江陵凹陷早第三纪玄武岩的地球化学特征与成岩构造环境

GEOCHEMICAL CHARACTERISTICS AND TECTONIC ENVIRONMENT OF EOGENE BASALTS OF THE JIANGLING HOLLOW

利用岩石化学、微量元素地球化学、同位素年代学等方法对江陵凹陷产出的基性火山岩类进行综合研究,确定其为早第三纪形成的石英拉斑玄武岩、橄榄拉斑玄武岩和碱性橄榄玄武岩等3种岩石类型,分别属于拉斑玄武岩系列与碱性玄武岩系列。拉斑玄武岩具有高钛、轻稀土富集型、高La/Lu值的大陆裂谷盆地成岩构造环境的特征。

The authors have studied basalts from the Jiangling hollow systematically using the methods of petrology,petrochemistry,geochemistry,isotope geology,isotope geochronology.The basalts are characterized by the depletion of K_2O and the enrichment of TiO_2,light REE and they are LILE and the high values of (La/Lu)_N and (La/Yb)_N;they are to continental rift basin tholeiites.