{"title":"铁同位素作为矿流体示踪剂——以辽宁青城子Pb - Zn - Au(‐Ag)矿田为例","authors":"Dedong Li, Yuwang Wang, Jingbin Wang, Chunkit Lai, J. Qiu, Wei Wang, Shenghui Li, Zhichao Zhang","doi":"10.1111/rge.12261","DOIUrl":null,"url":null,"abstract":"The Qingchengzi Pb‐Zn‐Au (‐Ag) orefield (eastern Liaoning province, NE China) is located in the northeastern margin of the North China Craton. The unconventional Fe isotopes of pyrites were analyzed to unravel the ore‐material source and migration pathway of the ore fluids. Pyrite samples of ores and wallrocks from various deposits in the orefield were collected and the solutions were analyzed by MC‐ICP‐MS. The results show that most pyrite samples contain heavier Fe isotopes than the international pyrite standard IRMM‐014. Within a particular deposit, Fe isotopes become lighter with depth. For example, the pyrite δ56Fe values drop from 0.216 ~ 0.408‰ (150‐m level) to −0.284 to −0.132‰ (210‐m level) at the Zhenzigou deposit. Gold deposits in the orefield also have similar features: At Baiyun (Huangdianzi), the pyrite δ56Fe values (0.394 ~ 0.627‰) of the silicic‐/potassic‐altered rock‐type ore (130‐m level) are significantly higher than that (0.359‰) of the quartz vein‐type ore (440‐m level). The lamprophyre δ56Fe values from different deposits are largely similar (0.040 ~ 0.024‰), whereas those in the wallrocks vary considerably (0.144 ~ 1.238‰). Compiling the pyrite δ56Fe values from many important sedimentary/metamorphic rock units in the region and magmatic‐hydrothermal deposits around the world, we concluded that the Qingchengzi Pb‐Zn‐Au(‐Ag) deposits belong to intrusion‐related magmatic‐hydrothermal type. The spatial fluid isotope variation pattern, and the fact that early‐formed sulfides have lighter isotopes than later ones, suggest that the Qingchengzi ore fluids may have originated from Zhenzigou‐Diannan (hydrothermal center) and outflown to Xiaotongjiapuzi, Gujiapuzi‐Baiyun and Erdao‐Xiquegou areas. The spatial fluid isotope variation pattern also suggests another possible hydrothermal center at Baiyun‐Gujiapuzi. The ability to identify hydrothermal center(s) and delineate fluid migration pathways suggests that pyrite Fe isotopes can serve as a tool for precious and base metals prospecting.","PeriodicalId":21089,"journal":{"name":"Resource Geology","volume":"7 1","pages":"283 - 295"},"PeriodicalIF":1.1000,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Iron isotopes as an ore‐fluid tracer: Case study of Qingchengzi Pb‐Zn‐Au(‐Ag) orefield in Liaoning, NE China\",\"authors\":\"Dedong Li, Yuwang Wang, Jingbin Wang, Chunkit Lai, J. Qiu, Wei Wang, Shenghui Li, Zhichao Zhang\",\"doi\":\"10.1111/rge.12261\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The Qingchengzi Pb‐Zn‐Au (‐Ag) orefield (eastern Liaoning province, NE China) is located in the northeastern margin of the North China Craton. The unconventional Fe isotopes of pyrites were analyzed to unravel the ore‐material source and migration pathway of the ore fluids. Pyrite samples of ores and wallrocks from various deposits in the orefield were collected and the solutions were analyzed by MC‐ICP‐MS. The results show that most pyrite samples contain heavier Fe isotopes than the international pyrite standard IRMM‐014. Within a particular deposit, Fe isotopes become lighter with depth. For example, the pyrite δ56Fe values drop from 0.216 ~ 0.408‰ (150‐m level) to −0.284 to −0.132‰ (210‐m level) at the Zhenzigou deposit. Gold deposits in the orefield also have similar features: At Baiyun (Huangdianzi), the pyrite δ56Fe values (0.394 ~ 0.627‰) of the silicic‐/potassic‐altered rock‐type ore (130‐m level) are significantly higher than that (0.359‰) of the quartz vein‐type ore (440‐m level). The lamprophyre δ56Fe values from different deposits are largely similar (0.040 ~ 0.024‰), whereas those in the wallrocks vary considerably (0.144 ~ 1.238‰). Compiling the pyrite δ56Fe values from many important sedimentary/metamorphic rock units in the region and magmatic‐hydrothermal deposits