Research on the origin of carbonates in Changdu Basin holds significant importance for understanding the regional potash formation model.Based on a comprehensive review of previous studies,field geological surveys,and...Research on the origin of carbonates in Changdu Basin holds significant importance for understanding the regional potash formation model.Based on a comprehensive review of previous studies,field geological surveys,and laboratory investigations,this study analyzes the origin and properties of carbonates within the context of regional potash formation.Petrographic studies show that magnesite deposits,with the characteristics of sedimentary origin.The results of elemental geochemical analysis show that the carbonates in this area were formed in the sedimentary environment via evaporation followed by concentration,and the formation of magnesite was possibly caused by the substitution of calcium in the dolomite with magnesium-rich brine.Theδ^(13)C values of carbonats in the study area are between5.9‰and 9.1‰.Theδ^(18)O values of magnesite samples range from-7.3‰to-1.3‰,and theδ^(18)O values of dolomites range from-10.3‰to-8.4‰.All the calculated Z values of oxygen isotopes of carbonates greater than 120.A comprehensive analysis of carbon and oxygen isotopes indicates that the magnesite was formed in a highly concentrated Marine sedimentary environment and does not show any relation with the metasomatism of hydrothermal fluids.The results on the correlation of magnesite with seawater and its sedimentary origin provide key information for explaining the migration direction of brine between the Changdu and Lanping-Simao Basins.The residual metamorphic seawater in the Changdu Basin migrated to the Lanping-Simao Basin,where potash underwent deposition.Whereas,magnesite and dolomite in the early stage of potash formation were left in the Changdu Basin.展开更多
Soil erosion by wind is one of the most important processes in the changing the earth's surface in semi-arid areas,Thus it is of great importance to study soil-erosion action.Using integrated technologies of remot...Soil erosion by wind is one of the most important processes in the changing the earth's surface in semi-arid areas,Thus it is of great importance to study soil-erosion action.Using integrated technologies of remote sensing and geochemistry radioactivity iso-tope to extract regional soil-erosion information and to calculate quantity of soil erosion is accomplished successfully in this paper by means of beneficial experiments in the Talatan region of the Gonghe Basin,which is located in northeastern Qinghai-Tibet Pla-teau in China.The results show that the soil erosion by wind is not intensive in this region;the erosion types belong to the classes of very-soft erosion and soft-erosion type,which account for 47.12 percent and 35.58 percent,respectively,of the total study area.In total,two kinds of soil erosion account for 82.70 percent of the study area;only a small area belongs to the classes of severe erosion and very-severe erosion;this area is about 22.14 km2.Severe deposition activity has taken place in this region,and has appeared in a large area(322.67 km2),which accounts for 11.78 percent of the total study area.The results of this study show that soil erosion and deposition inventories are 870,000-1,150,000 tons and 550,000-780,000 tons,respectively,per year.The soil in-ventory shows about 320,000-370,000 tons from Talatan to Longyangxia reservoir per year.Using remote-sensing technology and 137Cs techniques is a valid means to analyze and to evaluate the quantity of soil erosion by wind in semi-arid environments.展开更多
Identifying interactions among river water,groundwater and salt lake brine is important for sustainable exploitation of brine mineral resources.In this study,we investigated the water exchange rate in dry and wet seas...Identifying interactions among river water,groundwater and salt lake brine is important for sustainable exploitation of brine mineral resources.In this study,we investigated the water exchange rate in dry and wet seasons,and assessed the influence of seasonal water exchange on brine concentration and crystallization process in the Nalenggele(NLGL)catchment of Qaidam Basin,China.The results show that the surface water infiltration and groundwater recharge rates in the wet season were 2.81×10^(-3)and 1.15×10^(-3)m^(3)/(s·m)in upstream,1.63×10^(-2)and 1.53×10^(-2)m^(3)/(s·m)in midstream,and 2.83×10^(-4)and 6.82×10^(-5)m^(3)/(s·m)in downstream,respectively;while their counterparts in the dry season were 9.81×10^(-4)and 5.05×10^(-4)m^(3)/(s·m)in upstream,and 8.34×10^(-3)and 7.78×10^(-3)m^(3)/(s·m)in midstream,respectively.The water exchange strongly influenced brine concentration and crystallinzation process,with brine chemistry belonging to 3K_(2)SO_(4)·Na_(2)SO_(4) and KCl types in wet and dry seasons,respectively.The strong water exchange in wet season destroyed the water-salt balance,while the low water exchange rate in dry season facilitated preparation of KCl products.展开更多
