峨眉山大火成岩省含钒钛磁铁矿镁铁-超镁铁质侵入体中磷灰石主量元素地球化学特征及成岩成矿条件  

Major element geochemistry of apatite from Fe-Ti-V oxide-bearing mafic-ultramafic intrusions in the Emeishan large igneous province and their petrogenesis and mineralization

作　　者：汤庆艳 李璐 张燕[1] 黎卓明 宋宏 刘玮 赵驰 TANG QingYan;LI Lu;ZHANG Yan;LI ZhuoMing;SONG Hong;LIU Wei;ZHAO Chi(Gansu Key Laboratory of Mineral Resources in Western China,MNR Key Laboratory of Strategic Mineral Resources of the Upper Yellow River,School of Earth Sciences,Lanzhou University,Lanzhou 730000,China;National Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization,Baotou Research Institute of Rare Earths,Baotou 014030,China;National Geological Library of China,Beijing 100083,China)

机构地区：[1]兰州大学地质科学与矿产资源学院,自然资源部黄河上游战略性矿产资源重点实验室,甘肃省西部矿产资源重点实验室,兰州730000 [2]包头稀土研究院,白云鄂博稀土资源研究与综合利用全国重点实验室,包头014030 [3]中国地质图书馆,北京100083

出　　处：《岩石学报》2024年第7期2169-2185,共17页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(U2244204、41472070、41872073);国家重点研发计划项目(2023YFC2908700);第二次青藏高原综合科学考察研究(2019QZKK0704);甘肃省重点人才项目(2023RCXM90);甘肃省重点研发计划-工业类项目(23YFGA0001);自然资源部黄河上游战略性矿产资源重点实验室开放课题(YSMRKF202201)联合资助。

摘　　要：峨眉山大火成岩省红格、攀枝花及太和镁铁-超镁铁质侵入体赋存有超大型Fe-Ti-V氧化物矿床,对其磷灰石主量元素地球化学特征的研究可以揭示其成岩成矿条件。红格、攀枝花及太和侵入体磷灰石晶体具有富F(0.94%~1.83%)、贫Cl(0.10%~0.66%)、贫SO_(3)(<0.25%)的特征。F含量与Cl含量呈负相关,与F/Cl比值呈正相关;而SO_(3)含量与F之间的相关性不明显。与攀枝花及太和侵入体含矿辉长岩样品中磷灰石晶体相比,红格侵入体含矿橄榄单斜辉石岩和单斜辉石岩样品中磷灰石晶体F含量和SO_(3)含量较高,Cl含量较低。根据磷灰石中卤素组分和硫含量可推算与之平衡的岩浆熔体中的相应值。研究表明攀枝花侵入体与磷灰石平衡的岩浆中Cl含量最高;红格母岩浆中S含量高于攀枝花及太和。红格侵入体单斜辉石岩与橄榄单斜辉石岩相比,Cl含量较低,表明红格侵入体中发生了脱气作用。由于不同侵入体磷灰石δCe与SO_(3)含量之间没有明显的相关性,因此峨眉山大火成岩省不同侵入体磷灰石中SO_(3)含量高低可能与熔体中的S含量相关。磷灰石F/Cl比值较高,揭示峨眉山大火成岩省地幔源区存在俯冲沉积物质的混入。Mafic-ultramafic intrusions of Hongge,Panzhihua and Taihe in the Emeishan large igneous province host super-large Fe-Ti-V oxide deposits.The major elements of apatite are used to reveal the conditions for petrogenesis and mineralization of these intrusions.The apatite crystals of Hongge,Panzhihua and Taihe intrusions are rich in F(0.94%~1.83%),and poor in Cl(0.10%~0.66%)as well as SO_(3)(<0.25%).The F contents are negatively correlated with the Cl contents and positively correlated with the F/Cl ratios,while no obvious correlations occur between SO_(3) and F contents.Compared with the apatite crystals from the ore-bearing gabbro samples from Panzhihua and Taihe intrusions,the apatite crystals of ore-bearing olivine clinopyroxenite and clinopyroxenite samples of the Hongge intrusion have higher F contents and SO_(3) contents,but lower Cl contents.The halogen and sulfur contents in the melt can be calculated based on the corresponding values in apatite.It is shown that the magma in which the Panzhihua intrusion in equilibrium with apatite has the highest Cl content.The S content in the Hongge parent magma is higher than those of the Panzhihua and Taihe parent magma.The Cl contents in clinopyroxenite are lower than those in olivine clinopyroxenite from the Hongge intrusion,indicating degassing occurred in this intrusion.Due to the lack of a clear correlation between apatiteδCe and SO_(3) contents,the contents of SO_(3) in apatite crystals from different intrusions in the Emeishan large igneous province may be related to the S content in the melt.The apatite crystals have high F/Cl ratios,suggesting the mixing of subducted sedimentary materials in the mantle source of the Emeishan large igneous province.

关 键 词：成矿条件 富F熔体 镁铁-超镁铁质侵入体 钒钛磁铁矿矿床 峨眉山大火成岩省 

分 类 号：P578.922[天文地球—矿物学] P588.125[天文地球—地质学]