From 31 March to 9 April 2025,at the invitation of Friends of China Parliamentary Association of Italy,Albania-China Friendship Association of Albania and Lao Peace and Solidarity Committee of Laos,Liu Hongcai,Vice-Pr...From 31 March to 9 April 2025,at the invitation of Friends of China Parliamentary Association of Italy,Albania-China Friendship Association of Albania and Lao Peace and Solidarity Committee of Laos,Liu Hongcai,Vice-President of the Chinese Association for International Understanding(CAFIU),and former Vice-Minister of the International Department of the CPC Central Committee(IDCPC)led a CAFIU delegation to visit Italy,Albania and Laos.The delegation engaged in in-depth discussions with political leaders as well as think tanks and civil society representatives from the three countries on such issues as bilateral relations,people-to-people exchanges,dialogue among civilisations,as well as international and regional affairs.展开更多
The Sakay gold deposit in Vientiane,Laos,is located in the Indochina landmass of the southeastern segment of the Tethys orogenic belt,specifically within the Vientiane-Pakse micro-landmass and the Vientiane-Pakse meta...The Sakay gold deposit in Vientiane,Laos,is located in the Indochina landmass of the southeastern segment of the Tethys orogenic belt,specifically within the Vientiane-Pakse micro-landmass and the Vientiane-Pakse metallogenic belt.This area is regionally significant for the concentration of minerals such as gold,copper,and tin.The host rocks of the deposit are intermediate volcanic lavas and volcanic tuffs,occurring in near-east-west brittle shear structural fractures through hydrothermal filling and metasomatism.The ore exhibits granular texture,subhedral texture,porphyritic texture,and oriented polycrystalline texture,with structural features such as disseminated,vein-like,and cataclastic breccia.The main ore minerals are pyrite,sphalerite,galena,and chalcopyrite,while the gangue minerals are primarily quartz,calcite,and dolomite.Gold is mainly present as included gold or fissure gold within the crystal lattices and microfractures of minerals such as pyrite and sphalerite.Based on mineral assemblages and generation timing,the mineralization can be divided into three stages:arsenopyrite-pyrite-dolomite-quartz(Ⅰ),sphalerite-galena-chalcopyrite-calcite(Ⅱ),and siderite(Ⅲ),with the latter stages often overlaying the former,showing evident cross-cutting and metasomatic phenomena.The surrounding rocks in the mining area are altered,mainly showing silicification,carbonatization,limonitization,sericitization,and chloritization.Preliminary studies suggest that this deposit is a low-temperature hydrothermal gold deposit within a brittle shear zone.展开更多
The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic ev...The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic evolution of the eastern Paleotethyan Ocean.This study presents systematic stratigraphy,petrology,geochemistry,and detrital zircon U-Pb-Hf isotopic analyses for the Late Carboniferous-Jurassic sedimentary strata on both sides of the Luang Prabang Basin.Based on distinct stratigraphic ages and provenance characteristics,the clastic rock samples can be divided into four groups.The Group 1 Late Carboniferous-Early Permian samples from the western part of the basin yield detrital zircon age-peaks of~348 and~1425 Ma,with correspondingεHf(t)values ranging from-2.0 to+15.5 and+1.5 to+14,respectively.The age spectrum of Group 2 Late Carboniferous-Early Permian samples from the eastern part of the basin shows major age-peaks of~287 and~1860 Ma,withεHf(t)values of-5.9--0.9 and-3.6-+4.2,respectively.Group 3 Late Permian-Triassic samples exhibit age-peaks of~242 and~1853 Ma,along withεHf(t)values of-0.7-+14.4 and-5.4--1.8,respectively.Group 4 Middle-Late Jurassic samples yield agepeaks of~237,~431,~813,~1833,and~2460 Ma,lacking Late Devonian(413-345 Ma)detrital zircons.All these data collectively suggest that the Group 1 sample primarily originated from the Sukhothai arc in western Indochina,Group 2 was from the Kontum and Truong Son in eastern Indochina,and Group 3 has a combined provenance of the Sukhothai,Kontum,and Truong Son.Regional comparisons suggest that the Jurassic provenance was mainly derived from South China,which was imported through the northern river system.Our data,combined with the regional angular unconformities between the Jurassic continental strata and pre-Jurassic marine strata,suggest that the Luang Prabang Basin transformed into a superimposed collisional retroforeland basin during the Jurassic,and the closure of the Luang Prabang BAB occurred before the Late Triassic.展开更多
A new species, Bactrocera （Zeugodacus） gansuica Chen, Han et Zhou sp. nov., is discovered from China, and B （Z.） vultus （Hardy, 1973） is recorded for the first time in Laos. These two species are here described ...A new species, Bactrocera （Zeugodacus） gansuica Chen, Han et Zhou sp. nov., is discovered from China, and B （Z.） vultus （Hardy, 1973） is recorded for the first time in Laos. These two species are here described and illustrated.展开更多
The study on the factors affecting the performance of small and medium enterprises(SMEs)in Lao PDR aims at firstly investigating the general characteristics of SMEs in Lao PDR,and secondly defining the factors affecti...The study on the factors affecting the performance of small and medium enterprises(SMEs)in Lao PDR aims at firstly investigating the general characteristics of SMEs in Lao PDR,and secondly defining the factors affecting business performance of small and medium enterprises in Lao PDR.The secondary data(2018)surveyed by World Bank enterprises were employed.The descriptive statistics were employed in order to see whether independent and dependent variables have impacts on SMEs’business performance.It was found that all small and medium enterprises were from family-based enterprises with no competition and no application of science and technology.It also revealed that the experiences of managers,services,duration of business implementation,number of laborers,number of trainings,export,access to finance,and innovation have significant relationship with SMEs’business performance.Whereas,it was found that gender of managers,size of SMEs,location,type of enterprises:manufacturing and retail,have no significant relationship with SMEs’business performance in Lao PDR.展开更多
This study explores off-grid power generation business models in the Lao People's Democratic Republic(Lao PDR),with the objective of identifying viable pathways to expand energy access in rural and underserved reg...This study explores off-grid power generation business models in the Lao People's Democratic Republic(Lao PDR),with the objective of identifying viable pathways to expand energy access in rural and underserved regions.The research aims to analyze and evaluate various business models in terms of their technical,economic,and social viability within the unique geographic and policy context of Lao PDR.There are two level of the research objectives:High Level Objectives(HLO)and Concreted Research Objectives(CRO).For HLO is that an appropriated off-grid power generation business model for Laos supports the Lao PDR Government’s commitment to promote an inclusive green growth development agenda that ensures lowered GHG emissions and increased energy efficiency.The Lao PDR National Determined Contribution(NDC)to the United Nations Framework Convention on Climate Change(UNFCCC)notes the country’s ambitious plans to lower energy consumption and reduce GHG emissions.While the CRO are focused on learning strategies,regulation and practical lessons from other countries the ASEAN region on the off-grid development and business model.To analyze and investigate the environmental strategy of business model under external and internal context and related and considered factors.And finally,this is to conclude and recommend the off-grid power generation business model as the research conclusion,which will become a support mechanism for the companies to operate consistently over many years into the future according to ambitious goal for supplying modern and save energy for rural families by 2030.展开更多
