东天山尾亚钒钛磁铁矿矿床角闪石矿物学特征及成因意义

Mineralogical characteristics and petrogenetic significance of the amphibole in the Weiya V-Ti-magnetite deposit in the eastern Tianshan

尾亚钒钛磁铁矿矿床是东天山地区典型的层状岩体型钒钛磁铁矿，其矿石主体为浸染状-稠密浸染状矿石，同时含有少量半块状一块状富矿。应用电子探针对浸染状一稠密浸染状矿石和半块状一块状富矿中的角闪石进行成分分析，并探讨其形成的物理化学条件。结果表明，浸染状一稠密浸染状矿石就位深度浅，在10．1—16．9km之间，其母岩浆形成温度相对较低（950—981℃）。半块状一块状富矿形成于19．2～20．0km的深部岩浆房，矿浆具有相对高温（978—9930C）的特征。成矿的绝对氧逸度大于-9．6。深部岩浆房的分异演化对尾亚层状岩体型钒钛磁铁矿矿床富矿体的形成具有至关重要的作用。

The Weiya V -Ti magnetite deposit is a typical layered intrusion style V-Timagnetite deposit, the major ore type is disseminated and dense disseminated type, and minor massive and semi-massive ore. The compositional analysis of amphibole mineral in the disseminated ore and semi-massive ore was conducted by EMPA, and the physical and chemical parameters of the parental magma were calculated and discussed.The results suggest that disseminated ore and dense disseminated ore were formed in a shallow crust in the depth of from about 10.1 to 16.9 km, and the formation temperature of parental magma is relatively low ranging from 950℃ to 980℃. And the massive and semi-massive ore were formed by the deep magma source around the depth of from 19.2-20.0 km with high temperature ranging from 978 ℃ to 993℃. The metallogenic absolute oxygen fugaeity is higher than -9.6. The differential and evolution process of deep magma plays a key role in the formation of Weiya layered intrusion style V-Ti magnetite deposit.