H. Breitfeld, S. Burley, T. Galin, Juliane Hennig-Breitfeld, Roslan Rajali
The pre-Cretaceous history of Borneo remains relatively poorly studied. Limited exposures of Palaeozoic and lower Mesozoic rocks are located in NW Kalimantan and in West Sarawak, an area interpreted as the West Borneo basement. Lower Mesozoic sedimentary rocks in West Sarawak were analysed to study their depositional environments and implications for the tectonic evolution. Upper Triassic turbidites in West Sarawak, exposed in the northern part of Kuching city, informally named the Kuching Formation, are the deep marine equivalent to the more widespread, shallow marine Sadong Formation. The Kuching Formation comprises thinly-bedded stacked turbidites, consisting of incomplete Bouma sequences, with multiple, erosive channel sandstone bodies deposited under upper flow regime waning flows. Thin debrites with abundant coaly-material are interbedded with the channel sandstones. The Kuching and Sadong formations both contain volcaniclastic detritus that was derived from the westward-subducting Palaeo-Pacific plate, forming a Triassic Andean-type arc which extended from West Borneo in the south to southern China, Taiwan and Japan in the north. Palaeoproterozoic to Archean detrital zircons in the Kuching and Sadong formations reveal a Cathaysian basement source, providing insights into the nature of the West Borneo basement. Quartz-mica schists (Kerait Schist, Tuang Formation) in fault-contact with the two sedimentary successions may have formed during accretion.
{"title":"The Kuching Formation: A deep marine equivalent of the Sadong Formation, and its implications for the Early Mesozoic tectonic evolution of western and southern Borneo","authors":"H. Breitfeld, S. Burley, T. Galin, Juliane Hennig-Breitfeld, Roslan Rajali","doi":"10.7186/bgsm76202308","DOIUrl":"https://doi.org/10.7186/bgsm76202308","url":null,"abstract":"The pre-Cretaceous history of Borneo remains relatively poorly studied. Limited exposures of Palaeozoic and lower Mesozoic rocks are located in NW Kalimantan and in West Sarawak, an area interpreted as the West Borneo basement. Lower Mesozoic sedimentary rocks in West Sarawak were analysed to study their depositional environments and implications for the tectonic evolution. Upper Triassic turbidites in West Sarawak, exposed in the northern part of Kuching city, informally named the Kuching Formation, are the deep marine equivalent to the more widespread, shallow marine Sadong Formation. The Kuching Formation comprises thinly-bedded stacked turbidites, consisting of incomplete Bouma sequences, with multiple, erosive channel sandstone bodies deposited under upper flow regime waning flows. Thin debrites with abundant coaly-material are interbedded with the channel sandstones. The Kuching and Sadong formations both contain volcaniclastic detritus that was derived from the westward-subducting Palaeo-Pacific plate, forming a Triassic Andean-type arc which extended from West Borneo in the south to southern China, Taiwan and Japan in the north. Palaeoproterozoic to Archean detrital zircons in the Kuching and Sadong formations reveal a Cathaysian basement source, providing insights into the nature of the West Borneo basement. Quartz-mica schists (Kerait Schist, Tuang Formation) in fault-contact with the two sedimentary successions may have formed during accretion.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139201313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Fauzi, Edwin James, Muhammad Sufi Musa, Hamdan Ariffin, Abdullah Sulaiman, M. Sibon, Abdul Hadi Abdul Rahman, Muhammad Falah Zahri, Azizan Ali
This paper reports on the rare earth element (REE) deposit in Bukit Enggang Granite in Sik, Kedah, and its enrichment patterns. The granitic rock in the study area is porphyritic biotite granite with K-feldspar, quartz and biotite as the main minerals, with randomly arranged K-feldspar phenocrysts. The average REE content in rock samples is 340.9 ppm. The exposed weathered profiles are between 3 to 7 meters in thickness. The C horizon is thicker than the B horizon. The average REE content in soil samples taken from the weathered profiles is 943.9 ppm. Interpretations from laboratory results reveal that the REE deposit in the study area is of the ion adsorption-type, with the REE enrichment in the weathered profiles originating from easily weathered REE bearing minerals in the parent rock, rather than highly resistant minerals like monazite, xenotime and zircon.
