Fluid （and melt） inclusion studies have shown a marked devel- opment in the last decades, as indicated by the increasing number of papers and as covered under major themes in specialized meetings （e.g. ECROFI in Eu...Fluid （and melt） inclusion studies have shown a marked devel- opment in the last decades, as indicated by the increasing number of papers and as covered under major themes in specialized meetings （e.g. ECROFI in Europe, PACROFI in America, ACROFI in Asia）. However, a basic text book is lacking in current literature, available information being either somewhat outdated （e,g. Roedder, 1984） or scattered in multi-author ＂short course＂, mainly organized by the Mineralogical Societies of Canada, America or Europe. A result is that basic features of fluid inclusion studies, notably its key technique, microthermometry, and recently supplemented by micro Raman of infrared spectroscopy, is rarely taught in most universities, leaving the student alone to discover a field of study which has grown to the dimensions of a major science.展开更多
Large earthquakes can cause both casualties and economic losses, but they also provide invaluable opportunities for earthquake scientific research. Geofluids, due to their wide distribution, sensitive response to unde...Large earthquakes can cause both casualties and economic losses, but they also provide invaluable opportunities for earthquake scientific research. Geofluids, due to their wide distribution, sensitive response to underground conditions, and ease of observation, are widely applied in field investigations after earthquakes. Analyzing the origin of fluids, energy transfer processes, temperature/pressure conditions, and the spatial-temporal evolution of geofluids can provide valuable information concerning the mechanism of earthquake precursor anomalies, shortterm prediction methods, identification of the seismogenic faults, determination of earthquake risk, and the environmental impact of post-earthquake fluids. This article details post-earthquake scientific expeditions and research on fluid geochemistry in China and abroad, aimed at providing ideas and guidance for future scientific expedition work and geochemistry-related earthquake studies.展开更多
Combining the science of complexity with ore geology, the author puts forward a new theory of metallogenesis: “complexity and self organized criticality of metallogenic dynamic systems”, and three fundamental theor...Combining the science of complexity with ore geology, the author puts forward a new theory of metallogenesis: “complexity and self organized criticality of metallogenic dynamic systems”, and three fundamental theories are raised for it. The ore genesis and regularity of ore formation of four metallogenic districts around the Yangtze craton in China are studied with this theory. It is found that “metallogenic districts of Yangtze cratonic rim are all at the edge of chaos”. This proposition is expounded by four determinative criteria of the edge of chaos for metallogenic districts of Yangtze cratonic rim.展开更多
In this work,we provide a comprehensive review on the formation,evolution,properties,and effects of supercritical geofluid.In Earth's interior,enhanced miscibility between H_(2)O and silicate by the addition of sp...In this work,we provide a comprehensive review on the formation,evolution,properties,and effects of supercritical geofluid.In Earth's interior,enhanced miscibility between H_(2)O and silicate by the addition of special components or by the increase of pressure and temperature gives rise to supercritical geofluid with a significant amount of both H_(2)O and silicate solute.The formation of supercritical geofluid in magmatic-hydrothermal systems,typified by pegmatite system,is governed by meltfluid critical curve.The formation of supercritical geofluid in metamorphic systems,typified by subducted slab,is governed by the second critical end point.Experimental results suggest that the presence of boron and fluorine in pegmatite system makes it possible to form supercritical geofluid at crustal depths,but the release of supercritical geofluid from subducted slab is withheld until almost 100 km depth.A major presence of both H_(2)O and depolymerized structural units(monomers,dimers,etc.)endows supercritical geofluid with unique physical properties including low density,low elastic moduli,low viscosity,high diffusivity,and high electrical conductivity.Supercritical geofluid can effectively mobilize a variety of elements even including high field strength elements and heavy rare earth elements.The chemical signatures of supercritical geofluid can be inherited by metasomatized mantle and mantle-derived melts,and this could give an explanation of the oxidation of arc magmas.Phase separation of supercritical geofluid through the mechanism of spinodal decomposition leads to formation of a melt network.Multiphase fluid inclusions recovered from subduction zone rocks and pegmatites are possible relics of supercritical geofluid.Supercritical geofluid can cause electrical anomaly and low seismic velocity near the top of subducted slab,and can be linked with intermediate-focus earthquakes.Supercritical geofluid may have played a crucial role in the formation of pegmatites and associated ore deposits.展开更多
