文献类型：期刊文献

英文题名：Liquid immiscibility in the Panzhihua intrusion, SW China: Evidence from ore textures and Fe-Ti oxide-rich globules in gabbros

作者：Xiong, Feng Tao, Yan Liao, Mingyang Liao, Yuqi Ma, Jun

第一作者：Xiong, Feng

通信作者：Tao, Y[1]

机构：[1]Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Guizhou, Peoples R China;[2]Univ Chinese Acad Sci, Beijing 100049, Peoples R China;[3]Guizhou Inst Technol, Inst Min Engn, Guiyang 550003, Peoples R China

第一机构：Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Guizhou, Peoples R China

通信机构：corresponding author), Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Guizhou, Peoples R China.

年份：2021

卷号：209

外文期刊名：JOURNAL OF ASIAN EARTH SCIENCES

收录：;Scopus(收录号：2-s2.0-85100608360);WOS:【SCI-EXPANDED(收录号:WOS:000624652600002)】；

基金：We thank Drs. Christina Yan Wang, Dr. Tong Hou, and the other two anonymous reviewers for their constructive reviews. This study was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB18000000) , National Natural Science Foundation of China (42073048, 41473051) , and the High-Level Talent Initial Funding of Guizhou Institute of Technology (XJGC20190606) .

语种：英文

外文关键词：Liquid immiscibility; Panzhihua layered intrusion; Magmatic Fe-Ti oxide deposit; Emeishan large igneous province

摘要：The Panzhihua intrusion hosts a large Fe-Ti oxide deposit in the Permian Emeishan large igneous province (ELIP), SW China. The mechanism of such massive Fe-Ti oxide accumulation in the layered intrusion is still a matter of debate. In this study, we suggest that the ore formation occurred via density-driven liquid segregation of immiscible Fe-rich liquid, instead of simple mineral sorting of Fe-Ti oxides. Interstitial oxides and kinked plagioclase crystals reveal that the Fe-Ti oxides were crystallized in-situ after their surrounding silicate minerals. Dissolution texture of primocryst plagioclase is ubiquitous in the ores, indicating that the primocryst plagioclase grains were in disequilibrium with the surrounding melt. Fe-Ti oxide-rich globules (similar to 38 wt% FeO) are present in the ore-barren gabbro, and likely represent solidified pockets of the immiscible Fe-rich liquid. Olivine in the Fe-Ti oxide ores occurs as primocrysts (avg. Fo = 68.5) that crystalized before the interstitial Fe-Ti oxides, or as growth rims (avg. Fo = 77.5) that crystalized after interstitial Fe-Ti oxides. The primocryst olivine was likely in equilibrium with the Panzhihua parental magma, and its composition matches well with that of the basalt (Fe2O3T =-16 wt%) exposed near the intrusion. The olivine rim was likely in equilibrium with the residual melt produced from-33% crystallization of the Fe-Ti oxide-rich globule. This study confirms that the ore layers are formed by the sinking of dense immiscible Fe-rich liquid to squeeze out the original silicate melt in the crystal mush, forming the (semi-)massive Fe-Ti oxide layered ores.