{"title":"西伯利亚圈闭中的天然铁","authors":"M. D. Tomshin, A. G. Kopylova, A. E. Vasilyeva","doi":"10.1134/S0869591123020054","DOIUrl":null,"url":null,"abstract":"<p>The study of trap intrusions with a large-scale occurrence of native iron allowed us to identify general features in their composition and origin. Intrusive bodies are weakly differentiated and have similar structure and mineralogical, petrochemical and geochemical composition. Two associations of rock-forming minerals were found in all studied bodies: early deep-seated (pre-chamber) and intra-chamber. Native iron forms nodular segregations, with a subordinate amount of cohenite, troilite and magnetite–wüstite. Metallic iron can accumulate Ni, Co, Au, and PGE. Their content in metal increases by hundreds or even thousands of times compared to host silicate rock. The formation of native iron is based on the fluid-magmatic interaction between magma and reducing components of the fluid, mainly of methane–hydrogen composition. As a result, an initially homogeneous basalt liquid is dispersed into silicate and metallic components. In the course of transportation, finely dispersed iron phases form droplet-liquid segregations with a monomolecular gas layer on their surface, thus preventing enlargement of metallic droplets. In the hypabyssal chamber, magma, including metallic spherules, is degassed, and droplets are merged to form nodular segregations of native iron.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 2","pages":"223 - 236"},"PeriodicalIF":1.0000,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Native Iron in Siberian Traps\",\"authors\":\"M. D. Tomshin, A. G. Kopylova, A. E. Vasilyeva\",\"doi\":\"10.1134/S0869591123020054\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The study of trap intrusions with a large-scale occurrence of native iron allowed us to identify general features in their composition and origin. Intrusive bodies are weakly differentiated and have similar structure and mineralogical, petrochemical and geochemical composition. Two associations of rock-forming minerals were found in all studied bodies: early deep-seated (pre-chamber) and intra-chamber. Native iron forms nodular segregations, with a subordinate amount of cohenite, troilite and magnetite–wüstite. Metallic iron can accumulate Ni, Co, Au, and PGE. Their content in metal increases by hundreds or even thousands of times compared to host silicate rock. The formation of native iron is based on the fluid-magmatic interaction between magma and reducing components of the fluid, mainly of methane–hydrogen composition. As a result, an initially homogeneous basalt liquid is dispersed into silicate and metallic components. In the course of transportation, finely dispersed iron phases form droplet-liquid segregations with a monomolecular gas layer on their surface, thus preventing enlargement of metallic droplets. In the hypabyssal chamber, magma, including metallic spherules, is degassed, and droplets are merged to form nodular segregations of native iron.</p>\",\"PeriodicalId\":20026,\"journal\":{\"name\":\"Petrology\",\"volume\":\"31 2\",\"pages\":\"223 - 236\"},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2023-06-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Petrology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://link.springer.com/article/10.1134/S0869591123020054\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Petrology","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1134/S0869591123020054","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
The study of trap intrusions with a large-scale occurrence of native iron allowed us to identify general features in their composition and origin. Intrusive bodies are weakly differentiated and have similar structure and mineralogical, petrochemical and geochemical composition. Two associations of rock-forming minerals were found in all studied bodies: early deep-seated (pre-chamber) and intra-chamber. Native iron forms nodular segregations, with a subordinate amount of cohenite, troilite and magnetite–wüstite. Metallic iron can accumulate Ni, Co, Au, and PGE. Their content in metal increases by hundreds or even thousands of times compared to host silicate rock. The formation of native iron is based on the fluid-magmatic interaction between magma and reducing components of the fluid, mainly of methane–hydrogen composition. As a result, an initially homogeneous basalt liquid is dispersed into silicate and metallic components. In the course of transportation, finely dispersed iron phases form droplet-liquid segregations with a monomolecular gas layer on their surface, thus preventing enlargement of metallic droplets. In the hypabyssal chamber, magma, including metallic spherules, is degassed, and droplets are merged to form nodular segregations of native iron.
期刊介绍:
Petrology is a journal of magmatic, metamorphic, and experimental petrology, mineralogy, and geochemistry. The journal offers comprehensive information on all multidisciplinary aspects of theoretical, experimental, and applied petrology. By giving special consideration to studies on the petrography of different regions of the former Soviet Union, Petrology provides readers with a unique opportunity to refine their understanding of the geology of the vast territory of the Eurasian continent. The journal welcomes manuscripts from all countries in the English or Russian language.