滩间山群火山岩特征及其成岩构造背景

滩间山群火山岩分为下部火山碎屑岩组(O1-2h)和上部熔岩次火山岩组(O3y)。从岩石组合、岩石化学、地球化学等方面进行了研究,指出下部火山岩总体体现大陆裂谷环境特征,上部火山岩总体显现类岛弧环境特征,由下至上,由双峰式火山岩向类岛弧钙碱性火山岩演变,揭示其成岩构造背景是经历了大陆裂谷、逐渐稳定、俯冲到类岛弧火山岩形成的几个阶段。

Characteristics of Volcanic Rocks and Tectonic Setting of Diagenesis of the Tanjianshan Group

The volcanic rocks of Tanjianshan group can be divided into two parts: the Volcanic clastics of the lower part(O1-2h)and the Lava subvolcanics of the upper part (O3y). Much research had been done from Rock combination, Rock chemistry, Geochemistry and so on. The volcanic rocks of the lower part appear a valley environment characteristic and the upper part presents the characteristic of a type of island arc environment. From descend upwards, the bimodal volcanic rocks turn into the type of island arc calcium alkaline volcanic ,which can indicate the tectonic setting of diagenesis that experienced a few stages from the formation of the continental rift, gradual stability, the ocean-continent subduction to the formation of a type of island arc volcanic.