The 2023 China-ASEAN Expo was a big deal for Lao’s DAO Coffee.The Lao Prime Minister personally visited the DAO Coffee booth,an act that not only testified to the brand’s exceptional quality but also signaled strong...The 2023 China-ASEAN Expo was a big deal for Lao’s DAO Coffee.The Lao Prime Minister personally visited the DAO Coffee booth,an act that not only testified to the brand’s exceptional quality but also signaled strong support for the country’s burgeoning coffee industry.展开更多
Assessment of the forest land use change and proposed land suitability for tea for the area along Laos – China Border were the main purpose of this research paper. An integrated GIS-based analysis system （IGAS）, su...Assessment of the forest land use change and proposed land suitability for tea for the area along Laos – China Border were the main purpose of this research paper. An integrated GIS-based analysis system （IGAS）, supporting assessment of forest land-use and land suitability for the study area where along Laos-China border was developed. Multi criteria analysis and system dynamics techniques were used to assess forest land use and land suitability and to forecast potential land-use for tea. The total study area is estimated at 10 325.07 km2 according to the field data collection and data analysis. The area of current forest cover decreased rapidly from 6337.33 km2 （61.38%） in 1992 to 5106.28 km2 （49.46%） in 2002 in the study area. The current forest was mainly trans-ferred to potential forest and permanent agriculture especially to rubber plantation areas even in the National Conservation Biodiversity Conser-vation Areas. The main causes of forest land use change are poverty. In order to address the problems, land suitability classification for tea was developed based on the multi-criteria. And finally two options of land suitability classification for tea for the study areas were developed.展开更多
An integrated study of zircon U-Pb geochronology and petrochemistry, together with zircon Lu-Hf isotopes, has been carried out on the basaltic-andesitic tuff and volcanic breccia from the Nam Hang Formation and andesi...An integrated study of zircon U-Pb geochronology and petrochemistry, together with zircon Lu-Hf isotopes, has been carried out on the basaltic-andesitic tuff and volcanic breccia from the Nam Hang Formation and andesitic tuff from the Muang-Nan Formation in the Xaignabouli area, which had been mapped as the Permian–Early Triassic on the 1 : 1 000 000 geological map or Late Carboniferous on the 1 : 200 000 geological maps. Zircon U-Pb dating of three samples yielded weighted mean ages of 235±2.6, 232±1.4 and 278±2.8 Ma, respectively, suggesting a Late Triassic origin for the Nam Hang Formation and an Early Permian origin for the Muang-Nan Formation. Geochemically, they are characterized by depletions in HFSEs(e.g., Nb, Ta, Ti) and high LILE/HFSE ratios, and they have positive zircon ε_(Hf)(t) values of 8.7–15.9, which exhibits the continental arc volcanic affinity and partial melting of subducting oceanic slab in the magma source. Combined with spatial occurrence of the volcanic rock and existing geochronological and geochemical data, we suggest that the Xaignabouli-Luang Prabang volcanic belt can be linked to the Loei-Phetchabun belt. The Permian–Triassic volcanic rocks in this belt might be a product of the Nan back-arc basin eastward subduction.展开更多
The Phapon gold deposit, located in northern Laos, is a unique large-scale gold deposit in Luang Prabang-Loei metallogenic belt. It is hosted in the Lower Permian limestone and controlled by a NE-trending ductile-brit...The Phapon gold deposit, located in northern Laos, is a unique large-scale gold deposit in Luang Prabang-Loei metallogenic belt. It is hosted in the Lower Permian limestone and controlled by a NE-trending ductile-brittle fault system. There are three types of primary ore including auriferous calcite vein type, disseminated type, and breccia type, and the first two are important in the Phapon gold deposit. Based on fluid inclusion petrography and microthermometry, three types of primary fluid inclusions including type 1 liquid-rich aqueous, type 2 vapor-rich aqueous and type 3 daughter mineralbearing aqueous were identified in hydrothermal calcite grains. The ore-forming fluids are normally homogeneous, as indicated by the widespread type 1 inclusions with identical composition. The coexistence of type 1 and type 2 inclusions, showing similar final homogenization temperature but different compositions, indicate that fluid immiscibility did locally take place in both two types of ores. The results of microthermometry and H-O isotopes geochemistry indicate that there are little differences on ore-fluid geochemistry between the auriferous calcite vein-type and disseminated type ores. The oreforming fluids are characterized by medium-low temperatures(157–268 oC) and low salinity(1.6 wt.%–9.9 wt.% NaCl eq.). It is likely to have a metamorphic-dominant mixed source, which could be associated with dehydration and decarbonisation of Lower Permian limestone and Middle–Upper Triassic sandstones during the dynamic metamorphism. The fluid-wallrock interaction played a major role, and the locally occurred fluid-immiscible processes played a subordinate role in gold precipitation. Combined with the regional and ore deposit geology, and ore-fluid geochemistry, we suggest that the Phapon gold deposit is best considered to be a member of the epizonal orogenic deposit class.展开更多
