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High-precision modeling of tide-induced 3-D magnetic field and analysis of geomagnetic satellite orbit requirements

Science China Earth Sciences 2024年第1期67卷 165-178页

作者： Zhengyong REN Cong YANG Hongbo YAO Xu TANG Jingtian TANG Keke ZHANG Key Laboratory of Metallogenic Prediction of nonferrous metals and geological Environment Monitoring Ministry of Education Central South UniversityChangsha 410083China Hunan Key Laboratory of nonferrous Resources and geological Hazards exploration Changsha 410083China School of Geosciences and Info-Physics Central South UniversityChangsha 410083China State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao 999078China

Ground-based magnetic observatories and geomagnetic satellites can observe the induced magnetic field generated by the motion of seawater containing sodium and chlorine ions.Calculating the three-dimensional(3-D)spatial distribution of tide-induced magnetic fields(TIMF)is crucial for inverting the electrical conductivity structure of the oceanic lithosphere.It also serves as an essential basis for designing optimal geomagnetic observatories and satellite orbits.However,existing methods for simulating TIMF suffer from limitations in inaccurately modeling realistic coastlines,heterogeneous land and sea surface properties,and complex deep Earth structures,thereby the interpretational level of TIMF data is reduced.To overcome this issue,we developed a tetrahedral-based finite element method for simulating TIMF,which can efficiently approximate realistic coastlines,heterogeneous land and sea surface properties,and complex deep Earth structures.Firstly,we derived the boundary value problem for the seawater motion-induced electromagnetic field,which was solved using the vector finite element method based on tetrahedral elements.Secondly,using the latest ocean depth and seafloor sediment layer models,we constructed a 3-D conductivity model of the Earth,which includes realistic coastlines,heterogeneous land and sea conductivity distributions.We then computed the TIMF using the M_(2)tidal source as an example and validated our method by comparing it with results obtained from spherical harmonic finite element and integral equation methods.Finally,utilizing the computed high-precision M_(2),N_(2),and O1 TIMF signals,we marked global observatories capable of observing strong M_(2),N_(2),and O1 TIMF signals and predicted alternative stations suitable for tide signal observations.Additionally,we calculated TIMF at heights of 450 and 200 km for the Macao Science Satellite 1 and its subsequent satellites.The results indicate that the amplitude of the tidal-induced magnetic field at 200 km is approximately twice that at 450 km.Th

关键词： Ocean motional induction Electromagnetic induction Ocean tides Geomagnetic satellite Macao Science Satellite 1

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基于微震多参数的大规模岩体垮塌前兆特征研究

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Journal of Central South University 2024年第3期31卷 878-889页

作者：柳建新杨顺李磊潘新朋尹贤刚胡静云彭府华 Key Laboratory of Metallogenic Prediction of nonferrous metals and geological Environment Monitoring(Central South University) Ministry of EducationChangsha 410083China Hunan Key Laboratory of nonferrous Resources and geological Hazard exploration Changsha 410083China School of Geosciences and Info-Physics Central South UniversityChangsha 410083China Changsha Institute of Mining Research Co. Ltd.Changsha 410012China

微震监测技术能进行工程岩体失稳垮塌前兆特征的辨识和分析,对于地质灾害预警防控具有重要意义。本文基于已有室内岩石受压损伤破坏声发射实验规律,通过开展现场微震多参数定量分析,探究了柿竹园矿山6·21大爆破诱发山体滑移垮塌的前兆... 详细信息

微震监测技术能进行工程岩体失稳垮塌前兆特征的辨识和分析,对于地质灾害预警防控具有重要意义。本文基于已有室内岩石受压损伤破坏声发射实验规律,通过开展现场微震多参数定量分析,探究了柿竹园矿山6·21大爆破诱发山体滑移垮塌的前兆特征。大爆破诱发微震事件的b值和空间分形维数表现出下降趋势,b值急剧下降和分形维数降到最低可作为工程岩体失稳垮塌的前兆特征。此外,能量指数和累计视体积的变化可以分别表征应力和应变的变化。能量指数快速下降和累计视体积持续增加的组合特征反映了岩体的失稳状态。经过多个失稳破坏阶段后岩体发生最终的失稳垮塌。该案例表明微震监测能为工程岩体失稳垮塌的预警和防控提供重要信息,也为涉及爆破作业的诸多地质工程活动的安全监测提供了参考。

