Polyhalite generally formed in the early diagenetic stage.It is formed by the brine which rich in K+and Mg2+and adverse reaction with the gypsum,anhydrite,glauberite(Pierre,1985;Peryt et al.,2005;Leitner et al.,
1 Introduction The homogenization temperature of fluid inclusions reflects the temperatures of the brines from which halite crystals grew.Therefore,it is a powerful mean to reveal the paleoclimate.Northern Shaanxi Sal...1 Introduction The homogenization temperature of fluid inclusions reflects the temperatures of the brines from which halite crystals grew.Therefore,it is a powerful mean to reveal the paleoclimate.Northern Shaanxi Salt Basin is located in the central and eastern of Ordos Basin.We have detail petrographical research and the展开更多
1 Introduction It is the focus of geology and biology that the creature preserved in the geological history and the organic evolution.The creature preserved in geological history by these things:sedimentary,frozen ear...1 Introduction It is the focus of geology and biology that the creature preserved in the geological history and the organic evolution.The creature preserved in geological history by these things:sedimentary,frozen earth,chrysophoron and evaporation salt.Evaporation salt can preserve the展开更多
Sichuan Basin is one of the most important marine–salt forming basins in China. The Simian and Triassic have a large number of evaporites. The Triassic strata have found a large amount of polyhalite and potassium-ric...Sichuan Basin is one of the most important marine–salt forming basins in China. The Simian and Triassic have a large number of evaporites. The Triassic strata have found a large amount of polyhalite and potassium-rich brine. However, no soluble potassium salt deposit were found. In this study, the halite in well Changping 3 which is located at the eastern part of the Sichuan basin was studied using the characteristics, hydrogen and oxygen isotopes of the fluid inclusion in halite to reconstruct the paleoenvironment. The salt rocks in well Changping 3 can be divided into two types: grey salt rock and orange salt rock. The result shows that the isotopic composition of the halite fluid inclusion is distinct from the global precipitation line reflecting that the salt formation process is under strong evaporation conditions and the climate is extremely dry. At the same time, compared with the hydrogen and oxygen isotopes of brine in the Sichuan Basin and the hydrous isotope composition of the inclusions in the salt inclusions of other areas in China, it is shown that the evaporation depth of the ancient seawater in the Sichuan Basin was high and reached the precipitation of potassium and magnesium stage.展开更多
Evaporites with gigantic thickness had been developed in Kuqa Basin from Paleocene to early Miocene,and the sediment thickness changed from tens to thousands of meters.By 3D mine software,spatial distribution model
Fluid inclusions in halite can directly record the major composition of seawater,however Ordovician halite is very rare.Ordovician is a key time during the evolution history.However there are no Ordovician seawater da...Fluid inclusions in halite can directly record the major composition of seawater,however Ordovician halite is very rare.Ordovician is a key time during the evolution history.However there are no Ordovician seawater data reported except from the data from the halite from展开更多
A large number of fluid inclusions are formed in the crystal formation of halite,in which pure liquid phase ones supply a new method of paleo temperature inversion by means of cryogenic thermometry.In this study。
The Lanping−Simao Basin is located on the southeastern Tibetan Plateau,China,and contains massive evaporites.The origin of evaporites in the basin has been hotly debated because of the strong transformation by tectoni...The Lanping−Simao Basin is located on the southeastern Tibetan Plateau,China,and contains massive evaporites.The origin of evaporites in the basin has been hotly debated because of the strong transformation by tectonic movement.Forty halite samples from borehole MK-3 in the Mengyejing area of the basin were collected and analyzed using XRD,Cl-Sr isotopes and chemical compositions to trace the origin of the evaporites in the basin.The Br×10^(3)/Cl ratios of the halite samples are between 0 and 0.55,most of which are synchronized with the law of seawater evaporation and at the stage of halite precipitation from seawater,indicating that the evaporites are mainly of marine origin.The^(87)Sr/^(86)Sr