西藏地区侏罗、白垩及第三系地层泥质岩的微量元素聚类分析成果解释

GEOLOGICAL INTERPRETATION ON THE RESULTS OF CLUSTER ANALYSIS OF TRACE ELEMENTS FROM ARGILLACEOUS ROCKS IN THE JURASSIC,CRETACEOUS AND TERTIARY STRATA IN XIZANG

我们除了对该区侏罗、白垩及第三系地层中的泥质岩类(含部分泥质粉砂岩、泥灰岩)进行了详细的岩性和沉积特征的研究外,还对其所含的微量元素类型、含量及其分布规律做了系统的研究。由于在沉积过程中沉积物与沉积环境水介质间存在着一系列复杂的地球化学平衡,如沉积物与界面水之间的物质交换、沉积物质对元素的吸附,以及胶体的凝聚等。这种物质的聚集、交换,以及元素的再分配,不仅仅和元素本身的性质有关,同时还受制于各种外界条件,如母岩的风化特点、物质与元素的搬运状态、以及古气候、古沉积环境、水介质特征等。因此,在不同的背景条件下。

The present paper deals with the geological interpretation on the results of cluster analysis of the trace elements from the argillaceous rocks in the Jurassic, Cretaceous and Tertiary strata in the Xizang region. Due to distinctive sedimentary geochemical properties of different trace element associations and to the influence of a variety of palaeoclimatic, palaeotectonic and palaeohydrogeologic conditions on the formation of the trace elements, the dispersion and concentration of the trace elements in various sedimentary environments tend to display some regular changes, which may not only be employed as the criteria for recognition of sedimentary environments, but also provide the associated data on the fossil water media.