{"title":"Ion adsorption-type rare earth element deposits in western Peninsular Malaysia: A case study in Bukit Enggang Granite, Kedah","authors":"F. Fauzi, Edwin James, Muhammad Sufi Musa, Hamdan Ariffin, Abdullah Sulaiman, M. Sibon, Abdul Hadi Abdul Rahman, Muhammad Falah Zahri, Azizan Ali","doi":"10.7186/bgsm76202303","DOIUrl":"https://doi.org/10.7186/bgsm76202303","url":null,"abstract":"This paper reports on the rare earth element (REE) deposit in Bukit Enggang Granite in Sik, Kedah, and its enrichment patterns. The granitic rock in the study area is porphyritic biotite granite with K-feldspar, quartz and biotite as the main minerals, with randomly arranged K-feldspar phenocrysts. The average REE content in rock samples is 340.9 ppm. The exposed weathered profiles are between 3 to 7 meters in thickness. The C horizon is thicker than the B horizon. The average REE content in soil samples taken from the weathered profiles is 943.9 ppm. Interpretations from laboratory results reveal that the REE deposit in the study area is of the ion adsorption-type, with the REE enrichment in the weathered profiles originating from easily weathered REE bearing minerals in the parent rock, rather than highly resistant minerals like monazite, xenotime and zircon.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"73 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139204605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The question of uplift in the Sarawak Foreland is addressed in a multi-disciplinary approach, namely by assigning surface vitrinite reflectance measurements to depth, and by vitrinite reflectance-to-depth conversion using functions from two previous studies. Additional erosion and uplift data were obtained by comparing eroded anticlinal crests with adjacent synclines and their preserved sediments. The combined data pool suggests two types of uplift (I) a regional uplift in the Neogene affecting the entire coastal area, and (II) a tectonically focused uplift. The amount of the latter uplift and erosion is directly linked to rise of anticlinal structures during the Upper Pliocene, with a total uplift ranging from 700 to 4,000 m in areas along prominent regional faults. Within a very short time window major sedimentation, folding, trap formation and trap destruction took place both as a consequence of folding and erosion. Only anticlines in the offshore and the proximal onshore appear to have survived without major crestal erosion. Since the end of the Pleistocene, a rise of foreland sections by some 132 m is recognized. The rapid Pliocene burial and the erosion that consequently removed the overburden thereafter may have negatively affected the petroleum system and hydrocarbon accumulation within the Miri area, which was left largely intact only in the Siwa-Seria anticlinal trend. All anticlines were targeted by petroleum exploration. However, only the Siwa-Seria trend has proved to be economically successful. This has highlighted the significance of overburden in relation to depth of burial and the thermal effect needed to mature the source rocks capable to generate hydrocarbons.
{"title":"Estimation of uplift and erosion in the Miri area of northwest Sarawak, Malaysia: A multidisciplinary approach","authors":"Franz-Luitpold Kessler, Wan Hasiah Abdullah","doi":"10.7186/bgsm76202306","DOIUrl":"https://doi.org/10.7186/bgsm76202306","url":null,"abstract":"The question of uplift in the Sarawak Foreland is addressed in a multi-disciplinary approach, namely by assigning surface vitrinite reflectance measurements to depth, and by vitrinite reflectance-to-depth conversion using functions from two previous studies. Additional erosion and uplift data were obtained by comparing eroded anticlinal crests with adjacent synclines and their preserved sediments. The combined data pool suggests two types of uplift (I) a regional uplift in the Neogene affecting the entire coastal area, and (II) a tectonically focused uplift. The amount of the latter uplift and erosion is directly linked to rise of anticlinal structures during the Upper Pliocene, with a total uplift ranging from 700 to 4,000 m in areas along prominent regional faults. Within a very short time window major sedimentation, folding, trap formation and trap destruction took place both as a consequence of folding and erosion. Only anticlines in the offshore and the proximal onshore appear to have survived without major crestal erosion. Since the end of the Pleistocene, a rise of foreland sections by some 132 m is recognized. The rapid Pliocene burial and the erosion that consequently removed the overburden thereafter may have negatively affected the petroleum system and hydrocarbon accumulation within the Miri area, which was left largely intact only in the Siwa-Seria anticlinal trend. All anticlines were targeted by petroleum exploration. However, only the Siwa-Seria trend has proved to be economically successful. This has highlighted the significance of overburden in relation to depth of burial and the thermal effect needed to mature the source rocks capable to generate hydrocarbons.