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 homogenization展开更多
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.,
The Mengyejing potash deposit is located in the southern port of the Simao Basin, Yunnan Province, and is hosted in mid-Cretaceous strata. The chemical compositions of fluid inclusions in halite crystals, collected fr...The Mengyejing potash deposit is located in the southern port of the Simao Basin, Yunnan Province, and is hosted in mid-Cretaceous strata. The chemical compositions of fluid inclusions in halite crystals, collected from the level-610 adit in the deposit, were analysed by laser ablation inductively coupled plasma mass spectrometry（LA-ICP-MS）. The results show that the brine is of the Na-K-Mg-Ca-Cl type and has K concentrations that are distinctly higher than those of Mg and Ca, unlike normal brines associated with Cretaceous halite. The high K concentrations indicate that the degree of evaporation of the ancient Mengyejing saline lake was very high, reaching the sylvite deposition stage but rarely reaching the carnallite deposition stage. The trajectory of the H and O isotopic compositions of the brines in the halite-hosted fluid inclusions corresponds to intense evaporation, indicating that the net evaporation exceeded the net inflow of brines. These brine compositions in halite-hosted fluid inclusions were likely formed by the dissolution of previously deposited K-bearing minerals by fresh continental and/or seawater, forming a type of modified seawater, with deep hydrothermal fluids potentially supplying additional potassium. The basin likely experienced multiple seawater incursion, dissolution and redeposition events in a high-temperature environment with high evaporation rates.展开更多
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
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
Objective The Mengyejing potash deposit in the Simao Basin is the only producing area of solid potash at present in China. There is still controversy about the material source and distribution of the potash in this d...Objective The Mengyejing potash deposit in the Simao Basin is the only producing area of solid potash at present in China. There is still controversy about the material source and distribution of the potash in this deposit （Shen Lijian et al., 2017）, which has influenced not only the prospecting direction and efficiency but also the understanding of the control of Tethys tectonic evolution on the formation and distribution of the mineral resources. This work analyzed the Sr isotope geochemical characteristics of evaporites from core samples in the well MZK-3 in order to further clarify the material source and to explore the potash distribution in the Simao Basin.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 of
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 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 microbe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
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,we
Paleo-temperature and paleo-environment can be interpreted from measuring homogenization temperatures of fluid inclusions within halite. In order to conduct such measurements, vapor bubbles within low-temperature flui...Paleo-temperature and paleo-environment can be interpreted from measuring homogenization temperatures of fluid inclusions within halite. In order to conduct such measurements, vapor bubbles within low-temperature fluid inclusion often need to be created through cooling process by using cooling stage or freezer. Proper cooling is critical for interpreting measured temperature data. We tested two common cooling methods, using heating/freezing stage and freezer, for studying fluid inclusions in halite precipitated in laboratory at conrtolled temperature of 25＂C. While using the heating/freezing stage, halite samples were kept at -18＂C for 40-50 rain; whereas for freezer, samples were stored at -18＂C for 1, 10, 20 and 40 days, respectively. By comparing the homogenization temperatures of the two cooling processes, we explored the detailed experimental processes and developed an optimal cooling nucleation procedure for homogenization temperature analyses of fluid inclusions within surface-temperature halite. The results show that the maximum homogenization temperatures from both methods approximate the actual brine temperature of 25＂C. However, extended refrigeration time has noticeable influence on the results. The refrigeration time of the experiment can be shortened to meet requirements.展开更多
The Ordovician was an important transitional period for global climate and organic evolution,the global was in the flood and glacial,Onganism was extinction(Zhan,2007;Trotter et al.,2008;Axel et al.,2010).Under the in...The Ordovician was an important transitional period for global climate and organic evolution,the global was in the flood and glacial,Onganism was extinction(Zhan,2007;Trotter et al.,2008;Axel et al.,2010).Under the influence展开更多
Previous studies have investigated the boron isotopic composition of salt lake brines in the Qaidam Basin,western China.However,the research on boron isotopic composition of halite is very limited due to halite’s low