Rubber plantation is the major land use type in Southeast Asia. Monitoring the spa- tial-temporal pattern of rubber plantation is significant for regional land resource development, eco-environmental protection, and m...Rubber plantation is the major land use type in Southeast Asia. Monitoring the spa- tial-temporal pattern of rubber plantation is significant for regional land resource development, eco-environmental protection, and maintaining border security. With remote sensing tech- nologies, we analyzed the rubber distribution pattern and spatial-temporal dynamic; with GIS and a newly proposed index of Planted Intensity （PI）, we further quantified the impacts and limits of topographical factors on rubber plantation in the border region of China, Laos and Myanmar （BRCLM） between 1980 and 2010. The results showed that： （1） As the dominant land use type in this border region, the acreage of rubber plantation was 6014 km2 in 2010, accounting for 8.17% of the total area. Viewing from the rubber plantation structure, the ratio of mature- （〉10 year） and young rubber plantation （〈 10 year） was 5：7. （2） From 1980 to 2010, rubber plantation expanded significantly in BRCLM, from 705 km2 to 6014 km2, nearly nine times. The distribution characteristics of rubber plantation varied from concentrated toward dispersed, from border inside to outside, and expanded further in all directions with Jinghong City as the center. （3） Restricted by the topographical factors, more than 4/5 proportion of rubber plantation concentrated in the appropriate elevation gradients between 600 and 1000 m, rarely occurred in elevations beyond 1200 m in BRCLM. Nearly 2/3 of rubber plantation concentrated on slopes of 8^-25~, rarely distributed on slopes above 35~. Rubber plantation was primarily distributed in south and east aspects, relatively few in north and west aspects. Rubber planted intensity displayed the similar distribution trend. （4） Comparative studies of rubber plantation in different countries showed that there was a remarkable increase in area at higher elevations and steeper slopes in China, while there were large appropriate topog- raphical gradients for rubber plantation in Laos and Myanmar which benefited China for rubber trans-boundary expansion. （5） Rubber plantation in BRCLM will definitely expend cross borders of China to the territories of Laos and Myanmar, and the continuous expansion in the border region of China will be inevitable.展开更多
The volcanic rocks from the Sayabouli area in northwestern Laos have been poorly studied. These volcanic rocks are traditionally mapped as the Permian–Early Triassic sequences on the geological map. One basaltic-ande...The volcanic rocks from the Sayabouli area in northwestern Laos have been poorly studied. These volcanic rocks are traditionally mapped as the Permian–Early Triassic sequences on the geological map. One basaltic-andesite from the Sayabouli area yields a zircon U-Pb age of 237.7±1.7 Ma, suggesting a Middle Triassic origin. All basalt and basaltic-andesite samples from the Sayabouli area show depletions in HFSEs（e.g., Nb, Ta, Ti） and have high LILE/HFSE ratios, and exhibit the geochemical affinity to the continental arc volcanic rocks and are geochemically similar to the continental arc volcanic rocks from the Phetchabun belt in northeastern Thailand, suggesting a Late Permian–Middle Triassic continental margin in the Sayabouli area of northwestern Laos and Phetchabun area of northeastern Thailand. Our data indicate that the Phetchabun arc volcanic belt through the western Loei sub-belt can be linked to the Sayabouli area in northwestern Laos.展开更多
Swidden agriculture is an age-old, widespread but controversial farming practice in Montane Mainland Southeast Asia （MMSEA）. In the uplands of northern Laos, swidden ag- riculture has remained a predominant human-do...Swidden agriculture is an age-old, widespread but controversial farming practice in Montane Mainland Southeast Asia （MMSEA）. In the uplands of northern Laos, swidden ag- riculture has remained a predominant human-dominated land-use type for centuries. However swidden system has undergone dramatic transformations since the mid-1990s. Debates on changes in swidden cultivation are linked to globally critical issues, such as land use/cover changes （LUCC）, biodiversity loss and environmental degradation. Since the implementation of Reducing Emissions from Deforestation and Forest Degradation （REDD）, much attention has been paid nationally and internationally to swidden agriculture in the tropics. However, knowledge of the explicitly spatial characteristics of swidden agriculture and the conse- quences of these transitions at macroscopic scale is surprisingly scarce. In this study, the intensity of swidden use and fallow forest recovery in northern Laos in 1990, 2002, and 2011 were delineated by means of Landsat Thematic Mapper （TM） and Enhanced Thematic Mapper plus （ETM＋） imagery （30 m） using a decision tree classification approach, followed by an analysis of the spatio-temporal changes in swidden agriculture. Next, annual successive TM/ETM＋ images during 2000-2010 were used to delineate the dynamics of the burning and cropping phase. Subsequently, the burned pixels identified in 2000 were compared respectively with their counterparts in the following years （2001-2011） to investigate temporal trends, land-use frequency, and the swidden cycle using time-series Landsat-based Normalized Difference Vegetation Index （NDVI） data. Finally, as the swidden cycle changed from 1 to 11 years, the fallow vegetation recovery process was studied. The results showed that： （1） from 1990 to 2011, the area of swidden agriculture increased by 54.98%, from 1.54× 10^5 ha to 2.38×10^5 ha in northern Laos. The increased swidden cultivation area was mainly distributed in Luang Prabang and southern Bokeo, whereas the decreased parts were mainly found in Phongsali; （2） swidden agriculture increased mainly at elevations of 500-800 m, 300-500 m, and 800-1000 m and on slopes of 10°-20° and 200-30°. Over 80% of swidden fields were transformed from forests; （3） during 2000-2011, the frequency of swidden use in northern Laos was about two or three times. The interval between two successive utilization of a swidden ranged from one to seven years. Comparison of swidden cycles and the related proportions of swidden farming in 2000, 2003, and 2007 revealed that swidden cycles in most areas were shortened; and （4） there was a significant correlation （0.97） between fallow vegetation recovery and the swidden cycle. The NDVI of regenerated vegetation could approach the average level of forest when the swidden cycle reached 10 years.展开更多
The Truong Son Fold Belt,located at the northeastern margin of the Indochina Block,is considered to be tectonically linked to the subduction of the Paleotethys Ocean and subsequent collision.Sepon is one of the most i...The Truong Son Fold Belt,located at the northeastern margin of the Indochina Block,is considered to be tectonically linked to the subduction of the Paleotethys Ocean and subsequent collision.Sepon is one of the most important super large deposits of the Truong Son Fold Belt.Our LA-ICP-MS zircon U-Pb dating results show that granodiorite porphyry samples from the Sepon deposit have ages of 302.1-4-2.9 Ma, which is a crucial phase for magmatic-tectonical activities from the Late Carboniferous to Early Permian and has avital influence on the mineralization of copper and gold.Zircon from granodiorite porphyry yields εHf (t)values of 4.32 to 9.64,and TDM2 has an average age of 914 Ma,suggesting that the source of the granodiorite porphyry in the region were mainly mantle components but underwent mixing and contamination of crust materials.The Ce^4+/Ce^3+ value of zircon in the granodiorite porphyry varys greatly from 2.4 to 1438.29,which shows magma mixing might occur.Considering the characteristics of trace elements in the zircon and the whole rock geochemical characteristics of intrusion rocks as well as the characteristics of regional volcanic-sedimentary association,it is indicated that the tectonic setting may be the continental arc environment.The Sepon Au-Cu deposit is derived from emplacement of calc-alkaline intermediate-acid magma with coming from deep sources in the subduction process of the Paleotethys Ocean,forming porphyry Mo-Cu,skam Cu-Au mineralization and a hydrothermal sedimentary-hosted Au mineralization in the wall rocks.展开更多
