequent landslide occurrences generated significant damage to livestock, agricultural produce, homes and businesses in the Kelantan River basin. In this study, remote sensing data from the recently launched Landsat-8 and Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) on board the Advanced Land Observing Satellite-2 (ALOS-2) were used to map geologic structural and topographical features in the Kelantan River basin for identification of high potential risk and susceptible zones for landslides and flooding areas. The data were processed for a comprehensive analysis of major geological structures and detailed characterizations of lineaments, drainage patterns and lithology at both regional and district scales. The analytical hierarchy process (AHP) approach was used for landslide susceptibility mapping. Several factors such as slope, aspect, soil, lithology, normalized difference vegetation index (NDVI), land cover, distance to drainage, precipitation, distance to fault and distance to the road were extracted from remote sensing satellite data and fieldwork to apply the AHP approach. Directional convolution filters were applied to ALOS-2 data for identifying linear features in particular directions and edge enhancement in the spatial domain. Results indicate that lineament occurrence at regional scale was mainly linked to the N–S trending of the Bentong–Raub Suture Zone (BRSZ) in the west and Lebir Fault Zone in the east of the Kelantan state. The combination of different polarization channels produced image maps that contain important information related to water bodies, wetlands and lithological units. The N–S, NE–SW and NNE–SSW lineament trends and dendritic, sub-dendritic and rectangular drainage patterns were detected in the Kelantan River basin. The analysis of field investigation data indicates that many of flooded areas were associated with high potential risk zones for hydrogeological hazards such as wetlands, urban areas, floodplain scroll, meander bend, dendritic and sub-dendritic drainage patterns, which are located in flat topographic regions. Numerous landslide points were located in a rectangular drainage system that is associated with a topographic slope of metamorphic and quaternary rock units. Consequently, structural and topographical geology maps were produced for Kelantan River basin using PALSAR-2 data, which could be broadly applicable for landslide hazard mapping and identification of high potential risk zone for hydrogeological hazards. Geohazard mitigation programs could be conducted in the landslide recurrence regions and flooded areas to reduce natural catastrophes leading to loss of life and financial investments in the Kelantan River basin. In this investigation, Landsat-8 and ALOS-2 have proven to successfully provide advanced Earth observation satellite data for disaster monitoring in tropical environments.

Gondwana-Derived Terranes Structural Mapping Using PALSAR Remote Sensing Data

Gondwana-derived terranes are now separated by major faults or suture zone, which are rarely simple and easily recognizable lineaments. Different association of ore mineral systems such as deposits of sediment-hosted/orogenic gold and granite-related minerals is discovered in collision and subduction zones of the Gondwana-derived terranes. They are associated with large-scale, terrane-bounding fault systems and broad areas of deformation. Mineralization mostly associated with structurally-controlled complex lodes, veins, sheeted veins and veinlets in diverse orientations. Recognizing the structural significance of lineaments and curvilinear is very difficult in tropical, arid and Antarctic regions due to environmental obstacles. Remote sensing data could be used to detect geological structures associated with suture zones between Gondwana-derived terranes especially for large inaccessible regions where fieldwork is limited or nonexistent. In this investigation, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to map major geological structures in the Bentong-Raub Suture Zone of Peninsular Malaysia. It is one of the major structural zones in Sundaland, Southeast Asia, which forms the boundary between the Gondwana-derived the Sibumasu terrane and Sukhothai-Indochina arc. Structural features associated with sediment-hosted/orogenic gold deposits in the Central Gold Belt and tin mineralization in S-type granites in the Main Range were investigated using PALSAR data and comprehensive fieldwork. Results indicate that main faults strike along 340° to 350° that are intersected by many shear or lateral fault zones are high potential zone for gold mineralization in the Central Gold Belt. Hydrothermally alteration mineral zones and cataclastic rocks are also the other indicators of gold mineralized veins in the gold belt. High potential zones for tin mineralization are N–S strike-slip faults, fault zones and shear zones trending E–W, NE–SW and WNW–ESE in dissected crystalline granitic rocks that are associated with hydrothermal alteration zones in the Western Tin Belt. Lineament analysis using PALSAR satellite remote sensing data is a useful tool for mapping major geological structural features and detection of the boundary between the Gondwana-derived terranes and detailed structural analysis of fault systems and deformation with high potential for a variety of mineral resources, especially in tropical, arid and Antarctic regions.