This paper presents an experimental investigation of the microstructural development upon in situ compression and heating of pure and SiO2 gel-doped （5 wt%） polycrystalline halite, with grain sizes ranging from 45 ...This paper presents an experimental investigation of the microstructural development upon in situ compression and heating of pure and SiO2 gel-doped （5 wt%） polycrystalline halite, with grain sizes ranging from 45 μm to 〉70 μm （cold pressed at 200 MPa and heated at 150 ℃ for one week）, using high energy synchrotron x-ray radiation. Texture development of the samples was studied at room temperature, 100, 200 and 300 ℃. At each temperature, the samples were axially compressed keeping the load constant at every -500 N step up to the maximum 2,400 N （- 48 MPa）. At the different loads and temperatures, 2D images and load/elongation curves were recorded in situ to get information about the texture development and the rheological behaviour of the potycrystalline halite samples. At high stresses, the doped halite samples show an increase in the elastic moduli and in the microstrain The results were confirmed by the single grain orientation analyses using the FABLE program, where a sharpening of the texture was observed.展开更多
The formation of halite in continental basins is intimately linked to lake-level changes.Current research has revealed the connection between lake-level variations and astronomical forcing on a million-year scale.Othe...The formation of halite in continental basins is intimately linked to lake-level changes.Current research has revealed the connection between lake-level variations and astronomical forcing on a million-year scale.Other studies have also highlighted the influence of orbitally-induced climate cycles on halite deposition.However,our understanding of the impact of astronomically-paced lake-level changes on halite formation remains constrained.The Paleogene Dawenkou Formation in the Huanggang Basin of East China provides a continuous salt-bearing sedimentary record to investigate the lake-level changes in halite deposition.Lake-level fluctuations reconstructed by sedimentary noise modeling for the Middle and Upper members of the Dawenkou Formation indicate that the lake-level variations in the Huanggang Basin were linked to astronomical forcing with periods of∼2.4 Myr,∼1.2 Myr and/or∼100 kyr.Our results suggest that astronomical forcing,as a driver of lake-level variations,may have had an impact on halite deposition during the Paleogene.In the initial stage of halite formation within the Middle Member of the Dawenkou Formation,reduced heat and moisture transport during the∼1.2 Myr obliquity minima resulted in low lake levels in mid-to-high latitudes.The prolonged droughts caused by the low amplitude of∼2.4 Myr eccentricity created conditions more favorable for the development of thicker layers of halite.Subsequently,in the next halite-forming stage,a larger amplitude of∼2.4 Myr eccentricity led to a more humid climate.Warm/dry winters and cool summers paced by the∼100 kyr orbital eccentricity minima resulted in enhanced evaporation,relatively lower lake levels,and thinner halite deposition.Nevertheless,the possible transgressions may have contributed to complicated phase relationship between the lake-level change cycles and orbital cycles.This study offers an opportunity to delve deeper into the mechanism of halite deposition by objectively reconstructing lake levels using sedimentary noise modeling.展开更多
The distinctive characteristics exhibited by the aftershocks of Ms6.0 induced earthquakes in Changning,Sichuan,China,have attracted significant attention.The prevalence of salt rock(halite)in this area is closely asso...The distinctive characteristics exhibited by the aftershocks of Ms6.0 induced earthquakes in Changning,Sichuan,China,have attracted significant attention.The prevalence of salt rock(halite)in this area is closely associated with induced seismic events.The present study was conducted to examine the role of halite in frictional properties.To this end,laboratory measurements were taken for simulated fault gouge composed of halite.Slide-hold-slide(SHS)shear experiments were performed on gouges with grain size<106 mm at constant normal stress from 5 MPa to 30 MPa and constant shear velocity in the range of 1-10 mm/s.Halite gouge shows higher frictional strength and frictional healing rate than most minerals.The results reveal that the fault within halite can potentially generate intense seismic events and more significant aftershocks.An increase in normal stress leads to a reduction in frictional healing,with frictional strength initially increasing and then decreasing.The elevated shear velocity following fault activation facilitates fault dilation,diminishes the frictional strength of the fault,and contributes to fault healing during the inter-seismic period.The aforementioned findings will contribute to a comprehensive understanding of the potential for the healing property of induced seismicity on faults containing halite,particularly in the Changning region of China.展开更多