ratios range from 0.707489 to 0.711279;after correction,the^(87)Sr/^(86)Sr 145 Ma ratios range from 0.704721 to 0.707611,equivalent with the 87Sr/86Sr ratios of seawater at 145 Ma,indicating a marine origin.The decay of 87Rb in the evaporite during deposition,change of the depositional environment and the unsealed environment at a later period resulted in the present^(87)Sr/^(86)Sr ratios of some samples being high.The δ^(37)Cl value compositions range from−0.38‰to 0.83‰,which is consistent with the δ^(37)Cl value composition of the world marine halite(−0.6‰to 0.4‰),further confirming that seawater is the main origin.In addition,the high δ^(37)Cl value of some samples at the boundary of the upper and lower evaporite layers might be related to the influence of δ^(37)Cl-rich brine and the incomplete dissolution of the halite.展开更多
Trapped ancient microorganisms in halite fluid inclusions are of special interest to the understanding of biology and ecology in salt lake systems.With the integration of petrologic,microthermometric,and Raman spectro...Trapped ancient microorganisms in halite fluid inclusions are of special interest to the understanding of biology and ecology in salt lake systems.With the integration of petrologic,microthermometric,and Raman spectroscopic analyses,this study utilizes fluid inclusions from Chaka Salt Lake,eastern Qaidam Basin,NW China,to assess the possibility of microorganism-trapping by fluid inclusions.Here,we report that the solid phase of some primary fluid inclusions contains carotenoids,which is interpreted as evidence of Dunaliella algae,and that the coexisting liquid phase comprises SO_(4)^(2-).The homogenization temperatures of single-phase primary fluid inclusions indicate that the precipitation temperature of the Holocene halite in Chaka Salt Lake ranges from 13.5℃ to 36.4℃.This suggests that fluid inclusions in halite are a good medium for trapping and preserving ancient microorganisms and organic matter in salt lakes,and that Raman spectroscopy has good potential to identify halophilic archaea.展开更多
The Qaidam Basin is a large intermontane depression. It has been in existence since the Jurassic. The mean elevation of the basin floor is 2800 m. It covers an area of 120,000 km^2 with a catchment area of about 250,0...The Qaidam Basin is a large intermontane depression. It has been in existence since the Jurassic. The mean elevation of the basin floor is 2800 m. It covers an area of 120,000 km^2 with a catchment area of about 250,000 km^2. By the end of the Pliocene, great changes had taken place. Some of the lakes were evolving to the evaporite formation stage. The deposition continued through the Pliocene and the late Pleistocene to produce a sequence 2000—3000 m thick, and the total thickness of halite sequence is more than 1000 m. The Qaidam Basin contains some of the richest salt resources, the sediments deposited on展开更多
The majority of oil and gas resources in the world are related to saline sediments, which mainly occur in sedimentary strata in the form of cap rocks or salt-associated shales. A large number of shale oil resources ha...The majority of oil and gas resources in the world are related to saline sediments, which mainly occur in sedimentary strata in the form of cap rocks or salt-associated shales. A large number of shale oil resources have been discovered in the saline shale sediments of the Cenozoic terrestrial lake basin in China. The hydrocarbon generation ability and the reservoir capacity of shale control the oil and gas generation. The reservoir capacity is mainly characterized by pore type, structure and porosity. Most of China’s shale oil and gas resources belong to salt-bearing formations. The role of gypsum-salt rocks in the formation and evolution of organic matter (OM) in such formations has received extensive attention. However, systematic understanding is lacking. Research on the pore formation and evolution in shale under the action of gypsum-salt rock sediments is especially weak. Taking the shales in the third member of the Shahejie Formation (Es_(3)) of the Bohai Bay Basin as an example, the influence of halite on the formation and evolution process of pores was studied in this paper. The results show that halite and gypsum minerals were associated with OM, which made them more likely to develop OM pores. The samples with a high halite mineral content (HC) are more developed regarding the pore volume and specific surface area than those with a low HC. The formation of thick salt rocks is influenced by factors of deep thermal brine upwelling, sea erosion and arid environments. The frequent alternation between humid and arid environments led to the outbreak and death of organisms and the precipitation of gypsum-salt rock, which formed the simultaneous deposition of OM and halite minerals. Finally, we have established a model of shale pore evolution under the participation of the gypsum-salt rock, and halite minerals contribute to pore development in both Stage II and Stage IV. This study provides strong microscopic evidence for the pore system formation and evolution in salt-bearing reservoirs.展开更多