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"37 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139196564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subsidence analysis of Sarawak Basin using stratigraphic data from a selection of exploration wells revealed a multi-phase history of crustal extension (rifting), subsidence and uplift. A relatively rapid subsidence during the early rift phase from Eocene to Oligocene (ca. 37–28 Ma) was followed by a gradual decrease in subsidence rate as the extended lithosphere underwent post-rift thermal relaxation (ca. 28–22 Ma). A second phase of extension during the Early Miocene (ca. 22–17 Ma) resulted in an increase in subsidence rate, which coincided with a major episode of compressional deformation, uplift and localised erosion. This deformation event culminated in a major unconformity dated ~16 Ma, known as the Middle Miocene Unconformity (MMU), which is recognised throughout the Bunguran Trough and North Luconia regions of Sarawak Basin as a major stratigraphic hiatus spanning the Early to Middle Miocene. Since the Late Miocene, there had been an increase in the subsidence rate, probably due to progradation of the Sarawak shelf to its present-day configuration. The complex subsidence history of Sarawak Basin is similar to those reported from other parts of the South China Sea margin. The subsidence histories indicate a common, underlying tectonic factor which is probably related to rifting and sea-floor spreading in the southwestern prong of the South China Sea oceanic basin.
利用部分勘探井的地层数据对沙捞越盆地进行的沉降分析表明，地壳经历了延伸（断裂）、沉降和隆起等多个阶段。在始新世至渐新世的早期断裂阶段（约 37-28 千兆年），地壳下沉速度相对较快，之后，随着延伸的岩石圈经历断裂后的热松弛（约 28-22 千兆年），地壳下沉速度逐渐降低。早中新世的第二阶段延伸（约 22-17 Ma）导致下沉率上升，与此同时，发生了大规模的压缩变形、隆起和局部侵蚀。这一变形事件最终导致了一个年代约为 16 Ma 的主要不整合地层，即中新世不整合地层（MMU），整个砂拉越盆地的 Bunguran Trough 和 North Luconia 地区都将其视为横跨早中新世的一个主要地层断裂带。自晚中新世以来，沉降速度一直在加快，这可能是由于砂拉越陆架逐渐隆升到了今天的构造。砂拉越盆地复杂的沉降历史与南海边缘其他地区的沉降历史相似。这些沉降历史表明了一个共同的、潜在的构造因素，它可能与南海大洋盆地西南棱的断裂和海底扩张有关。
{"title":"Multi-phase subsidence history of the Sarawak continental margin and its regional significance","authors":"M. Madon, J. Jong","doi":"10.7186/bgsm76202307","DOIUrl":"https://doi.org/10.7186/bgsm76202307","url":null,"abstract":"Subsidence analysis of Sarawak Basin using stratigraphic data from a selection of exploration wells revealed a multi-phase history of crustal extension (rifting), subsidence and uplift. A relatively rapid subsidence during the early rift phase from Eocene to Oligocene (ca. 37–28 Ma) was followed by a gradual decrease in subsidence rate as the extended lithosphere underwent post-rift thermal relaxation (ca. 28–22 Ma). A second phase of extension during the Early Miocene (ca. 22–17 Ma) resulted in an increase in subsidence rate, which coincided with a major episode of compressional deformation, uplift and localised erosion. This deformation event culminated in a major unconformity dated ~16 Ma, known as the Middle Miocene Unconformity (MMU), which is recognised throughout the Bunguran Trough and North Luconia regions of Sarawak Basin as a major stratigraphic hiatus spanning the Early to Middle Miocene. Since the Late Miocene, there had been an increase in the subsidence rate, probably due to progradation of the Sarawak shelf to its present-day configuration. The complex subsidence history of Sarawak Basin is similar to those reported from other parts of the South China Sea margin. The subsidence histories indicate a common, underlying tectonic factor which is probably related to rifting and sea-floor spreading in the southwestern prong of the South China Sea oceanic basin.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139200155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhamad Kadri, Nordiana MOHD MUZTAZA, Mohd Nawawi Mohd Nordin, M. Zakaria, F. Rosli, Mustapha Adeejo Mohammed, Siti Zulaika
The manifestations of some hot springs in Siogung-Ogung, North Sumatra, Indonesia have increased speculation of likely geothermal sources. Therefore, integrated geochemical and geophysical methods were employed to identify the geothermal prospect of the area. Two-dimensional electrical resistivity and geomagnetic methods were used for the geophysical survey. The geochemical survey used three concentration measurements: geothermometer silica (SiO2), geothermometer Na-K, and geothermometer Na-K-Ca. A Wenner Schlumberger array with a 5-meter electrode spacing was used to acquire the 2-D resistivity data, which was processed using Res2Dinv software. The geomagnetic method was performed with a proton precession magnetometer, and the data were processed using Surfer to produce the magnetic residual map. The 2-D electrical resistivity results show that the area has low resistivity values (1-700 Ωm). The resistivity values from 1 to 100 Ωm could be due to the presence of hot waters in alluvium, and the resistivity values > 400 indicate andesite rock, which can function as a hot water conductor from the source. The magnetic residual map shows geomagnetic values from 150 nT to 360 nT, which infer the potentiality of geothermal within the study area. The geochemical results show that the reservoir temperature is 572 °C. Based on the integrated results, the study area has promising geothermal potential.
