首页|期刊导航|中国地球化学学报（英文版）|Petrogenetic significance of rare-earth element behavior in the basement rocks of southern Obudu Plateau, Bamenda Massif, southeastern Nigeria
中国地球化学学报（英文版）2005，Vol.24Issue(2)：129-135,7.
Petrogenetic significance of rare-earth element behavior in the basement rocks of southern Obudu Plateau, Bamenda Massif, southeastern Nigeria
Petrogenetic significance of rare-earth element behavior in the basement rocks of southern Obudu Plateau, Bamenda Massif, southeastern Nigeria
摘要
Abstract
Rock samples representing various igneous and metamorphic rocks of southern Obudu Plateau were analyzed for rare-earth element (REE) behavior by ICP-MS. Results of the analyses indicate a range of REE abundances and distinctive patterns from highly fractionated patterns with negative Eu anomalies in granitic rocks to relatively low abundances and less REE fractionated flat patterns with little Eu anomaly in some paragneisses, schists, enderbites and dolerites to unfractionated patterns with positive Eu anomalies in some paragneisses and charnockites. Over all, there are low to high ∑REE contents with negative to positive Eu anomalies. The ratios of different parameters, especially La/Yb and Ce/Yb, show behaviors consistent with crustal to mantle derivation. The heterogeneity of REE abundances and REE patterns reflects mantle to crustal petrogenetic variations of different rock suites on the Plateau. The LREE content is higher than the HREE content in the highly differentiated rocks, as evidenced by their La/Yb, Ce/Yb and La/Sm ratios, which are normally higher in residual products than in primary melts. The dominantly intermediate nature of the source rock of the orthogneisses is suggested by the generally low ∑REE . The granites enriched in LREE and depleted in HREE and some of the charnockites with negative Eu anomalies were probably formed by partial melting and crystallization.关键词
rare-earth element/abundance/pattern/fractionation/petrogenesisKey words
rare-earth element/abundance/pattern/fractionation/petrogenesis分类
天文与地球科学引用本文复制引用
UKAEGBU V.U.,EKWUEME B.N...Petrogenetic significance of rare-earth element behavior in the basement rocks of southern Obudu Plateau, Bamenda Massif, southeastern Nigeria[J].中国地球化学学报（英文版）,2005,24(2):129-135,7.基金项目
Funding for this research came from Senate/ Nigeria Universities Commission Research Grant Number UPH/DVC.AC/11/SD.022/COM.4 of the University of Port Harcourt. （）
