某地羊脂黑曜岩的岩石矿物学特征  

Petrological and mineralogical characteristics of mutton-fat obsidian

作　　者：李珊 席佳鑫 曾庆进 王辅亚[1,3] 李坤明 魏景明 LI Shan;XI Jiaxin;ZENG Qingjin;WANG Fuya;LI Kunming;WEI Jingming(Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;University of the Chinese Academy of Sciences,Beijing 100049,China;Guangdong Provincial Key Laboratory of Mineral Physics and Materials,Guangzhou 510640,China;Guangzhou Shuiyanxuan Commercial and Trading Co.,Ltd,Guangzhou 510370,China)

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640 [2]中国科学院大学,北京100049 [3]广东省矿物物理与材料研究开发重点实验室,广东广州510640 [4]广州市水筵轩商贸有限公司,广东广州510370

出　　处：《矿物学报》2024年第1期65-72,共8页Acta Mineralogica Sinica

基　　金：广东省科技计划项目(编号:2020B1212060055)。

摘　　要：采用微区X射线衍射(μXRD)、X射线荧光光谱(XRF)、电感耦合等离子体质谱仪(ICP-MS)、扫描电子显微镜(SEM)和显微红外光谱(Miro-FTIR)等岩石矿物学分析测试手段,对某一地区的羊脂黑曜岩的物相组成、显微结构和化学成分等进行了系统研究。结果表明,该羊脂黑曜岩的基本组成特征与其他2个产地的黑曜岩类似,其化学组成都以SiO_(2)、Al_(2)O_(3)、K_(2)O、Na_(2)O为主,属于流纹岩化学成分范围。宏观上表现为非晶质熔体,但熔体内存在微米-亚微米粒径的细小矿物,以羊脂黑曜岩所含微纳米粒径矿物最为丰富。其中所含的钾霞石、磁赤铁矿和黄铁矿都是具有特殊化学性质的矿物,这可能是羊脂黑曜岩的物理化学性质明显优于其他2类黑曜岩的原因。Modern petrological and mineralogical analytical and testing methods,such as Microzone X-ray diffraction(μXRD),X-ray fluorescence spectroscopy(XRF),inductively coupled plasma mass spectrometry(ICP-MS),scanning electron microscopy(SEM),micro-infrared spectroscopy(MIRO-FTIR),have been applied to systematically study the phase composition,microstructure and chemical composition of the mutton-fat obsidian from an area.The results show that basic characteristics of the mutton-fat obsidian are similar to those of obsidians from other two sources.They are mainly composed of SiO_(2),Al_(2)O_(3),K_(2)O,Na_(2)O,belonging to the chemical composition range of rhyolite.These obsidians consist of amorphous glass on a macroscopic basis,with lots of micro-nano sized minerals in the glass.Especially,the mutton-fat obsidian has most abundantly distributed micro-nano sized minerals including potassium nepheline,magnetic hematite and pyrite which are minerals having special chemical properties.This may be the reason why physicochemical properties of the mutton-fat obsidian are obviously superior to those of other two types of obsidian.

关 键 词：黑曜岩 纳米矿物 钾霞石 磁赤铁矿 

分 类 号：P575[天文地球—矿物学] P579[天文地球—地质学]