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| GEOCHEMISTRY AND GENESIS OF THE NEOARCHEAN METAMORPHIC PLUTONIC ROCKS IN BEIZHEN AREA, LIAONING PROVINCE |
| WANG Xiao-han |
| Liaoning Institute of Geology and Mineral Survey, Shenyang 110031, China |
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Abstract The Neoarchean metamorphic plutonic rocks in Beizhen area of Liaoning Province are the oldest crystalline basement in the region. With general metamorphism and deformation of plutons, the structures of protolith have changed. The plutonic rocks can be divided into two rock units of Xiaoqianmaling gneiss complex (Ar3xqgnc) and Baichangmen gneiss (Ar3bgn) according to the characteristics and distribution of rock mass. The SiO2 content in Ar3xqgnc is 59.69%-76.22%. The liquidus temperatures of the two rocks are 720-1024℃ and 776-1024℃ respectively. The Ar3xqgnc is characterized by high degree of magmatic differentiation, while Ar3bgn with high differentiation index (DI) of 68.99-91.68. The Ba/Sr ratios of both rocks are close to each other with approximately parallel right-dipping REE patterns, showing unobvious Eu anomalies with enrichment of LREEs, which indicates that the two rocks are derived from similar material sources.
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Received: 16 March 2016
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2018, Vol. 27 