Laser Ablation ICPMS Analysis of Pyrite and U-Pb Zircon Dating of Host Rocks From the Tersang Gold Deposit, Malaysia

The Central gold belt of peninsular Malaysia comprises a number of gold deposits located in the east of the N-S striking Bentong-Raub Suture Zone. The Tersang gold deposit is a mesothermal, orogenic gold deposit, which is hosted in sandstone, shale, rhyolite and breccia. The deposit has an inferred and indicated resource of 120,000 ounces of gold in the JORC category. Detrital zircon grains from the host sandstones returned a maximum depositional age ranging from Early Carboniferous to Early Permian (333.5 ± 2.5 Ma-261.5 ± 4.9 Ma) and those of the rhyolite indicated a crystallization age of 218.8 ± 1.7 Ma. Pyrite trace element mapping has revealed four pyrite phases. Laser Ablation ICPMS analyses on pyrite has shown that pyrite phase 1 has the lowest Au concentration (mean 0.4 ppm) and is interpreted to have preceded the main Au mineralisation stage. Pyrite phases 2 and 3 are the main Au mineralisation stage with Au mean range from 1.5 to 4.5 ppm and contributed most of the invisible gold to the ore-forming system. Pyrite phase 4 has low gold concentrations (mean 0.5 ppm) and post-dated the main Au mineralisation stage recorded in pyrite phases 2 and 3. The trace element chemistry of pyrite indicates that Au mineralisation recorded in pyrite is likely a product of four stages ore forming system centred on the rhyolite corridor. In terms of gold exploration, gold has a positive correlation with As, Ag, Cu, Se, Sb, Pb and Tl in pyrite. These metals can be used as pathfinders to detect proximity to ore for orogenic gold deposit type in the central gold belt of Peninsular Malaysia.

GEOLOGICAL FEATURES MAPPING USING PALSAR-2 DATA IN KELANTAN RIVER BASIN, PENINSULAR MALAYSIA

Abstract. In this study, the recently launched Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) onboard the Advanced Land Observing Satellite-2 (ALOS-2), remote sensing data were used to map geologic structural and topographical features in the Kelantan river basin for identification of high potential risk and susceptible zones for landslides and flooding areas. A ScanSAR and two fine mode dual polarization level 3.1 images cover Kelantan state were processed for comprehensive analysis of major geological structures and detailed characterizations of lineaments, drainage patterns and lithology at both regional and district scales. Red-Green-Blue (RGB) colour-composite was applied to different polarization channels of PALSAR-2 data to extract variety of geological information. Directional convolution filters were applied to the data for identifying linear features in particular directions and edge enhancement in the spatial domain. Results derived from ScanSAR image indicate that lineament occurrence at regional scale was mainly linked to the N-S trending of the Bentong-Raub Suture Zone (BRSZ) in the west and Lebir Fault Zone in the east of the Kelantan state. Combination of different polarization channels produced image maps contain important information related to water bodies, wetlands and lithological units for the Kelantan state using fine mode observation data. The N-S, NE-SW and NNE-SSW lineament trends were identified in the study area using directional filtering. Dendritic, sub-dendritic and rectangular drainage patterns were detected in the Kelantan river basin. The analysis of field investigations data indicate that many of flooded areas were associated with high potential risk zones for hydro-geological hazards such as wetlands, urban areas, floodplain scroll, meander bend, dendritic and sub-dendritic drainage patterns, which are located in flat topograghy regions. Numerous landslide points were located in rectangular drainage system that associated with topographic slope of metamorphic and Quaternary rock units. Some large landslides were associated with N-S, NNE-SSW and NE-SW trending fault zones. Consequently, structural and topographical geology maps were produced for Kelantan river basin using PALSAR-2 data, which could be broadly applicable for landslide hazard mapping and identification of high potential risk zone for hydro-geological hazards.

Structural Mapping of the Bentong‐Raub Suture Zone Using PALSAR Remote Sensing Data, Peninsular Malaysia: Implications for Sediment‐hosted/Orogenic Gold Mineral Systems Exploration