基金the financial support from the Second Tibetan Plateau Scientific Expedition and Research(Grant No.2019QZKK0805)the postdoctoral project of Qinghai Institute of Salt Lakes(Grant No.E260DZ0401)+1 种基金the Kunlun Talent Project in Qinghai Province(Grant No.E340DZ0801)the Qinghai Provincial Department of Science and Technology Project(Grant No.2024-ZJ-722)。
文摘Research on the origin of carbonates in Changdu Basin holds significant importance for understanding the regional potash formation model.Based on a comprehensive review of previous studies,field geological surveys,and laboratory investigations,this study analyzes the origin and properties of carbonates within the context of regional potash formation.Petrographic studies show that magnesite deposits,with the characteristics of sedimentary origin.The results of elemental geochemical analysis show that the carbonates in this area were formed in the sedimentary environment via evaporation followed by concentration,and the formation of magnesite was possibly caused by the substitution of calcium in the dolomite with magnesium-rich brine.Theδ^(13)C values of carbonats in the study area are between5.9‰and 9.1‰.Theδ^(18)O values of magnesite samples range from-7.3‰to-1.3‰,and theδ^(18)O values of dolomites range from-10.3‰to-8.4‰.All the calculated Z values of oxygen isotopes of carbonates greater than 120.A comprehensive analysis of carbon and oxygen isotopes indicates that the magnesite was formed in a highly concentrated Marine sedimentary environment and does not show any relation with the metasomatism of hydrothermal fluids.The results on the correlation of magnesite with seawater and its sedimentary origin provide key information for explaining the migration direction of brine between the Changdu and Lanping-Simao Basins.The residual metamorphic seawater in the Changdu Basin migrated to the Lanping-Simao Basin,where potash underwent deposition.Whereas,magnesite and dolomite in the early stage of potash formation were left in the Changdu Basin.
基金financed by the Institute of Qinghai Salt Lakes,Chinese Academy of Sciences (contract KZCX2-SW-118)The open fund of State Key Laboratory of Estuarine and Coastal Research also supported this research.
文摘Soil erosion by wind is one of the most important processes in the changing the earth's surface in semi-arid areas,Thus it is of great importance to study soil-erosion action.Using integrated technologies of remote sensing and geochemistry radioactivity iso-tope to extract regional soil-erosion information and to calculate quantity of soil erosion is accomplished successfully in this paper by means of beneficial experiments in the Talatan region of the Gonghe Basin,which is located in northeastern Qinghai-Tibet Pla-teau in China.The results show that the soil erosion by wind is not intensive in this region;the erosion types belong to the classes of very-soft erosion and soft-erosion type,which account for 47.12 percent and 35.58 percent,respectively,of the total study area.In total,two kinds of soil erosion account for 82.70 percent of the study area;only a small area belongs to the classes of severe erosion and very-severe erosion;this area is about 22.14 km2.Severe deposition activity has taken place in this region,and has appeared in a large area(322.67 km2),which accounts for 11.78 percent of the total study area.The results of this study show that soil erosion and deposition inventories are 870,000-1,150,000 tons and 550,000-780,000 tons,respectively,per year.The soil in-ventory shows about 320,000-370,000 tons from Talatan to Longyangxia reservoir per year.Using remote-sensing technology and 137Cs techniques is a valid means to analyze and to evaluate the quantity of soil erosion by wind in semi-arid environments.
基金supported by the Key Deployment projects of the Chinese academy of sciences(No.ZDRW-ZS-2020-3)the Funds for the Qinghai Province(Nos.2020-ZJ-932Q+4 种基金2020-ZJ-732)the National Natural Science Foundation of China(No.42007169)the“Western Light”of Chinese Academy of Sciencesthe Fourth Batch of Qinghai Province“Thousand Talents Program for High-end Innovative Talents”(No.2020000051)supported by the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0805)。
文摘Identifying interactions among river water,groundwater and salt lake brine is important for sustainable exploitation of brine mineral resources.In this study,we investigated the water exchange rate in dry and wet seasons,and assessed the influence of seasonal water exchange on brine concentration and crystallization process in the Nalenggele(NLGL)catchment of Qaidam Basin,China.The results show that the surface water infiltration and groundwater recharge rates in the wet season were 2.81×10^(-3)and 1.15×10^(-3)m^(3)/(s·m)in upstream,1.63×10^(-2)and 1.53×10^(-2)m^(3)/(s·m)in midstream,and 2.83×10^(-4)and 6.82×10^(-5)m^(3)/(s·m)in downstream,respectively;while their counterparts in the dry season were 9.81×10^(-4)and 5.05×10^(-4)m^(3)/(s·m)in upstream,and 8.34×10^(-3)and 7.78×10^(-3)m^(3)/(s·m)in midstream,respectively.The water exchange strongly influenced brine concentration and crystallinzation process,with brine chemistry belonging to 3K_(2)SO_(4)·Na_(2)SO_(4) and KCl types in wet and dry seasons,respectively.The strong water exchange in wet season destroyed the water-salt balance,while the low water exchange rate in dry season facilitated preparation of KCl products.
