The present study focuses on geology and geochemical environment of the Pb Zn Ag ore deposition. Mineralization, mineralization age, mineral assemblage, mineral chemistry, host rock alteration, fluid inclusion and sta...The present study focuses on geology and geochemical environment of the Pb Zn Ag ore deposition. Mineralization, mineralization age, mineral assemblage, mineral chemistry, host rock alteration, fluid inclusion and stable isotope geochemistry are briefly presented in this paper. The origin and evolution of ore forming fluid in this mineralization are concluded.展开更多
Oxygen isotope (δ18O) serves as paleothermometer, and provides paleotemperature for carbonates. δ18O signature was used to estimate the temperature of fractionation of dolomite and calcite in Montney Formation, empi...Oxygen isotope (δ18O) serves as paleothermometer, and provides paleotemperature for carbonates. δ18O signature was used to estimate the temperature of fractionation of dolomite and calcite in Montney Formation, empirically calculated to have precipitated, between approximately 13°C to ±33°C during Triassic time in northeastern British Columbia, Western Canada Sedimentary Basin (WCSB). Measurements of stable isotopes (δ13C and δ18O) fractionation, supported by quantitative X-ray diffraction evidence, and whole-rock geochemical characterization of the Triassic Montney Formation indicates the presence of calcite, dolomite, magnesium, carbon and other elements. Results from isotopic signature obtained from bulk calcite and bulk dolomite from this study indicates depleted δ13CPDB (-2.18‰ to -8.46‰) and depleted δ18OPDB (-3.54‰ to -16.15‰), which is interpreted in relation to oxidation of organic matter during diagenesis. Diagenetic modification of dolomitized very fine-grained, silty-sandstone of the Montney Formation may have occurred in stages of progressive oxidation and reduction reactions involving chemical elements such as Fe, which manifest in mineral form as pyrite, particularly, during early burial diagenesis. Such mineralogical changes evident in this study from petrography and SEM, includes cementation, authigenic quartz overgrowth and mineral replacement involving calcite and dolomite, which are typical of diagenesis. High concentration of chemical elements in the Montney Formation?-Ca and Mg indicates dolomitization. It is interpreted herein, that calcite may have been precipitated into the interstitial pore space of the intergranular matrix of very fine-grained silty-sandstone of the Montney Formation as cement by a complex mechanism resulting in the interlocking of grains.展开更多
A systematic spectroscopic study including Raman, Mid-IR, N1R, and VIS-NIR, is used to investigate four endmember lunar soils. Apollo soils （〈45 μm） 14163, 15271, 67511, and 71501 were selected as endmembers to st...A systematic spectroscopic study including Raman, Mid-IR, N1R, and VIS-NIR, is used to investigate four endmember lunar soils. Apollo soils （〈45 μm） 14163, 15271, 67511, and 71501 were selected as endmembers to study, based on their soil chemistry, maturity against space weathering, and the sampling locations. These endmembers include an anorthositic highlands soil （67511）, a low-Ti basaltic soil （15271）, a high-Ti basaltic soil （71501）, and a mafic, KREEPy, impact-melt-rich soil （14163）. We used a laser Raman point-counting procedure to derive mineral modes of the soils and the compositional distributions of major mineral phases, which in turn reflect characteristics of the main source materials for these soils. The Mid-IR, NIR, and VIS-NIR spectroscopic properties also yield distinct information on mineralogy, geochemistry, and maturity among the four soils. Knowledge of the mineralogy resulting from the Raman point-counting procedure corresponds well with bulk mineralogy and soil properties based on Mid-IR, NIR, and VIS-NIR spectroscopy. The future synergistic application of these spectroscopy methods on the Moon will provide a linkage between the results from in situ surface exploration and those from orbital remotesensing observations.展开更多
文摘The present study focuses on geology and geochemical environment of the Pb Zn Ag ore deposition. Mineralization, mineralization age, mineral assemblage, mineral chemistry, host rock alteration, fluid inclusion and stable isotope geochemistry are briefly presented in this paper. The origin and evolution of ore forming fluid in this mineralization are concluded.
文摘Oxygen isotope (δ18O) serves as paleothermometer, and provides paleotemperature for carbonates. δ18O signature was used to estimate the temperature of fractionation of dolomite and calcite in Montney Formation, empirically calculated to have precipitated, between approximately 13°C to ±33°C during Triassic time in northeastern British Columbia, Western Canada Sedimentary Basin (WCSB). Measurements of stable isotopes (δ13C and δ18O) fractionation, supported by quantitative X-ray diffraction evidence, and whole-rock geochemical characterization of the Triassic Montney Formation indicates the presence of calcite, dolomite, magnesium, carbon and other elements. Results from isotopic signature obtained from bulk calcite and bulk dolomite from this study indicates depleted δ13CPDB (-2.18‰ to -8.46‰) and depleted δ18OPDB (-3.54‰ to -16.15‰), which is interpreted in relation to oxidation of organic matter during diagenesis. Diagenetic modification of dolomitized very fine-grained, silty-sandstone of the Montney Formation may have occurred in stages of progressive oxidation and reduction reactions involving chemical elements such as Fe, which manifest in mineral form as pyrite, particularly, during early burial diagenesis. Such mineralogical changes evident in this study from petrography and SEM, includes cementation, authigenic quartz overgrowth and mineral replacement involving calcite and dolomite, which are typical of diagenesis. High concentration of chemical elements in the Montney Formation?-Ca and Mg indicates dolomitization. It is interpreted herein, that calcite may have been precipitated into the interstitial pore space of the intergranular matrix of very fine-grained silty-sandstone of the Montney Formation as cement by a complex mechanism resulting in the interlocking of grains.
基金supported by the Funds from Shandong University and Washington University,the Postdoctoral Science Foundation of China (No. 20090450580)the National Natural Science Foundation of China (No. 11003012)+1 种基金the Natural Science Foundation of Shandong Province (No. ZR2011AQ001)the National High Technology Research and Development Program of China (Nos. 2009AA122201, 2010AA122200)
文摘A systematic spectroscopic study including Raman, Mid-IR, N1R, and VIS-NIR, is used to investigate four endmember lunar soils. Apollo soils （〈45 μm） 14163, 15271, 67511, and 71501 were selected as endmembers to study, based on their soil chemistry, maturity against space weathering, and the sampling locations. These endmembers include an anorthositic highlands soil （67511）, a low-Ti basaltic soil （15271）, a high-Ti basaltic soil （71501）, and a mafic, KREEPy, impact-melt-rich soil （14163）. We used a laser Raman point-counting procedure to derive mineral modes of the soils and the compositional distributions of major mineral phases, which in turn reflect characteristics of the main source materials for these soils. The Mid-IR, NIR, and VIS-NIR spectroscopic properties also yield distinct information on mineralogy, geochemistry, and maturity among the four soils. Knowledge of the mineralogy resulting from the Raman point-counting procedure corresponds well with bulk mineralogy and soil properties based on Mid-IR, NIR, and VIS-NIR spectroscopy. The future synergistic application of these spectroscopy methods on the Moon will provide a linkage between the results from in situ surface exploration and those from orbital remotesensing observations.
