地学前缘 ›› 2019, Vol. 26 ›› Issue (6): 309-319.DOI: 10.13745/j.esf.sf.2019.11.20

• 学术争鸣 • 上一篇    下一篇

板块运动的机制与动力来源学术争鸣

万天丰,李三忠,杨巍然,梁光河,毛小平,刘银河,於文辉,陈志耕,丁卫平, 胡宝群,付虹,方曙,唐春安,莫宣学   

  1. 1. 中国地质大学(北京), 北京 100083
    2. 中国海洋大学, 山东 青岛 266100
    3. 中国地质大学(武汉), 湖北 武汉 430074
    4. 中国科学院 地质与地球物理研究所, 北京 100029
    5. 中国石油勘探开发研究院, 北京 100083
    6. 河北地质大学, 河北 石家庄 050031
    7. 中化地质矿山总局 地质研究院, 北京 100101
    8. 东华理工大学, 江西 南昌 330013
    9. 云南省地震局, 云南 昆明 650224
    10. 内蒙古自治区第十地质矿产勘查开发院, 内蒙古 赤峰 024005
    11. 大连理工大学, 辽宁 大连 116024
  • 收稿日期:2019-06-01 修回日期:2019-11-10 出版日期:2019-11-30 发布日期:2019-11-30
  • 通讯作者: 毛小平(1965—),男,副教授,矿产普查与勘探专业,主要从事油气勘探与构造研究。
  • 作者简介:万天丰(1938—),男,教授,博士生导师,构造地质学专业,主要从事构造地质、大地构造学的基础理论与应用研究。E-mail:wan-tianfeng@163.com
  • 基金资助:

    国家重点研发计划“深地资源勘查开采”重点专项项目“北方增生造山成矿系统的深部结构与成矿过程”(2017YFC0601204);国家自然科学基金项目(41472069);广西干热岩选区预测与分级评价(2019016110,2019016207);科学技术部国际合作项目(2008DF20700)

Academic controversy on the mechanism and driving forces of plate movement

WAN Tianfeng,LI Sanzhong,YANG Weiran,LIANG Guanghe,MAO Xiaoping,LIU Yinhe,YU Wenhui,CHEN Zhigeng,DING Weiping,HU Baoqun,FU Hong,et al   

  1. 1. China University of Geosciences(Beijing), Beijing 100083, China
    2. Ocean University of China, Qingdao 266100, China
    3. China University of Geosciences(Wuhan), Wuhan 430074, China
    4. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
    5. Research Institute of Petroleum Exploration & Development, Beijing 100083, China
    6. Hebei GEO University, Shijiazhuang 050031, China
    7. Geology Institute of China Chemical Geology and Mine Bureau, Beijing 100101, China
    8. East China University of Technology, Nanchang 330013, China
    9. Yunnan Earthquake Prevention and Disaster Reduction, Kunming 650224, China
    10. Inner Mongolia Tenth Geological Mineral Exploration and Development Co., Ltd., Chifeng 024005, China
    11. Dalian University of Technology, Dalian 116024, China
  • Received:2019-06-01 Revised:2019-11-10 Online:2019-11-30 Published:2019-11-30

摘要:

目前人类对地球的认识仍很肤浅,无论国外还是国内对于地球动力学问题仍在探索过程中,Science杂志2005年公布的125个重大科学问题中的第10个问题是“地球内部是如何运行的”,提出地球动力来源还尚未解决。 2017年出版的《中国学科发展战略——板块构造与大陆动力学》认为板块构造理论虽然取得了巨大成功,但该学说依然存在其形成以来就存在的难题,即板块动力、板块起源及板块上陆三大问题,驱动板块运动的动力机制是最为重要的问题,也是亟待解决的问题。
研讨会分两个环节,一是主要观点报告环节,二是讨论争鸣环节。
在报告环节,涉及动力机制的主要有5位报告人,分别阐述了他们的主要观点。梁光河提出了新大陆漂移说,通过大量证据分析认为传统的海底扩张驱动大陆漂移的模式存在很多问题,很多地质和地球物理观测事实说明持续推动大陆漂移的动力不是海底的持续扩张,而是大陆板块后下方持续的岩浆上涌推动大陆板块向前漂移,那是一个自发的连锁反应。万天丰认为传统的海底扩张传送带模式很难解释大陆板块漂移速度远远大于地幔对流速度这个问题,提出了陨击说。陨石撞击诱发地幔底劈推动大陆板块运动这个新的驱动模式。唐春安提出了地球龟裂说,认为地球内部热能的积累与释放,使得地质历史上岩石圈地幔具有冷热交替的周期。毛小平分析认为,目前所提出的地球动力中,只有周向应力具有足够数量级的应力,可以推动板块运动;周向应力在岩石圈薄弱处释放从而产生地壳相对运动;长期以来解释不了的“地壳异常压力”其实就是周向应力,而可独立于重力的构造力、碰撞力并不存在。
在讨论争鸣环节,大家针对地壳运动的动力来源自由发言。梁光河指出万天丰提出的陨石撞击可以较好地解释超大陆裂解的初始动力,但不同意陨石撞击可以提供持续的大陆漂移的动力,以印度板块的北漂为例,因为地幔的巨大黏滞阻力,需要无数个陨石定点撞击印度板块后面才可能持续推动印度板块漂移。唐春安提出地球的锅盖效应,因此上地幔具有冷热周期,在热周期地壳才会大规模漂移,按照力学机制,大洋中脊和转换断层不可能是海底扩张产生的,应该是大陆漂移拉开产生的断裂系统。最后杨巍然总结发言,认为陨石撞击是一个重要因素,地球上的构造运动都可以归结为开合运动,海底扩张和大陆漂移都是存在的,地体构造也是科学的。研讨会取得的共识是:大陆的确存在大规模水平运动,传统的地幔对流传送带驱动模式存在很多与观测事实不符的问题,需要重新认识驱动机制和驱动力的问题,对板块俯冲问题多数持怀疑甚至反对的观点。其驱动力应该来自重力和地球内部热力,但它们之间是如何相互作用的,仍需要进行更深入的研究。