AbstractThe Bentong‐Raub Suture Zone (BRSZ) of Peninsular Malaysia is one of the major structural zones in Sundaland, Southeast Asia. It forms the boundary between the Gondwana‐derived Sibumasu terrane in the west and Sukhothai Arc in the east. The BRSZ is genetically related to the sediment‐hosted/orogenic gold deposits associated with the major lineaments in the Central Gold Belt of Peninsular Malaysia. In this investigation, the Phased Array type L‐band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to map major geological structures in Peninsular Malaysia and provide detailed characterization of lineaments and curvilinear structures in the BRSZ, as well as their implication for sediment‐hosted/orogenic gold exploration in tropical environments. Major structural lineaments such as the Bentong‐Raub Suture Zone (BRSZ) and Lebir Fault Zone, ductile deformation related to crustal shortening, brittle disjunctive structures (faults and fractures) and collisional mountain range (Main Range granites) were detected and mapped at regional scale using PALSAR ScanSAR data. The major geological structure directions of the BRSZ were N–S, NNE–SSW, NE–SW and NW–SE, which derived from directional filtering analysis to PALSAR fine and polarimetric data. The pervasive array of N–S faults in the Central Gold Belt and surrounding terrain is mainly linked to the N–S trending of the Suture Zone. N–S striking lineaments are often cut by younger NE–SW and NW–SE‐trending lineaments. Gold mineralized trend lineaments are associated with the intersection of N–S, NE–SW, NNW–SSE and ESE–WNW faults and curvilinear features in shearing and alteration zones. Compressional tectonic structures such as the NW–SE trending thrust, ENE–WSW oriented faults in mylonite and phyllite, recumbent folds and asymmetric anticlines in argillite are high potential zones for gold prospecting in the Central Gold Belt. Three generations of folding events in Peninsular Malaysia have been recognized from remote sensing structural interpretation. Consequently, PALSAR satellite remote sensing data is a useful tool for mapping major geological structural features and detailed structural analysis of fault systems and deformation areas with high potential for sediment‐hosted/orogenic gold deposits and polymetallic vein‐type mineralization along margins of Precambrian blocks, especially for inaccessible regions in tropical environments.

GOLD MINERAL PROSPECTING USING PHASED ARRAY TYPE L-BAND SYNTHETIC APERTURE RADAR (PALSAR) SATELLITE REMOTE SENSING DATA, CENTRAL GOLD BELT, MALAYSIA

Abstract. The Bentong-Raub Suture Zone (BRSZ) of Peninsular Malaysia is one of the significant structural zones in Sundaland, Southeast Asia. It forms the boundary between the Gondwana-derived Sibumasu terrane in the west and Sukhothai arc in the east. The BRSZ is also genetically related to the sediment-hosted/orogenic gold deposits associated with the major lineaments and form-lines in the central gold belt Central Gold Belt of Peninsular Malaysia. In tropical environments, heavy tropical rainforest and intense weathering makes it impossible to map geological structures over long distances. Advances in remote sensing technology allow the application of Synthetic Aperture Radar (SAR) data in geological structural analysis for tropical environments. In this investigation, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to analyse major geological structures in Peninsular Malaysia and provide detailed characterization of lineaments and form-lines in the BRSZ, as well as its implication for sediment-hosted/orogenic gold exploration in tropical environments. The major geological structure directions of the BRSZ are N-S, NNE-SSW, NE-SW and NW-SE, which derived from directional filtering analysis to PALSAR data. The pervasive array of N-S faults in the study area and surrounding terrain is mainly linked to the N-S trending of the Suture Zone. N-S striking lineaments are often cut by younger NE-SW and NW-SE-trending lineaments. Gold mineralized trends lineaments are associated with the intersection of N-S, NE-SW, NNW-SSE and ESE-WNW faults and curvilinear features in shearing and alteration zones. Lineament analysis on PALSAR satellite remote sensing data is a useful tool for detecting the boundary between the Gondwana-derived terranes and major geological features associated with suture zone especially for large inaccessible regions in tropical environments.

GOLD MINERAL PROSPECTING USING PHASED ARRAY TYPE L-BAND SYNTHETIC APERTURE RADAR (PALSAR) SATELLITE REMOTE SENSING DATA, CENTRAL GOLD BELT, MALAYSIA