{"title":"Integrated geophysical methods used to explore geothermal potential areas in Siogung-Ogung, North Sumatra, Indonesia","authors":"Muhamad Kadri, Nordiana MOHD MUZTAZA, Mohd Nawawi Mohd Nordin, M. Zakaria, F. Rosli, Mustapha Adeejo Mohammed, Siti Zulaika","doi":"10.7186/bgsm76202304","DOIUrl":"https://doi.org/10.7186/bgsm76202304","url":null,"abstract":"The manifestations of some hot springs in Siogung-Ogung, North Sumatra, Indonesia have increased speculation of likely geothermal sources. Therefore, integrated geochemical and geophysical methods were employed to identify the geothermal prospect of the area. Two-dimensional electrical resistivity and geomagnetic methods were used for the geophysical survey. The geochemical survey used three concentration measurements: geothermometer silica (SiO2), geothermometer Na-K, and geothermometer Na-K-Ca. A Wenner Schlumberger array with a 5-meter electrode spacing was used to acquire the 2-D resistivity data, which was processed using Res2Dinv software. The geomagnetic method was performed with a proton precession magnetometer, and the data were processed using Surfer to produce the magnetic residual map. The 2-D electrical resistivity results show that the area has low resistivity values (1-700 Ωm). The resistivity values from 1 to 100 Ωm could be due to the presence of hot waters in alluvium, and the resistivity values > 400 indicate andesite rock, which can function as a hot water conductor from the source. The magnetic residual map shows geomagnetic values from 150 nT to 360 nT, which infer the potentiality of geothermal within the study area. The geochemical results show that the reservoir temperature is 572 °C. Based on the integrated results, the study area has promising geothermal potential.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":" 59","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139207327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marcus R. Dobbs, Q. A. Rosle, Dalila Ahmad, Helen F. Burke
The objective of UN Sustainable Development Goal 11 is to make cities and human settlements inclusive, safe, resilient and sustainable. Geoscience can play a significant role in achieving targets within this goal by developing a better understanding of geological properties and processes within urban environments, and by ensuring that this understanding is integrated into urban development. A key step in this process will be enhancing awareness of urban geology among non-geoscience decision-makers, so that inherent subsurface risks and benefits are understood and accounted for during all phases of development. Three-dimensional geological models are an effective tool for geologists to communicate with stakeholders in government and industry during that process. They can also provide a framework to enable geological data and information to be integrated into Building and City Information Models, and thus facilitate more effective infrastructure and utility asset management. This paper describes the modelling workflow adopted by a consortium of geoscientists from government, industry and academia to deliver the first 3D geological model of Kuala Lumpur – 3DKL v1.0. The modelling workflow involved: digitising borehole logs from site investigation reports and storing them in a dedicated geospatially-enabled SQLite borehole database; viewing and interpreting that borehole data using QGIS software; generating multiple orthogonally oriented cross-section profiles across the modelled area using Groundhog Desktop software; and integrating the information derived from the interpreted boreholes, surface data and cross-section profiles to generate a 3D geological model in Leapfrog Geo software. 3DKL v1.0 has demonstrated proof-of-concept: we have developed a workflow, based largely on freely-available software, for transforming borehole information, previously captured in paper records, into a conceptual 3D model. The modelling process has also identified areas where geological knowledge and data need to be enhanced if 3DKL is to fulfil its potential to support more sustainable and resilient urban development in Kuala Lumpur.