The NM copper polymetal deposit is located in the middle north part of the Truong Son metallogenic belt in Laos,which is the skarn-typed deposit and located in the contact between Indosinian granite and Lower Carbonif...The NM copper polymetal deposit is located in the middle north part of the Truong Son metallogenic belt in Laos,which is the skarn-typed deposit and located in the contact between Indosinian granite and Lower Carboniferous limestone.All the ore-bodies in NM deposit can be divided into four types according to their occurrences:I copper ore-body as the massive restite developed in inner contact near the granite in north part;Ⅱ-1 zinc-copper ore body and Ⅱ-2 copper-iron ore body developed within contact betwee...展开更多
This paper analyzed forest land use change in Trans-Boundary Laos-China Biodiversity Conservation Area which is called Namha National Biodiversity Conservation Areas （Namha NBCAs）, with 1992 and 2002 TM （ETM）. Bas...This paper analyzed forest land use change in Trans-Boundary Laos-China Biodiversity Conservation Area which is called Namha National Biodiversity Conservation Areas （Namha NBCAs）, with 1992 and 2002 TM （ETM）. Based on GIS and statistical methods, the intensity, state index of land use change and transfer matrix were used to study spatio-temporal land use change in the region. The results showed that the area of forest land decreased greatly, also the area of bamboo and grassland decreased. The other way round, the area of unstocked forest, slash and burn and rice paddy land increased. As a whole, the intensity of forest land change was higher, but others were lower. From the transfer matrix, most of the forest land changed into unstocked forest and urban area, some to slash and burn The grassland and bamboo were mainly transferred to forest and unstocked forest. The unstocked forest land mostly came from forest land and grassland. It was showed there were three main causes of the land use change namely： opium poppy cultivation, rubber plantation and also ecotourism activities and finally some policies were developed in order to address the land use change in the study areas.展开更多
The giant potash deposit on the Khorat Plateau is one of the most promising targets for exploitation of potassium salts.So far,many researches and geologic survey have been conducted on the giant potash deposits.Hence...The giant potash deposit on the Khorat Plateau is one of the most promising targets for exploitation of potassium salts.So far,many researches and geologic survey have been conducted on the giant potash deposits.Hence,it is necessary to make an overall review on the potash deposits.The potash deposit on the Khorat Plateau was formed during the Middle to Late Cretaceous,during which seawater was enriched in Ca2+and depleted in SO42-compared with those of modern seawater.In addition to seawater,continental water and hydrothermal fluids could have affected the evaporite basins.The seawater was probably derived from Tethys ocean,and the brine should have evaporated to some extent before entering into the basin systems based on the evidence of absence of carbonates and unproportionate sulphate compared with chloride salts.The paleo-climate during Middle to Late Cretaceous was characterized as high temperature and extremely arid environment,which is favourable for deposition of potassium-magnesium saline minerals.The major saline minerals are of anhydrite,halite,carnallite,sylvite and,tachyhydrite,with trace amounts of borates.The resources of the potash deposit on the Khorat Plateau could be approximately as much as 400×109 t of carnallite and 7×109 t of sylvite.The evaporite sequences have been deformed and altered by postdepositinal processes,including tectonic movements and chemical alteration.Salt domes were formed in the postdepositional processes.Based on the analyses of geophysical surveys and drilling projects,high-quality sylvinite ores are commonly found at the flanks of those salt domes due to incongruent dissolution of carnallite.The furure potential prospecting areas for the highquality sylvinite ores would be on the edges of the Khorat Plateau.展开更多
Xinzhai sandstone-type copper deposit located in northern Laos lies in the Jiangcheng-Phongsaly-Phrae Mesozoic basin(JPMB), which is regarded as southern extension of the Lanping-Simao Mesozoic basin in China. The cop...Xinzhai sandstone-type copper deposit located in northern Laos lies in the Jiangcheng-Phongsaly-Phrae Mesozoic basin(JPMB), which is regarded as southern extension of the Lanping-Simao Mesozoic basin in China. The copper deposit belt is bounded by the AilaoshanHeishui River fault and the Dian Bien Phu-Luang Prabang fault at the east and Lancang RiverBannankan faults at the west. Two types of orebodies are identified in the Xinzhai area based on geological investigation. One is lamellar copper orebody hosted by the fine lithic feldspar sandstones and feldspar lithic sandstones; another is vein-type orebody. The sulfur isotopic compositions of the chalcopyrite and tetrahedrite are from -11.6‰ to -1.8‰, indicating that sulfur is derived from bacterial sulfate reduction(BSR). δD values of fluid inclusions in ore-bearing quartz samples are from -99‰ to -78‰. The calculated δ^(18)OH_2O values of ore-forming fluid vary from -2.3‰ to 0.4‰ using the quartz-water fractionation equations and the mineralization temperature. Oxygen and hydrogen isotopic compositions show that the ore-forming fluid was derived from basin fluid. Rock-mineral identifications show that both of the mineral grain maturity and the structural maturity are high in the Jurassic Huakaizuo Formation, reflecting a far-source accumulation and lake facies sedimentatary environment. Based on tectonic determination diagram of the Al_2O_3/SiO_2-TFe+MgO, the sandstone samples collected from the Huakaizuo Formation were plotted in the passive continental margin. The collision of the Indian and Eurasian blocks during the Cenozoic formed large-scale strikeslips and thrust nappe structures in margin of the basin. With the tectonic movement, Cu-rich basin fluid from the basement of basin migrated upward along the contemporaneous fault and into the high porosity strata. At the same time, in organic matter-riched condition, bacterial sulfate reduction(BSR) has been triggered, forming a large number of S^(2-) ions, and then precipitation of sulfide started. This mechanism describes the process of copper mineral deposition in the Xinzhai deposit.展开更多
文摘From 31 March to 9 April 2025,at the invitation of Friends of China Parliamentary Association of Italy,Albania-China Friendship Association of Albania and Lao Peace and Solidarity Committee of Laos,Liu Hongcai,Vice-President of the Chinese Association for International Understanding(CAFIU),and former Vice-Minister of the International Department of the CPC Central Committee(IDCPC)led a CAFIU delegation to visit Italy,Albania and Laos.The delegation engaged in in-depth discussions with political leaders as well as think tanks and civil society representatives from the three countries on such issues as bilateral relations,people-to-people exchanges,dialogue among civilisations,as well as international and regional affairs.