The phenomenon of'bamboo-like'thin interlayers developed in rock salt is one of the most prominent features of Paleogene salt-bearing strata in eastern China,where centimeter-thick rock salts appear separately...The phenomenon of'bamboo-like'thin interlayers developed in rock salt is one of the most prominent features of Paleogene salt-bearing strata in eastern China,where centimeter-thick rock salts appear separately,forming rhythmic units.At present,detailed analyses of these rhythms of rock salt are still limited,which directly affects the achievement of comprehensive and in-depth understanding of the developmental laws pertaining to this kind of saline lake.Therefore,we selected the typical rhythmic'bamboo-like'rock salts of the Shizhai Depression in Jiangsu Province as the research subject.Through careful observation of rock salts in hand samples and detailed petrographic and mineralogical analyses,we analyzed the hydrogen and oxygen isotopic compositions,homogenization temperatures and chemical compositions of individual fluid inclusions in halite crystals.Early-stage rhythmic deposition was a product of continental saline lake evolution in winter or spring,late-stage rhythmic deposition being the product of evolution in the summer.The seasonal evolution of the halite sequences was determined and two brine enrichment events were identified.In addition,the quiet saline lake environment with concentrated brine represented by rock salt was more likely to precipitate potassium.This study provides a new reference for the evolution of both Paleogene climate and saline lakes in eastern China.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
Pollution of petroleum hydrocarbons, in particular oil spills, has attracted much attention in the past and recent decades. Oil spills influence natural microbial community, and physical and chemical properties of the...Pollution of petroleum hydrocarbons, in particular oil spills, has attracted much attention in the past and recent decades. Oil spills influence natural microbial community, and physical and chemical properties of the affected sites. The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. The impact of the Nakhodka oil spill resulted in a viscous sticky fluid fouling the shores and affected natural ecosystems. This paper describes the weathering of hydrocarbon-degrading bacteria （genus Pseudomonas） and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years. The Nakhodka oil has hardened and formed crust of crystalline paraffin wax as shown by XRD analysis （0.422, 0.377, and 0.250 nm d-spacing） in association with graphite and calcite after 9 years of bioremediation. Anaerobic reverse side of the oil crust contained numerous coccus typed bacteria associated with halite. The finding of hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9- year bioremediation.展开更多
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 homogenization
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.,
基金supported by the Basic Research Project for the Central Public Welfare Scientific Institutions of China (No.K1405)the National Key Project for Basic Research of China (No.2011CB403007)the National Natural Science Foundation of China (No.41572067)
文摘The Mengyejing potash deposit is located in the southern port of the Simao Basin, Yunnan Province, and is hosted in mid-Cretaceous strata. The chemical compositions of fluid inclusions in halite crystals, collected from the level-610 adit in the deposit, were analysed by laser ablation inductively coupled plasma mass spectrometry（LA-ICP-MS）. The results show that the brine is of the Na-K-Mg-Ca-Cl type and has K concentrations that are distinctly higher than those of Mg and Ca, unlike normal brines associated with Cretaceous halite. The high K concentrations indicate that the degree of evaporation of the ancient Mengyejing saline lake was very high, reaching the sylvite deposition stage but rarely reaching the carnallite deposition stage. The trajectory of the H and O isotopic compositions of the brines in the halite-hosted fluid inclusions corresponds to intense evaporation, indicating that the net evaporation exceeded the net inflow of brines. These brine compositions in halite-hosted fluid inclusions were likely formed by the dissolution of previously deposited K-bearing minerals by fresh continental and/or seawater, forming a type of modified seawater, with deep hydrothermal fluids potentially supplying additional potassium. The basin likely experienced multiple seawater incursion, dissolution and redeposition events in a high-temperature environment with high evaporation rates.
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 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supported by the"national Key R&D Program of China"(grant No.2017YFC0602801)geological survey project of"Investigation and Evaluation of the Potash Deposit Prospect in West China"(grant No.DD20160054)
文摘Objective The Mengyejing potash deposit in the Simao Basin is the only producing area of solid potash at present in China. There is still controversy about the material source and distribution of the potash in this deposit （Shen Lijian et al., 2017）, which has influenced not only the prospecting direction and efficiency but also the understanding of the control of Tethys tectonic evolution on the formation and distribution of the mineral resources. This work analyzed the Sr isotope geochemical characteristics of evaporites from core samples in the well MZK-3 in order to further clarify the material source and to explore the potash distribution in the Simao Basin.
