我国某地区岩浆岩化学成分与区域地球化学特征

Based on a review of the available petrological and petrochemical data on magmarie rocks in a certain district in China, the average chemical composition of magmarie rocks has been calculated, and the frequenee distribution of elements in rocks,mineralization of rock bodies and regional geochemical characteristics have been discussed. In response to the temporal and. spatiai variations during the evolutionary process of magmatie activity, a systematic variation is obvious from this study in the chemical compositions of magmatie rocks, the frequence distribution patterns of elements, the concentration levels of various elements, the calc-alkaline index of the rocks as well as in the average atomic weight and average atomie valence. Particularly,different geochemical indicators have been observed for mineralized and barren rock bodies respectively. Crystallization-differentiation and postmagmatic metasomatism constitute the most important mechanisms controlling mineralization.