ODP 1144站钻孔沉积物中微玻璃陨石的元素地球化学特征  

Major and trace elemental compositions of the microtektites from ODP Site 1144

作　　者：韦刚健[1] 梁细荣[1] 李献华[1] 赵泉鸿[2] 邵磊[2] 朱照宇[1] 

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]同济大学海洋地质教育部重点实验室,上海200092

出　　处：《地球化学》2002年第1期35-42,共8页Geochimica

基　　金：国家自然科学基金重大项目(49999560)

摘　　要：利用电子探针和激光探针等离子体质谱方法分析了取自南海北部的ODP1144钻孔沉积物中的微玻璃陨石和取自邻近的广东省湛江和吴川玻璃陨石的主元素和微量元素组成。结果显示,这些微玻璃陨石属于亚洲-澳大利亚散落区的普通微玻璃陨石。从成分上看,这些微玻璃陨石存在两种不同的类型,其中的绝大部分Al2O3含量在19.0%以上,属于高Al类型,相应的难熔微量元素含量也比较高;个别微玻璃陨石Al2O3含量(13.0%)和难熔微量元素含量较低,微量元素含量和特征比值都与邻近的广东省湛江和吴川的玻璃陨石相近。元素地球化学特征意味着,这些微玻璃陨石来源于同一靶源区,但靶区的物质组成并不均一。Major and trace elements of several microtektites from sediments of ODP Site 1144 in the South China Sea and two tektites from Zhanjiang and Wuchuan are measured by microprobe and laser probe inductively coupled plasma mass spectrometry (LP ICPMS), respectively. The results indicate that the microtektites of ODP 1144 are part of the normal microtektites of the Australiasian strew area. According to the elemental compositions, there are two types of microtektites among the ODP 1144 microtektites. The majority of these microtektites exhibit high Al2O3 abundance, between 19.0% and 22.1%, which lie within the high Al end members of the Australiasian microtektites. Accordingly, their refractory element contents are higher than those of the Australiasian tektites. Only one out of the 9 spherules of the ODP 1144 microtektites exhibits low Al2O3 abundance, 13.0%. Also, the contents and some ratios of the refractory elements of this spherule differ much from the other ODP 1144 microtektites, but similar to those of the tektites from Zhanjiang and Wuchun. The elemental compositions of these microtektites indicate that they are all from the same target spot. However, the compositions of the source rocks at the target spot were probably heterogeneous.

关 键 词：ODP钻孔 微玻璃陨石 元素地球化学 电子探针 激光探针 

分 类 号：P68[天文地球—地质学] P595