Was the Panzhihua Large Fe-Ti Oxide Deposit,SW China,Formed by Silicate Immiscibility?  

作　　者：DING Xiangli CHEN Xuanhua SHAO Zhaogang 

机构地区：[1]Chinese Academy of Geological Sciences,Beijing 100037,China

出　　处：《Acta Geologica Sinica(English Edition)》2023年第5期1451-1461,共11页地质学报（英文版）

基　　金：co-supported by the China Geological Survey(Grant Nos.DD20230229,DD20190011,DD20221643);the National Key Research and Development Project of China(Grant No.2018YFC0603701)。

摘　　要：The Panzhihua mafic intrusion,which hosts a world-class Fe-Ti-V ore deposit,is in the western Emeishan region,SW China.The formation age(~260 Ma),and Sr and Nd isotopes indicate that the Panzhihua intrusion is part of the Emeishan large igneous province and has little crustal contamination.To assess ore genesis of the Panzhihua Fe-Ti-V ore deposit,two different models have been provided to explain the formation,namely silicate immiscibility and normal fractional crystallization.Silicate immiscibility occurring around 1,000℃at the late stage of basaltic magma evolution argues against the silicate immiscibility model.Apatite-hosted melt inclusion research indicates that silicate immiscibility occurred at the late stage of Panzhihua magma evolution,which may not have offered potential to form such large ore deposits as Panzhihua.Alternatively,continuous compositional variations of the Panzhihua intrusion and calculations using thermodynamic modelling software support the hypothesis that the Panzhihua deposit was formed by normal fractional crystallization.Reciprocal trace element patterns of the Panzhihua intrusion and nearby felsic rocks also coincide with the fractional crystallization model.Normal fractional crystallization of high-Ti basaltic magma played a key role in the formation of the Panzhihua Fe-Ti-V ore deposit.

关 键 词：liquid immiscibility fractional crystallization mafic intrusion Fe-Ti oxide deposit Panzhihua 

分 类 号：P618.2[天文地球—矿床学]