{"title":"华北克拉通邯郸-邢台地区白涧矽卡岩铁-钴矿床的钴富集:矿物痕量元素和黄铁矿硫同位素的启示","authors":"","doi":"10.1016/j.jseaes.2024.106265","DOIUrl":null,"url":null,"abstract":"<div><p>Cobalt (Co) in skarn deposits generally occurs as discrete Co minerals, or dispersed in sulfides. Recent studies have shown that magnetite from Baijian Fe-Co deposit (North China Craton) contains significant amounts of Co, but the mechanism for its enrichment was unclear. In this study, we present <em>in situ</em> mineral trace element and pyrite sulfur isotopic data from Baijian deposit (reserves of 112 Mt Fe at an average grade of 48.5 %): our results show that Co is mainly hosted in cobaltite, magnetite, and pyrite. Magnetite contains 47.6 ppm Co on average, accounting for most of the Co resource in the deposit. Elevated Co concentrations correspond to elevated levels of both Ti + V and Al + Mn, indicating the influence of elevated temperature. Pyrite grains from different lithologies in the deposit have variable Co contents, with those from the related diorite intrusion having the highest (averaging 9264 ppm Co). Sulfur isotopes of pyrite from the magnetite ores range from 16.6 to 19.4 ‰, similar to those from the Cixian Formation limestone and dolemite, which suggests that the sulfur was mainly derived from evaporites in those strata. Pyrite in magnetite-bearing skarn exhibits core-rim zoning, with the core having higher <em>δ</em><sup>34</sup>S<sub>V-CDT</sub> values than the rim, which has values similar to those of pyrite in the diorite. A comparison of our results with other skarn Fe deposits shows that magnetite tends to have a higher Co concentration with increasing <em>δ</em><sup>34</sup>S<sub>V-CDT</sub> values, suggesting that oxygen fugacity has an important influence on Co enrichment in magnetite.</p></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Enrichment of cobalt at Baijian skarn Fe-Co deposit in the Handan-Xingtai region, North China Craton: Insights from mineral trace elements and pyrite sulfur isotopes\",\"authors\":\"\",\"doi\":\"10.1016/j.jseaes.2024.106265\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Cobalt (Co) in skarn deposits generally occurs as discrete Co minerals, or dispersed in sulfides. Recent studies have shown that magnetite from Baijian Fe-Co deposit (North China Craton) contains significant amounts of Co, but the mechanism for its enrichment was unclear. In this study, we present <em>in situ</em> mineral trace element and pyrite sulfur isotopic data from Baijian deposit (reserves of 112 Mt Fe at an average grade of 48.5 %): our results show that Co is mainly hosted in cobaltite, magnetite, and pyrite. Magnetite contains 47.6 ppm Co on average, accounting for most of the Co resource in the deposit. Elevated Co concentrations correspond to elevated levels of both Ti + V and Al + Mn, indicating the influence of elevated temperature. Pyrite grains from different lithologies in the deposit have variable Co contents, with those from the related diorite intrusion having the highest (averaging 9264 ppm Co). Sulfur isotopes of pyrite from the magnetite ores range from 16.6 to 19.4 ‰, similar to those from the Cixian Formation limestone and dolemite, which suggests that the sulfur was mainly derived from evaporites in those strata. Pyrite in magnetite-bearing skarn exhibits core-rim zoning, with the core having higher <em>δ</em><sup>34</sup>S<sub>V-CDT</sub> values than the rim, which has values similar to those of pyrite in the diorite. A comparison of our results with other skarn Fe deposits shows that magnetite tends to have a higher Co concentration with increasing <em>δ</em><sup>34</sup>S<sub>V-CDT</sub> values, suggesting that oxygen fugacity has an important influence on Co enrichment in magnetite.</p></div>\",\"PeriodicalId\":50253,\"journal\":{\"name\":\"Journal of Asian Earth Sciences\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2024-07-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Asian Earth Sciences\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1367912024002608\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Asian Earth Sciences","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1367912024002608","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
