Warta Geologi最新文献

Soil moisture retention characteristics of saprock in a weathering profile over rhyolite in Peninsular Malaysia 马来西亚半岛流纹岩风化剖面中腐积层土壤水分保持特征

Warta Geologi Pub Date : 2023-08-30 DOI: 10.7186/wg492202302

John Kuna Raj

{"title":"Soil moisture retention characteristics of saprock in a weathering profile over rhyolite in Peninsular Malaysia","authors":"John Kuna Raj","doi":"10.7186/wg492202302","DOIUrl":"https://doi.org/10.7186/wg492202302","url":null,"abstract":"Three broad zones can be differentiated at the weathering profile; an upper 3.9 m thick pedological soil (zone I), an intermediate 21.4 m thick saprock (zone II), and the underlying bedrock (zone III). To determine the soil moisture retention characteristics of saprock, samples were collected at vertical depths of 5.7 m (sample A), 9.1 m (sample B), 12.7 m (sample C) and 16.9 m (sample D). Samples A and B with porosities of 39% and 48%, had 7% and 6% gravel fractions, 48% and 57% sand fractions, 32% and 30% silt fractions, and 13% and 7% clay fractions, respectively. Samples C and D with similar porosities of 46%, had 6% and 17% gravel fractions, 56% and 45% sand fractions, 32% silt fractions, and 6% clay fractions, respectively. Laboratory determinations employing the pressure plate method show increasing suctions from 0 kPa through 0.98 kPa and 9.8 kPa to 33 kPa and 1,500 kPa to result in gravimetric soil moisture retentions of 28.3% through 24.0% and 19.2% to 15.0% and 5.7% for sample A, and from 21.7% through 21.1% and 17.8% to 11.9% and 3.8% for sample B. Similarly increasing auctions yield gravimetric soil moisture retentions of 28.3% through 34.7% and 29.1% to 23.2% and 7.0% for sample C, and from 28.4% to 28.1% and 23.4% to 18.6% and 5.0% for sample D. Regression analyses of gravel, sand and clay fractions plotted against moisture contents retained at large suctions (33 kPa and 1500 kPa) yield variable trends with low correlation coefficients (R2<0.179), though plots involving silt contents yield positive trends with larger correlation coefficients (R2 >0.525). It is concluded that the adsorption of water on the surfaces of silt particles that most likely results in retention of soil moisture by saprock.","PeriodicalId":272380,"journal":{"name":"Warta Geologi","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130921624","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}

引用次数: 0

The Paleo-Lupar: Bathymetric and seismic evidence for a submerged Late Pleistocene river valley on the Sunda Shelf, off Sarawak 古卢帕尔:沙捞越巽他陆架上一个淹没的晚更新世河谷的测深和地震证据

Warta Geologi Pub Date : 2023-08-30 DOI: 10.7186/wg492202301

M. Madon

引用次数: 0

Advancing science, technology and innovation for disaster risk reduction: The Kuala Lumpur Consensus on Disaster Risk Reduction 推动科学、技术和创新以减少灾害风险:关于减少灾害风险的吉隆坡共识

Warta Geologi Pub Date : 2023-04-30 DOI: 10.7186/wg491202303

J. Pereira, Tariqur Rahman Bhuiyan, Nurfashareena Muhamad, Saini Yang, R. Shaw

{"title":"Advancing science, technology and innovation for disaster risk reduction: The Kuala Lumpur Consensus on Disaster Risk Reduction","authors":"J. Pereira, Tariqur Rahman Bhuiyan, Nurfashareena Muhamad, Saini Yang, R. Shaw","doi":"10.7186/wg491202303","DOIUrl":"https://doi.org/10.7186/wg491202303","url":null,"abstract":"The Kuala Lumpur Consensus on Disaster Risk Reduction was the outcome of the 2020 Asia Pacific Science and Technology Conference for Disaster Risk Reduction (APSTCDRR), documenting renewed commitment to accelerate the implementation of the Sendai Framework for Disaster Risk Reduction in four priority areas, drawing on multi-disciplinary knowledge including geoscience. The 2020 APSTCDRR offered an opportunity for science-policy interfacing to enhance the appropriate role of science, technology and innovation, facilitate the inclusion of empowered young scientists, and accentuate the integration of risk from all perspectives into planning and development at all levels. Highlights of the 2020 APSTCDRR include the status of disaster risk reduction (DRR) in the Asia Pacific, and means of addressing systemic risk including Natural Hazards Triggering Technological Disasters (NATECH) and its associated shortcomings in the region. There was also focus on climate risk and local action spotlighting the Kuala Lumpur Multi-hazard Platform, as well as youth engagement in science and technology through U-INSPIRE Alliance, an alliance of young professionals in DRR. Many of the initiatives showcased in the 2020 APSTCDRR are of relevance to the geoscience community, to strengthen their role in DRR in Malaysia and the region.","PeriodicalId":272380,"journal":{"name":"Warta Geologi","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134480963","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}