Melt inclusions in kimberlitic minerals and diamonds indicate that chlorides are important constituents of mantle carbonatite melts.Besides,alkaline chlorides are important constituents of saline high-density fluids(H...Melt inclusions in kimberlitic minerals and diamonds indicate that chlorides are important constituents of mantle carbonatite melts.Besides,alkaline chlorides are important constituents of saline high-density fluids(HDFs)found in diamonds from kimberlites and placers around the world.Continuous compositional variations suggest that saline and carbonatitic HDFs could be genetically linked.However,the essence of this link remains unclear owing to the lack of data on phase relations in the chloridecarbonate systems under pressure.Here we studied subsolidus and melting phase relations in the system NaCl–CaCO_(3)–MgCO_(3)at 6 GPa and 1000–1600℃using a Kawai-type multianvil press.We found that at 1000℃,subsolidus assemblage consists of halite,magnesite,and aragonite.At higher temperatures,the stabilization of dolomite splits the subsolidus area into two partial ternary fields:halite+magnesite+dolomite and halite+dolomite+aragonite.The minimum on the liquidus surface corresponds to the halite-dolomite-aragonite ternary eutectic,situated at 1100℃.The eutectic melt has Ca#89 and contains 30 wt.%Na Cl(26 mol%2NaCl).The system has two ternary peritectics:halite+dolomite=magnesite+liquid located near the ternary eutectic and magnesite+dolomite=Mg-dolomite+liquid situated between 1300 and 1400℃.Although under dry conditions incipient melting yields carbonatedominated melt,the addition of water facilitates the fusion of Na Cl and expands the liquid field to Na Cl-rich compositions with up to 70 wt.%Na Cl.The obtained results favor the idea that hydrous saline melts/fluids(brines)found as inclusions in diamonds could be a lower temperature derivative of mantle carbonatite melts and disagree with the hypothesis on chloride melt generation owing to the chloridecarbonate liquid immiscibility since no such immiscibility was established.We also studied the interaction of the NaCl–CaCO_(3)–MgCO_(3)system with iron metal and found that carbonate reduction produces Cbearing species(Fe^(0),Fe-C melt,Fe_(3)C,Fe_(7)C_(3),C^(0))and wüstite containing Na_(2)O,CaO,and MgO.Besides,a carbonate chloride compound,Ca_(2)Cl_(2)CO_(3),was established among the reaction products.The interaction between Na Cl-bearing carbonate melt shifts its composition toward Mg-poor and Na Cl-rich.Given the above,an alternative hypothesis can be proposed,according to which the interaction of alkaline chloride-bearing carbonate melts formed in the subduction zones with the reduced mantle should be accompanied by diamond crystallization and shift the composition of the melt from carbonatitic to alkali-rich saline.展开更多
Polycrystalline rock salt’s compression is a function of applied stresses,exposure duration to the applied stresses,ambient temperature,and water content.Rock salt’s compressional behavior under different conditions...Polycrystalline rock salt’s compression is a function of applied stresses,exposure duration to the applied stresses,ambient temperature,and water content.Rock salt’s compressional behavior under different conditions and its effects on the specimens’mechanical properties have been investigated in the literature.However,the one-dimensional(1D)compression behavior of polycrystalline rock salt at various water contents and how the specimen’s compression at different water contents further affects its physical and mechanical properties are not fully understood yet.In this study,polycrystalline rock salt specimens were prepared under nominally dry and wet conditions and some of the dry and wet specimens were annealed after the preparation.The relationship between the porosity of the specimens and the logarithm of the applied axial stresses during the 1D compression was