摘要
岩浆侵入构造系统属地球科学复杂性理论和成矿系统理论的前沿研究。本文在总结构造岩相学填图理论和应用研究基础上,建立了岩浆侵入构造系统的构造岩相学研究内容和方法。在研究内容上从物质域-时间域-空间域,厘定构造岩相学格架、基本填图单位和独立填图单元,对岩浆侵入构造系统物质-时间-空间分布规律进行圈定。在研究层次上,遵循大地构造岩相学与成矿带构造、区域构造岩相学与矿集区构造、矿田构造岩相学与矿田构造、矿床构造岩相学与矿床构造、矿体构造岩相学与矿体构造等五个研究尺度,对岩浆侵入构造系统与成矿系统进行研究,探索岩浆侵入构造系统形成的动力学机制与金属超常富集规律。研究方法包括三维构造岩相学综合填图技术系列、构造岩相学专题研究方法和深部隐伏构造岩相学填图专题方法。以云南东川铁铜金矿集区、智利月亮山IOCG矿集区和海南丰收钨铯多金属矿床为例,论述了构造岩相学填图理论和新技术方法、岩浆侵入构造系统和找矿预测应用效果。在研究智利侏罗纪-白垩纪火山岩和侵入岩的构造岩相学特征基础上,认为白垩纪富磷灰石铁质超基性岩-铁质安山岩-铁质粗安岩等岩石组合,为IOCG成矿系统根部相和寻找IOCG矿集区的勘查标志。在月亮山IOCG矿床深部,新圈定了深部隐蔽岩浆热液角砾岩构造系统,认为电气石岩浆热液角砾岩筒为岩浆热液角砾岩构造系统中心相,赤铁矿电气石化蚀变岩属岩浆叠加热液蚀变中心相,为IOCG成矿系统的热液叠加成矿中心相标志。将云南东川和邻区新太古界-元古宙火山喷发-岩浆侵入事件序列划分为7个火山喷发-岩浆侵入旋回,建立了三大类元古宙岩浆侵入构造系统和构造岩相学分带样式,包括中元古代因民期-落雪期火山喷发-岩浆侵入构造系统、格林威尔期岩浆叠加侵入构造系统和晋宁期岩浆侵入构造系统等。通过大比例尺地面和矿山井巷工程的系列构造岩相学填图,揭示了东川铁铜金多金属矿集区内成矿系统类型的多样性,东川铁铜金多金属矿集区内成矿模型为"9层立交地铁式",探索了成矿系统深部结构,为东川铁铜金多金属矿集区深部(5000 m以浅)构造岩相学填图和找矿预测、资源高效利用和生态环境保护等提供了依据。
Magmatic intrusive tectonic system is one of the frontiers in the complex geosystems and in metallogenic systems. On the bases of his researches, the author proposes an objective methodology of lithofacies-mapping for magmatic intrusive tectonic system. Research objectives of magmatic intrusive tectonic system include determination the framework of tectonic lithofacies, basic mapping units of tectonic lithofacies, and independent units of tectonic lithofacies, and deciphering the distribution of magmatic intrusive tectonic system in material, time, and space dimensions. In theoretical aspects, recognition of tectonic lithofacies in scales ranging from metallogenic zone,ore-concentrated area, ore-field, deposit, and individual orebody will contribute to the understanding of the relationship between magmatic intrusive tectonic system and mineralization system, and their dynamic processes. Tectonic lithofacies-mapping for magmatic intrusive tectonic system includes comprehensive three dimensional mapping of tectonic lithofacies, especially the tectonic lithofacies at depth. Method of tectonic lithofacies-mapping for magmatic intrusive tectonic system is illustrated by case studies of the Dongchuan Fe-Cu-Au ore-concentrated area in Yunnan,China, and the Moon Mountain IOCG ore-concentrated area in Chile, the Fengshou W-Cs-Rb-polymetallic metals deposit in Hainan, China. It was believed that the Cretaceous Fe-rich andesite, trachyandesit, and ultrabasic rocks could be the root lithofacies of the IOCG mineralization system and can be used as exploration indication for IOCG deposits in Chile. Some of deep-buried tectonic systems of magmatic hydrothermal breccia were delineated by drill-logging mapping of tectonic lithofacies. It is considered that the tourmaline magmatic hydrothermal breccia indicates the center-focusing facies of magmatic hydrothermal breccia, whereas the hematite-tourmaline altered rocks represents the center lithofacies of magmatic superimposed hydrothermal alteration, and the center lithofacies of the IOCG mineral system. Six cycles of igneous activities in the period of the Neo-Archean to Proterozoic have been recognized in Dongchuan and adjacent areas, and three types of magmatic intrusive tectonic system and associated tectonic lithofacies have been established. The large-scale surface and underground tectonic lithofacies mapping revealed the diversity of metallogenic system in the Dongchuan Fe-Cu-Au ore-concentrated area. The results provide the basis for deep prospecting and exploitation of up to 5000 m deep, high-efficient utilization of resources, and ecosystem and environment protection in the Dongchuan Fe-Cu-Au ore-concentrated area.
作者
方维萱
FANG Weixuan(China Nonferrous Metals Resource Geology Survey, Beijing 100012, China;Beijing Institute of Geology for Mineral Resources, Beijing 100012, China)
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2019年第3期473-506,共34页
Geotectonica et Metallogenia
基金
科技部科技支撑项目(2006BAB01809)
科技部转制科研院所专项资金项目(2011EG115022、2013EG115018、2014EG115019)
国土资源部公益性行业科研专项(201511016-1)联合资助
