CAJ | 학술논문

利用显微镜、地球化学、ELA-ICPMS定年等技术,对鄂尔多斯盆地西缘汝箕沟大岭-鼓鼓台玄武岩及其样品中的锆石进行了内部结构、元素组成分析和原位定年.汝箕沟大岭-鼓鼓台玄武岩为典型的大陆拉斑玄武岩,所获得的锆石年龄分别为1966±15 Ma、344±22 Ma和241±7 Ma,其中1966±15 Ma为继承锆石年龄,344±22 Ma为岩浆第一次分离结晶年龄,而241±7 Ma代表了玄武质岩浆最后喷出时的锆石结晶年龄.可见,中晚三叠世盆地西缘北部贺兰山地区处于区域挤压背景下的局部伸展环境.可能为一小型裂谷盆地.
이용현미경、지구화학、ELA-ICPMS정년등기술,대악이다사분지서연여기구대령-고고태현무암급기양품중적고석진행료내부결구、원소조성분석화원위정년.여기구대령-고고태현무암위전형적대륙랍반현무암,소획득적고석년령분별위1966±15 Ma、344±22 Ma화241±7 Ma,기중1966±15 Ma위계승고석년령,344±22 Ma위암장제일차분리결정년령,이241±7 Ma대표료현무질암장최후분출시적고석결정년령.가견,중만삼첩세분지서연북부하란산지구처우구역제압배경하적국부신전배경.가능위일소형렬곡분지.
Based on an analysis of data obtained by such means as microscope observation, geochemistry and ELA-ICPMS, the authors studied the Daling-Gugutai basalt in such aspects as the internal structure, element composition and original location dating of its zircons. It is shown that the Daling-Gugutai basalt is a typical tholeiitic basalt, with its zircon ages being 1966±15Ma, 344±22 Ma and 241±7Ma, respectively. Of these data,1966±15Ma is the age of inherited zircon, 344±22Ma is the first fractional crystallization age of magma, and 241±7Ma is the age of zircon crystallization during the last eruption of basaltic magma. It is thus suggested that the Helan Mountain area was probably a rift under an extending condition in Middle-Late Triassic period.