From the study of the Strengbach and Ringelbach watersheds we propose to illustrate the interest of combining the geochemical tracing and geochemical modeling approaches on surface and deep borehole waters,to decipher...From the study of the Strengbach and Ringelbach watersheds we propose to illustrate the interest of combining the geochemical tracing and geochemical modeling approaches on surface and deep borehole waters,to decipher the diversity of the water flow and the associated water–rock interactions in such elementary mountainous catchments. The results point to a clear geochemical typology of waters depending on the water circulations(deep vs. hypodermic) within the substratum.展开更多
A study was conducted by collecting eight seepage water samples that drain through the sedimentary rocks, mainly sandstone and shale, to evaluate the hydro- geochemical characteristics. The collected samples were anal...A study was conducted by collecting eight seepage water samples that drain through the sedimentary rocks, mainly sandstone and shale, to evaluate the hydro- geochemical characteristics. The collected samples were analyzed for physico-chemical parameters using standard procedures. Three water types were identified in the Piper plot and the hydrogeochemical evolution starts from a Ca- C1 facies （type 1） via mixed Ca-Mg-C1 and Ca-Na-HCO3 facies （type 2） to Na-C1 facies （type 3）. Increasing trend of electrical conductivity （EC） values were observed from type 1 water to type 3 water. Lower ionic concentrations with an average EC value of 35.7 kts/cm in Ca-C1 facies indicate the recharge water by monsoonal rainfall, and ion exchange/weathering process is reflected in the mixing zone. Higher ionic concentration with an average EC value of 399 kts/cm is noted in Na-C1 facies, which indicates the ion exchange during water-rock interaction. Higher log pCO2 values are also found in this facies, revealing the longer residence time of seepage water in the rock matrix, which release more ions into the water. The relative mobility of elements during weathering suggest that the order of mobility in both sandstone and shale is Na 〉 Ca 〉 Mg 〉 K. It was observed that thehydrogeochemistry of seepage water is mainly controlled by the bedrock geology.展开更多
Monitoring and study of dynamic characteristics of groundwater are significant methods of earthquake monitoring and forecasting. For research on groundwater dynamics,groundwater dating can qualitatively and quantitati...Monitoring and study of dynamic characteristics of groundwater are significant methods of earthquake monitoring and forecasting. For research on groundwater dynamics,groundwater dating can qualitatively and quantitatively provide scientific analysis on the characteristics of groundwater recharge and runoff as well as renewal capacity. This article illustrates the methods used globally and summarizes the main advances and achievements in groundwater dating. It also focuses on the relationships between groundwater renewal capacity and seismic monitoring,groundwater movement and seismic activity,shallow groundwater recharge and abnormal interference elimination. The studies show that groundwater dating plays an important role in water-rock interaction,and geological tectonic and seismic activity evaluation. Therefore,groundwater dating can be widely used to monitor and analyze the precursor information in seismic underground fluid observations in the near future.展开更多
Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrolo...Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrology, mineralogy, carbon and oxygen isotope ratios and enclosure homogenization temperatures to study the precipitation mechanism, pore fluid evolu- tion, and distribution of different types of carbonate cement in reservoir sand in the study area. Crystalline calcite has relatively heavy carbon and oxygen isotope ratios （δ13C = 2.14%o, 8180 = -5.77‰）, and was precipitated early. It was precipitated di- rectly from supersaturated alkaline fluid under normal temperature and pressure conditions. At the time of precipitation, the fluid oxygen isotope ratio was very light, mainly showing the characteristics of a mixed meteoric water-seawater fluid（ δ180 = -3‰）, which shows that the fluid during precipitation was influenced by both meteoric water and seawater. The calcite cement that fills in the secondary pores has relatively lighter carbon and oxygen isotope ratios （δ13C = -2.36%0, 8180 = -15.68‰）. This cement was precipitated late, mainly during the Middle and Late Jurassic. An important material source for this carbonate cement was the feldspar corrosion process that involved organic matter. The Ca2＋, Fe3＋ and Mg2＋ ions released by the clay mineral transformation process were also important source materials. Because of water-rock interactions during the buri- al process, the oxygen isotope ratio of the fluid significantly increased during precipitation, by about 3‰. The dolomite ce- ments in calcarenaceous sandstone that was precipitated during the Middle Jurassic have heavier carbon and oxygen isotope ratios, which are similar to those of carbonate debris in the sandstone （δ13C = 1.93%o, δ180 = -6.11‰）, demonstrating that the two are from the same source that had a heavier oxygen isotope ratio （δ180 of about 2.2‰）. The differences in fluid oxygen isotope ratios during cement precipitation reflect the influences of different water-rock interaction systems or different wa- ter-rock interaction strengths. This is the main reason why the sandstone containing many rigid particles （lithic quartz sand- stone） has a relatively negative carbon isotope ratio and why the precipitation fluid in calcarenaceous sandstone has a relatively heavier oxygen isotope ratio.展开更多
基金financially supported by funding from the CPER-Alsace REALISE program,the Equipex program CRITEX,the CNRS SOERE RBV and the LABEX"G-Eau-Thermie profonde"funding from the French ANR Program under grant agreement ANR-15-CE06-0014(Projet CANTAREAlsace)
文摘From the study of the Strengbach and Ringelbach watersheds we propose to illustrate the interest of combining the geochemical tracing and geochemical modeling approaches on surface and deep borehole waters,to decipher the diversity of the water flow and the associated water–rock interactions in such elementary mountainous catchments. The results point to a clear geochemical typology of waters depending on the water circulations(deep vs. hypodermic) within the substratum.
