Porphyry-skarn deposits are genetically associated with multistage intrusive complexes.However,their ore fertility varies markedly,as exemplified by the coexistence of mineralized and barren intrusions within a single...Porphyry-skarn deposits are genetically associated with multistage intrusive complexes.However,their ore fertility varies markedly,as exemplified by the coexistence of mineralized and barren intrusions within a single pluton.The factors controlling this disparity,particularly whether high oxygen fugacity(fO_(2))and volatile-rich magmas are essential,remain poorly constrained.This study investigates the Fengyan Zn-Pb-Mo deposit in the central Fujian region by comparing geochronological and geochemical features of ore-associated granite porphyry and barren monzogranite.SIMS zircon U-Pb dating reveals the mineralized intrusion crystallized at 142.5±1.6 Ma,significantly later than the barren monzogranite(150.3±1.3 Ma).The ore-associated porphyry exhibits higher magma temperatures and sulfur contents,yet lower fO_(2)and water content relative to the barren monzogranite.Hf-O isotopes reveal greater mantle input in the ore-related granite porphyry(ε_(Hf)(t)=-11.5 to-7.5;δ^(18)O=6.50‰to 7.11‰)than in the ore-barren monzogranite(ε_(Hf)(t)=-16.0 to-9.5;δ^(18)O=6.81‰to 8.00‰).Furthermore,elevated fO_(2)and volatile-rich conditions are not prerequisites for Zn-Pb-Mo mineralization,implying other factors are key.The barren rock formed during low-angle subduction of the Paleo-Pacific plate,whereas the mineralized porphyry originated during slab rollback and lithospheric extension.This study highlights that medium-low fO_(2)(meanΔFMQ+0.39 in granite porphyry vs.+1.80 in monzogranite),volatile-poor magmatic systems in extensional settings can form significant mineralization,offering new insights for exploration in central Fujian and analogous regions.展开更多
Earthquake early warning （EEW） systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the...Earthquake early warning （EEW） systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the Southeast coast of China. It is anticipated that the system will be completed in time to be tested at the end of this year （2013）. In order to evaluate how much advanced warning the EEW system will be able to provide different cities in Fujian, we established an EEW information release scheme based on the seismic monitoring stations distributed in the region. Based on this scheme, we selected 71 historical earthquakes. We then obtained the delineation of the region＇s potential seismic source data in order to estimate the highest potential seismic intensities for each city as well as the EEW system warning times. For most of the Fujian Province, EEW alarms would sound several seconds prior to the arrival of the destructive wave. This window of time gives city inhabitants the opportunity to take protective measures before the full intensity of the earthquake strikes.展开更多
基金jointly funded by Innovation Youth Project of Natural Science Foundation of Fujian Province(No.2024J08144)the Open Fund Project of the Key Laboratory of Ionic Rare Earth Resources and Environment,Ministry of Natural Resources(Grant no.2022IRERE101)+2 种基金the National Natural Science Foundation of China(No.41820104010)Basic Scientific Research Fund of Chinese Academy of Geological Sciences(No.JYYWF20180601)China Scholarship Council(CSC,201908110163)。
文摘Porphyry-skarn deposits are genetically associated with multistage intrusive complexes.However,their ore fertility varies markedly,as exemplified by the coexistence of mineralized and barren intrusions within a single pluton.The factors controlling this disparity,particularly whether high oxygen fugacity(fO_(2))and volatile-rich magmas are essential,remain poorly constrained.This study investigates the Fengyan Zn-Pb-Mo deposit in the central Fujian region by comparing geochronological and geochemical features of ore-associated granite porphyry and barren monzogranite.SIMS zircon U-Pb dating reveals the mineralized intrusion crystallized at 142.5±1.6 Ma,significantly later than the barren monzogranite(150.3±1.3 Ma).The ore-associated porphyry exhibits higher magma temperatures and sulfur contents,yet lower fO_(2)and water content relative to the barren monzogranite.Hf-O isotopes reveal greater mantle input in the ore-related granite porphyry(ε_(Hf)(t)=-11.5 to-7.5;δ^(18)O=6.50‰to 7.11‰)than in the ore-barren monzogranite(ε_(Hf)(t)=-16.0 to-9.5;δ^(18)O=6.81‰to 8.00‰).Furthermore,elevated fO_(2)and volatile-rich conditions are not prerequisites for Zn-Pb-Mo mineralization,implying other factors are key.The barren rock formed during low-angle subduction of the Paleo-Pacific plate,whereas the mineralized porphyry originated during slab rollback and lithospheric extension.This study highlights that medium-low fO_(2)(meanΔFMQ+0.39 in granite porphyry vs.+1.80 in monzogranite),volatile-poor magmatic systems in extensional settings can form significant mineralization,offering new insights for exploration in central Fujian and analogous regions.
基金National Key Technology R&D Program (2009BAK55B03)
文摘Earthquake early warning （EEW） systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the Southeast coast of China. It is anticipated that the system will be completed in time to be tested at the end of this year （2013）. In order to evaluate how much advanced warning the EEW system will be able to provide different cities in Fujian, we established an EEW information release scheme based on the seismic monitoring stations distributed in the region. Based on this scheme, we selected 71 historical earthquakes. We then obtained the delineation of the region＇s potential seismic source data in order to estimate the highest potential seismic intensities for each city as well as the EEW system warning times. For most of the Fujian Province, EEW alarms would sound several seconds prior to the arrival of the destructive wave. This window of time gives city inhabitants the opportunity to take protective measures before the full intensity of the earthquake strikes.
