地质论评2017，Vol.63Issue(2)：441-457,17.DOI:10.16509/j.georeview.2017.02.014
昌乐地区新生代碱性玄武岩中刚玉、尖晶石巨晶岩目学、矿物化学特征
Petrography and Mineral Chemistry of Corundum and Spinel Menocryst in the Cenozoic Basalt at Changle, Shandong Prinvice
摘要
Abstract
Objectives:The Chinese largest gem quality corundum—sapphire deposits is located in Changle,Shandong Province.Changle corundum occurs as megacryst in the Cenozonic basalt,showing roundish shape and having sharp boundary contact with host basalt.The well developed reaction rim of Al-riched spinel and titanium magnetite,around corundum megacrysts indicate they are deep mantle derived xenocryst.The study of corundum megacryst and its reaction rim can reveal their genesis and evolution information.Methods:The petrography,electron microprobe and LA-ICP-MS (Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry) study methods are applied in this paper.Results:The major and trace mineral compositions,key elements such as Ga/Mg、Cr/Ga、Fe/Ti、Fe/Mg ratios of two groups samples of the corundum megacrysts (CL-1 and CL-2) indicate they are magmatic origin.In compared with the the CL-1 group samples,the CL-2 group samples of Changle corundum obviously overprint the features of late melt infiltration metasomatism.The reaction spinel rim diaplays transitional compsition characteristics from corundum megacryst to spinel megacryst,and the key element data of corundum and spinel megacrysts exhibit obvious affinity.Conclusions:The spinel megacryst is the product of corundum after complicated metasomatic evolution.In adation,Changle corundums present mineral chemical features of crystallization from alkali melt that most likely derive from low extraction of metasomatic enriched mantle rocks.关键词
昌乐/刚玉巨晶/尖晶石巨晶/矿物地球化学Key words
Changle/corundum megacryst/spinel megacryst/mineral geochemistry引用本文复制引用
孔凡梅,李旭平,赵令权,陈爽,尹启航..昌乐地区新生代碱性玄武岩中刚玉、尖晶石巨晶岩目学、矿物化学特征[J].地质论评,2017,63(2):441-457,17.基金项目
本文为中国地质调查局资源部“中国大型—超大型矿床成矿地球动力学背景、过程和定量评价综合研究”专题“鲁西岩石圈结构与深部过程探讨”(编号:1212011220928)、山东省自然基金(ZR2016DM04)和山东科技大学科研启动基金(编号:2014RCJJ009)的成果.The current study is supported by "Chinese large—very large deposit,geodynamic,and quantitative evaluation of the comprehensive study process" (No.1212011220928) and Shandong University of Science and Technology Scientific Research Foundation (No.2014RCJJ009) （编号:1212011220928）