基金University of Malaya for the rock analysis by payment basis through RPI fund
文摘A study was conducted by collecting eight seepage water samples that drain through the sedimentary rocks, mainly sandstone and shale, to evaluate the hydro- geochemical characteristics. The collected samples were analyzed for physico-chemical parameters using standard procedures. Three water types were identified in the Piper plot and the hydrogeochemical evolution starts from a Ca- C1 facies （type 1） via mixed Ca-Mg-C1 and Ca-Na-HCO3 facies （type 2） to Na-C1 facies （type 3）. Increasing trend of electrical conductivity （EC） values were observed from type 1 water to type 3 water. Lower ionic concentrations with an average EC value of 35.7 kts/cm in Ca-C1 facies indicate the recharge water by monsoonal rainfall, and ion exchange/weathering process is reflected in the mixing zone. Higher ionic concentration with an average EC value of 399 kts/cm is noted in Na-C1 facies, which indicates the ion exchange during water-rock interaction. Higher log pCO2 values are also found in this facies, revealing the longer residence time of seepage water in the rock matrix, which release more ions into the water. The relative mobility of elements during weathering suggest that the order of mobility in both sandstone and shale is Na 〉 Ca 〉 Mg 〉 K. It was observed that thehydrogeochemistry of seepage water is mainly controlled by the bedrock geology.
基金sponsored by the Special Foundation for Earthquake Scientific Research,CEA(201308006)
文摘Monitoring and study of dynamic characteristics of groundwater are significant methods of earthquake monitoring and forecasting. For research on groundwater dynamics,groundwater dating can qualitatively and quantitatively provide scientific analysis on the characteristics of groundwater recharge and runoff as well as renewal capacity. This article illustrates the methods used globally and summarizes the main advances and achievements in groundwater dating. It also focuses on the relationships between groundwater renewal capacity and seismic monitoring,groundwater movement and seismic activity,shallow groundwater recharge and abnormal interference elimination. The studies show that groundwater dating plays an important role in water-rock interaction,and geological tectonic and seismic activity evaluation. Therefore,groundwater dating can be widely used to monitor and analyze the precursor information in seismic underground fluid observations in the near future.
基金supported by the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Foundation (Grant No. PLC201101)the National Natural Science Foundation of China (Grant Nos. 41172119 and 41272130)
文摘Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrology, mineralogy, carbon and oxygen isotope ratios and enclosure homogenization temperatures to study the precipitation mechanism, pore fluid evolu- tion, and distribution of different types of carbonate cement in reservoir sand in the study area. Crystalline calcite has relatively heavy carbon and oxygen isotope ratios （δ13C = 2.14%o, 8180 = -5.77‰）, and was precipitated early. It was precipitated di- rectly from supersaturated alkaline fluid under normal temperature and pressure conditions. At the time of precipitation, the fluid oxygen isotope ratio was very light, mainly showing the characteristics of a mixed meteoric water-seawater fluid（ δ180 = -3‰）, which shows that the fluid during precipitation was influenced by both meteoric water and seawater. The calcite cement that fills in the secondary pores has relatively lighter carbon and oxygen isotope ratios （δ13C = -2.36%0, 8180 = -15.68‰）. This cement was precipitated late, mainly during the Middle and Late Jurassic. An important material source for this carbonate cement was the feldspar corrosion process that involved organic matter. The Ca2＋, Fe3＋ and Mg2＋ ions released by the clay mineral transformation process were also important source materials. Because of water-rock interactions during the buri- al process, the oxygen isotope ratio of the fluid significantly increased during precipitation, by about 3‰. The dolomite ce- ments in calcarenaceous sandstone that was precipitated during the Middle Jurassic have heavier carbon and oxygen isotope ratios, which are similar to those of carbonate debris in the sandstone （δ13C = 1.93%o, δ180 = -6.11‰）, demonstrating that the two are from the same source that had a heavier oxygen isotope ratio （δ180 of about 2.2‰）. The differences in fluid oxygen isotope ratios during cement precipitation reflect the influences of different water-rock interaction systems or different wa- ter-rock interaction strengths. This is the main reason why the sandstone containing many rigid particles （lithic quartz sand- stone） has a relatively negative carbon isotope ratio and why the precipitation fluid in calcarenaceous sandstone has a relatively heavier oxygen isotope ratio.
