北大别饶拔寨退变质榴辉岩的地球化学特征  

GEOCHEMICAL CHARACTERISTICS OF RETROMETAMORPHIC ECLOGITE IN RAOBAZAI, NORTHERN DABIE MOUNTAINS

作　　者：吴元保[1] 陈道公[1] 程昊[1] 夏群科[1] 

机构地区：[1]中国科学技术大学地球与空间科学系,合肥230026

出　　处：《地震地质》2000年第B12期99-103,共5页Seismology and Geology

基　　金：国家重点基础研究发展项目! (19990 7550 3);国家自然科学基金项目! (49794 0 4 2 )

摘　　要：北大别饶拔寨退变质榴辉岩贫Na2 O ,K2 O。微量元素MORB标准化图中富集部分大离子亲石元素 (Rb ,Ba) ,其它元素分馏小 ,无明显的Nb ,Ta等负异常。稀土总量低 ,轻稀土亏损到轻度富集 ,无明显的Eu异常。这些特征反映其原岩为大洋拉斑玄武岩。北大别可能是扬子俯冲板块的北缘。In the eclogite from Raobazai ,Na 2O and K 2O are negative.They display MORB-normalized trace element diagrams characterized by partial LILE(Rb、Ba) positive anomalies, with no significant other elements fractionation, and without significant Nb and Ta anomalies. In the chondrite-normalized REE pattern, they show LREE depleted to slight enriched, without Eu anomaly. All of these indicate the original rocks may be oceanic tholeiitic basalt. The northern part of Northern Dabie Mountains may represent the leading edge of the subducted Yangtze craton.

关 键 词：退变质 榴辉岩 地球化学特征 大洋 俯冲板块 原岩 异常 离子 富集 稀土 

分 类 号：P588[天文地球—岩石学] P571[天文地球—地质学]