CAJ | 학술논문

利用阴极发光和LA-ICP-MS微区定年分析方法,对西秦岭南缘勉略构造带琵琶寺基性火山岩进行了单颗粒锆石U-Pb同位素分析.研究确定,所测定锆石为岩浆锆石.琵琶寺基性火山岩的LA-ICP-MS锆石U-Pb同位素定年结果表明,其同位素年龄为783～754Ma,形成时代为新元古代中晚期南华纪.结合前人资料,认为勉略构造带不仅在晚古生代发育有限洋盆,且在新元古代时期还有更古老的洋盆存在.这一新资料,对进一步研究勉略构造带西段新元古代大地构造格局及演化以及探讨扬子地块北缘Rodinia超大陆裂解等大陆动力学问题具有重要意义.
이용음겁발광화LA-ICP-MS미구정년분석방법,대서진령남연면략구조대비파사기성화산암진행료단과립고석U-Pb동위소분석.연구학정,소측정고석위암장고석.비파사기성화산암적LA-ICP-MS고석U-Pb동위소정년결과표명,기동위소년령위783～754Ma,형성시대위신원고대중만기남화기.결합전인자료,인위면략구조대불부재만고생대발육유한양분,차재신원고대시기환유경고로적양분존재.저일신자료,대진일보연구면략구조대서단신원고대대지구조격국급연화이급탐토양자지괴북연Rodinia초대륙렬해등대륙동역학문제구유중요의의.
The LA-ICP-MS dating technique was applied to analyze the single grain zircon of basic volcanic rocks which is from the Pipasi area of the southern margin of Western Qinlin. This research indicates that the zircons measured are magmatic ones. The LA-ICP-MS zircon dating result of the rocks show an isotopic age of 783～754Ma, which represents the Neoproterozoic. Combining previous research, we believe that not only a limited ocean basin developed in late Paleozoic, but also a more ancient ocean basin existed in Neoproterozoic. Therefore, this study has great significance both in further studying the Mian-Lue tectonic zone structure and tectonic evolution as well as addressing continental dynamic issues such as the breakup of Rodinia supercontinent and other continents in the Yangtze block north margin.