摘要
青藏高原南羌塘石炭纪-二叠世地层中侵入大量的辉绿玢岩岩墙群,其侵位时代为晚古生代.区域资料显示,这一时期该地区处于冈瓦纳大陆北部边缘.岩石化学、地球化学特征表明,辉绿玢岩与洋脊型、洋岛型及典型的大陆裂谷玄武岩都有明显区别,显示出大陆拉张带(或初始裂谷)的拉斑玄武岩特征.辉绿玢岩是冈瓦纳被动陆缘在晚古生代裂解的产物.
A great number of diabase-porphyrite dikes emplaced in the Carbonaceous-Middle Permian Strata in southern Qiangtang of the Qinghai-Tibet Plateau in Late Paleozoic, Regional data shows that this region was on the northern margin of the Gondwana Continent at that time. Petrochemistry and geochemistry indicate that the diabase-porphyrite is quite different from basalts formed at ocean ridge, ocean island and typical continental rift, but similar to tholeiite formed at continental extension zone （or initial rift）. Diabase-porphyrite was the splitting product of passive margin of Gondwana Continent in Late Jurassic.
出处
《安徽地质》
2005年第3期170-174,共5页
Geology of Anhui
关键词
晚古生代
辉绿玢岩
裂解
南羌塘
late Paleozoic
diabase-porphyrite
splitting
Southern Qiangtang
