Prof. Xingong Tang

Prof. Xingong Tang Yangtze University, China Research Area: Electromagnetic Exploration, Gravity Exploration, Petrophysics and Geodynamics Web: https://dqwl.yangtzeu.edu.cn/info/1024/2139.htm Tang is currently the director of the Key Laboratory of Oil and Gas Resources and Exploration Technology of the Ministry of Education (Changjiang University). He is the director of the Chinese Geophysical Society(CGS) and vice chairman of the Hubei Geophysical Society. In recent years, he is mainly engaged in teaching and researching in the direction of electromagnetic exploration,gravity exploration, petrophysics and geodynamics. He presided over 4 projects of National Natural Science Foundation of China, 1 project of CNPC Innovation Fund, and participated in "973", "863", National Natural Science Foundation of China, National Key Research and Development Program, International Cooperation Project of Ministry of Science and Technology of China, CNPC Group Corporation. He has hosted and participated in more than 30 projects including "973", "863", National Natural Science Foundation of China, National Key Research and Development Program, International Cooperation Program of National Ministry of Science and Technology, China National Petroleum Corporation, Provincial Department of Education and Horizontal Research Projects. He has published in IEEE ACCESS, Journal of Applied Geophysics, Applied Geophysics, Geophysics,Chinese Journal of Geophysics, Journal of Seismology, Petroleum Geophysical Exploration, Pure and Applied Geophysics and other academic journals and international conferences. He has published more than 110 academic papers in various academic journals and international conferences, including 18 SCI and EI indexed papers. He is a famous teaching teacher of Changjiang University and a high-end talent of Changjiang University. He has been awarded 1 first prize and 1 second prize at provincial and ministerial level, 1 special prize for teaching research achievements at university level, 1 prize for outstanding contribution to teaching, 8 authorized national invention patents and 1 US national invention patent. He has been to the United States, Canada, Japan, Spain, Greece, Germany, Brazil, Korea, France, Singapore, Australia, Norway, Denmark, Thailand and other countries to participate in scientific and technological cooperation and international academic exchanges. He is a member of European Association of Geologists and Engineers (EAGE), Society of Exploration Geophysicists (SEG), and an instructor of SEG student chapter in Changjiang University. 博士生导师。1992年和1999年分别毕业于江汉石油学院矿场地球物理（测井）专业和地球探测与信息技术专业，获学士和硕士学位，2006年毕业于北京大学地球物理学专业，获博士学位。2005年9月晋升副教授，2013年4月晋升为教授。近年来主要从事电磁法勘探、重磁勘探、岩石物理学与地球动力学方向的教学与研究。主持国家自然科学基金面上项目4项，中石油创新基金1项，主持与参与“973”、“863”、国家自然科学基金、国家重点研发计划、国家科技部国际合作项目、中石油集团公司重点攻关项目、省教育厅优秀中青年科技项目及横向科研项目等30余项。公开在《IEEE ACCESS》、《Journal of Applied Geophysics》、《Applied Geophysics》、《Geophysics》、《地球物理学报》、《地震学报》、《石油地球物理勘探》、《Pure and Applied Geophysics》等各类学术期刊和国际会议发表学术论文110余篇，其中SCI和EI收录18篇。长江大学教学名师，长江大学高端人才。先后获省部级一等奖1项，二等奖1项，校级教学研究成果特等奖1项，教学突出贡献奖1项，获得授权国家发明专利8项，美国国家发明专利1项。多次赴美国、加拿大、日本、西班牙、希腊、德国、巴西、韩国、法国、新加坡、澳大利亚、挪威、丹麦、泰国等国家参加科技合作和国际学术交流。现为中国地球物理学会（CGS）会员、欧洲地质学家与工程师学会（EAGE）会员和美国勘探地球物理学家学会(SEG)会员兼长江大学SEG学生分会指导教师。 现任“油气资源与勘探技术”教育部重点实验室（长江大学）主任。中国地球物理学会理事，湖北省地球物理学会副理事长。

Speech Title & Abstract

Title: The Effective Elastic Thickness of the Lithosphere in North China and its Geodynamic Implications

Abstract:

The strength of the lithosphere controls the spatial configuration and evolution of the lithosphere to the long-term loading. Its distribution characteristics play an important role in controlling the uplift and subsidence of the plate and the tectonic evolution of the plate boundary. The lithospheric strength can be characterized by the effective elastic thickness (Te) of the lithosphere. The effective elastic thickness reflects the comprehensive strength of the current continental lithosphere and the ability of the continental lithosphere to resist deformation under long-term ( > 1Ma ) tectonic interaction. The continental Te is mainly influenced by lithospheric thermal structure, crustal thickness, stress state and lithospheric composition. Quantitative analysis of the size and distribution of Te is important for understanding of the relationship between tectonic evolution, seismic distribution and lithospheric rheology. 

North China is located in the southeast of Eurasia plate. Since the Mesozoic, the relatively stable North China Craton has been strongly activated and reformed. The large-scale tectonic deformation such as earthquakes, lithospheric thinning, magmatic activity and basin reconstruction have occurred, resulting in obvious destruction from its original craton structure. Strong earthquakes with a magnitude of more than 7 in North China had been taken place. North China Craton is considered to be the best place and natural laboratory for studying the transformation, thinning and replacement of ancient lithosphere in the world. Therefore, it is of great scientific significance to understand the deep structural characteristics and lithospheric dynamic evolution in North China for understanding the lithospheric mechanical strength and craton destruction in North China.