{"title":"3DKL v1.0: Creating the first 3D geological model of Kuala Lumpur","authors":"Marcus R. Dobbs, Q. A. Rosle, Dalila Ahmad, Helen F. Burke","doi":"10.7186/bgsm76202302","DOIUrl":"https://doi.org/10.7186/bgsm76202302","url":null,"abstract":"The objective of UN Sustainable Development Goal 11 is to make cities and human settlements inclusive, safe, resilient and sustainable. Geoscience can play a significant role in achieving targets within this goal by developing a better understanding of geological properties and processes within urban environments, and by ensuring that this understanding is integrated into urban development. A key step in this process will be enhancing awareness of urban geology among non-geoscience decision-makers, so that inherent subsurface risks and benefits are understood and accounted for during all phases of development. Three-dimensional geological models are an effective tool for geologists to communicate with stakeholders in government and industry during that process. They can also provide a framework to enable geological data and information to be integrated into Building and City Information Models, and thus facilitate more effective infrastructure and utility asset management. This paper describes the modelling workflow adopted by a consortium of geoscientists from government, industry and academia to deliver the first 3D geological model of Kuala Lumpur – 3DKL v1.0. The modelling workflow involved: digitising borehole logs from site investigation reports and storing them in a dedicated geospatially-enabled SQLite borehole database; viewing and interpreting that borehole data using QGIS software; generating multiple orthogonally oriented cross-section profiles across the modelled area using Groundhog Desktop software; and integrating the information derived from the interpreted boreholes, surface data and cross-section profiles to generate a 3D geological model in Leapfrog Geo software. 3DKL v1.0 has demonstrated proof-of-concept: we have developed a workflow, based largely on freely-available software, for transforming borehole information, previously captured in paper records, into a conceptual 3D model. The modelling process has also identified areas where geological knowledge and data need to be enhanced if 3DKL is to fulfil its potential to support more sustainable and resilient urban development in Kuala Lumpur.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139200226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Bulletin of the Geological Science of Malaysia is a peer-reviewed open access interdisciplinary Earth Science journal. Over the decades, the Bulletin has documented about 1400 articles covering trending research topics and original findings in geology that contribute both directly and indirectly to sustainable development. Areas covered include economic geology, engineering geology, environmental geology, geochemistry, geological heritage, geomorphology, geophysics, hydrogeology, mining geology, palaeontology, petroleum geology, regional geology, sedimentology, stratigraphy, structural geology and tectonics. While the geographic focus is primarily Malaysia and Southeast Asia, comparative studies from other regions that are of current interest and have potential impact on sustainable development are also considered important. This includes findings related to oil and gas, mining, environmental management, heritage conservation, geotourism, earthquake and hazard assessment, disaster risk reduction and climate change. It is a pleasure to present to you the 76th volume of the Bulletin of the Geological Society of Malaysia that comprises seven articles. The lead article by Dobbs et al. (2023) is relevant to the United Nations Sustainable Development Goal 11 (SDG 11) on Sustainable Cities and Communities. The following two articles by Fauzi et al. (2023) and Kadri et al. (2023) contribute to SDG 9 on Clean and Affordable Energy as well as SDG 13 on Climate Action. The article by Raj (2023) is rooted in the field of engineering geology. The remaining articles by Kessler & Abdullah (2023), Madon & Jong (2023) and Breitfeld et al. (2023) draw on multiple fields of geology such as regional geology, sedimentology, stratigraphy and tectonics. All these articles document geological knowledge that indirectly support sustainable development.