The Bentong-Raub Suture Zone (BRSZ) of Peninsular Malaysia is one of the significant structural zones in Sundaland, Southeast Asia. It forms the boundary between the Gondwana-derived Sibumasu terrane in the west and Sukhothai arc in the east. The BRSZ is also genetically related to the sediment-hosted/orogenic gold deposits associated with the major lineaments and form-lines in the central gold belt Central Gold Belt of Peninsular Malaysia. In tropical environments, heavy tropical rainforest and intense weathering makes it impossible to map geological structures over long distances. Advances in remote sensing technology allow the application of Synthetic Aperture Radar (SAR) data in geological structural analysis for tropical environments. In this investigation, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to analyse major geological structures in Peninsular Malaysia and provide detailed characterization of lineaments and form-lines in the BRSZ, as well as its implication for sediment-hosted/orogenic gold exploration in tropical environments. The major geological structure directions of the BRSZ are N-S, NNE-SSW, NE-SW and NW-SE, which derived from directional filtering analysis to PALSAR data. The pervasive array of N-S faults in the study area and surrounding terrain is mainly linked to the N-S trending of the Suture Zone. N-S striking lineaments are often cut by younger NE-SW and NW-SE-trending lineaments. Gold mineralized trends lineaments are associated with the intersection of N-S, NE-SW, NNW-SSE and ESE-WNW faults and curvilinear features in shearing and alteration zones. Lineament analysis on PALSAR satellite remote sensing data is a useful tool for detecting the boundary between the Gondwana-derived terranes and major geological features associated with suture zone especially for large inaccessible regions in tropical environments.

Kinematics of post-orogenic extension and exhumation of the Taku Schist, NE Peninsular Malaysia

Recent studies imply that the formation and evolution of many SE Asian basins was driven by extensional detachments or systems of low-angle normal faults that created significant crustal exhumation in their footwalls. In this context, the architecture of the Triassic Indosinian orogen presently exposed in Peninsular Malaysia is compatible with significant extension post-dating the orogenic event. In this study we performed a kinematic analysis based on fieldwork and microstructural observations in the Taku Schist, Kemahang granite and the surrounding Gua Musang sediments of northern Peninsular Malaysia in order to shed light on processes related to the build-up and subsequent demise of the Indosinian orogen. The first three phases of deformation were related to an overall period of E–W oriented contraction and burial metamorphism. These phases of deformation are characterized by isoclinal folding with flat lying axial plane cleavages (D1), asymmetrical folding, top-to-the-W–SW shearing (D2) and upright folding (D3). All are in general agreement with observations of the previously inferred Permo–Triassic Indosinian orogeny. During these times, the Taku Schist, a sequence of Paleozoic clastic sediments with mafic intercalations was metamorphosed to amphibolite facies. These rocks are most likely equivalent to the ones exposed in the Bentong–Raub suture zone. Structural relations suggest that the Triassic Kemahang pluton is syn-kinematic, which provides important constraints for the timing of these contractional events. We demonstrate that the overall shortening was followed by a hitherto undescribed extension in NW–SE direction resulting in the formation of a large-scale detachment, the Taku detachment, in northern Peninsular Malaysia. Extension probably reactivated the former subduction plane as a detachment and exhumed previously buried and metamorphosed rocks of similar lithological composition to the neighboring Bentong–Raub suture zone. Such a mechanism is similar to that observed in other regions, such as the Aegean, Apennines, Dinarides or the Betics–Rif system, where exhumation of (high-pressure) metamorphic rocks is largely controlled by detachments or low angle normal shear/fault systems.

Sediment-hosted/orogenic gold mineral systems exploration using PALSAR remote sensing data in Peninsular Malaysia

The Bentong-Raub Suture Zone (BRSZ) is genetically related to the sediment-hosted/orogenic gold deposits associated with the major lineaments and form-lines in the Central Gold Belt of Peninsular Malaysia. In this investigation, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to analyse major geological structures in Peninsular Malaysia and provide detailed characterization of lineaments and form-lines in the BRSZ, as well as its implications for sediment-hosted/orogenic gold exploration in tropical environments. The pervasive array of N-S faults in the study area and surrounding terrain is mainly linked to the N-S trending of the BRSZ Suture Zone. N-S striking lineaments are often cut by younger NE-SW and NW-SE-trending lineaments. Three generations of folding event have been discerned from remote sensing structural analysis. Gold mineralized trends lineaments are associated with the intersection of N-S, NE-SW, NNW-SSE and ESE-WNW faults and curvilinear features in shearing and alteration zones. Compressional tectonics structures such as NW-SE trending thrust, ENE-WSW oriented faults in mylonite and phyllite, recumbent folds and asymmetric anticlines in argillite are high potential zones for gold prospecting.