文摘The Sakay gold deposit in Vientiane,Laos,is located in the Indochina landmass of the southeastern segment of the Tethys orogenic belt,specifically within the Vientiane-Pakse micro-landmass and the Vientiane-Pakse metallogenic belt.This area is regionally significant for the concentration of minerals such as gold,copper,and tin.The host rocks of the deposit are intermediate volcanic lavas and volcanic tuffs,occurring in near-east-west brittle shear structural fractures through hydrothermal filling and metasomatism.The ore exhibits granular texture,subhedral texture,porphyritic texture,and oriented polycrystalline texture,with structural features such as disseminated,vein-like,and cataclastic breccia.The main ore minerals are pyrite,sphalerite,galena,and chalcopyrite,while the gangue minerals are primarily quartz,calcite,and dolomite.Gold is mainly present as included gold or fissure gold within the crystal lattices and microfractures of minerals such as pyrite and sphalerite.Based on mineral assemblages and generation timing,the mineralization can be divided into three stages:arsenopyrite-pyrite-dolomite-quartz(Ⅰ),sphalerite-galena-chalcopyrite-calcite(Ⅱ),and siderite(Ⅲ),with the latter stages often overlaying the former,showing evident cross-cutting and metasomatic phenomena.The surrounding rocks in the mining area are altered,mainly showing silicification,carbonatization,limonitization,sericitization,and chloritization.Preliminary studies suggest that this deposit is a low-temperature hydrothermal gold deposit within a brittle shear zone.
基金supported by the National Key Research and Development Program of China(No.2023YFF0803701)the National Natural Science Foundation of China(Nos.42330302 and 42472265)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.SML2023SP239)。
文摘The Late Paleozoic-Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance,paleogeographic patterns,and the tectonic evolution of the eastern Paleotethyan Ocean.This study presents systematic stratigraphy,petrology,geochemistry,and detrital zircon U-Pb-Hf isotopic analyses for the Late Carboniferous-Jurassic sedimentary strata on both sides of the Luang Prabang Basin.Based on distinct stratigraphic ages and provenance characteristics,the clastic rock samples can be divided into four groups.The Group 1 Late Carboniferous-Early Permian samples from the western part of the basin yield detrital zircon age-peaks of~348 and~1425 Ma,with correspondingεHf(t)values ranging from-2.0 to+15.5 and+1.5 to+14,respectively.The age spectrum of Group 2 Late Carboniferous-Early Permian samples from the eastern part of the basin shows major age-peaks of~287 and~1860 Ma,withεHf(t)values of-5.9--0.9 and-3.6-+4.2,respectively.Group 3 Late Permian-Triassic samples exhibit age-peaks of~242 and~1853 Ma,along withεHf(t)values of-0.7-+14.4 and-5.4--1.8,respectively.Group 4 Middle-Late Jurassic samples yield agepeaks of~237,~431,~813,~1833,and~2460 Ma,lacking Late Devonian(413-345 Ma)detrital zircons.All these data collectively suggest that the Group 1 sample primarily originated from the Sukhothai arc in western Indochina,Group 2 was from the Kontum and Truong Son in eastern Indochina,and Group 3 has a combined provenance of the Sukhothai,Kontum,and Truong Son.Regional comparisons suggest that the Jurassic provenance was mainly derived from South China,which was imported through the northern river system.Our data,combined with the regional angular unconformities between the Jurassic continental strata and pre-Jurassic marine strata,suggest that the Luang Prabang Basin transformed into a superimposed collisional retroforeland basin during the Jurassic,and the closure of the Luang Prabang BAB occurred before the Late Triassic.
基金supported by the National Natural Science Foundation of China (30770267)Special Fund for Entry-Exit Inspections and Quarantine Scientific Research in the Public Interest (201210079)
文摘A new species, Bactrocera （Zeugodacus） gansuica Chen, Han et Zhou sp. nov., is discovered from China, and B （Z.） vultus （Hardy, 1973） is recorded for the first time in Laos. These two species are here described and illustrated.
文摘The study on the factors affecting the performance of small and medium enterprises(SMEs)in Lao PDR aims at firstly investigating the general characteristics of SMEs in Lao PDR,and secondly defining the factors affecting business performance of small and medium enterprises in Lao PDR.The secondary data(2018)surveyed by World Bank enterprises were employed.The descriptive statistics were employed in order to see whether independent and dependent variables have impacts on SMEs’business performance.It was found that all small and medium enterprises were from family-based enterprises with no competition and no application of science and technology.It also revealed that the experiences of managers,services,duration of business implementation,number of laborers,number of trainings,export,access to finance,and innovation have significant relationship with SMEs’business performance.Whereas,it was found that gender of managers,size of SMEs,location,type of enterprises:manufacturing and retail,have no significant relationship with SMEs’business performance in Lao PDR.