矽卡岩矿床中的钴(Co)一般以离散的钴矿物形式存在,或分散在硫化物中。最近的研究表明,白涧铁钴矿床(华北克拉通)的磁铁矿中含有大量的钴,但其富集机制尚不清楚。在本研究中,我们展示了白涧矿床(储量为 1.12 亿吨铁,平均品位为 48.5%)的矿物微量元素和黄铁矿硫同位素数据:结果显示,钴主要赋存于钴铁矿、磁铁矿和黄铁矿中。磁铁矿的平均钴含量为百万分之 47.6,占该矿床钴资源的大部分。钴浓度的升高与 Ti + V 和 Al + Mn 含量的升高相对应,表明受到了高温的影响。矿床中不同岩性的黄铁矿颗粒的钴含量各不相同,其中来自相关闪长岩侵入体的黄铁矿颗粒的钴含量最高(平均为 9264 ppm)。磁铁矿石中黄铁矿的硫同位素在 16.6 至 19.4 ‰之间,与慈县地层石灰岩和闪长岩中的硫同位素相似,这表明硫主要来源于这些地层中的蒸发岩。含磁铁矿矽卡岩中的黄铁矿呈现核心-边缘分带,核心的硫值高于边缘,而边缘的硫值与闪长岩中的黄铁矿相似。将我们的结果与其他矽卡岩铁矿床进行比较后发现,随着 S 值的增加,磁铁矿中的钴浓度往往更高,这表明氧富集度对磁铁矿中的钴富集有重要影响。
Enrichment of cobalt at Baijian skarn Fe-Co deposit in the Handan-Xingtai region, North China Craton: Insights from mineral trace elements and pyrite sulfur isotopes
Cobalt (Co) in skarn deposits generally occurs as discrete Co minerals, or dispersed in sulfides. Recent studies have shown that magnetite from Baijian Fe-Co deposit (North China Craton) contains significant amounts of Co, but the mechanism for its enrichment was unclear. In this study, we present in situ mineral trace element and pyrite sulfur isotopic data from Baijian deposit (reserves of 112 Mt Fe at an average grade of 48.5 %): our results show that Co is mainly hosted in cobaltite, magnetite, and pyrite. Magnetite contains 47.6 ppm Co on average, accounting for most of the Co resource in the deposit. Elevated Co concentrations correspond to elevated levels of both Ti + V and Al + Mn, indicating the influence of elevated temperature. Pyrite grains from different lithologies in the deposit have variable Co contents, with those from the related diorite intrusion having the highest (averaging 9264 ppm Co). Sulfur isotopes of pyrite from the magnetite ores range from 16.6 to 19.4 ‰, similar to those from the Cixian Formation limestone and dolemite, which suggests that the sulfur was mainly derived from evaporites in those strata. Pyrite in magnetite-bearing skarn exhibits core-rim zoning, with the core having higher δ34SV-CDT values than the rim, which has values similar to those of pyrite in the diorite. A comparison of our results with other skarn Fe deposits shows that magnetite tends to have a higher Co concentration with increasing δ34SV-CDT values, suggesting that oxygen fugacity has an important influence on Co enrichment in magnetite.
期刊介绍:
Journal of Asian Earth Sciences has an open access mirror journal Journal of Asian Earth Sciences: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review.
The Journal of Asian Earth Sciences is an international interdisciplinary journal devoted to all aspects of research related to the solid Earth Sciences of Asia. The Journal publishes high quality, peer-reviewed scientific papers on the regional geology, tectonics, geochemistry and geophysics of Asia. It will be devoted primarily to research papers but short communications relating to new developments of broad interest, reviews and book reviews will also be included. Papers must have international appeal and should present work of more than local significance.
The scope includes deep processes of the Asian continent and its adjacent oceans; seismology and earthquakes; orogeny, magmatism, metamorphism and volcanism; growth, deformation and destruction of the Asian crust; crust-mantle interaction; evolution of life (early life, biostratigraphy, biogeography and mass-extinction); fluids, fluxes and reservoirs of mineral and energy resources; surface processes (weathering, erosion, transport and deposition of sediments) and resulting geomorphology; and the response of the Earth to global climate change as viewed within the Asian continent and surrounding oceans.