关键词：微震监测岩体垮塌前兆特征预警

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exploration and Practice of“Guiding Interactive”Teaching in Advanced Geochemistry Courses from the Perspective of Constructivist Theory

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Journal of Contemporary Educational Research 2024年第1期8卷 52-57页

作者： Lei Liu Chunming Liu Weijian Zhou Key Laboratory of Metallogenic Prediction of nonferrous metals and geological Environment Monitoring Ministry of Education in Central South UniversityChangsha 410083Hunan ProvinceChina School of Geosciences and Info-Physics Central South UniversityChangsha 410083Hunan ProvinceChina Hunan Vocational College of Engineering Changsha 410151Hunan ProvinceChina

The construction of geochemical disciplines has brought new vitality to the development of traditional geology.In the new round of“Double First-Class”discipline construction at Central South University,the course of Advanced Geochemistry has effectively stimulated students’interest in learning and further improved their scientific thinking and research innovation skills through the implementation of“Guiding Interactive”teaching reform measures,which has important theoretical significance and practical value.

关键词： Geochemistry Advanced Geochemistry Teaching reform Guiding Interactive

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Dynamic prediction of landslide life expectancy using ensemble system incorporating classical prediction models and machine learning

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Geoscience Frontiers 2024年第2期15卷 202-219页

作者： Lei-Lei Liu Hao-Dong Yin Ting Xiao Lei Huang Yung-Ming Cheng Key Laboratory of Metallogenic Prediction of nonferrous metals and geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South UniversityChangsha 410083China College of Civil Engineering and Architecture Wenzhou UniversityWenzhou 325035China Key Laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation of zhejiang province Wenzhou 325035China Wenzhou Key Laboratory of Traffic Piezoelectric Engineering Technology Wenzhou 325035China zhejiang International Science and Technology Cooperation Base of Ultra-soft Soil Engineering and Smart Monitoring Wenzhou 325035China School of Civil Engineering Qingdao University of TechnologyQingdao 266033China

With the development of landslide monitoring system,many attempts have been made to predict landslide failure-time utilizing monitoring data of displacements.Classical models(e.g.,Verhulst,GM(1,1),and Saito models)that consider the characteristics of landslide displacement to determine the failuretime have been investigated extensively.In practice,monitoring is continuously implemented with monitoring data-set updated,meaning that the predicted landslide life expectancy(i.e.,the lag between the predicted failure-time and time node at each instant of conducting the prediction)should be re-evaluated with time.This manner is termed“dynamic prediction”.However,the performances of the classical models have not been discussed in the context of the dynamic prediction yet.In this study,such performances are investigated firstly,and disadvantages of the classical models are then reported,incorporating the monitoring data from four real landslides.Subsequently,a more qualified ensemble model is proposed,where the individual classical models are integrated by machine learning(ML)-based meta-model.To evaluate the quality of the models under the dynamic prediction,a novel indicator termed“discredit index(b)”is proposed,and a higher value of b indicates lower prediction quality.It is found that Verhulst and Saito models would produce predicted results with significantly higher b,while GM(1,1)model would indicate results with the highest mean absolute error.Meanwhile,the ensemble models are found to be more accurate and qualified than the classical models.Here,the performance of decision tree regression-based ensemble model is the best among the various ML-based ensemble models.

关键词： Dynamic prediction Landslide life expectancy Machine learning Ensemble system

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Time domain method for calculating free field motion of a layered half-space subjected to obliquely incident body waves

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Earthquake Engineering and Engineering Vibration 2007年第2期6卷 191-196页

作者：李山有朱海燕高淑芳 Institute of Engineering Mechanics China Earthquake Administration Earthquake Administration of Fujian province No.703 Team of bureau of geological exploration of nonferrous metals of Heilongjiang province

In numerical simulation of wave scattering under oblique incident body waves using the finite element method, the free field motion at the incident lateral boundary induced by the background layered half-space complicates the computational area. In order to replace the complex frequency domain method, a time-domain method to calculate the free field motion of a layered half-space subjected to oblique incident body waves is developed in this paper. The new method decouples the equations of motion used in the finite element method and offers an interpolation formula of the free field motion. This formula is based on the fact that the apparent horizontal velocity of the free field motion is constant and can be calculated exactly. Both the theoretical analysis and numerical results demonstrate that the proposed method offers a high degree of accuracy.