文摘This study explores off-grid power generation business models in the Lao People's Democratic Republic(Lao PDR),with the objective of identifying viable pathways to expand energy access in rural and underserved regions.The research aims to analyze and evaluate various business models in terms of their technical,economic,and social viability within the unique geographic and policy context of Lao PDR.There are two level of the research objectives:High Level Objectives(HLO)and Concreted Research Objectives(CRO).For HLO is that an appropriated off-grid power generation business model for Laos supports the Lao PDR Government’s commitment to promote an inclusive green growth development agenda that ensures lowered GHG emissions and increased energy efficiency.The Lao PDR National Determined Contribution(NDC)to the United Nations Framework Convention on Climate Change(UNFCCC)notes the country’s ambitious plans to lower energy consumption and reduce GHG emissions.While the CRO are focused on learning strategies,regulation and practical lessons from other countries the ASEAN region on the off-grid development and business model.To analyze and investigate the environmental strategy of business model under external and internal context and related and considered factors.And finally,this is to conclude and recommend the off-grid power generation business model as the research conclusion,which will become a support mechanism for the companies to operate consistently over many years into the future according to ambitious goal for supplying modern and save energy for rural families by 2030.
文摘The 2023 China-ASEAN Expo was a big deal for Lao’s DAO Coffee.The Lao Prime Minister personally visited the DAO Coffee booth,an act that not only testified to the brand’s exceptional quality but also signaled strong support for the country’s burgeoning coffee industry.
文摘Assessment of the forest land use change and proposed land suitability for tea for the area along Laos – China Border were the main purpose of this research paper. An integrated GIS-based analysis system （IGAS）, supporting assessment of forest land-use and land suitability for the study area where along Laos-China border was developed. Multi criteria analysis and system dynamics techniques were used to assess forest land use and land suitability and to forecast potential land-use for tea. The total study area is estimated at 10 325.07 km2 according to the field data collection and data analysis. The area of current forest cover decreased rapidly from 6337.33 km2 （61.38%） in 1992 to 5106.28 km2 （49.46%） in 2002 in the study area. The current forest was mainly trans-ferred to potential forest and permanent agriculture especially to rubber plantation areas even in the National Conservation Biodiversity Conser-vation Areas. The main causes of forest land use change are poverty. In order to address the problems, land suitability classification for tea was developed based on the multi-criteria. And finally two options of land suitability classification for tea for the study areas were developed.
基金financially supported by the China Geological Survey (No. 121201010000150013)
文摘An integrated study of zircon U-Pb geochronology and petrochemistry, together with zircon Lu-Hf isotopes, has been carried out on the basaltic-andesitic tuff and volcanic breccia from the Nam Hang Formation and andesitic tuff from the Muang-Nan Formation in the Xaignabouli area, which had been mapped as the Permian–Early Triassic on the 1 : 1 000 000 geological map or Late Carboniferous on the 1 : 200 000 geological maps. Zircon U-Pb dating of three samples yielded weighted mean ages of 235±2.6, 232±1.4 and 278±2.8 Ma, respectively, suggesting a Late Triassic origin for the Nam Hang Formation and an Early Permian origin for the Muang-Nan Formation. Geochemically, they are characterized by depletions in HFSEs(e.g., Nb, Ta, Ti) and high LILE/HFSE ratios, and they have positive zircon ε_(Hf)(t) values of 8.7–15.9, which exhibits the continental arc volcanic affinity and partial melting of subducting oceanic slab in the magma source. Combined with spatial occurrence of the volcanic rock and existing geochronological and geochemical data, we suggest that the Xaignabouli-Luang Prabang volcanic belt can be linked to the Loei-Phetchabun belt. The Permian–Triassic volcanic rocks in this belt might be a product of the Nan back-arc basin eastward subduction.
基金financially supported by the China Geological Survey Project (No. 121201010000150013)
文摘The Phapon gold deposit, located in northern Laos, is a unique large-scale gold deposit in Luang Prabang-Loei metallogenic belt. It is hosted in the Lower Permian limestone and controlled by a NE-trending ductile-brittle fault system. There are three types of primary ore including auriferous calcite vein type, disseminated type, and breccia type, and the first two are important in the Phapon gold deposit. Based on fluid inclusion petrography and microthermometry, three types of primary fluid inclusions including type 1 liquid-rich aqueous, type 2 vapor-rich aqueous and type 3 daughter mineralbearing aqueous were identified in hydrothermal calcite grains. The ore-forming fluids are normally homogeneous, as indicated by the widespread type 1 inclusions with identical composition. The coexistence of type 1 and type 2 inclusions, showing similar final homogenization temperature but different compositions, indicate that fluid immiscibility did locally take place in both two types of ores. The results of microthermometry and H-O isotopes geochemistry indicate that there are little differences on ore-fluid geochemistry between the auriferous calcite vein-type and disseminated type ores. The oreforming fluids are characterized by medium-low temperatures(157–268 oC) and low salinity(1.6 wt.%–9.9 wt.% NaCl eq.). It is likely to have a metamorphic-dominant mixed source, which could be associated with dehydration and decarbonisation of Lower Permian limestone and Middle–Upper Triassic sandstones during the dynamic metamorphism. The fluid-wallrock interaction played a major role, and the locally occurred fluid-immiscible processes played a subordinate role in gold precipitation. Combined with the regional and ore deposit geology, and ore-fluid geochemistry, we suggest that the Phapon gold deposit is best considered to be a member of the epizonal orogenic deposit class.
