勃利双兴铜矿床侵人岩年代学、岩石地球化学特征及岩石成因

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中图分类号：P597 文献标志码：A

Abstract： Cu polymetalic deposits are developed in the Bolishuangxing area， Heilongjiang Province. The ore-forming rock masses （granodiorite and granodiorite porphyry）are closely related to Cu deposits. In order to determine its mineralization era and geodynamic background，based on field survey work， this paper investigate the petrographic，chronological， and geochemical characteristics of intrusive rocks in Cu deposits of Bolishuangxing area，and explores the formation age， petrogenesis，and tectonic background of the intrusive rocks in the study area.The results show that the LA-ICP-MS zircon U- Pb products of Late Mesozoic Early Cretaceous magmatic activity （granodiorite at （120.94±0.70）Ma ， granodiorite porphyry at （120.88±0.61）Ma ），which indicates that the formation time in Cu deposits of Bolishuangxing area was approximately 120.9Ma ， consistent with the peak period of mineralization in the region. Research on rock geochemistry shows that granodiorite and granodiorite porphyry contain （w（SiO2 ） （61.04%-67.08%） ， w（Al2O3 ） （14.07%-15.86%） ， w 0 （Na2O+K2O） 》 （6.40%-7.15%） ， （20 z℘（TFeO） （4.52%-6.69%） ， w（CaO）（2.30%-4.43%） ， δEu（0.74-1.27）） ， the europium anomaly is not obvious. They are enriched in light rare earth elements and large ion lithophile elements（Rb，Ba，Sr， etc.），and relatively deficient in heavy rare earth elements and high field strength elements （Nb，Ta，Zr ， etc.）.The magma source area is partial melting of newly enriched lower crustal material， showing I- type granite characteristics. Based on relevant research results，it is considered that the geodynamic seting of the formation of granodiorite and granodiorite porphyry in the study area is an extensional environment formed by the subduction and retreat of the ancient Pacific plate towards the Eurasian continent.

Key words： Early Cretaceous;geochemistry;intrusive rocks; petrogenesis;sbduction;Cu deposits of Bolishuangxing area

0 引言

黑龙江省作为中国东北地区重要的铜矿产区，矿产资源丰富。（剩余27422字）