Developments of fluid inclusion analysis by using high-energy ion beam

在这项研究中，定量微量元素分析技术的单个流体包裹体使用质子诱导X射线发射（PIXE）已被开发来研究元素的地球流体的运输。主要内容如下：1）矿物基质中流体包裹体X射线总发射量的定量和计算方法的发展; 2）用自制的具有已知含量和形状的流体包裹体模拟样品的PIXE测量来评价所发展的定量和计算方法; 3）天然流体包裹体微量元素测定的分析误差估计：4）热液石英脉中单个流体包裹体的微量元素测定。定量和计算是在坎贝尔（1993）的PIXE测定固体中微量元素的方法和Ryan等人（1993）的PIXE单一流体包裹体分析方法的基础上发展起来的。通过使用开发的方法， 关于我们 对单个流体包裹体中10 ~ 1000 ppm的Hods、元素进行了测定，平均相对误差为± 7%。对于石英中半径为30 μm、深度为20 μm的天然流体包裹体，考虑到包裹体深度的显微测量不确定性，计算出Ca、Fe、Zn、Sr、Br和Rb的总分析误差分别为±40%、±16%、±13%、±12%和±11%。在1.0 μC的积分电荷下，对石英中半径30 μm、深度20 μm的球形流体包裹体进行分析，质量数25-50的元素的检出限为4 ~ 46 ppm。用该方法测定了日本中部长野县川上村热液石英脉中单个流体包裹体的微量元素组成。夹杂物中的元素浓度变化很大：Ca和Fe为0.2-9重量%，Mn和Zn为300-8000 ppm，Cu为40-3000 ppm，Br、Rb、Sr和Pb为100-4000 ppm，Ge小于100 ppm。少

In this study, quantitative trace element analytical techniques for single fluid inclusions using proton-induced X-ray emission(PIXE) have been developed to investigate an elemental transportation by Earth's fluid. The main subjects were as follows : 1)developments of the quantification and the calculation method of total X-ray emission from a fluid inclusion buried in mineral matrix : 2)evaluation of the developed quantification and the calculation by using PIXE measurements of house-made fluid-inclusion analogue samples with known contents and shape : 3)estimation of the analytical error for trace-element determinations of natural fluid inclusion : 4)trace-element determinations of single fluid inclusions in a hydrothermal quartz vein. The quantification and the calculation were developed on the basis of Campbell (1993)'s method for PIXE determination of trace elements in solids and Ryan et al. (1993)'s method for single fluid inclusion analysis using PIXE. By using the developed met … More hods, elements with concentrations of 10 to 1000 ppm in single fluid inclusion were measured with average estimated relative error of ±7%. For natural fluid inclusions with 30 μm radius and 20 μm depth in quartz, the total analytical errors were estimated to be ±40% relative for Ca,±16% for Fe,±13% for Zn,±12% for Sr,and ±11% for Br and Rb,by considering uncertainties in microscopic measurements of inclusion depths. Detection limits of 4 to 46 ppm for elements of mass numbers 25-50 were achieved for analyses of a spherical fluid inclusion with 30-μm radius and 20-μm depth in quartz at an integrated charge of 1.0 μC. The trace element compositions of single fluid inclusions in hydrothermal quartz veins from Kawakami village, Nagano Prefecture, Central Japan, were also determined by using the developed method. The elemental concentrations in the inclusions varied widely : 0.2-9 wt% for Ca and Fe,300-8000 ppm for Mn and Zn,40-3000 ppm for Cu,100-4000 ppm for Br,Rb,Sr,and Pb,and lessthan 100 ppm for Ge. Less