新疆北部晚古生代大规模岩浆作用与成矿耦合关系研究主要进展及成果

新疆北部晚古生代地质构造演化复杂,岩浆作用形式多样,造就了大规模的成矿作用。本研究紧紧围绕岩浆铜镍矿床、斑岩型铜(钼)矿床及火山岩型磁铁矿矿床,从含矿岩体的岩浆起源、岩浆演化及成矿特点,系统研究深部相应岩浆活动的地质过程。通过典型矿床的深入剖析,建立相应矿床类型的成矿模式,破解制约找矿突破的控制因素,系统阐述了板块构造与地幔柱体制叠加并存的地质特征与成矿表现。鉴于塔里木地幔柱的活动特点和成矿表现,将其与新疆北部三类主要矿床类型建立关联,对比岩石学、年代学及地球化学特点,发现其成矿类型与塔里木地幔柱及板块构造存有密切关系,可能是两种构造体制叠加并存的结果。塔里木克拉通深部熔融的地幔物质,围绕刚性塔里木克拉通边缘不断上涌,并与表壳物质发生交换,随着俯冲板块的持续和减弱,深部上涌的地幔物质不断加强,先后形成因深部地幔物质多寡而金属聚集的不同矿床类型。

Major Progress and Achievements on Coupling Relationship of Magmatism and Metallogenesis in Late Paleozoic of Northern Xinjiang

The large scale of metallogenesis in northern Xinjiang is controlled by complicated tectonic evolution and magmatism evolution in Late Paleozoic. This paper focused on magmatic Cu-Ni deposits, porphyry Cu-Mo deposits, and volcanic magnetite deposits. Geological process of magma activity was studied by origin, evolution and mineralization characteristic of ore-bearing intrusions. On the basis of typical deposits analysis, metallogenic models of different deposit types were established, restricted factors in prospecting breakthrough were revealed, geological characteristics and mineralization features caused by activity of plate tectonics and mantle plume were proposed. Characteristics of petrology, geochronology, geochemistry, magmatism and mineralization of Tarim mantle plume were closely related with the typical deposits in northern Xinjiang, and these indicated the mineralization in northern Xinjiang was controlled by Tarim mantle plume and plate tectonics. It is inferred that constantly decreased continental subduction and strengthened mantle upwelling may be responsible for the metallogenesis in northern Xinjiang, and the melt mantle material upwelled and mixed crustal rocks along the margin of rigid Tarim craton.