高级检索

    长江中下游金属矿找矿前景与找矿方法

    Ore prospects and ore exploration methods for metal deposits in the middle and lower Yangtze River valley

    • 摘要: 提要:本文论述了长江中下游地区金属矿床的地质、地球物理和地球化学特点,提出今后深部找矿的主要对象是:找隐伏含矿岩体及有关的各类矿体,找岩体中的大型斑岩型矿床,找受岩体和五通砂岩联合控制的层状矿;讨论了地球物理和地球化学方法应用中要注意解决的几个主要问题,强调应发挥包括重力、磁法、激发极化法、电磁法、岩性探测仪及多种天然地震法和化探方法等综合方法的作用,并与地质矿床成矿规律研究密切结合;讨论了方法应用试验中要注意的几个问题。文章最后一部分是从本区大地构造的演化探讨了区域构造岩浆活动与成矿前景,认为这一地区是扬子板块与华北板块陆-陆碰撞挤压造山带及其前陆区,在岩石圈强烈挤压下形成地壳增厚和深部物质的挤出折返,使深部的高压和超高压变质岩层推到地壳浅部;深部生成的柯石英等高压超高压矿物及地幔熔融岩浆同时上侵;生成大量钙碱性岩浆并存储在中地壳部位,通过长期与中下地壳金属物质进行交换,形成矿液的集中优势,通过后期出现的张性断裂构造而进入地壳表层,再经过与围岩发生物理化学成矿作用后沉淀成矿。归纳出扬子板块与华北板块陆-陆碰撞造山带一种新的构造模式。

       

      Abstract: Abstract:This paper deals with the geological, geophysical and geochemical characteristics of ore deposits in the middle and lower Yangtze River valley and proposes the main targets of ore search at depth in the future, i.e.: hidden mineralized intrusions and related various types of orebody, large porphyry ore deposits in intrusions and stratiform deposits controlled by intrusions and the Wutong sandstone. It also discusses several main problems that should be solved in applications of geophysical and geochemical methods and emphasizes that we should bring into play the roles of integrated methods including the gravity method, magnetic method, induced polarization method, electromagnetic method and petrosonde, as well as several seismic methods and geochemical methods, which are closely combined with studies of geology and metallogenic characteristics of ore deposits. Some problems that should be paid attention to in applied tests of the methods are also discussed. Finally, the paper discusses the regional tectono-magmatic activity and metallogenic prospects from the tectonic evolution in the study region. The author thinks that: this region is the continent-continent collision-compression orogenic belt between the Yangtze plate and North China plate and its foreland area and strong lithospheric compression resulted in crustal thickening and extrusion and exhumation of deep materials, thus pushing the deep high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic rocks to the shallow crustal level; HP and UHP minerals such as coesite formed at depth and molten mantle magma intruded upward simultaneously; large amount of calc-alkaline magma was generated and stored in the middle crustal level, and a long period of material exchange between the calc-alkaline magma and metallic materials in the middle and lower crust formed concentrated ore fluids, which entered the superficial layer of the crust through tensile faults that occurred in the late stage;finally after physical and chemical Processes occurred between the ore fluids and country rocks, metallic minerals were deposited to form ore deposits. A new tectonic model in the continent-continent collisional orogenic belt of the Yangtze plate and North China plate has been summed up.

       

    /

    返回文章
    返回