| 陈 静.东昆仑拉陵灶火钼多金属矿床含矿岩体地质地球化学特征及其成矿意义[J].地质与勘探,2013,49(5):813-824 |
| 东昆仑拉陵灶火钼多金属矿床含矿岩体地质地球化学特征及其成矿意义 |
| Geological and Gechemical Characteristics of the Ore-Bearing Intrusions from the Lalingzaohuo Mo Polymetallic Deposit and its Metallogenic Significance |
| 投稿时间：2012-12-18 修订日期：2013-02-06 |
| DOI： |
| 中文关键词: 锆石U-Pb年龄 壳幔相互作用 拉陵灶火钼多金属矿床 东昆仑 |
| 英文关键词: zircon U-Pb age, Crust-mantle interaction, Lalingzaohuo Mo polymetallic deposit, East Kunlun |
| 基金项目:青海省科技支撑计划项目（2011-J-113A）和青海省自然科学基金项目（2012-Z-934Q）联合资助 |
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| 中文摘要: |
| 摘要：拉陵灶火钼多金属矿床是青海祁漫塔格成矿带新发现矽卡岩-斑岩型矿床。本文对矿区内与斑岩型矿化有关的花岗闪长岩开展了详细的年代学、岩石地球化学研究，结果表明：拉陵灶火似斑状花岗闪长岩年龄为242.6±3.4Ma，外围细粒花岗闪长岩年龄为250.4±4.0Ma，岩体为多期侵入体，成矿年龄与内部似斑状花岗闪长岩能很好的吻合；地球化学分析结果显示，含矿花岗闪长岩为高钾钙碱性到钾玄岩系列，其成因类型为I型花岗岩，源区经历了明显的流体交代，结合野外地质调查显示，该期花岗岩类含大量暗色微粒包体，具有明显的岩浆底侵和混合的证据。区域上，中三叠世正处于洋壳俯冲结束向碰撞造山开始转换的阶段，可以很好的解释源区发生过俯冲板片流体的交代富集作用，而壳幔物质混合的产生机制应与俯冲板片的断离作用有关。洋壳拆沉作用是一种快速的主动的拆沉，与中三叠世岩浆活动爆发的地质事实吻合。同时，该成矿岩体显示壳幔混合成因及较高的分异程度，是成钼矿的有利条件。 |
| 英文摘要: |
| Abstract: The Lalingzaohuo molybdenum polymetallic deposit in the Qimantage metallogenic belt of Qinhai Province is a newly discovered skarn –porphyry type deposit. Detailed studies on petrology, geochronology and element geochemistry of the granodiorites suggest that they are associated with the porphyry-type mineralization. The results show that: the age of porphyritic granodiorite is 242.6 ± 3.4Ma, and the age of the peripheral fine-grained granodiorite is 250.4 ± 4.0Ma. This may suggest they are multi-phase intrusions. The mineralization age is in agreement with porphyritic granodiorites. Major and trace elements analysis shows that the ore-bearing granodiorites belong to high-K calc-alkaline to shoshonitic series, I-type with crust-mantle source which has experienced significant fluid metasomatism. Field investigations show a large number of dark xenoliths contained in the Trassic granotoids, with the evidence of magma underplating and mixing. In the middle Triassic, this area was just in the conversion stage from the oceanic subduction to collision orogeny in Eastern Kunlun, which can explain the fluid metasomatism and enrichment of the source region. The mechanism of crust-mantle mixing should be associated with the subducted slab breaking. Delamination of the oceanic crust is a quick active process which coincides with the geological fact of the outbreak of the Triassic magmatism. At the same time, the mineralization intrusions show the characteristics of crust-mantle mixing sources and a higher degree of differentiation, which are the favorable conditions for molybdenum mineralization. |
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