Abstract
本文首次报道了侵位于狮泉河蛇绿岩（蛇纹石化超基性岩）中的具有OIB性质的辉绿岩以及赞岐岩型的高镁闪长岩。其中闪长岩具有较高的TiO2、Y及Yb含量，较低的Sr/Y比值和La/Yb比值，与日本Setouchi火山岩带的赞岐岩以及前人报道的同期洋内初始俯冲成因相关的高镁安山岩性质一致。辉绿岩富LREE，高Zr/Y、TiO2/Yb和Nb/Yb比值，Nb、Ti负异常，Pb正异常，表现出了俯冲带相关的OIB性质；采用LA-ICP-MS锆石U-Pb定年方法，测得辉绿岩脉的成岩年龄为163.7±0.54Ma（MSWD=3.8），且该年龄与前人报道的160.8±2.3Ma的高镁安山岩年龄较为接近。综合分析本文及前人年代学与岩石地球化学相关数据，认为狮泉河辉绿岩和闪长岩同时形成于洋内俯冲的初始阶段。这种岩石组合与太平洋IBM岛链初始俯冲的岩石组合相似，但该OIB成因机制中俯冲作用与地幔柱之间的相互关系仍需进一步讨论。
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