Various types of geofluids exist in deep and ultra-deep layers in petroliferous basins.The geofluids are much more active under high-temperature and high-pressure(HTHP)conditions,but their properties are unclear.We si...Various types of geofluids exist in deep and ultra-deep layers in petroliferous basins.The geofluids are much more active under high-temperature and high-pressure(HTHP)conditions,but their properties are unclear.We simulated the mixing of different fluids in CH_(4)/C_(3)H_(8)/C_(6)H_(14)/C_(8)H_(18)-water systems and C_(6)H_(14)/C_(8)H_(18)-CO_(2)-H_(2)O systems at temperatures of 25℃ to 425℃ and pressures of 5 MPa to 105 MPa,using an in-situ micron quartz capillary tube thermal simulation system and molecular dynamics numerical simulation software.The mixing processes,patterns,and mechanisms of various fluids were analyzed at microscale under increasing temperature and pressure conditions.The results show that the miscibility of fluids in the different alkane-H_(2)O and alkane-CO_(2)-H_(2)O systems is not instantaneous,but the miscibility degree between different fluid phases increases as the temperature and pressure rise during the experiments.The physical thermal experiments(PTEs)show that the mixing process can be divided into three stages:initial miscibility,segmented dynamic miscibility,and complete miscibility.The molecular dynamics numerical simulations(MDNSs)indicate that the mixing process of fluids in the alkane-H_(2)O and alkane CO_(2)-H_(2)O systems can be divided into seven and eight stages,respectively.The carbon number affects the miscibility of alkanes and water,and the temperature and pressure required to reach the same miscibility stage with water increase with the carbon number(C_(3)H_(8),C_(6)H_(14),CH_(4),C_(8)H_(18)).CO_(2) has a critical bridge role in the miscibility of alkanes and water,and its presence significantly reduces the temperatures required to reach the initial,dynamic,and complete miscibility of alkanes and water.The results are of great significance for analyzing and understanding the miscibility of geofluids in deep and ultra-deep HTHP systems.展开更多
The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajie...The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuang- shan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2―0.4 m/a.展开更多
文摘Fluid （and melt） inclusion studies have shown a marked devel- opment in the last decades, as indicated by the increasing number of papers and as covered under major themes in specialized meetings （e.g. ECROFI in Europe, PACROFI in America, ACROFI in Asia）. However, a basic text book is lacking in current literature, available information being either somewhat outdated （e,g. Roedder, 1984） or scattered in multi-author ＂short course＂, mainly organized by the Mineralogical Societies of Canada, America or Europe. A result is that basic features of fluid inclusion studies, notably its key technique, microthermometry, and recently supplemented by micro Raman of infrared spectroscopy, is rarely taught in most universities, leaving the student alone to discover a field of study which has grown to the dimensions of a major science.
基金supported by the National Nature Science Foundation of China [Grant number 42073063, 41402298]Central Public-interest Scientific Institution Basal Research Fund (CEAIEF2022060101)+2 种基金Special Fund of the Institute of Earthquake Forecasting (2021IEF0101)United Laboratory of High-Pressure Physics and Earthquake Science(Grant number 2022HPPES01)a contribution to IGCP Project 724。
文摘Large earthquakes can cause both casualties and economic losses, but they also provide invaluable opportunities for earthquake scientific research. Geofluids, due to their wide distribution, sensitive response to underground conditions, and ease of observation, are widely applied in field investigations after earthquakes. Analyzing the origin of fluids, energy transfer processes, temperature/pressure conditions, and the spatial-temporal evolution of geofluids can provide valuable information concerning the mechanism of earthquake precursor anomalies, shortterm prediction methods, identification of the seismogenic faults, determination of earthquake risk, and the environmental impact of post-earthquake fluids. This article details post-earthquake scientific expeditions and research on fluid geochemistry in China and abroad, aimed at providing ideas and guidance for future scientific expedition work and geochemistry-related earthquake studies.
