摘要
目的探讨柴北缘野马滩超高压地体的成因。方法利用锆石LA-ICP—MS原位微区分析技术，对超高压榴辉岩中两种类型的副片麻岩夹层进行年代学研究。结果得到榴辉岩中两类副片麻岩夹层的变质年龄介于421—458Ma之间，与超高压榴辉岩的变质年龄一致。结论柴北缘野马滩超高压榴辉岩和围岩片麻岩是同一期变质事件的产物，其形成可能不应属于典型洋壳深俯冲成因，而很可能是陆壳深俯冲的结果。
Aim To provide new evidence for the discussion of the formation mechanism of the Yematan UHP terrane in the North Qaidam belt. Methods Integrated study of Cathodolumineseence （CL） imaging, LA-ICP-MS in situ trace element analyses and U-Pb dating were carried out for zircon grains from two paragneisses interbed in the Yematan ultrahigh pressure metamorphic eclogite. Results The metamorphic age of these two paragneisses are between 421 - 458 Ma, which is well consistent with that of the Yematan UHP eclogite. Conclusion The Yematan eelogite and their country rock paragneisses underwent coeval Early Paleozoic HP/UHP metamorphism, they may not be the product of typical oceanic crustal deep subduction but the continental deep subduetion.
出处
《西北大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第4期631-638,共8页
Journal of Northwest University（Natural Science Edition）
基金
国家"973"基金资助项目(2009CB825003)
西北大学大陆动力学国家重点实验室基金项目
国家自然科学基金资助项目(40472043)
