砂岩副矿物的物源区分析新进展  

Applications of Geochemistry and Geochronology of Accessory Minerals in Sandstone to Provenance Analysis

作　　者：王建刚[1] 胡修棉[1] 

机构地区：[1]南京大学地球科学系,南京210093

出　　处：《地质论评》2008年第5期670-678,共9页Geological Review

基　　金：国家重点基础研究发展规划项目(批准号2006CB701402);国家自然科学基金(批准号40772070 40302017)的成果。

摘　　要：物源区分析是盆地分析和古地理重建的重要研究方法,有很长的研究历史。随着分析测试技术的进步,物源区分析的方法不断发展,分析精度也不断提高。电子探针、离子探针和LA-ICP-MS等微区原位分析技术的发展,使得基于单矿物地球化学和同位素年代学的物源区分析方法取得了长足的进步,代表了物源区分析的最新发展方向。本文介绍了砂岩中常见副矿物铬尖晶石、金红石的地球化学分析以及锆石U-Pb年龄、白云母Ar-Ar年龄在物源区分析中的应用。同时,作者认为物源区分析往往是基于碎屑矿物的化学成分或年龄与可能物源区的对比,且只具有统计意义。因此,深入了解区域地质情况和可能的物源区的地质信息,测试一定数量的颗粒进行统计分析,才能得出合理的结果。With a great development in the last century, provenance analysis becomes an important approach in basin research and paleogeography reconstruction. Over past decades, the development of in situ microanalytical techniques, such as electron microprobe, ion microprobe and LA-ICP-MS, allow more easily and accurately the geochemical and geochronological study of single mineral. This greatly boosted the development of provenance analysis approaches. This paper reviewed recently applications of geochemistry and geochronology of accessory minerals in sandstones to provenance analysis. Chemical composition of chromian spinel and rutile and isotopic dating of detrital zircon and muscovite are good provenance indicators. It is effective to discriminate sedimentary source by comparing data of detrital minerals with possible source regions, because it can distinguish various sedimentary sources which coexist at the deposition time and also could avoid influence from weathering. In addition, since applications of detrital mineral to provenance analysis are mainly based on the statistic occurrences of different components in one sample, more grains will be useful for provenance analysis of detrital minerals.

关 键 词：砂岩 物源区分析 副矿物 地球化学 同位素年代学 

分 类 号：P597[天文地球—地球化学]