关键词: 地壳运动, 大地构造, 地球动力学, 岩石圈, 板块运动, 地槽学说

Abstract:

The present day human understanding of the Earth is still superficial, and the issue of geodynamics is still exploratory both foreign or domestically. The 10th major scientific question, out of total of 125, identified by the Science magazine in 2005 was “How does the Earths interior work”, noting that the source of the earths driving force had not yet been resolved. The book, “Chinese disciplinary Developmental strategy-Plate Tectonics and continental Dynamics” published in 2017, believed that although the plate tectonics theory has achieved great success, the theory still has three major inherent problems, namely the plate driving force, plate origin and plate theory when applied to continents. Among them, the driving mechanism of plate motion is the most important and urgent problem to be solved.
The seminar is divided into two parts: reporting of main views, and discussion of the controversy. In the reporting section, five speakers expound their views on the driving force mechanism. Liang Guanghe puts forward a new theory of continental drift. Through analyses of a wealth of data, he believes that there are many problems in the traditional model of seafloor spreading being the driving force. He cites many geological and geophysical observations that the persistent driving force for continental drift is not the sustained seafloor spreading but continuous magma upwelling behind and beneath the continental plate in a spontaneous chain reaction. Wan Tianfeng proposes a new driving mode based on meteorite impact theory, believing that the traditional seafloor spreading conveyor model cannot explain why the continental drift speed is much larger than the mantle convection velocity. He hypothesizes that the meteorite impact induces mantle diapirs to promote continental plate movement. Tang Chunan puts forth an Earth cracking theory. He believes that the accumulation and release of thermal energy inside the Earth make the lithospheric mantle going through alternating hot and cold cycles in the geological history. According to Mao Xiaopings analysis, only the circumferential-direction stress is strong enough to be the proposed earth driving force that promotes the plate motion, that the circumferential-direction stress is released at the weak point of the lithosphere to promote the relative movement of the crust, and that the long time unexplained “crustal abnormal pressure” is in fact circumferential-direction stress, but the tectonic force and collision force that can be independent of gravity do not exist.
During discussion and contention, everyone is free to speak on the driving force of crustal movement. Liang Guanghe acknowledges that the meteorite impact proposed by Wan Tianfeng may better explain the initial driving force of the supercontinent break-up, but he does not agree that meteorite impact can provide the driving force for continuous continental drift. Because, he explains, taking the northward drift of the Indian Plate as an example, the huge viscous resistance of the mantle requires numerous meteorites to hit the back of the Indian plate at fixed points before the Indian plate can continue to drift. Tang Chunan points to the Earths pot-cover effect: the upper mantle has a cold and hot period, and the crust will drift on a large scale during the hot period. According to the mechanical mechanism, the mid-ocean ridge and transform fault cannot be caused by seafloor spreading, but should be a fracture system caused by continental drift. Finally, Yang Weiran concludes that meteorite impact is an important factor; tectonic movements on the earth can be attributed to opening-closing movements; and seafloor spreading and continental drift exist, and terrane tectonics is scientific.
The consensus reached at the seminar is that there are indeed large-scale horizontal movements in the mainland continent, but the traditional mantle convection conveyor belt drive model has many problems in its inconsistency with the observation facts, therefore it is necessary to re-recognize the driving mechanism and the driving force. Most of the seminar participants express doubts or even opposition to the plate subduction argument. They consider the driving force should come from gravity and internal heat of the Earth, and more in-depth researches are required to understand their interactions.

Key words: crustal movement, geotectonics, geodynamics, lithosphere, plate movement, geosyncline theory

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