found to follow a linear relationship after reaching unique critical porosities of 32%and 37%for the dry and wet specimens,respectively.Unloading and reloading the specimens did not result in any major changes in the porosity of the specimens.The specimens compressed under wet condition showed an average final porosity of 2.6%compared to 6.9%for the dry specimens.The dry and wet specimens that were annealed after the compression exhibited a lower porosity in comparison to the dry and wet specimens,respectively.Unconfined compression experiments on the specimens showed dry and wet specimens possess averaged unconfined compressive strengths(σ_(u))of 64.3 and 16.2 MPa,respectively.Annealing decreased σ_(u)of the dry specimens to 39.6 MPa and increased σ_(u)of the wet specimens to 41 MPa.展开更多
基金supported by Major state basic research development program (No.2011CB 403007)
文摘Polyhalite generally formed in the early diagenetic stage.It is formed by the brine which rich in K+and Mg2+and adverse reaction with the gypsum,anhydrite,glauberite(Pierre,1985;Peryt et al.,2005;Leitner et al.,
文摘1 Introduction The homogenization temperature of fluid inclusions reflects the temperatures of the brines from which halite crystals grew.Therefore,it is a powerful mean to reveal the paleoclimate.Northern Shaanxi Salt Basin is located in the central and eastern of Ordos Basin.We have detail petrographical research and the
基金supported by the China Geological Survey project (12120113019100)the project the Public Welfare Major Program from MLR(201011001-4)
文摘1 Introduction It is the focus of geology and biology that the creature preserved in the geological history and the organic evolution.The creature preserved in geological history by these things:sedimentary,frozen earth,chrysophoron and evaporation salt.Evaporation salt can preserve the
基金This study was supported by the National Natural Science Foundation of China (Grant No.41902065, 41772197)Open Reserch Fund from the State Key Laboratory Breeding base of Nuclear Resources and environment (Grant NRE1803)+1 种基金the Chongqing Science and Technology Innovation Project (Zhu Zhengjie)the Major State Basic Research Development Program (No.2011CB40300)
文摘Sichuan Basin is one of the most important marine–salt forming basins in China. The Simian and Triassic have a large number of evaporites. The Triassic strata have found a large amount of polyhalite and potassium-rich brine. However, no soluble potassium salt deposit were found. In this study, the halite in well Changping 3 which is located at the eastern part of the Sichuan basin was studied using the characteristics, hydrogen and oxygen isotopes of the fluid inclusion in halite to reconstruct the paleoenvironment. The salt rocks in well Changping 3 can be divided into two types: grey salt rock and orange salt rock. The result shows that the isotopic composition of the halite fluid inclusion is distinct from the global precipitation line reflecting that the salt formation process is under strong evaporation conditions and the climate is extremely dry. At the same time, compared with the hydrogen and oxygen isotopes of brine in the Sichuan Basin and the hydrous isotope composition of the inclusions in the salt inclusions of other areas in China, it is shown that the evaporation depth of the ancient seawater in the Sichuan Basin was high and reached the precipitation of potassium and magnesium stage.
基金national "Twelfth Five-Year" Technology Support Plan (2011BAB06B06) for funds for this paper
文摘Evaporites with gigantic thickness had been developed in Kuqa Basin from Paleocene to early Miocene,and the sediment thickness changed from tens to thousands of meters.By 3D mine software,spatial distribution model
基金supported by Major State Basic Research Development Program(973 Program,no. 2011CB403000)National Natural Science Foundation of China (Nos: 40703018+1 种基金 41173051 41172131)
文摘Fluid inclusions in halite can directly record the major composition of seawater,however Ordovician halite is very rare.Ordovician is a key time during the evolution history.However there are no Ordovician seawater data reported except from the data from the halite from
文摘A large number of fluid inclusions are formed in the crystal formation of halite,in which pure liquid phase ones supply a new method of paleo temperature inversion by means of cryogenic thermometry.In this study。
基金supported by the National Natural Science Foundation of China(Grant No.U1407207)the project of China Geological Survey(Grant No.DD20201115).
