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Facies development and sedimentology of the Middle Miocene carbonates of the Raghama Formation, northeastern Saudi Arabia

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Acta Geochimica 2024年第1期43卷 87-96页

作者： Mansour H.Al-Hashim Abdelbaset S.El-Sorogy Meshal Wadani Department of Geology and geophysics College of ScienceKing Saud University2455Riyadh 11451Saudi Arabia

Ragahama Formation comprises a siliciclastic continental deposits followed by marine carbonates, representing prograding alluvial fans from adjacent high hinterlands seaward into lagoons and fringing reef environments. The present work aimed to document the facies development and sedimentology of the Raghama carbonates exposed along the eastern coastal plain of the Red Sea, northwestern Saudi Arabia. Four stratigraphic sections were measured and sampled(D1–D4) and thin sections and major and trace element analyses were prepared and applied for petrographic and geochemical approaches. The carbonates were subdivided into three successive fore-reef, reef-core, and back-reef depositional facies. Sandy stromatolitic boundstone, microbial laminites, dolomitic ooidal grainstone, bioclastic coralline algal wackestone, sandy bioclastic wackestone, and coral boundstones were the reported microfacies types. Petrographic analysis reveals that the studied carbonates were affected by dissolution, dolomitization, and aggrading recrystallization, which affects both the original micrite matrix and grains or acts as fracture and veinlet filling leading to widespread vuggy and moldic porosity. No evidence of physical compaction, suggesting rapid lithification and recrystallization during early diagenesis and prior to substantial burial and intensive flushing by meteoric waters. Most of the original microstructure of corals were leached and destructed. This is indicated by the higher depletion in Sr and Ca levels and increase in Mg,Na, Fe, and Mn levels, especially in section D1, in comparison with the worldwide carbonates.

关键词： Raghama Formation Miocene Diagenesis Geochemistry Saudi Arabia

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Seismicity and Seismotectonics of Jeddah-Makkah Region, West-Central Saudi Arabia

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Journal of Earth Science 2015年第5期26卷 746-754页

作者： Mohammed Fnais Abdullah Al-Amri Kamal Abdelrahman Enayat Abdelmonem Sherif El-Hady Geology & geophysics Dept. College of Science King Saud University Seismology Dept. National Research Institute of Astronomy and Geophysics geophysics Dept. College of Earth Sciences King Abdul Aziz University

Jeddah-Makkah regionis have been suffering from earthquake crisis where some moderate to destructive earthquakes have been recorded. These earthquake activities are oriented along major faults or clustered in certain spots. Moreover, these earthquake events have annual recurrence periods, so the identification of these seismogenic source zones is of utmost importance for mapping the most hazardous localities which should be avoided in the future urban planning. Historical and instrumental earthquakes have been collected from national and international data centers and unified in catalogue. The existence of microearthquakes inland suggests that there is a significant level of tectonic activity at away from the axial trough of the Red Sea. Then, seismogenic source zones have been defined depending on the major tectonic trends; distribution of earthquake epicenters, seismicity rate（a ＆ b- values） and fault plane solution of major earthquakes. It is concluded that Jeddah-Makkah region is affected by the outlined five seismogenic source zones; three of these zones aligned of the main Red Sea axial trough（southwestern Jeddah, western Jeddah, and northwestern Jeddah zones）, while the other two zones are located in the land area of the region（Thewal-Rabegh and Jeddah-Makkah zones）. These inland zones correlated well with the main trends of major tectonics which refleet the reactivation of tectonic movements along these fault trends. The Red Sea zones are in agreement with the main path of the axial trough. The range of b-value in these identified zones is 0.65 to 1.03 through these identified zones. The area characterized by higher b-values could be indicative of a relative low stress regime which was a result of resulting from the stress release by the earthquakes. Whereas, the areas of lower b-values can be considered as an evidence of a relatively higher stress regime associated with a dominantly extensional stresses. Based on aforementioned, the region is suffering from different stress level accumulations which, in

关键词： seismicity,seismotectonic source zones,b-value,Jeddah

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Crack mystery of the damaging Kumamoto earthquakes

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Science Bulletin 2016年第11期61卷 868-870页