In this paper, the effective elastic thickness of lithosphere in North China is calculated by the joint inversion method of admittance method and correlation function method, and its relationship with North China craton destruction, seismic activity and surface heat flow is discussed according to the Te distribution. Firstly, the correlation function method and the joint inversion method are evaluated by Bayesian inference method to verify the reliability of the joint inversion method. Then, based on the Bouguer gravity anomaly data of EIGEN-6C4 model, V19.1 terrain data and CRUST1.0 model crustal data, the Te distribution in North China is inverted. The results show that the Te value distribution in North China has obvious lateral inhomogeneity. The western Ordos block is a high value area, and the Te thickness value is about 30-50 km. The North China Plain in the middle is a low value area, and the thickness of Te is about 5-25 km. The eastern Shandong Yellow Sea block is a medium value area, and the Te thickness is about 20-50 km. The high Te value area of the North China Craton corresponds to the stable Ordos block, while the medium and low Te values correspond to the relatively active Taihang Mountain tectonic belt and Tanlu fault zone. From the relationship between Te value and surface heat flow, the area with high Te value generally corresponds to the area with low heat flow value, while the area with low Te value generally has high heat flow value, which is consistent with the general distribution feature of lithospheric thickness and surface heat flow. From the spatial distribution of Te and earthquakes, the seismic activity in North China is mainly concentrated in the middle and low value areas of Te, indicating that the area with thinner Te has poor stability and may be more conducive to the preparation and occurrence of earthquakes. Combined with the geological tectonic background and Te distribution in North China, it is considered that the comprehensive strength of lithosphere in North China is mainly affected by the deep mantle structure. The subduction of the Pacific plate and the collision between the South China block and the North China block have caused the mantle thermal dynamic activity to strongly activate and transform the lithosphere in North China, affecting the complex tectonic evolution and deformation of the lithosphere.

报告题目：华北地区岩石圈有效弹性厚度及其地球动力学意义

摘要：

岩石圈强度控制着岩石圈对长期负载的响应、空间构型和演化过程，其分布特征对地壳的隆升和沉降以及板块边界构造演化具有重要的控制作用。岩石圈强度可以用岩石圈有效弹性厚度（Te）来表征，岩石圈有效弹性厚度反映了现今大陆岩石圈的综合强度和大陆岩石圈在长期（>1Ma）构造作用下抵抗变形的能力。大陆岩石圈的有效弹性厚度主要受岩石圈热结构、地壳厚度、应力状态及岩石圈组分等综合因素的影响，通过定量分析Te值大小及分布状态, 对认识构造演化、地震分布和岩石圈流变学关系等至关重要。

华北地区位于欧亚大陆的东南部，自中生代以来，相对稳定的华北克拉通遭受了强烈的活化改造，发生了大规模的构造变形、岩石圈减薄、岩浆活动和盆地再造，致使其原有的克拉通结构遭受了明显的破坏。华北地区地质构造和沉积层结构也相当复杂，因此华北克拉通被认为是世界上研究古老岩石圈减薄、改造和置换的最佳场所和天然实验室。华北地区活动断裂丰富，地震频发，历史上曾发生过多次7级以上的强震，因此认识华北地区的深部构造特征及岩石圈动力演化，对于认识华北岩石圈力学强度、克拉通破坏机理以及防震减灾都具有重要的科学意义。

    本文采用导纳法和相关函数法联合反演，获得了华北地区岩石圈的有效弹性厚度，根据Te的分布特征探讨了其与华北克拉通破坏、地震活动性和地表热流的关系。首先采用贝叶斯推断法，对相关函数法和联合反演方法进行模型评估，验证了联合反演方法的稳定性与可靠性。以EIGEN-6C4模型布格重力异常数据、V19.1地形数据和CRUST1.0模型地壳数据为基础，反演得到了华北地区Te值分布。从反演结果看，首先华北地区Te值分布存在着明显的横向不均匀性，西部鄂尔多斯地块为高Te值区，其厚度大约为30-50 km；中部的华北平原为低值区，其厚度大约为5-25 km；鲁东黄海地块为中、高值区，其厚度约为20-50 km。华北克拉通高Te值区与稳定的鄂尔多斯地块相对应，中、低Te值则对应着构造相对活跃的太行山构造带和郯庐断裂带。其次，从Te分布与地表热流值的关系来看，Te值高的区域一般对应着热流值低的区域，而Te值低的区域其热流值也较高，这与Te与地表热流的一般分布规律一致。最后，从Te与地震的空间分布来看，华北地区的地震活动主要集中在中、低Te值区域，表明了Te较薄的地区其稳定性也较差，可能更有利于地震的孕育和发生。结合华北地区的地质构造背景，可以认为华北地区岩石圈的综合强度主要受深部地幔结构的影响，太平洋板块的俯冲作用和华南陆块与华北陆块的碰撞作用，引发的地幔热动力活动对华北地区岩石圈进行了强烈的活化改造，最终导致了华北岩石圈具有复杂构造演化和变形的动力学特征。