文摘The Lanping−Simao Basin is located on the southeastern Tibetan Plateau,China,and contains massive evaporites.The origin of evaporites in the basin has been hotly debated because of the strong transformation by tectonic movement.Forty halite samples from borehole MK-3 in the Mengyejing area of the basin were collected and analyzed using XRD,Cl-Sr isotopes and chemical compositions to trace the origin of the evaporites in the basin.The Br×10^(3)/Cl ratios of the halite samples are between 0 and 0.55,most of which are synchronized with the law of seawater evaporation and at the stage of halite precipitation from seawater,indicating that the evaporites are mainly of marine origin.The^(87)Sr/^(86)Sr ratios range from 0.707489 to 0.711279;after correction,the^(87)Sr/^(86)Sr 145 Ma ratios range from 0.704721 to 0.707611,equivalent with the 87Sr/86Sr ratios of seawater at 145 Ma,indicating a marine origin.The decay of 87Rb in the evaporite during deposition,change of the depositional environment and the unsealed environment at a later period resulted in the present^(87)Sr/^(86)Sr ratios of some samples being high.The δ^(37)Cl value compositions range from−0.38‰to 0.83‰,which is consistent with the δ^(37)Cl value composition of the world marine halite(−0.6‰to 0.4‰),further confirming that seawater is the main origin.In addition,the high δ^(37)Cl value of some samples at the boundary of the upper and lower evaporite layers might be related to the influence of δ^(37)Cl-rich brine and the incomplete dissolution of the halite.
基金This work was supported by the National Natural Science Foundation of China(41873070,U1762108 and 41172111).
文摘Trapped ancient microorganisms in halite fluid inclusions are of special interest to the understanding of biology and ecology in salt lake systems.With the integration of petrologic,microthermometric,and Raman spectroscopic analyses,this study utilizes fluid inclusions from Chaka Salt Lake,eastern Qaidam Basin,NW China,to assess the possibility of microorganism-trapping by fluid inclusions.Here,we report that the solid phase of some primary fluid inclusions contains carotenoids,which is interpreted as evidence of Dunaliella algae,and that the coexisting liquid phase comprises SO_(4)^(2-).The homogenization temperatures of single-phase primary fluid inclusions indicate that the precipitation temperature of the Holocene halite in Chaka Salt Lake ranges from 13.5℃ to 36.4℃.This suggests that fluid inclusions in halite are a good medium for trapping and preserving ancient microorganisms and organic matter in salt lakes,and that Raman spectroscopy has good potential to identify halophilic archaea.
文摘The Qaidam Basin is a large intermontane depression. It has been in existence since the Jurassic. The mean elevation of the basin floor is 2800 m. It covers an area of 120,000 km^2 with a catchment area of about 250,000 km^2. By the end of the Pliocene, great changes had taken place. Some of the lakes were evolving to the evaporite formation stage. The deposition continued through the Pliocene and the late Pleistocene to produce a sequence 2000—3000 m thick, and the total thickness of halite sequence is more than 1000 m. The Qaidam Basin contains some of the richest salt resources, the sediments deposited on
基金funded by the National Natural Science Foundation of China(41872128)Postdoctoral Foundation of China University of Petroleum(Beijing)(ZX20220102).
文摘The majority of oil and gas resources in the world are related to saline sediments, which mainly occur in sedimentary strata in the form of cap rocks or salt-associated shales. A large number of shale oil resources have been discovered in the saline shale sediments of the Cenozoic terrestrial lake basin in China. The hydrocarbon generation ability and the reservoir capacity of shale control the oil and gas generation. The reservoir capacity is mainly characterized by pore type, structure and porosity. Most of China’s shale oil and gas resources belong to salt-bearing formations. The role of gypsum-salt rocks in the formation and evolution of organic matter (OM) in such formations has received extensive attention. However, systematic understanding is lacking. Research on the pore formation and evolution in shale under the action of gypsum-salt rock sediments is especially weak. Taking the shales in the third member of the Shahejie Formation (Es_(3)) of the Bohai Bay Basin as an example, the influence of halite on the formation and evolution process of pores was studied in this paper. The results show that halite and gypsum minerals were associated with OM, which made them more likely to develop OM pores. The samples with a high halite mineral content (HC) are more developed regarding the pore volume and specific surface area than those with a low HC. The formation of thick salt rocks is influenced by factors of deep thermal brine upwelling, sea erosion and arid environments. The frequent alternation between humid and arid environments led to the outbreak and death of organisms and the precipitation of gypsum-salt rock, which formed the simultaneous deposition of OM and halite minerals. Finally, we have established a model of shale pore evolution under the participation of the gypsum-salt rock, and halite minerals contribute to pore development in both Stage II and Stage IV. This study provides strong microscopic evidence for the pore system formation and evolution in salt-bearing reservoirs.