{"title":"Contributing geological knowledge for sustainable development","authors":"Joy Jacqueline Pereira","doi":"10.7186/bgsm76202301","DOIUrl":"https://doi.org/10.7186/bgsm76202301","url":null,"abstract":"The Bulletin of the Geological Science of Malaysia is a peer-reviewed open access interdisciplinary Earth Science journal. Over the decades, the Bulletin has documented about 1400 articles covering trending research topics and original findings in geology that contribute both directly and indirectly to sustainable development. Areas covered include economic geology, engineering geology, environmental geology, geochemistry, geological heritage, geomorphology, geophysics, hydrogeology, mining geology, palaeontology, petroleum geology, regional geology, sedimentology, stratigraphy, structural geology and tectonics. While the geographic focus is primarily Malaysia and Southeast Asia, comparative studies from other regions that are of current interest and have potential impact on sustainable development are also considered important. This includes findings related to oil and gas, mining, environmental management, heritage conservation, geotourism, earthquake and hazard assessment, disaster risk reduction and climate change. It is a pleasure to present to you the 76th volume of the Bulletin of the Geological Society of Malaysia that comprises seven articles. The lead article by Dobbs et al. (2023) is relevant to the United Nations Sustainable Development Goal 11 (SDG 11) on Sustainable Cities and Communities. The following two articles by Fauzi et al. (2023) and Kadri et al. (2023) contribute to SDG 9 on Clean and Affordable Energy as well as SDG 13 on Climate Action. The article by Raj (2023) is rooted in the field of engineering geology. The remaining articles by Kessler & Abdullah (2023), Madon & Jong (2023) and Breitfeld et al. (2023) draw on multiple fields of geology such as regional geology, sedimentology, stratigraphy and tectonics. All these articles document geological knowledge that indirectly support sustainable development.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139208321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Concentric layers of weathered materials around core-stones show the rhyolite to experience sequential, but gradational, changes in visible features, textures and mineralogy as it transforms from ‘rock’ into ‘soil’. The changes start with the opening-up of grain boundaries and micro-cracks (stage 1) followed by their dark brown staining (stage 2) and the subsequent alteration (to sericite and clay minerals) of plagioclase feldspar groundmass grains and phenocrysts (stage 3). Biotite flakes are then bleached and altered (to chlorite and clay minerals) (stage 4) before there starts alteration (to sericite and clay minerals) of groundmass alkali feldspar grains (stage 5) and finally alteration of alkali feldspar phenocrysts (stage 6). Quartz grains are not altered during these stages of weathering but disaggregate and reduce in size due to continual opening-up of grain boundaries and micro-cracks. Increasing stages of weathering are marked by decreasing dry unit weights, dry densities and uniaxial compressive strengths, but increasing apparent porosities. The transition between ‘rock’ and ‘soil’ occurs during weathering stage 6 when all plagioclase groundmass grains and phenocrysts have been altered as have been all alkali feldspar groundmass grains and most phenocrysts. Stage 6 is marked by large apparent porosities (>14%) but low values of dry unit weight (<21.90 kN/m3) and dry density (<2,232 kg/m3).