基金National Natural Science Foundation of China, No.41271117 Strategy of Science and Technology Planning Project of Institute of Geographic Sciences and Natural Resources Research, CAS, No.2012SJ008
文摘Rubber plantation is the major land use type in Southeast Asia. Monitoring the spa- tial-temporal pattern of rubber plantation is significant for regional land resource development, eco-environmental protection, and maintaining border security. With remote sensing tech- nologies, we analyzed the rubber distribution pattern and spatial-temporal dynamic; with GIS and a newly proposed index of Planted Intensity （PI）, we further quantified the impacts and limits of topographical factors on rubber plantation in the border region of China, Laos and Myanmar （BRCLM） between 1980 and 2010. The results showed that： （1） As the dominant land use type in this border region, the acreage of rubber plantation was 6014 km2 in 2010, accounting for 8.17% of the total area. Viewing from the rubber plantation structure, the ratio of mature- （〉10 year） and young rubber plantation （〈 10 year） was 5：7. （2） From 1980 to 2010, rubber plantation expanded significantly in BRCLM, from 705 km2 to 6014 km2, nearly nine times. The distribution characteristics of rubber plantation varied from concentrated toward dispersed, from border inside to outside, and expanded further in all directions with Jinghong City as the center. （3） Restricted by the topographical factors, more than 4/5 proportion of rubber plantation concentrated in the appropriate elevation gradients between 600 and 1000 m, rarely occurred in elevations beyond 1200 m in BRCLM. Nearly 2/3 of rubber plantation concentrated on slopes of 8^-25~, rarely distributed on slopes above 35~. Rubber plantation was primarily distributed in south and east aspects, relatively few in north and west aspects. Rubber planted intensity displayed the similar distribution trend. （4） Comparative studies of rubber plantation in different countries showed that there was a remarkable increase in area at higher elevations and steeper slopes in China, while there were large appropriate topog- raphical gradients for rubber plantation in Laos and Myanmar which benefited China for rubber trans-boundary expansion. （5） Rubber plantation in BRCLM will definitely expend cross borders of China to the territories of Laos and Myanmar, and the continuous expansion in the border region of China will be inevitable.
基金supported by the National Natural Science Foundation of China(Nos.41172202,41190073,41302178)the China Geological Survey(No.1212011121256)the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences in Wuhan(No.MSFGPMR201202)
文摘The volcanic rocks from the Sayabouli area in northwestern Laos have been poorly studied. These volcanic rocks are traditionally mapped as the Permian–Early Triassic sequences on the geological map. One basaltic-andesite from the Sayabouli area yields a zircon U-Pb age of 237.7±1.7 Ma, suggesting a Middle Triassic origin. All basalt and basaltic-andesite samples from the Sayabouli area show depletions in HFSEs（e.g., Nb, Ta, Ti） and have high LILE/HFSE ratios, and exhibit the geochemical affinity to the continental arc volcanic rocks and are geochemically similar to the continental arc volcanic rocks from the Phetchabun belt in northeastern Thailand, suggesting a Late Permian–Middle Triassic continental margin in the Sayabouli area of northwestern Laos and Phetchabun area of northeastern Thailand. Our data indicate that the Phetchabun arc volcanic belt through the western Loei sub-belt can be linked to the Sayabouli area in northwestern Laos.
基金National Natural Science Foundation of China, No.41301090, No.41271117 Key Program for Strategic Science and Technology, Chinese Academy of Sciences, No.2014SJCB006
文摘Swidden agriculture is an age-old, widespread but controversial farming practice in Montane Mainland Southeast Asia （MMSEA）. In the uplands of northern Laos, swidden ag- riculture has remained a predominant human-dominated land-use type for centuries. However swidden system has undergone dramatic transformations since the mid-1990s. Debates on changes in swidden cultivation are linked to globally critical issues, such as land use/cover changes （LUCC）, biodiversity loss and environmental degradation. Since the implementation of Reducing Emissions from Deforestation and Forest Degradation （REDD）, much attention has been paid nationally and internationally to swidden agriculture in the tropics. However, knowledge of the explicitly spatial characteristics of swidden agriculture and the conse- quences of these transitions at macroscopic scale is surprisingly scarce. In this study, the intensity of swidden use and fallow forest recovery in northern Laos in 1990, 2002, and 2011 were delineated by means of Landsat Thematic Mapper （TM） and Enhanced Thematic Mapper plus （ETM＋） imagery （30 m） using a decision tree classification approach, followed by an analysis of the spatio-temporal changes in swidden agriculture. Next, annual successive TM/ETM＋ images during 2000-2010 were used to delineate the dynamics of the burning and cropping phase. Subsequently, the burned pixels identified in 2000 were compared respectively with their counterparts in the following years （2001-2011） to investigate temporal trends, land-use frequency, and the swidden cycle using time-series Landsat-based Normalized Difference Vegetation Index （NDVI） data. Finally, as the swidden cycle changed from 1 to 11 years, the fallow vegetation recovery process was studied. The results showed that： （1） from 1990 to 2011, the area of swidden agriculture increased by 54.98%, from 1.54× 10^5 ha to 2.38×10^5 ha in northern Laos. The increased swidden cultivation area was mainly distributed in Luang Prabang and southern Bokeo, whereas the decreased parts were mainly found in Phongsali; （2） swidden agriculture increased mainly at elevations of 500-800 m, 300-500 m, and 800-1000 m and on slopes of 10°-20° and 200-30°. Over 80% of swidden fields were transformed from forests; （3） during 2000-2011, the frequency of swidden use in northern Laos was about two or three times. The interval between two successive utilization of a swidden ranged from one to seven years. Comparison of swidden cycles and the related proportions of swidden farming in 2000, 2003, and 2007 revealed that swidden cycles in most areas were shortened; and （4） there was a significant correlation （0.97） between fallow vegetation recovery and the swidden cycle. The NDVI of regenerated vegetation could approach the average level of forest when the swidden cycle reached 10 years.
基金the National Science Foundation of China (41373036, 41002027)the Geological Survey of China Geological Survey Project (121201103000150006,121201066307).
文摘The Truong Son Fold Belt,located at the northeastern margin of the Indochina Block,is considered to be tectonically linked to the subduction of the Paleotethys Ocean and subsequent collision.Sepon is one of the most important super large deposits of the Truong Son Fold Belt.Our LA-ICP-MS zircon U-Pb dating results show that granodiorite porphyry samples from the Sepon deposit have ages of 302.1-4-2.9 Ma, which is a crucial phase for magmatic-tectonical activities from the Late Carboniferous to Early Permian and has avital influence on the mineralization of copper and gold.Zircon from granodiorite porphyry yields εHf (t)values of 4.32 to 9.64,and TDM2 has an average age of 914 Ma,suggesting that the source of the granodiorite porphyry in the region were mainly mantle components but underwent mixing and contamination of crust materials.The Ce^4+/Ce^3+ value of zircon in the granodiorite porphyry varys greatly from 2.4 to 1438.29,which shows magma mixing might occur.Considering the characteristics of trace elements in the zircon and the whole rock geochemical characteristics of intrusion rocks as well as the characteristics of regional volcanic-sedimentary association,it is indicated that the tectonic setting may be the continental arc environment.The Sepon Au-Cu deposit is derived from emplacement of calc-alkaline intermediate-acid magma with coming from deep sources in the subduction process of the Paleotethys Ocean,forming porphyry Mo-Cu,skam Cu-Au mineralization and a hydrothermal sedimentary-hosted Au mineralization in the wall rocks.