基金financially supported by Russian Science Foundation (project No 21-17-00024)。
文摘Melt inclusions in kimberlitic minerals and diamonds indicate that chlorides are important constituents of mantle carbonatite melts.Besides,alkaline chlorides are important constituents of saline high-density fluids(HDFs)found in diamonds from kimberlites and placers around the world.Continuous compositional variations suggest that saline and carbonatitic HDFs could be genetically linked.However,the essence of this link remains unclear owing to the lack of data on phase relations in the chloridecarbonate systems under pressure.Here we studied subsolidus and melting phase relations in the system NaCl–CaCO_(3)–MgCO_(3)at 6 GPa and 1000–1600℃using a Kawai-type multianvil press.We found that at 1000℃,subsolidus assemblage consists of halite,magnesite,and aragonite.At higher temperatures,the stabilization of dolomite splits the subsolidus area into two partial ternary fields:halite+magnesite+dolomite and halite+dolomite+aragonite.The minimum on the liquidus surface corresponds to the halite-dolomite-aragonite ternary eutectic,situated at 1100℃.The eutectic melt has Ca#89 and contains 30 wt.%Na Cl(26 mol%2NaCl).The system has two ternary peritectics:halite+dolomite=magnesite+liquid located near the ternary eutectic and magnesite+dolomite=Mg-dolomite+liquid situated between 1300 and 1400℃.Although under dry conditions incipient melting yields carbonatedominated melt,the addition of water facilitates the fusion of Na Cl and expands the liquid field to Na Cl-rich compositions with up to 70 wt.%Na Cl.The obtained results favor the idea that hydrous saline melts/fluids(brines)found as inclusions in diamonds could be a lower temperature derivative of mantle carbonatite melts and disagree with the hypothesis on chloride melt generation owing to the chloridecarbonate liquid immiscibility since no such immiscibility was established.We also studied the interaction of the NaCl–CaCO_(3)–MgCO_(3)system with iron metal and found that carbonate reduction produces Cbearing species(Fe^(0),Fe-C melt,Fe_(3)C,Fe_(7)C_(3),C^(0))and wüstite containing Na_(2)O,CaO,and MgO.Besides,a carbonate chloride compound,Ca_(2)Cl_(2)CO_(3),was established among the reaction products.The interaction between Na Cl-bearing carbonate melt shifts its composition toward Mg-poor and Na Cl-rich.Given the above,an alternative hypothesis can be proposed,according to which the interaction of alkaline chloride-bearing carbonate melts formed in the subduction zones with the reduced mantle should be accompanied by diamond crystallization and shift the composition of the melt from carbonatitic to alkali-rich saline.
基金This material is based on work supported by the National Science Foundation under Grant No.CMMI-1641054.
文摘Polycrystalline rock salt’s compression is a function of applied stresses,exposure duration to the applied stresses,ambient temperature,and water content.Rock salt’s compressional behavior under different conditions and its effects on the specimens’mechanical properties have been investigated in the literature.However,the one-dimensional(1D)compression behavior of polycrystalline rock salt at various water contents and how the specimen’s compression at different water contents further affects its physical and mechanical properties are not fully understood yet.In this study,polycrystalline rock salt specimens were prepared under nominally dry and wet conditions and some of the dry and wet specimens were annealed after the preparation.The relationship between the porosity of the specimens and the logarithm of the applied axial stresses during the 1D compression was found to follow a linear relationship after reaching unique critical porosities of 32%and 37%for the dry and wet specimens,respectively.Unloading and reloading the specimens did not result in any major changes in the porosity of the specimens.The specimens compressed under wet condition showed an average final porosity of 2.6%compared to 6.9%for the dry specimens.The dry and wet specimens that were annealed after the compression exhibited a lower porosity in comparison to the dry and wet specimens,respectively.Unconfined compression experiments on the specimens showed dry and wet specimens possess averaged unconfined compressive strengths(σ_(u))of 64.3 and 16.2 MPa,respectively.Annealing decreased σ_(u)of the dry specimens to 39.6 MPa and increased σ_(u)of the wet specimens to 41 MPa.
