中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Early Crystallized Titanomagnetite from Evolved Magmas and Magma Recharge in the Mesoproterozoic Zhuqing Oxide-Bearing Gabbroic Intrusions, Sichuan, SW China

文献类型:期刊论文

作者Hongpeng FAN;Weiguang ZHU
刊名Acta Geologica Sinica
出版日期2017
卷号91期号:2页码:486-499
关键词Fe-ti Oxide Mineral Chemistry Patrogenesis Mesoproterozoic Zhuqing Oxide Ore Deposits Kangdian Region Sw China East Margin Of Tibetan Plateau Proto-tethys
英文摘要

The ca. 1.5 Ga mafic intrusions in the Zhuqing area, predominantly composed of alkaline gabbroic rocks in the Kangdian region of SW China, occur as dykes or irregular small intrusions hosting Fe-Ti-V mineralization. All of the intrusions that intrude the dolomite or shales of the Mesoproterozoic Heishan Formation of the Huili Group are composed of three cyclic units from the base upward: a marginal cyclic unit, a lower cyclic unit and an upper cyclic unit. The Fe-Ti-V oxide ore bodies are hosted in the lower and upper cyclic units. The textural relationships between minerals in the intrusions suggest that titanomagnetite formed earlier than silicate grains because euhedral magnetite and ilmenite grains were enclosed in clinopyroxene and plagioclase. Both the magnetite(ss)-ilmenite(ss) intergrowths due to subsolidus oxidation-exsolutions and the relative higher V distribution coefficient between magnetite and silicate melts in the gabbros from the Zhuqing area are different from those of other typical Fe-Ti bearing mafic rocks, suggesting that the oxygen fugacity was low in the gabbric rocks from the Zhuqing area. This finding was further confirmed by calculations based on the compositions of magnetite and ilmenite pairs. The clinopyroxene, magnetite and ilmenite in the intrusions from the Zhuqing area had considerably lower MgO than those of other typical Fe-Ti oxide-rich complexes, suggesting that the titanomagnetite from the intrusion may have crystallized at a relatively late stage of evolution from a more evolved magma. Titanomagnetite first fractionally crystallized and subsequently settled in the lower parts of the magma chamber, where it concentrated and formed Fe-Ti-V oxide ore layers at the bases of the lower and upper cycles. Moreover, the occurrence of multiple Fe-Ti oxide layers alternating with Fe-Ti oxide-bearing silicate layers suggests that multiple pulses of magma were involved in the formation of the intrusions and related Fe-Ti-V oxide deposits in the Zhuqing area.

语种英语
源URL[http://ir.gyig.ac.cn/handle/42920512-1/7766]  
专题地球化学研究所_矿床地球化学国家重点实验室
作者单位State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, Guizhou, China
推荐引用方式
GB/T 7714
Hongpeng FAN;Weiguang ZHU. Early Crystallized Titanomagnetite from Evolved Magmas and Magma Recharge in the Mesoproterozoic Zhuqing Oxide-Bearing Gabbroic Intrusions, Sichuan, SW China[J]. Acta Geologica Sinica,2017,91(2):486-499.
APA Hongpeng FAN;Weiguang ZHU.(2017).Early Crystallized Titanomagnetite from Evolved Magmas and Magma Recharge in the Mesoproterozoic Zhuqing Oxide-Bearing Gabbroic Intrusions, Sichuan, SW China.Acta Geologica Sinica,91(2),486-499.
MLA Hongpeng FAN;Weiguang ZHU."Early Crystallized Titanomagnetite from Evolved Magmas and Magma Recharge in the Mesoproterozoic Zhuqing Oxide-Bearing Gabbroic Intrusions, Sichuan, SW China".Acta Geologica Sinica 91.2(2017):486-499.

入库方式: OAI收割

来源:地球化学研究所

浏览0
下载0
收藏0
其他版本

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。