{"title":"Rock - soil transition during weathering of rhyolite","authors":"John Kuna Raj","doi":"10.7186/bgsm76202305","DOIUrl":"https://doi.org/10.7186/bgsm76202305","url":null,"abstract":"Concentric layers of weathered materials around core-stones show the rhyolite to experience sequential, but gradational, changes in visible features, textures and mineralogy as it transforms from ‘rock’ into ‘soil’. The changes start with the opening-up of grain boundaries and micro-cracks (stage 1) followed by their dark brown staining (stage 2) and the subsequent alteration (to sericite and clay minerals) of plagioclase feldspar groundmass grains and phenocrysts (stage 3). Biotite flakes are then bleached and altered (to chlorite and clay minerals) (stage 4) before there starts alteration (to sericite and clay minerals) of groundmass alkali feldspar grains (stage 5) and finally alteration of alkali feldspar phenocrysts (stage 6). Quartz grains are not altered during these stages of weathering but disaggregate and reduce in size due to continual opening-up of grain boundaries and micro-cracks. Increasing stages of weathering are marked by decreasing dry unit weights, dry densities and uniaxial compressive strengths, but increasing apparent porosities. The transition between ‘rock’ and ‘soil’ occurs during weathering stage 6 when all plagioclase groundmass grains and phenocrysts have been altered as have been all alkali feldspar groundmass grains and most phenocrysts. Stage 6 is marked by large apparent porosities (>14%) but low values of dry unit weight (<21.90 kN/m3) and dry density (<2,232 kg/m3).","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139201086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marking the 75th volume of Bulletin of the Geological Society of Malaysia
纪念《马来西亚地质学会公报》第75卷
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Muhamad Shafiq Mohd Ali, Zuliskandar Ramli, Nur Farriehah Azizan
Gua Kelew is one of the newly discovered caves by archaeological researchers in Malaysia. This cave has the potential to become one of Malaysia’s prehistoric sites from the findings from site surveys and archaeological excavations. Among the artifacts that were found are stone tools, earthenware, ceramics, snail shells, cave paintings and animal bones. The discovered earthenwares were analyzed for their mineral content in order to determine whether they were made locally around the cave or brought from elsewhere. The outcome of this analysis is vital as the data would provide proof that the community living in the cave or the surrounding area had its own technology for manufacturing the earthenwares. However, if the earthenwares were brought from elsewhere, it is believed that trade or the exchange of goods between communities living inland and near the coast had occurred. Composition of the earthenware samples was obtained by X-Ray Diffraction (XRD) analysis for mineral content and also X-Ray Flouresence (XRF) analysis for major, minor and trace elements. Findings from the XRD analysis show that the mineral content in the earthenware samples are quartz, calcite and anorthoclase, while the XRF analysis shows a high content of silica and aluminium. The analysis also discovered that all of the earthenwares found in Gua Kelew used the same raw materials obtained from the same area. Based on the graph plot analysis, the data exhibits differences in the elements between the earthenware samples and the surrounding area’s clay samples. Hence, it is suggested that the earthenwares found in Gua Kelew were not produced in the Hulu Kelantan area. This also indicates that the earthenwares may have been brought from another location to the area through trade deal between the local and foreign communities.
{"title":"Geochemistry and mineralogy of prehistoric pottery shards found at Gua Kelew, Nenggiri Valley, Kelantan, Malaysia","authors":"Muhamad Shafiq Mohd Ali, Zuliskandar Ramli, Nur Farriehah Azizan","doi":"10.7186/bgsm75202308","DOIUrl":"https://doi.org/10.7186/bgsm75202308","url":null,"abstract":"Gua Kelew is one of the newly discovered caves by archaeological researchers in Malaysia. This cave has the potential to become one of Malaysia’s prehistoric sites from the findings from site surveys and archaeological excavations. Among the artifacts that were found are stone tools, earthenware, ceramics, snail shells, cave paintings and animal bones. The discovered earthenwares were analyzed for their mineral content in order to determine whether they were made locally around the cave or brought from elsewhere. The outcome of this analysis is vital as the data would provide proof that the community living in the cave or the surrounding area had its own technology for manufacturing the earthenwares. However, if the earthenwares were brought from elsewhere, it is believed that trade or the exchange of goods between communities living inland and near the coast had occurred. Composition of the earthenware samples was obtained by X-Ray Diffraction (XRD) analysis for mineral content and also X-Ray Flouresence (XRF) analysis for major, minor and trace elements. Findings from the XRD analysis show that the mineral content in the earthenware samples are quartz, calcite and anorthoclase, while the XRF analysis shows a high content of silica and aluminium. The analysis also discovered that all of the earthenwares found in Gua Kelew used the same raw materials obtained from the same area. Based on the graph plot analysis, the data exhibits differences in the elements between the earthenware samples and the surrounding area’s clay samples. Hence, it is suggested that the earthenwares found in Gua Kelew were not produced in the Hulu Kelantan area. This also indicates that the earthenwares may have been brought from another location to the area through trade deal between the local and foreign communities.","PeriodicalId":39503,"journal":{"name":"Bulletin of the Geological Society of Malaysia","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135996839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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