作者： Dapeng Zhao Xin Liu Department of geophysics Tohoku University college of Marine Geosciences Ocean University of China

The 2016 Kumamoto earthquake(M 7.3 in the Japan Meteorological Agency(JMA)scale)sequence wrote a new chapter of active seismotectonics and subduction dynamics in the Japan Islands.This earthquake sequence,

关键词：地震序列破坏性日本气象厅裂缝活动构造 Moto 动力学上地壳

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Large-scale inverted-V channels of upflowing oxygen ions pumped by Alfvén waves

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Earth and Planetary Physics 2023年第6期7卷 640-654页

作者： Hui Zhang Jun Zhong SuiYan Fu ZuYin Pu Yong Wei Lun Xie LiBo Liu QiAn Chen Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China college of Earth Sciences University of Chinese Academy of SciencesBeijing 100049China Heilongjiang Mohe National Observatory of geophysics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Earth and Space Sciences Peking UniversityBeijing 100871China

Large-scale inverted-V channels of upflowing oxygen ions are frequently identified in data collected by Cluster,at all local times,near the open-closed field line boundary over Earth’s high-latitude ionosphere-occur with downward propagating MHD Alfvén waves which have cascaded into kinetic regimes of plasma.The transverse acceleration of the oxygen ions in the center of these structures is interpreted as the integrated energization by these waves along the channels.Also observed within the channels are upward parallel electric fields,a key characteristic of kinetic Alfvén waves,which may contribute not only to lifting the ions but also to precipitating aurora electrons that might initiate ion upflow in the ionosphere below.Statistics on five-year observations of Cluster show that the channels typically form during geomagnetic perturbations,particularly when solar-wind dynamic pressure is high or highly fluctuated.Near the open-closed field line boundary,the stronger the wave power,the higher the upward oxygen flux and the higher the beam energy,indicating that these waves provide a simple but efficient way to drive oxygen upflows.

关键词： oxygen ions dispersive Alfvén waves ion outflow parallel electric field

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P-and S-wavefield simulations using both the firstand second-order separated wave equations through a high-order staggered grid finite-difference method

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Earthquake Science 2013年第2期26卷 83-98页

作者： Chao-ying Bai Xin Wang Cai-xia Wang Department of geophysics College of Geology Engineering and Geomatics Chang'an University Institute of Computing geophysics Chang'an University

In seismic exploration, it is common practice to separate the P-wavefield from the S-wavefield by the elastic wavefield decomposition technique, for imaging purposes. However, it is sometimes difficult to achieve this, especially when the velocity field is complex. A useful approach in multi-component analysis and modeling is to directly solve the elastic wave equations for the pure P- or S-wavefields, referred as the separate elastic wave equa- tions. In this study, we compare two kinds of such wave equations： the first-order （velocity-stress） and the second- order （displacement-stress） separate elastic wave equa- tions, with the first-order （velocity-stress） and the second- order （displacement-stress） full （or mixed） elastic wave equations using a high-order staggered grid finite-differ- ence method. Comparisons are given of wavefield snap- shots, common-source gather seismic sections, and individual synthetic seismogram. The simulation tests show that equivalent results can be obtained, regardless of whether the first-order or second-order separate elastic wave equations are used for obtaining the pure P- or S-wavefield. The stacked pure P- and S-wavefields are equal to the mixed wave fields calculated using the corre- sponding first-order or second-order full elastic wave equations. These mixed equations are computationallyslightly less expensive than solving the separate equations. The attraction of the separate equations is that they achieve separated P- and S-wavefields which can be used to test the efficacy of wave decomposition procedures in multi-com- ponent processing. The second-order separate elastic wave equations are a good choice because they offer information on the pure P-wave or S-wave displacements.