文摘Combining the science of complexity with ore geology, the author puts forward a new theory of metallogenesis: “complexity and self organized criticality of metallogenic dynamic systems”, and three fundamental theories are raised for it. The ore genesis and regularity of ore formation of four metallogenic districts around the Yangtze craton in China are studied with this theory. It is found that “metallogenic districts of Yangtze cratonic rim are all at the edge of chaos”. This proposition is expounded by four determinative criteria of the edge of chaos for metallogenic districts of Yangtze cratonic rim.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0702700)the National Natural Science Foundation of China(Grant Nos.42330301,42488101)the Fundamental Research Funds for the Central Universities of China(Grant No.WK3410000019)。
文摘In this work,we provide a comprehensive review on the formation,evolution,properties,and effects of supercritical geofluid.In Earth's interior,enhanced miscibility between H_(2)O and silicate by the addition of special components or by the increase of pressure and temperature gives rise to supercritical geofluid with a significant amount of both H_(2)O and silicate solute.The formation of supercritical geofluid in magmatic-hydrothermal systems,typified by pegmatite system,is governed by meltfluid critical curve.The formation of supercritical geofluid in metamorphic systems,typified by subducted slab,is governed by the second critical end point.Experimental results suggest that the presence of boron and fluorine in pegmatite system makes it possible to form supercritical geofluid at crustal depths,but the release of supercritical geofluid from subducted slab is withheld until almost 100 km depth.A major presence of both H_(2)O and depolymerized structural units(monomers,dimers,etc.)endows supercritical geofluid with unique physical properties including low density,low elastic moduli,low viscosity,high diffusivity,and high electrical conductivity.Supercritical geofluid can effectively mobilize a variety of elements even including high field strength elements and heavy rare earth elements.The chemical signatures of supercritical geofluid can be inherited by metasomatized mantle and mantle-derived melts,and this could give an explanation of the oxidation of arc magmas.Phase separation of supercritical geofluid through the mechanism of spinodal decomposition leads to formation of a melt network.Multiphase fluid inclusions recovered from subduction zone rocks and pegmatites are possible relics of supercritical geofluid.Supercritical geofluid can cause electrical anomaly and low seismic velocity near the top of subducted slab,and can be linked with intermediate-focus earthquakes.Supercritical geofluid may have played a crucial role in the formation of pegmatites and associated ore deposits.
基金supported by the National Natural Science Foundation of China(Grant Nos.42222208,41821002)the Special Fund for Taishan Scholar Project(Grant No.tsqn201909061)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.20CX06067A)Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(Grant No.2021QNLM020001)。
文摘Various types of geofluids exist in deep and ultra-deep layers in petroliferous basins.The geofluids are much more active under high-temperature and high-pressure(HTHP)conditions,but their properties are unclear.We simulated the mixing of different fluids in CH_(4)/C_(3)H_(8)/C_(6)H_(14)/C_(8)H_(18)-water systems and C_(6)H_(14)/C_(8)H_(18)-CO_(2)-H_(2)O systems at temperatures of 25℃ to 425℃ and pressures of 5 MPa to 105 MPa,using an in-situ micron quartz capillary tube thermal simulation system and molecular dynamics numerical simulation software.The mixing processes,patterns,and mechanisms of various fluids were analyzed at microscale under increasing temperature and pressure conditions.The results show that the miscibility of fluids in the different alkane-H_(2)O and alkane-CO_(2)-H_(2)O systems is not instantaneous,but the miscibility degree between different fluid phases increases as the temperature and pressure rise during the experiments.The physical thermal experiments(PTEs)show that the mixing process can be divided into three stages:initial miscibility,segmented dynamic miscibility,and complete miscibility.The molecular dynamics numerical simulations(MDNSs)indicate that the mixing process of fluids in the alkane-H_(2)O and alkane CO_(2)-H_(2)O systems can be divided into seven and eight stages,respectively.The carbon number affects the miscibility of alkanes and water,and the temperature and pressure required to reach the same miscibility stage with water increase with the carbon number(C_(3)H_(8),C_(6)H_(14),CH_(4),C_(8)H_(18)).CO_(2) has a critical bridge role in the miscibility of alkanes and water,and its presence significantly reduces the temperatures required to reach the initial,dynamic,and complete miscibility of alkanes and water.The results are of great significance for analyzing and understanding the miscibility of geofluids in deep and ultra-deep HTHP systems.
基金This work was supported by the 973 Program(Grant No.G1999043210)the National Natural Science Foundation of China(Grant Nos.40073007 and 40272080).
文摘The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuang- shan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2―0.4 m/a.