around the world, we concluded that the Qingchengzi Pb‐Zn‐Au(‐Ag) deposits belong to intrusion‐related magmatic‐hydrothermal type. The spatial fluid isotope variation pattern, and the fact that early‐formed sulfides have lighter isotopes than later ones, suggest that the Qingchengzi ore fluids may have originated from Zhenzigou‐Diannan (hydrothermal center) and outflown to Xiaotongjiapuzi, Gujiapuzi‐Baiyun and Erdao‐Xiquegou areas. The spatial fluid isotope variation pattern also suggests another possible hydrothermal center at Baiyun‐Gujiapuzi. The ability to identify hydrothermal center(s) and delineate fluid migration pathways suggests that pyrite Fe isotopes can serve as a tool for precious and base metals prospecting.\",\"PeriodicalId\":21089,\"journal\":{\"name\":\"Resource Geology\",\"volume\":\"7 1\",\"pages\":\"283 - 295\"},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2021-06-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Resource Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1111/rge.12261\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Resource Geology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1111/rge.12261","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOLOGY","Score":null,"Total":0}
Iron isotopes as an ore‐fluid tracer: Case study of Qingchengzi Pb‐Zn‐Au(‐Ag) orefield in Liaoning, NE China
The Qingchengzi Pb‐Zn‐Au (‐Ag) orefield (eastern Liaoning province, NE China) is located in the northeastern margin of the North China Craton. The unconventional Fe isotopes of pyrites were analyzed to unravel the ore‐material source and migration pathway of the ore fluids. Pyrite samples of ores and wallrocks from various deposits in the orefield were collected and the solutions were analyzed by MC‐ICP‐MS. The results show that most pyrite samples contain heavier Fe isotopes than the international pyrite standard IRMM‐014. Within a particular deposit, Fe isotopes become lighter with depth. For example, the pyrite δ56Fe values drop from 0.216 ~ 0.408‰ (150‐m level) to −0.284 to −0.132‰ (210‐m level) at the Zhenzigou deposit. Gold deposits in the orefield also have similar features: At Baiyun (Huangdianzi), the pyrite δ56Fe values (0.394 ~ 0.627‰) of the silicic‐/potassic‐altered rock‐type ore (130‐m level) are significantly higher than that (0.359‰) of the quartz vein‐type ore (440‐m level). The lamprophyre δ56Fe values from different deposits are largely similar (0.040 ~ 0.024‰), whereas those in the wallrocks vary considerably (0.144 ~ 1.238‰). Compiling the pyrite δ56Fe values from many important sedimentary/metamorphic rock units in the region and magmatic‐hydrothermal deposits around the world, we concluded that the Qingchengzi Pb‐Zn‐Au(‐Ag) deposits belong to intrusion‐related magmatic‐hydrothermal type. The spatial fluid isotope variation pattern, and the fact that early‐formed sulfides have lighter isotopes than later ones, suggest that the Qingchengzi ore fluids may have originated from Zhenzigou‐Diannan (hydrothermal center) and outflown to Xiaotongjiapuzi, Gujiapuzi‐Baiyun and Erdao‐Xiquegou areas. The spatial fluid isotope variation pattern also suggests another possible hydrothermal center at Baiyun‐Gujiapuzi. The ability to identify hydrothermal center(s) and delineate fluid migration pathways suggests that pyrite Fe isotopes can serve as a tool for precious and base metals prospecting.
期刊介绍:
Resource Geology is an international journal focusing on economic geology, geochemistry and environmental geology. Its purpose is to contribute to the promotion of earth sciences related to metallic and non-metallic mineral deposits mainly in Asia, Oceania and the Circum-Pacific region, although other parts of the world are also considered.
Launched in 1998 by the Society for Resource Geology, the journal is published quarterly in English, making it more accessible to the international geological community. The journal publishes high quality papers of interest to those engaged in research and exploration of mineral deposits.