摘要
那丹哈达增生杂岩为中国东部古太平洋板块俯冲最为可靠的地质记录之一,对限定古大洋板块的西向俯冲具有重要的理论意义.饶河杂岩位于那丹哈达增生杂岩的核心位置,发育典型的增生杂岩组合,其中玄武岩类多呈构造透镜体状产出于超镁铁质-镁铁质杂岩带,变形轻微,没有遭受变质.对饶河杂岩中枕状玄武岩样品进行的同位素年代学和地球化学研究结果表明:饶河杂岩中枕状玄武岩锆石LA-ICP-MS U-Pb年龄为中侏罗世(168±2 Ma),枕状玄武岩大离子亲石元素Rb、Sr亏损,高场强元素Nb、Ta富集,Th元素丰度较高,形成于洋岛(OIB型)环境.饶河杂岩中枕状玄武岩的形成时代和成因环境,对于该区侏罗纪时期构造动力学背景研究具有意义.
As one of the most reliable geological records of paleo-Pacific Plate subduction in eastern China, the Nadanhada accretionary complex is of great importance to define the westward subduction of paleo-oceanic plate. The Raohe Complex is located in the core of the complex, developed with typical accretionary complex association, among which the basaltoids, mostly in structural lenticles, are occurred in the ultramafic-mafic complex zone with slight deformation but no metamorphism. Study on the isotopic chronology and geochemistry of the pillow basalt samples from Raohe Complex shows that the LA-ICP-MS zircon U-Pb age is Middle Jurassic(168±2 Ma), with depletion of LILEs (Rb and Sr), enrichment of HFSEs(Nb and Ta) and high-abundant Th, which was formed in the ocean island environment (OIB). Its formation age and genetic environment is significant to study the tectonic dynamic background of the area during the Jurassic period.
作者
曾振
孙雷
张兴洲
崔维龙
蒋力
ZENG Zhen;SUN Lei;ZHANG Xing-zhou;CUI Wei-long;JIANG Li(China Aerospace Architectural Design and Research Institute Co.,Ltd.,Beijing 100162,China;College of Earth Sciences,Jilin University,Changchun 130061,China;Shenyang Center of Geological Survey,CGS,Shenyang 110034,China)
出处
《地质与资源》
CAS
2019年第2期119-127,共9页
Geology and Resources
基金
国家自然科学基金重点项目"兴蒙海槽晚古生代构造演化"(编号40739905)
中国地质调查局项目"黑龙江省东部隐伏盆地页岩气地质条件综合调查"(编号1212011120973)
"松辽外围西部盆地油气基础地质调查"(编号DD20160163)
