四川锦屏山地区部分地层时代、玄武岩和花岗岩地球化学特征及构造环境

锦屏地区的地质研究程度较低，部分地层时代争议较大，玄武岩、花岗岩的性质、物质来源和构造环境等尚未深入研究。为了切实评价区域稳定性，基础地质研究十分重要。通过同位素年代学和孢粉分析，改盐塘组时代由中三叠世为早二叠世，皮罗渡桥西黑色砂页岩层为晚三叠世；稀土元素、过渡元素、微量元素和岩石化学分析表明，在金一箐断裂东西两侧分布的玄武岩为上地幔来源、不同于陆海环境的大陆裂谷喷发产物，花岗岩的分异和重熔程度不同，代表造山期挤压向造山期后拉张环境转化。上述结论为该区构造发展演化和区域稳定性评价、矿产资源寻找提供了重要基础资料。

GEOCHEMICAL FEATURES AND STRUCTURAL ENVIRONMENTS OF THE BASALT AND GRANITE OF SOME STRATIGRAPHIC TIMES IN JINPING AREA, SICHUAN PROVINCE

Due to insufficient geological reseaxch in Jinping area, dispute on some stratigraphic timesremains unsettled and properties, material sources and structund environments of the basaltand granite unclear as yet. Research on basic geology is essential for making a good evaluationof regional stability. Based on the analyses of isotope-chronology and sporo-pollen,authors advanced the Yantang Formation from theddle Triassic epoch to early Pedmian epoch and theblack shale bed on the west of Piluedu Bridge to late Triassic epoch. The arialyses of REE,transitiotal elements, trace elements and Petrochewhtry indicate that the basalt scattered onboth sides of Jinping Xift is derived from upper mantle and different from preducts erUPtedfrom continental rift valley. The differentiation of granite and different remeting degrees indicate the tranSition from orogenic crumpling to post-orogenic tension. It has provided importantbasic materials for the development and evoution of the structures in the region and also foxmaking a good evaluation of regional stability and ore-prospecting.