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对贵州修文地区铝质岩进行了显微镜特征、常量化学成分、XRD等分析,3个综合样的主要矿物为一水硬铝石和粘土矿物,主要化学成分为SiO2、Al2O3和Fe2O3等,Al2O3主要赋存于一水硬铝石、勃姆石和粘土矿物中,SiO2主要以粘土矿物的形式存在,TiO2则主要赋存于锐钛矿中。ICP-MS测试结果表明:铝质岩中V、Cr、Zr和Sr等元素含量较高,V/Cr比值小于1,反映了成岩的富氧环境,Co/Ni比值则反映了该地区的热水沉积环境;样品明显见轻稀土元素富集特征,并且轻稀土元素含量偏高;稀土元素分配模式图表明:Eu明显呈负异常,Ce除XL-2接近1外,其他两个样均呈现负异常,反映了沉积环境为相对氧化的海相环境,海水中的Ce3+浓度较低,易被氧化为Ce4+,在搬运过程中易形成CeO2沉淀,导致铝质岩中的Ce负异常形成。
Microstructures, constitutive chemical compositions and XRD were used to analyze the alluvial rocks in Xiuwen area, Guizhou Province. The main minerals of the three samples were diaspore and clay minerals. The main chemical components were SiO2, Al2O3 and Fe2O3. The main Al2O3 In diaspore, boehmite and clay minerals, SiO2 is mainly in the form of clay minerals, while TiO2 is mainly found in anatase. ICP-MS results show that the content of V, Cr, Zr and Sr in alluvial rocks is high, V / Cr ratio is less than 1, reflecting diagenetic oxygen-rich environment and Co / Ni ratio reflecting the heat Water sedimentary environment. The samples are obviously characterized by light rare earth element (REE) enrichment and the content of light rare earth elements is high. The distribution pattern of rare earth elements shows that Eu is obviously negative anomaly, while Ce except XL-2 is near 1 Negative anomalies, reflecting the sedimentary environment is a relatively oxidized marine environment, the concentration of Ce3 + in seawater is low, easily oxidized to Ce4 +, easy to form CeO2 precipitation in the process of transport, leading to the negative anomaly formation of Ce in the aluminous rocks.