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 of
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 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 microbe
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,we
基金supported by National Natural Science Foundation of China(No.41302059)Major State Basic Research Development Program(No.2011CB403007)
文摘Paleo-temperature and paleo-environment can be interpreted from measuring homogenization temperatures of fluid inclusions within halite. In order to conduct such measurements, vapor bubbles within low-temperature fluid inclusion often need to be created through cooling process by using cooling stage or freezer. Proper cooling is critical for interpreting measured temperature data. We tested two common cooling methods, using heating/freezing stage and freezer, for studying fluid inclusions in halite precipitated in laboratory at conrtolled temperature of 25＂C. While using the heating/freezing stage, halite samples were kept at -18＂C for 40-50 rain; whereas for freezer, samples were stored at -18＂C for 1, 10, 20 and 40 days, respectively. By comparing the homogenization temperatures of the two cooling processes, we explored the detailed experimental processes and developed an optimal cooling nucleation procedure for homogenization temperature analyses of fluid inclusions within surface-temperature halite. The results show that the maximum homogenization temperatures from both methods approximate the actual brine temperature of 25＂C. However, extended refrigeration time has noticeable influence on the results. The refrigeration time of the experiment can be shortened to meet requirements.
文摘The Ordovician was an important transitional period for global climate and organic evolution,the global was in the flood and glacial,Onganism was extinction(Zhan,2007;Trotter et al.,2008;Axel et al.,2010).Under the influence
基金supported by the National Natural Science Foundation of China (Grant Nos. 41002060, 41272274)the Foundation of Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant to QS Fan)
文摘Previous studies have investigated the boron isotopic composition of salt lake brines in the Qaidam Basin,western China.However,the research on boron isotopic composition of halite is very limited due to halite’s low
文摘This paper presents an experimental investigation of the microstructural development upon in situ compression and heating of pure and SiO2 gel-doped （5 wt%） polycrystalline halite, with grain sizes ranging from 45 μm to 〉70 μm （cold pressed at 200 MPa and heated at 150 ℃ for one week）, using high energy synchrotron x-ray radiation. Texture development of the samples was studied at room temperature, 100, 200 and 300 ℃. At each temperature, the samples were axially compressed keeping the load constant at every -500 N step up to the maximum 2,400 N （- 48 MPa）. At the different loads and temperatures, 2D images and load/elongation curves were recorded in situ to get information about the texture development and the rheological behaviour of the potycrystalline halite samples. At high stresses, the doped halite samples show an increase in the elastic moduli and in the microstrain The results were confirmed by the single grain orientation analyses using the FABLE program, where a sharpening of the texture was observed.
基金supported by the Deep Earth Probe and Mineral Resources Exploration—National Science and Technology Major Project of China(No.2024ZD1001105).
文摘The formation of halite in continental basins is intimately linked to lake-level changes.Current research has revealed the connection between lake-level variations and astronomical forcing on a million-year scale.Other studies have also highlighted the influence of orbitally-induced climate cycles on halite deposition.However,our understanding of the impact of astronomically-paced lake-level changes on halite formation remains constrained.The Paleogene Dawenkou Formation in the Huanggang Basin of East China provides a continuous salt-bearing sedimentary record to investigate the lake-level changes in halite deposition.Lake-level fluctuations reconstructed by sedimentary noise modeling for the Middle and Upper members of the Dawenkou Formation indicate that the lake-level variations in the Huanggang Basin were linked to astronomical forcing with periods of∼2.4 Myr,∼1.2 Myr and/or∼100 kyr.Our results suggest that astronomical forcing,as a driver of lake-level variations,may have had an impact on halite deposition during the Paleogene.In the initial stage of halite formation within the Middle Member of the Dawenkou Formation,reduced heat and moisture transport during the∼1.2 Myr obliquity minima resulted in low lake levels in mid-to-high latitudes.The prolonged droughts caused by the low amplitude of∼2.4 Myr eccentricity created conditions more favorable for the development of thicker layers of halite.Subsequently,in the next halite-forming stage,a larger amplitude of∼2.4 Myr eccentricity led to a more humid climate.Warm/dry winters and cool summers paced by the∼100 kyr orbital eccentricity minima resulted in enhanced evaporation,relatively lower lake levels,and thinner halite deposition.Nevertheless,the possible transgressions may have contributed to complicated phase relationship between the lake-level change cycles and orbital cycles.This study offers an opportunity to delve deeper into the mechanism of halite deposition by objectively reconstructing lake levels using sedimentary noise modeling.
