赣南燕山早期双峰式火山岩的厘定和意义

Ascertainment and Implication of the Early Yianshanian Bimodal Volcanic Associations from South Jiangxi Province

研究表明分布在赣南寻邬县的白面石—菖蒲火山—沉积盆地和龙南县的东坑—临江火山—沉积盆地火山岩系下部的玄武岩与流纹岩具有紧密的时、空关系,是一套中侏罗世形成的双峰式火山岩组合。玄武岩和流纹岩的不相容元素地球化学特征与板内玄武岩一致,表明中国东南大陆存在燕山早期的裂谷作用或碰撞后伸展作用。

Our studies show that the basalts distributed in the lower volcanic—sedimentary sequences of the Baimianshi—Changpu and Dongkeng—Linjiang volcanic—sedimentary basins, south Jiangxi province, are closely related to rhyolites in space and time, forming a suit of bimodal volcanic associations of the early Yanshanian. Geochemical characteristics of incompatible elements for the basalts and rhyolites are consistent with that of the intraplate basalts.this suggests that continental rifting or post-collision extension took place in the early Yanshanian in the southeast China continent.