引用次数: 0

Does the Caribbean hold lessons for SE Asia? Part 2 加勒比对东南亚有什么借鉴意义吗?第2部分

Warta Geologi Pub Date : 2023-04-30 DOI: 10.7186/wg491202301

H. Doust

引用次数: 0

The sea level rose fast, but Sarawak was rising faster 海平面上升得很快，但沙捞越上升得更快

Warta Geologi Pub Date : 2023-04-30 DOI: 10.7186/wg491202302

F. Kessler

引用次数: 0

Does the Caribbean hold lessons for SE Asia? Part 1: The geology of Trinidad 加勒比对东南亚有什么借鉴意义吗?第一部分:特立尼达的地质

Warta Geologi Pub Date : 2022-12-30 DOI: 10.7186/wg483202201

H. Doust

引用次数: 0

Characterizing a weathering profile over quartz-mica schists in undulating terrain in Peninsular Malaysia 马来西亚半岛起伏地形中石英-云母片岩风化剖面特征

Warta Geologi Pub Date : 2022-12-30 DOI: 10.7186/wg483202202

John Kuna Raj

{"title":"Characterizing a weathering profile over quartz-mica schists in undulating terrain in Peninsular Malaysia","authors":"John Kuna Raj","doi":"10.7186/wg483202202","DOIUrl":"https://doi.org/10.7186/wg483202202","url":null,"abstract":"The weathering profile can be differentiated into an upper, 4.8 m thick, pedological soil (zone I) and a lower, >16.2 m thick, saprock (zone II). Zone I comprises thin IA and IB soil horizons of firm, clayey sand with lateritic concretions, and a IC soil horizon of stiff, clayey silt with quartz clasts and lateritized core-stones. Zone II comprises steeply dipping to vertical, bands of pinkish to grey, stiff silt with distinct relict foliation (highly weathered schist) inter-fingering with bands of reddish yellow, firm clayey silt with indistinct foliation (completely weathered schist) towards its top, and bands of white to light grey, hard silt with distinct foliation (moderately weathered schist) towards its bottom. Lateral variations in abundance of differently weathered schist and preservation of fracture planes allow zone II to be separated into IIA, IIB and IIC sub-zones. The pedological soil (zone I) can be correlated with Class VI of standard rock mass weathering classifications, whilst the saprock sub-zones IIA, IIB and IIC are correlated with Classes V, IV and III, respectively. Silt fractions in the profile consist predominantly of sericite flakes, whilst the sand fractions are mostly of quartz grains and the clay fractions of mainly illite and kaolinite. Decreasing densities, unit weights and silt contents up the profile, but increasing porosities and clay contents, indicate increasing in situ alteration of the schist bedrock. Lowering of an unconfined groundwater table as a result of down-cutting by rivers in adjacent valleys is considered responsible for development of the weathering profile.","PeriodicalId":272380,"journal":{"name":"Warta Geologi","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116087051","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}

引用次数: 0

Characterizing a weathering profile over serpentinite in the Senaling area, Negeri Sembilan Darul Khusus Sembilan Negeri Darul Khusus的Senaling地区蛇纹岩风化剖面特征