GEOLGICAL STRUCTURE MAPPING OF THE BENTONG-RAUB SUTURE ZONE, PENINSULAR MALAYSIA USING PALSAR REMOTE SENSING DATA

Abstract. The Bentong-Raub Suture Zone (BRSZ) of peninsular Malaysia was selected as case study to evaluate the capability of the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data for structural geology mapping in tropical environments. The structural elements in the BRSZ were enhanced using multi-polarization configuration of PALSAR data at a regional scale. Adaptive local sigma and directional filters were applied to PALSAR data for detailed structural mapping. Numerous tectonic lineaments with consistent variation in trend, length and density were detected in the study area. Structural analysis of the BRSZ reveals that two distinct parts can be defined, a western part affected mainly by ductile fabrics in the Cameron Highlands and an eastern part affected mainly by brittle deformation in the BRSZ. Ductile deformation indicates several generation of folding in the Cameron Highlands. Several faults, joints and fractures represent brittle deformation events in the BRSZ. The results of this study demonstrate the usefulness of PALSAR satellite remote sensing data for mapping geological structures in tropical environments.

Petrogenesis of Malaysian granitoids in the Southeast Asian tin belt: Part 2. U-Pb zircon geochronology and tectonic model

In our complementary geochemical study (Part 1), the Malaysian granitoids of the Southeast Asian tin belt were divided into a Middle Permian to Late Triassic I-type–dominated Eastern province (Indochina terrane) and a Triassic to Early Jurassic transitional I/S-type Main Range province (Sibumasu terrane), separated by the Bentong-Raub suture zone which closed in the Late Triassic. Previous geochronology has relied on only a few U-Pb zircon ages together with K-Ar and whole rock Rb-Sr ages that may not accurately record true magmatic ages. We present 39 new high-precision U-Pb zircon ion microprobe ages from granitoids and volcanics across the Malay Peninsula. Our results show that ages from the Eastern province granitoids span 289–220 Ma, with those from the Main Range province granitoids being entirely Late Triassic, spanning 227–201 Ma. A general westerly younging magmatic trend across the Malay Peninsula is considered to reflect steepening and roll-back of the Bentong-Raub subduction zone during progressive closure of Paleo-Tethys. The youngest ages of subduction-related granites in the Eastern province roughly coincide with the youngest ages of marine sedimentary rocks along the Paleo-Tethyan suture zone. Our petrogenetic and U-Pb zircon age data support models that relate the Eastern province granites to pre-collisional Andean-type magmatism and the western Main Range province granites to syn- and post-collisional crustal melting of Sibumasu crust during the Late Triassic. Tin mineralization was mainly associated with the latter phase of magmatism. Two alternative tectonic models are discussed to explain the Triassic evolution of the Malay Peninsula. The first involves a second Late Triassic to Jurassic or Early Cretaceous east-dipping subduction zone west of Sibumasu where subduction-related hornblende and biotite–bearing granites along Sibumasu are paired with Main Range crustal-melt tin-bearing granites, analogous to the Bolivia Cordilleran tin-bearing granite belt. The second model involves westward underthrusting of Indochina beneath the West Malaya Main Range province, resulting in crustal thickening and formation of tin-bearing granites of the Main Ranges. Cretaceous granitoids are also present locally in Singapore (Ubin diorite), on Tioman Island, in the Noring pluton, of the Stong complex (Eastern Province), and along the Sibumasu terrane in southwest Thailand and Burma (Myanmar), reflecting localized crustal melting.

Structural analysis and vein episode of the Penjom Gold Deposit, Malaysia: Implications for gold mineralisation and tectonic history in the Central Belt of Malaysia

Gold mineralisation at the Penjom Gold Deposit, in the Central Belt of Peninsular Malaysia is dominantly hosted in structurally controlled quartz-carbonate veins that display a variable degree of overprinting events under a ductile–brittle regime. Mineralised veins are categorised into two main episodes: fold and thrust-related veins mainly comprised of bedding and Penjom Thrust parallel shear veins and associated extension veins developed during a D2 event. In addition, NE to NNE trending splays and Penjom-Thrust-parallel reverse–dextral and locally NNW to NS reverse-sinistral faults overprint earlier vein events forming a new episode of extensional veins during D3 event, mostly at the fault contacts of intrusives either as shallow-dipping or vertical sheeted, stockwork or brecciated veins. At least two episodes of faulting D4–D5 are evident which postdates the main episodes of veining and mineralisation. This is indicated by a series of late episodes NS trending sinistral and oblique to normal faults which transect and displace the Penjom Thrust and the folded footwall sequence at low angles and responsible for intensive vein deformation along the Penjom Thrust and displacement of ore body. Structural interpretations of mineralised veins suggest that the veins were formed under a compressional to transpressional regime with later post-vein displacement in a transtensional to extensional regime. Vein formation in response to deformation observed at Penjom reflects regional structural deformation within the Central Belt of Peninsular Malaysia and specifically along the Bentong–Raub Suture zone.