资源调查与环境Issue(3)：192-201,10.
皖南新元古代双峰式岩墙群的年龄、地球化学特征及地质意义
Age and geochemistry of the Neoproterozoic series of bimodal dikes in the Southern Anhui Province and their geological significance
摘要
Abstract
A series of dikes composed of gabbros and granodiorite porphyries are developed near the Xucun town in the Southern Anhui Province .The dikes are inseparably associated in time-space and closely related in genesis .The SiO2 contents in the rocks from the dikes are concentratedly a lack of SiO 2 contents between 56% ~63% consistent with the intermediate and intermediate-acidic composition ranges ,constitu-ting an assemblage of bimodal intrusive rocks .The high-precision LA-ICP-MS U-Pb zircon dating of 822 ± 6 .6Ma obtained by the present study may indicate The intrusion age of the bimodal dikes .The gabbros have positiveεHf (t) values of 2 .1~4 .4 ,enriched large ion lithophile elements and LREE ,showing charac-teristies of petrochemical and isotopic compositions of the continental tholeiite basalts .The granodiorite porphyries have enriched Zr ,Hf and REE ,relativity higher Ga/Al values ,and relatively lower Ba ,Sr ,P ,Ti , being overall analogous to the geochemical characteristics of A 2-type granites ,withεHf (t) values of 1 .8~4 .6 basically similar to those of gabbros .Therefore ,in the Xucun series of bimodal dikes ,the basic and member gabbros may have produced from the basaltic magma originated by the partial melting of the de-plated lithospheric mantle in South China in a tensional settling ,whereas the acidic end member granodior-ite porphyries are likely resulted from the remelting of the crust caused by the heat source provided by the basaltic magma during its upwelling and underplating accompanied by hybridism of the crust .关键词
双峰式岩墙/新元古代/锆石U-Pb定年/地球化学/皖南Key words
series of bimodal dikes/Neoproterzoic/U-Pb zircon dating/geochemistry/Southern An-hui Province分类
天文与地球科学引用本文复制引用
黄文成,叶海敏,孟庆秀..皖南新元古代双峰式岩墙群的年龄、地球化学特征及地质意义[J].资源调查与环境,2014,(3):192-201,10.基金项目
中国地质调查局地质调查项目《晋宁期-加里东期构造-岩浆活动及构造格局演变对区域成矿作用的制约》（项目编号1212011121097）资助。 （）
