古生代珊瑚和腕足化石的成岩蚀变判断方法

About 63 samples of paleozoic brachiopods and coral were collected from Yunnan-Guizhou plateau, China. Its conduct of trace elements, cathodoluminescence, scanning electron microscopy(SEM), boron isotopic composition and other indicators together to judge the diagenetic alteration of sample preservation. The results show that each method has its limitations. The diagenetic alteration of the sample can only be judged by the integrated method.     

H2O2浸泡对无机碳酸盐沉积11B的影响

Pretreatments were used to remove organic “contaminant” material prior to isotopic analyses of coral skeletal samples. We conducted one experiments to test the pretreatment effect of 30% hydrogen peroxide (H₂O₂) on the boron isotopic composition of inorganic carbonate. The experimental results indicate that H₂O₂ can change the boron isotopic composition.     

TIMS（Triton）测定质量范围的扩展及其在溴同位素测定中的应用

稳定溴同位素可用来识别和评价地下水的来源、成因及其形成的水文地球化学与物理过程。由于热电离质谱仪Triton的加速电压是固定10 kV不可调节的,因此,其最大的测定质量数为310 u。为了测定质量数更高的Cs₂Br⁺（m/z 345,347）离子,本研究通过对热电离质谱仪Triton加速电压单元的改造,成功地将加速电压由10 kV降低到8 kV,使可测定的离子质量数从310 u扩展到350 u。在此基础上,建立了在8 kV加速电压下相应的质量校正曲线,进行了基于¹³³Cs₂⁷⁹Br⁺（m/z 345）和¹³³Cs₂⁸¹Br⁺（m/z 347）离子的稳定溴同位素静态多接收测量。结果表明：当溴含量低于10 μg时,测定结果偏低;当溴含量高于10 μg时,测定结果正常。该方法测定溴同位素具有涂样量少（10~20 μg Br）,测定外精度高（0.09‰~0.18‰）和采集数据时间短（8 min可采集100 个数据）等优点,可为地质样品中溴同位素地球化学的研究提供参考。