关键词： layered half-space wave scattering obliquely incidence artificial botmdary explicit finite element method Snell law

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Magma source and tectonic setting of the Dunde granite in the Western Tianshan:constraints from geochronology,geochemistry,and Sr–Nd–Hf isotopes

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地球化学学报(英文) 2023年第5期42卷 879-894页

作者： Zhaode Xia Haibo Ding Yanjiao Ru School of Earth Science and Resources Chang’an UniversityXi’an 710054ShaanxiChina The Third geological Branch Xinjiang Geological and Mineral BureauKuerleXinjiang 841000China Geophysical and Geochemical exploration Corporation Bureau of Geological Exploration for Nonferrous Metals in Northwest ChinaXi’an 710068ShaanxiChina

The Dunde iron-zinc polymetallic deposit is one of large iron deposits occurred in the Awulale Metallogenetic Belt,Western Tianshan(NW-China).This study reports new geochronology and geochemistry for granite in the Dunde mining area in order to constrain the tectonicmagmatic activities and metallogenesis of this region.Granites in the southwest of Dunde mining area are mainly syenogranites intruded into volcanics of the Dahalajunshan Formation in the Early Carboniferous,and they are far from the area where ore bodies and mineralized altered rocks are widely developed.LA-ICP-MS U–Pb zircon dating indicates that Dunde syenogranite was at 306.8±1.0 Ma,which could constrain the upper limit of metallogenic age for this deposit.The Dunde granites are high SiO_(2)(73.41–80.07 wt%),high differentiation index(D.I.=89.7–95.0),weakly peraluminous to metaluminous(A/CNK=0.94–1.08),and they are enriched in LILE and LREE and depleted in Eu,Ba,Sr and P_(2)O_(5),indicating that they belong to highly fractionated Ⅰ-type granite.Based on εHf values(+9.2 to+10.5)for zircon and high εNd(-t)values(+4.7 to+5.8)for whole-rock,and the two-stage model ages for 601–735 Ma,suggest that the magma source could be the juvenile lower crust.Combined with regional geological setting,the 306.8 Ma Dunde granites are formed in post-collision extensional tectonic setting.

关键词： Granite Geochemistry Magma source Tectonic setting Dunde deposit Western Tianshan

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Geochronological Framework of Paleoproterozoic Intrusive Rocks and Its Constraints on Tectonic Evolution of the Liao-Ji Belt,Sino-Korean Craton

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Journal of Earth Science 2021年第1期32卷 8-24页

作者： Jingsheng Chen Zhongzhu Yang Dexin Tian Dehe Xing Lidong Zhang Fan Yang Bin Li Miao Liu Yi Shi Chao Zhang Shenyang geological Survey Center of China geological Survey Shenyang 110034China Non-Ferrous metals geological exploration bureau of zhejiang province Shaoxing 312000China

The Liao-Ji belt(LJB)is one of the Paleoproterozoic tectonic belts located in the North China Craton.A large number of Paleoproterozoic meta-volcanic-sedimentary rock and intrusive rocks are preserved in the LJB,which provide reliable carriers for the study of the Paleoproterozoic tectonic evolution of the North China Craton.The Paleoproterozoic intrusive rock in the LJB can be divided into the following seven types:syenogranite,quartz diorite,porphyry granite,migmatitic granite,sye-nite,metamorphic plutonic rock,and granitic pegmatite and metagabbro(metamorphic diabase).Zir-con U-Pb dating of 15 samples from intrusive rocks was carried out in this study.The chronology framework of the Paleoproterozoic intrusive rock in the LJB was established,and the magmatism of intrusive rocks can be divided into three stages:2200 to 2110,2010 to 1937,1900 to 1820 Ma.The chronological framework supported the evolution model of subduction accretionary arc-continent colli-sion in the LJB effectively.Combined with previous geochemical work,it was a passive continental margin environment at approximately 2200 Ma,and then transformed into and active continental margin.The bimodal intrusive rocks between 2180 and 2150 Ma indicated a back-arc tension envi-ronment which lasted until approximately 2110 Ma with a large number of basic intrusive rocks.And then the back-arc basin began to contract and the magmatic activities were reduced,with only a small number of intrusive rock activities occurring at approximately 2040,2010 and 1937 Ma.After the orogenic activities,there was a post-orogenic extension stage from 1900 to 1820 Ma.Magmatic activi-ties caused by the environmental extension started to occur more frequently and subsequently resulted in the large-scale intrusive rocks in eastern Liaoning.