基金supported by the National Key Research and Development Project(Grant No.2023YFE0110900)the National Natural Science Foundation of China(Grant Nos.42320104003 and 42077247).
文摘The distinctive characteristics exhibited by the aftershocks of Ms6.0 induced earthquakes in Changning,Sichuan,China,have attracted significant attention.The prevalence of salt rock(halite)in this area is closely associated with induced seismic events.The present study was conducted to examine the role of halite in frictional properties.To this end,laboratory measurements were taken for simulated fault gouge composed of halite.Slide-hold-slide(SHS)shear experiments were performed on gouges with grain size<106 mm at constant normal stress from 5 MPa to 30 MPa and constant shear velocity in the range of 1-10 mm/s.Halite gouge shows higher frictional strength and frictional healing rate than most minerals.The results reveal that the fault within halite can potentially generate intense seismic events and more significant aftershocks.An increase in normal stress leads to a reduction in frictional healing,with frictional strength initially increasing and then decreasing.The elevated shear velocity following fault activation facilitates fault dilation,diminishes the frictional strength of the fault,and contributes to fault healing during the inter-seismic period.The aforementioned findings will contribute to a comprehensive understanding of the potential for the healing property of induced seismicity on faults containing halite,particularly in the Changning region of China.
基金supported by the Natural Science Foundation of Jiangxi Province,China(Grant No.20242BAB20130)the Basic Research Funds Program of the Chinese Academy of Geological Sciences(Grant No.YYWF201607)the National Natural Science Foundation of China(Grant No.41902064)。
文摘The phenomenon of'bamboo-like'thin interlayers developed in rock salt is one of the most prominent features of Paleogene salt-bearing strata in eastern China,where centimeter-thick rock salts appear separately,forming rhythmic units.At present,detailed analyses of these rhythms of rock salt are still limited,which directly affects the achievement of comprehensive and in-depth understanding of the developmental laws pertaining to this kind of saline lake.Therefore,we selected the typical rhythmic'bamboo-like'rock salts of the Shizhai Depression in Jiangsu Province as the research subject.Through careful observation of rock salts in hand samples and detailed petrographic and mineralogical analyses,we analyzed the hydrogen and oxygen isotopic compositions,homogenization temperatures and chemical compositions of individual fluid inclusions in halite crystals.Early-stage rhythmic deposition was a product of continental saline lake evolution in winter or spring,late-stage rhythmic deposition being the product of evolution in the summer.The seasonal evolution of the halite sequences was determined and two brine enrichment events were identified.In addition,the quiet saline lake environment with concentrated brine represented by rock salt was more likely to precipitate potassium.This study provides a new reference for the evolution of both Paleogene climate and saline lakes in eastern China.
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
文摘Pollution of petroleum hydrocarbons, in particular oil spills, has attracted much attention in the past and recent decades. Oil spills influence natural microbial community, and physical and chemical properties of the affected sites. The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. The impact of the Nakhodka oil spill resulted in a viscous sticky fluid fouling the shores and affected natural ecosystems. This paper describes the weathering of hydrocarbon-degrading bacteria （genus Pseudomonas） and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years. The Nakhodka oil has hardened and formed crust of crystalline paraffin wax as shown by XRD analysis （0.422, 0.377, and 0.250 nm d-spacing） in association with graphite and calcite after 9 years of bioremediation. Anaerobic reverse side of the oil crust contained numerous coccus typed bacteria associated with halite. The finding of hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9- year bioremediation.
