Author(s): CHENG Yongsheng, Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education, Central South University, School of Geosciences and Info-Physics, Central South University, State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences
Pages: 586-594
Year: 2015 Issue:  2
Journal: Journal of Central South University of Technology
Keyword:  intrusive rock; geochemistry; petrogenesis; tectonic environment; Dachang in Guangxi;
Abstract: Based on the analysis of the major elements, trace elements and rare earth elements, the petrogenesis and evolution of intrusion and the tectonic environment of diagenesis and mineralization were discussed. The results show that w(LREE), w(HREE) and w(ΣREE) are(28.25-144.85)×10-6,(4.28-14.75)×10-6 and(32.53-159.6)×10-6, respectively. The range of w(LREE)/w(HREE), δw(Eu), δw(Ce), w(Gd)/w(Yb) w(Sm)/w(Nd), w(Eu)/w(Sm) and w(La)/w(Sm) varies from6.22 to 12.33,0.29 to 0.71,0.94 to 0.97,1.61 to 2.31,0.16 to 0.23,0.10 to 0.24 and 6.06 to 9.41,respectively. The intrusions are mainly of aluminum-strongly peraluminous series, characterized by silica poor, relative stable content of the large ion lithophile elements, high content of the inactive elements, low content of the high field strength elements, high concentration of LREE, depleted in HREE and high fractionation for REE. Chondrite-normalized REE patterns with good consistency suggest maybe the same or similar magma source and evolutionary history. The intrusions, whose evolutions are affected by the crust-mantle which supplied the material source, belong to the product of the crust-mantle interaction.The rock may be the result of the partial melting in means of the crust and mantle mixed in the period of collision orogeny and intra-plate, special in the conversion period both of them, in the tensile tectonic environment.