基金supported by China Postdoctoral Science Foundation,Institute of Geochemistry under Chinese Academy of Sciences and "Research of quick-locating-technical methods for Xaisomboun metallogenic target in Laos"a innovative fund of China non-ferrous Metals Resource Geological Survey
文摘The NM copper polymetal deposit is located in the middle north part of the Truong Son metallogenic belt in Laos,which is the skarn-typed deposit and located in the contact between Indosinian granite and Lower Carboniferous limestone.All the ore-bodies in NM deposit can be divided into four types according to their occurrences:I copper ore-body as the massive restite developed in inner contact near the granite in north part;Ⅱ-1 zinc-copper ore body and Ⅱ-2 copper-iron ore body developed within contact betwee...
文摘This paper analyzed forest land use change in Trans-Boundary Laos-China Biodiversity Conservation Area which is called Namha National Biodiversity Conservation Areas （Namha NBCAs）, with 1992 and 2002 TM （ETM）. Based on GIS and statistical methods, the intensity, state index of land use change and transfer matrix were used to study spatio-temporal land use change in the region. The results showed that the area of forest land decreased greatly, also the area of bamboo and grassland decreased. The other way round, the area of unstocked forest, slash and burn and rice paddy land increased. As a whole, the intensity of forest land change was higher, but others were lower. From the transfer matrix, most of the forest land changed into unstocked forest and urban area, some to slash and burn The grassland and bamboo were mainly transferred to forest and unstocked forest. The unstocked forest land mostly came from forest land and grassland. It was showed there were three main causes of the land use change namely： opium poppy cultivation, rubber plantation and also ecotourism activities and finally some policies were developed in order to address the land use change in the study areas.
基金This study is finished through the cooperation project between China Geological Survey and Department of Mineral Resources(Thailand)supported by the National Key Project for Basic Research of China(2011CB403007)+2 种基金the National Natural Science Foundation of China(41572067,91855104,41802111)the Geological Survey Project(DD20190437)"Mineral potential exploration and assessment for potash"by the Government of Thailand.
文摘The giant potash deposit on the Khorat Plateau is one of the most promising targets for exploitation of potassium salts.So far,many researches and geologic survey have been conducted on the giant potash deposits.Hence,it is necessary to make an overall review on the potash deposits.The potash deposit on the Khorat Plateau was formed during the Middle to Late Cretaceous,during which seawater was enriched in Ca2+and depleted in SO42-compared with those of modern seawater.In addition to seawater,continental water and hydrothermal fluids could have affected the evaporite basins.The seawater was probably derived from Tethys ocean,and the brine should have evaporated to some extent before entering into the basin systems based on the evidence of absence of carbonates and unproportionate sulphate compared with chloride salts.The paleo-climate during Middle to Late Cretaceous was characterized as high temperature and extremely arid environment,which is favourable for deposition of potassium-magnesium saline minerals.The major saline minerals are of anhydrite,halite,carnallite,sylvite and,tachyhydrite,with trace amounts of borates.The resources of the potash deposit on the Khorat Plateau could be approximately as much as 400×109 t of carnallite and 7×109 t of sylvite.The evaporite sequences have been deformed and altered by postdepositinal processes,including tectonic movements and chemical alteration.Salt domes were formed in the postdepositional processes.Based on the analyses of geophysical surveys and drilling projects,high-quality sylvinite ores are commonly found at the flanks of those salt domes due to incongruent dissolution of carnallite.The furure potential prospecting areas for the highquality sylvinite ores would be on the edges of the Khorat Plateau.
基金jointly supported by the project of the National Science Foundation of China (No. 41663006)the innovation team of KMUST ore-forming dynamics and prediction of concealed deposits (2008)
文摘Xinzhai sandstone-type copper deposit located in northern Laos lies in the Jiangcheng-Phongsaly-Phrae Mesozoic basin(JPMB), which is regarded as southern extension of the Lanping-Simao Mesozoic basin in China. The copper deposit belt is bounded by the AilaoshanHeishui River fault and the Dian Bien Phu-Luang Prabang fault at the east and Lancang RiverBannankan faults at the west. Two types of orebodies are identified in the Xinzhai area based on geological investigation. One is lamellar copper orebody hosted by the fine lithic feldspar sandstones and feldspar lithic sandstones; another is vein-type orebody. The sulfur isotopic compositions of the chalcopyrite and tetrahedrite are from -11.6‰ to -1.8‰, indicating that sulfur is derived from bacterial sulfate reduction(BSR). δD values of fluid inclusions in ore-bearing quartz samples are from -99‰ to -78‰. The calculated δ^(18)OH_2O values of ore-forming fluid vary from -2.3‰ to 0.4‰ using the quartz-water fractionation equations and the mineralization temperature. Oxygen and hydrogen isotopic compositions show that the ore-forming fluid was derived from basin fluid. Rock-mineral identifications show that both of the mineral grain maturity and the structural maturity are high in the Jurassic Huakaizuo Formation, reflecting a far-source accumulation and lake facies sedimentatary environment. Based on tectonic determination diagram of the Al_2O_3/SiO_2-TFe+MgO, the sandstone samples collected from the Huakaizuo Formation were plotted in the passive continental margin. The collision of the Indian and Eurasian blocks during the Cenozoic formed large-scale strikeslips and thrust nappe structures in margin of the basin. With the tectonic movement, Cu-rich basin fluid from the basement of basin migrated upward along the contemporaneous fault and into the high porosity strata. At the same time, in organic matter-riched condition, bacterial sulfate reduction(BSR) has been triggered, forming a large number of S^(2-) ions, and then precipitation of sulfide started. This mechanism describes the process of copper mineral deposition in the Xinzhai deposit.