Warta Geologi Pub Date : 2022-08-30 DOI: 10.7186/wg482202201

John Kuna Raj

{"title":"Characterizing a weathering profile over serpentinite in the Senaling area, Negeri Sembilan Darul Khusus","authors":"John Kuna Raj","doi":"10.7186/wg482202201","DOIUrl":"https://doi.org/10.7186/wg482202201","url":null,"abstract":"Three broad morphological zones can be differentiated; the top, 2.5 m thick, pedological soil comprising IA and IB sub-zones of brown, soft clays, and IC1 and IC2 sub-zones of reddish brown, stiff silty clays with lateritic concretions and lateritized core stones. The intermediate, 1.5 m thick, saprock zone consists of brown, stiff, silty clays with indistinct relict fault planes and core-stones, whilst the bottom bedrock zone consists of serpentinite with effects of weathering along discontinuity planes. Constant volume samples show the earth materials to be rather loose with dry unit weights of 10.32 to 16.28 kN/m3 and porosities of 39 to 60%. Particle size distributions are variable with depth; silt contents decreasing from 38 to 58% in saprock to 28 to 44% in the pedological soil zone. Increasing fine clay (<2 μm) contents up the profile from 34 to 43% in saprock to 40 to 51% in sub-zones IA and IB indicate that pedological processes result in continued disintegration of weathered serpentinite. Plastic and liquid limits have limited variation ranging from 24 to 33%, and from 36 to 50%, respectively. Weathered rims around core-stones show alteration of serpentinite to start with the opening-up of grain boundaries and formation of micro-cracks (Stage 1) followed by staining along chrysotile veinlets (Stage 2). More extensive staining then occurs with decomposition (to clay minerals) of most antigorite and chrysotile grains (Stage 3) and ending with formation of a brown, stiff silty clay (Stage 4). Increasing stages of weathering are marked by decreasing dry unit weights and uniaxial compressive strengths, but increasing apparent porosities. It is concluded that in situ alteration of serpentinite through lowering of an unconfined groundwater table has led to development of the weathering profile.","PeriodicalId":272380,"journal":{"name":"Warta Geologi","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127174713","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}

引用次数: 0

Geology, resource potential and organic petrography of the Neogene coals in the Miri area of Northwest Sarawak, Malaysia 马来西亚砂拉越西北部Miri地区新近系煤的地质、资源潜力及有机岩石学

Warta Geologi Pub Date : 2022-08-30 DOI: 10.7186/wg482202202

W. Abdullah, Say-Gee Sia

引用次数: 0

What Makes A Hot Spring, Hot? 温泉为什么这么热?

Warta Geologi Pub Date : 2022-04-28 DOI: 10.7186/wg481202204

Nurul Afiqah Rosli, M. Anuar, Muhammad Hasiib Mansor, Nur Syazwani Izzati Abdul Rahim, M. H. Arifin

{"title":"What Makes A Hot Spring, Hot?","authors":"Nurul Afiqah Rosli, M. Anuar, Muhammad Hasiib Mansor, Nur Syazwani Izzati Abdul Rahim, M. H. Arifin","doi":"10.7186/wg481202204","DOIUrl":"https://doi.org/10.7186/wg481202204","url":null,"abstract":"Hot springs naturally are groundwater that emerges to the surface after being heated up by geothermal activities. There are various classifications of hot springs according to the surface temperature. Still, in Malaysia, it is referred to as the spring that is higher than an average body temperature or 40 °C and above. Two types of hot spring origin are volcanic and non-volcanic sources. The Quaternary magmatic intrusion of Maria volcanic complex in Sabah is the only volcanic-related hot spring. Meanwhile, Sungai Klah, Ulu Slim, Gadek, and other hot springs in Malaysia originated from regional granite intrusion that slowly cooled down since the Triassic period. In Peninsular Malaysia, there is a geological trend of hot springs distribution based on three different intrusion and localities of granite batholiths: Eastern, Central and Western belts of granite. Tectonically, most of these hot springs are associated with fault zones related to highly fractured and deep-seated fault areas with high permeability host rock, such as Bok Bak Fault. Later it can conduit meteoric water to seep deep beneath the subsurface and be subjected to a high geothermal gradient zone. High dissolved minerals in the hot springs are beneficial for balneotherapy, while the excess heat and brine can be harnessed into electrical energy. The development of geothermal potential in Malaysia is still unhurried compared to our neighbouring countries, for example, Thailand’s Fang Geothermal Power Plant is a non-volcanic hot spring with a sound temperature of 130°C which can generate 300 kW of electricity. Lastly, effort has been made by researchers in gathering the data on hot spring distribution in Malaysia which can be viewed with just a click. A new app is developed for Android user named Malaysia’s Hot Springs that can be freely downloaded from the ‘Apps Store’ in hope that the application can serve as hot springs tourism and publication reference purposes.","PeriodicalId":272380,"journal":{"name":"Warta Geologi","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126135884","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}

引用次数: 0