Volatile and C-H-O isotopic compositions of giant Fe-Ti-V oxide deposits in the Panxi region and their implications for the sources of volatiles and the origin of Fe-Ti oxide ores

作     者：WANG Christina Yan 

作者机构：Key Laboratory of Mineralogy and MetallogenyGuangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2012年第55卷第11期

页      面：1782-1795页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 081803[工学-地质工程] 07[理学] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supported by the Main Direction Program of Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No. KZCX2-YW-Q04-06) National Basic Research Program of China (Grant No. 2011CB808903) National Natural Science Foundation of China (Grant No. 41073030) Hundred Talents Program of the Chinese Academy of Sciences to CYW 

主　　题：magnetite volatiles C-H-O isotope Fe-Ti-V oxide ore Panxi region 

摘      要：The Panzhihua,Hongge,and Baima Fe-Ti-V oxide deposits in the Panzhihua-Xichang(Panxi) region are hosted in large layered mafic-ultramafic *** layered intrusions intrude either the Neoproterozoic Dengying Formation,composed mainly of limestone,or the Paleoproterozoic Hekou Formation,composed of meta-sedimentary-volcanic *** remains unclear if the wall rocks have been involved during the fractionation of magmas and have affected the sequence of crystallization of Fe-Ti *** and their C-H-O isotopic compositions of magnetite,apatite,clinopyroxene,and plagioclase of different types of ores from the three intrusions are analyzed using a technique of stepwise heating mass spectrometer to evaluate the role of wall rocks in the formation of Fe-Ti oxide *** released from magnetite are composed mainly of H 2 O and CO 2,whereas the other minerals are composed mainly of H 2 O,CO 2 and H *** 800-1200°C temperature interval,the average 13 C values of CO 2 of all the minerals from the three intrusions range from 7.7‰ to 13.5‰ and the average 18 O CO 2 values from 19.1‰ to 19.5‰,which are scattered in a mixed field with basalt and the two types of wall rocks as end-members,indicating that CO 2 from the wall rocks may have been involved in the magmas from which the three intrusions *** 400-800 C temperature interval,both 13 C values(13.7‰ to 17.9‰ on the average) and 18 O values(16.2‰ to 19.2‰ on the average) of CO 2 of all the minerals are lower than those for 800-1200 C temperature interval,and much closer to the values of the wall *** H 2 O released at the 400-800 C temperature interval has relatively low D values ranging from 90‰ to 115‰,also indicating the involvement of fluids from the wall *** average bulk contents of volatiles released from magnetite of the Hongge,Baima,and Panzhihua intrusions are 4891,2996,and 1568 mm 3 STP/g,respectively,much higher than those released from other minerals in total,which are 382