地学前缘 ›› 2018, Vol. 25 ›› Issue (6): 20-41.DOI: 10.13745/j.esf.sf.2018.11.19

• 岩石探针与全球构造 • 上一篇    下一篇

同位素填图与深部物质探测(Ⅱ):揭示地壳三维架构与区域成矿规律

侯增谦,王涛   

  1. 1. 自然资源部深地动力学重点实验室, 北京 100037
    2. 北京离子探针中心, 北京 100037
    3. 中国地质科学院 地质研究所, 北京 100037
  • 收稿日期:2018-10-10 修回日期:2018-11-09 出版日期:2018-11-30 发布日期:2018-11-30
  • 作者简介:侯增谦(1961—),男,中国科学院院士,矿物学、岩石学、矿床学专业,主要从事矿床学研究。E-mail:houzengqian@126.com
  • 基金资助:
    国家重点研发计划项目(2016YFC0600310,2017YFC0601301);中国科学院A类战略性先导科技专项(XDA20070304);国家自然科学联合基金项目(U1403291)和国际合作基金项目(41320104004);中国地质调查局项目(DD20160123,DD20160345,DD20160024)

Isotopic mapping and deep material probing (Ⅱ):imaging crustal architecture and its control on mineral systems.

HOU Zengqian,WANG Tao   

  1. 1. Key Laboratory of the Deep Earth Geodynamics, Ministry of Natural Resources, Beijing 100037, China
    2. Beijing SHRIMP Center, Beijing 100037, China
    3. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China
  • Received:2018-10-10 Revised:2018-11-09 Online:2018-11-30 Published:2018-11-30

摘要: 地球深部是大规模成矿作用的“驱动机”、“供应源”和“传输带”。深入揭示深部物质组成与分布、物质循环与能量转换、三维架构与动力过程,对理解成矿作用至关重要。岩浆岩“探针”及区域同位素(如全岩Nd、锆石Hf)填图是探索深部物质组成与演化过程的主要手段,可以探测地壳深部物质组成的三维架构,揭示新生地壳/古老地壳/再造地壳的空间分布与时空演变,从而为提升区域成矿规律认识提供深部物质制约证据,有助于成矿潜力的定量半定量评价及其区域成矿预测。文章重点总结和探讨了岩浆岩全岩Nd同位素和锆石Hf同位素区域填图在解决地壳三维架构与成矿规律方面的应用成果,深入探讨了巨量岩浆岩发育的深部驱动机制及其成矿制约,对比总结了不同类型造山带(如中亚增生造山带、青藏高原碰撞造山带、秦岭复合造山带等)和不同克拉通的地壳深部组成结构与成矿制约特色。研究显示:不论是什么造山带和克拉通,深部年轻地壳分布区制约了铜金、铜镍等矿床的形成分布;古老地壳控制了大型钼矿、铅锌矿、稀有金属等矿产;两者过渡地带常常发育铁矿等。这些研究不仅揭示了区域成矿规律,而且对成矿预测与成矿潜力评价有潜在的应用价值,有可能成为成矿规律研究特别是深部物质探测及成矿背景研究的新方向。

关键词: 岩石探针, 同位素填图, 深部物质组成, 三维架构, 区域成矿

Abstract: The deep Earth is the “engine”, “supply source” and “transfer belt” for large-scale mineralization. The mineralization process, therefore, is best understood by revealing deep material composition and distribution, deep material cycle and energy conversion, and deep crustal three-dimensional structure and dynamic process. Magmatic rock “probe”, or lithoprobe, and regional isotopic mapping (such as whole rock Nd and in situ zircon Hf isotope) are the main techniques used for exploring compositional and evolutionary processes of deep Earth. These probing techniques can detect deep crustal composition and three-dimensional architecture to reveal the spatial distribution and temporal evolution of the new, old and recycled crust, providing deep Earth constrains on regional metallogenic regularity to assist quantitative and semi-quantitative evaluation of metallogenic potential and improve regional prediction model. Here, we examined magmatic whole-rock Nd and zircon Hf isotopic mapping in solving deep crustal three-dimensional structure and its control on metallogenesis, and discussed the developmental mechanism of massive magmatic rock deep inside Earth and its metallogenic constraints. We also examined the deep crustal architecture and its control on mineralization of different-types of orogens (e.g., the Central Asian accretionary orogenic belt, the Qinghai-Tibet plateau collisional orogen and the Qinling composite orogen) and several cratons. The results show that the distribution of copper, gold, copper and nickel deposits is controlled by the distribution of juvenile crust independent of orogenic belt and craton types. They also show that large-scale molybdenum and lead-zinc ores as well as rare metals and other minerals occur in old crust, and iron ores often developed in the transition zone between the old and new crust. In addition to revealing the regional metallogenic rules, our findings may applicable in metallogenic prediction and metallogenic potential evaluation, an expected new direction for studying regional metallogenic regularity including especially studies of detection and metallogenic background of deep crustal material.

Key words:  lithoprobe, isotopic mapping, deep material composition, three-dimensional structure, regional metallogenesis

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