Metamorphosed mafic rocks with N-type MORE geochemical features in Hainan Island-Remnants of the Paleo-Tethys Oceanic Crust?  

作　　者：LI Xianhua, ZHOU Hanwen, DING Shijiang, LEE Chi-yu, ZHANG Renjie, ZHANG Yeming & GE Wenchun1. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China 2. Hainan Geological Survey, Haikou 570206, China 3. Department of Geology, Taiwan University, Taipei 106-17, China 4. Yichang Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Yichang 443003, China 

出　　处：《Chinese Science Bulletin》2000年第10期956-961,共6页

摘　　要：A number of metamorphosed mafic rocks occurred within the Paleozoic strata in the Chenxing and Bangxi regions at the northern side of the Changjiang-Qionghai Fault in Central Hainan Island. These metamorphosed mafic rocks are tholeiites in chemistry. They are characterized by extreme depletion of Th, Nb, Ta and LREEs, resembling the depleted N-type mid-ocean ridge basalts (MORE). Field relations suggest that the protolith of the metamorphosed mafic rocks were likely formed in Paleozoic. These metamorphosed mafic rocks with N-type MORB geochemical features were probably the remnants of the Paleo-Tethys oceanic crust.A number of metamorphosed mafic rocks occurred within the Paleozoic strata in the Chenxing and Bangxi regions at the northern side of the Changjiang-Qionghai Fault in Central Hainan Island. These metamorphosed mafic rocks are tholeiites in chemistry. They are characterized by extreme depletion of Th, Nb, Ta and LREEs, resembling the depleted N-type mid-ocean ridge basalts (MORE). Field relations suggest that the protolith of the metamorphosed mafic rocks were likely formed in Paleozoic. These metamorphosed mafic rocks with N-type MORB geochemical features were probably the remnants of the Paleo-Tethys oceanic crust.

关 键 词：N-TYPE MORB metamorphosed MAFIC rocks element geochemistry HAINAN Island. 

分 类 号：P578[天文地球—矿物学]