长江中下游成矿带及邻区Moho深度与成矿背景探讨

发布时间：2018-02-11 11:52

本文关键词： 卫星重力异常卫星磁异常莫霍面长江中下游成矿带钦杭成矿带　出处：《地质学报》2017年06期 　论文类型：期刊论文

【摘要】：长江中下游成矿带是我国最主要的铜铁金多金属成矿带之一。本文利用卫星重力数据计算布格重力异常,采用波数域迭代的Parker-Oldenburg位场迭代反演方法,通过重力数据反演获得长江中下游成矿带及邻区的三维Moho面结构,结合研究区已有的研究成果,探讨了研究区的深部构造格局。研究结果表明:研究区范围内Moho面总体从南西往北东有逐渐变浅趋势,最浅处位于长江口海域和杭州湾海域约28~29km,最深处位于大别山区约38~39km;长江中下游及邻区下方Moho面的隆起形态呈"V"字型,与地表的"V"字型构造特征相呼应,Moho面隆起的最深处位于"V"字型转折端附近,向两侧Moho面呈抬升状,北东走向的"V"字型东支隆起幅度和规模都要明显大于北西走向的"V"字型西支;卫星化极磁异常显示长江中下游成矿带的正磁异常高值集中分布在"V"字型东支的宁芜、庐枞、繁昌、怀宁等火山岩盆地;钦杭成矿带东段Moho面也明显上隆,隆起的中心沿钦杭成矿带的南侧边界断裂的东南侧线性分布。长江中下游成矿带和钦杭成矿带东段的Moho面条带状隆起带可能指示了地幔上隆、岩浆上涌并在壳幔边界处与下地壳发生底侵作用的深部边界,来自于壳、幔的深部含矿岩浆通过深大断裂等地壳薄弱点向上运移,并在适当的位置形成金属矿集区。
[Abstract]:The metallogenic belt in the middle and lower reaches of the Yangtze River is one of the most important copper, iron, gold and polymetallic metallogenic belts in China. In this paper, the Bouguer gravity anomaly is calculated by using satellite gravity data, and the Parker-Oldenburg potential field iterative inversion method in wavenumber domain is used. The three-dimensional Moho plane structure of the metallogenic belt and adjacent area of the middle and lower reaches of the Yangtze River is obtained by inversion of gravity data. The deep tectonic pattern of the study area is discussed. The results show that the Moho surface in the study area is gradually shallower from the south west to the north east. The shallowest part is located in the Changjiang Estuary and Hangzhou Bay, and the deepest in the Dabie Mountains is about 3839 km. the shape of the Moho surface in the middle and lower reaches of the Yangtze River and its adjacent areas is "V" shaped. The deepest part of the uplift of the "V" surface is located near the "V" type turning point and is uplifted to the two sides of the Moho plane. The range and scale of the "V" type eastern branch in the north-east strike is obviously larger than that in the "V" type west branch in the north-west strike. Satellite polar magnetic anomalies show that the high values of positive magnetic anomalies in the metallogenic belt of the middle and lower reaches of the Yangtze River are concentrated in the volcanic basins such as Ningwu, Luzong, Fanchang and Huining in the eastern branch of the "V" zigzag, and the Moho surface of the eastern segment of the Qinghang metallogenic belt is also obviously upwelling. The center of the uplift is linearly distributed along the southeast side of the southern boundary fault of the Qinghang metallogenic belt. The Moho noodle belt in the middle and lower reaches of the Yangtze River and the eastern segment of the Qinghang metallogenic belt may indicate the mantle uplift. The deep boundary where magma upwelled and underpenetrated with the lower crust at the crust-mantle boundary originated from the crust and mantle deep ore-bearing magma migrated upward through crustal weak points such as deep and large faults and formed metal ore concentration areas at appropriate locations.
【作者单位】：合肥工业大学资源与环境工程学院;合肥工业大学矿床成因与勘查技术研究中心;
【基金】：国家自然科学基金重大国际(地区)合作与交流项目(编号41320104003) 国家重点研发计划项目(2016YFC0600206)联合资助的成果
【分类号】：P618.2

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