摘要
小狐狸山钼矿成矿岩体地球化学特征表现为酸性铝过饱和的钙碱性系列花岗岩,里特曼指数δ=0.87～2.23,A/CNK值为1.03～1.07,稀土元素∑REE=(97.21～246.57)×10-6,∑LREE/∑HREE=6.27～8.99,δEu=0.27～0.35,铕强烈亏损。成岩物质以壳源为主,形成于挤压构造环境;成矿岩体具有高温元素W、Sn、Mo、Bi高背景含量,且中温元素Cu、Pb、Zn背景含量偏低;岩体蚀变类型主要有钾化、钠化和云英岩化;小狐狸山钼矿化主要产在边缘相和过渡相内,集中分布在岩体超覆于地层之上的南部地段,表明矿化主要与岩浆演化到晚期的热液作用相关联。黑鹰山-雅干成矿带存在着海西中晚期至印支期的多期成矿作用,海西中晚期对应于古亚洲洋闭合事件,为火山弧构造环境,小狐狸山钼矿与印支期中酸性岩浆活动有关,对应于古亚洲洋闭合后的板内构造环境。
In geochemistry,the Xiaohulishan Mo-mineralized granite is characterized by acid aluminium supersaturated and calcium-alkalinity with δ=0.87～2.23,A/CNK = 1.03～1.07 and ∑REE=（97.21～246.57）×10^-6,∑LREE/∑HREE=6.27～8.99,and δEu=0.27～0.35.It is originated from the partial melting of crustal rocks in an compressive tectonic setting with high contents of W,Sn,Mo,Bi and low contents of Cu,Pb,Zn.Mo-mineralization occurred in marginal and transitional zones of the southern granite which overlies Ordovician sequences.The rock alteration can be classified into K-felspar,albite and greisenization types.Magmatism and related Mo-mineralization occurred in the Hercynian and Indo-China epoch in the Heiyingshan-Yagan ore belt.In middle and late Hercynian time,this area was situated in a volcanic arc tectonic setting related with the closure of the ancient Asian ocean.And the Mo-mineralization in the Xiaohulishan deposit is associated with the medium-acid magma activity in an intraplate tectonic setting during the Indo-China period.
出处
《地质与勘探》
CAS
CSCD
北大核心
2010年第2期291-298,共8页
Geology and Exploration
基金
内蒙古自治区地质矿产勘查开发局<内蒙古自治区内生金属成矿规律及靶区筛选>(ND2007004)
关键词
成矿岩体
地球化学特征
小狐狸山钼矿
北山地区
Mo-mineralized granite
geochemical characteristics
Xiaohulishan molybdenum deposit
Beishan area