关键词： Liao-Ji belt Paleoproterozoic intrusive rocks geochronological framework tectonic evolution

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Crustal Thermo-Structure and Geothermal Implication of the Huangshadong Geothermal Field in Guangdong province

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Journal of Earth Science 2023年第1期34卷 194-204页

作者： Zhicai Xiao Shuai Wang Shihua Qi Jian Kuang Min Zhang Hailong Li School of Applied Technology Lijiang Teachers CollegeLijiang674199China School of Earth Resources China University of GeosciencesWuhan430074China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan430078China No.935 geological Brigade Geology Bureau for Nonferrous Metals of Guangdong ProvinceHuizhou516000China SinoProbe Center-China Deep exploration Center Chinese Academy of Geological SciencesBeijing100037China

Dense distribution of granites and surrounding hot springs, the high anomalous heating rates of geothermal fluids and the high geothermal gradients in shallow crust in Southeast China are revealed by previous geothermal explorations. However, there have always been debates on the genesis of geothermal anomalies of Southeast China. It is imperative to look into the genesis mechanism of geothermal anomalies through selecting a typical geothermal field, and constructing fine crustal thermostructure. In this study, in-depth excavation is implemented for the previous data of geophysical exploration and deep drilling exploration in the Huangshadong area. We synthetically analyze the results of radioactive heat productions(RHPs), thermophysical properties of rocks and audio-frequency magnetotellurics(AMT) sounding. This study concludes that the coefficient of radioactive heat generation(RHG) of crustal rocks and conduction heat of concealed granites is the main formation mechanism of geothermal anomalies of South China, where occurs a Great Granite province. There is a regional indicating implication for the genesis of geothermal anomalies, taking the Huangshadong geothermal field as a typical example. It is also an important reference to guide the exploration, evaluation, development and utilization of geothermal resources in this region.

关键词： Huangshadong geothermal field thermo-structure geothermal genesis radioactive heat geothermal exploration

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Sulphide melt evolution in upper mantle to upper crust magmas,Tongling, China

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Geoscience Frontiers 2014年第2期5卷 237-248页

作者： Yilun Du Xinlong Qin Calvin G.Barnes Yi Cao Qian Dong Yangsong Du School of Earth Sciences and Resources China University of Geosciences (Beijing) nonferrous metals geological exploration bureau of East China in Jiangsu province Department of Geosciences Texas Technology University

Sulphide inclusions, which represent melts trapped in the minerals of magmatic rocks and xenoliths, provide important clues to the behaviour of immiscible sulphide liquids during the evolution of magmas and the formation of NieCueFe deposits. We describe sulphide inclusions from unique ultramafic clots within mafic xenoliths, from the mafic xenoliths themselves, and from the three silica-rich host plutons in Tongling, China. For the first time, we are able to propose a general framework model for the evolution of sulphide melts during the evolution of mafic to felsic magmas from the upper mantle to the upper crust. The model improves our understanding of the sulphide melt evolution in upper mantle to upper crust magmas, and provides insight into the formation of stratabound skarn-type FeeCu polymetallic deposits associated with felsic magmatism, thus promising to play an important role during prospecting for such deposits.

关键词： Ore petrology Intermediate-acidic intrusion Lower Yangtze River Valley Sulfide inclusions Upper mantle to upper crust

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Hydrothermal mineralization on Dengfuxian W-Sn-Pb-Zn orefield, SE China

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Acta Geologica Sinica(English Edition) 2017年第S1期91卷 243-244页

作者： XIONG Yiqu SHAO Yongjun ZHENG Minghong ZHOU Haodi WU Shichong ZHU Haofeng Key Laboratory of Metallogenic Prediction of nonferrous metals and geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South University Non-Ferrous metals and Nuclear Industry geological exploration bureau of Guizhou 416 geological Team Bureau of Geology and Mineral Exploration and Development of Hunan Province

1 Introduction Dengfuxian orefield lies at the intersection of the Qin-Hang Combined Zone(QCZ)and the Nanling Metallogenic,and comprises Xiangdong W-Sn deposit(Also known as Dengfuxian W-Sn deposit),Jiguanshi

关键词： Pb Sn Hydrothermal mineralization on Dengfuxian W-Sn-Pb-Zn orefield Zn

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