关键词： Finite-difference method Staggeredgrid First-order separate elastic wave equation Second-order separate elastic wave equation Multiple arrival tracking

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Intracontinental lithospheric delamination:Constraints from imaging the mantle transition zone beneath the southwestern part of the Sichuan Basin

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中国科学:地球科学英文版 2023年第10期66卷 2340-2352页

作者： Fan YANG Juan LI Sidan CHEN Yun CHEN Long LI Yinshuang AI Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China college of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China Heilongjiang Mohe Observatory of geophysics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China CAS Center for Excellence in Deep Earth Science Guangzhou510640China

The southwestern part of the Sichuan Basin(SW-SCB)is adjacent to the eastern Himalayan syntaxis.Affected by the Indo-Eurasian collision and subsequent intrusion of the Indian plate into the Eurasian plate during the Cenozoic,this region is ideal for the study of the tectonic evolution of the intracontinental lithosphere and the dynamic processes of deep and shallow structures.In this study,we applied the receiver function technique to the data obtained from a recently deployed high-density broadband seismic array across the Sichuan Basin and Sichuan-Yunnan block(SCB-SYB).We conducted a multi-frequency and multi-model correction analysis to image the structure of the mantle transition zone beneath this region.The results showed the660-km discontinuity gradually increasing in depth by 10-30 km beneath the western side of the Anninghe-Xiaojiang Fault,suggesting the presence of thermal anomalies caused by the subducted Indian plate from west to east.At the junction of the SCBSYB,the 410-km discontinuity exhibited a slight uplift of 5-10 km,while the 660-km discontinuity showed a significant depression of~30 km over a lateral range of~150 km.Based on previous surface GPS observation and dynamic numerical simulation studies,we suggest that the sharp lateral small-scale topography of this 660-km discontinuity beneath the SW-SCB may have resulted from dripping delamination of the lithosphere within the strain localization area.Furthermore,the aggregation of delaminated lithospheric material at the base of the 660-km discontinuity determines the regional topography of mantle transition zone discontinuities.In this study,we provided seismological evidence for the challenging detection of small-scale intracontinental lithosphere dripping delamination.Moreover,it provides a new view for studying deep and shallow dynamic processes in intracontinental regions with stress concentration resulting from plate/continental subduction and collision.

关键词： Mantle transition zone Receiver function Southwestern part of the Sichuan Basin Dripping lithospheric delamination Sichuan-Yunnan block

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Experimental Investigation on Vortex-Induced Vibration of Steel Catenary Riser

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China Ocean Engineering 2015年第5期29卷 691-704页

作者：范宇婷毛海英郭海燕刘庆海李效民 Institute of Geology and geophysics Chinese Academy of Sciences college of Engineering Ocean University of China

Steel catenary riser（SCR） is the transmission device between the seabed and the floating production facilities. As developments move into deeper water, the fatigue life of the riser can become critical to the whole production system, especially due to the vortex-induced vibration（VIV）, which is the key factor to operational longevity. As a result, experimental investigation about VIV of the riser was performed in a large plane pool which is 60 m long, 36 m wide and 6.5 m deep. Experiments were developed to study the influence of current speed and seabed on VIV of SCR. The results show that amplitudes of strain and response frequencies increase with the current speed both in cross-flow（CF） and in-line（IL）. When the current speed is high, multi-mode response is observed in the VIV motion. The amplitudes of strain in IL direction are not much smaller than those in CF direction. The seabed has influence on the response frequencies of riser and the positions of damage for riser.

关键词： vortex-induced vibration（VIV） steel catenary riser（SCR） current speed seabed

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3-D multi-parameter type traveltime tomography in a spherical coordinate frame: comparison of double and triple class simultaneous inversions

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Earthquake Science 2018年第2期31卷 62-74页

作者： Chaoying Bai Jiayu Sun Xingwang Li Stewart Greenhalgh Department of geophysics College of Geology Engineering and Geomatics Chang'an University Institute of Computational geophysics Chang'an University Department of Geosciences King Fahd University of Petroleum and Minerals

It is now common practice to perform simultaneous traveltime inversion for the velocity field and the reflector geometry in reflection/refraction tomography, or the velocity field and the hypocenter locations in regional earthquake tomography, but seldom are all three classes of model parameters updated simultaneously. This is mainly due to the trade-off between the different types of model parameters and the lack of different seismic phases to constrain the model parameters. Using a spherical-coordinate ray tracing algorithm for first and later（primary reflected） arrival tracing algorithm in combination with a popular linearized inversion solver, it is possible to simultaneously recover the three classes of model parameters in regional or global tomographic studies. In this paper we incorporate the multistage irregular shortest-path ray tracing algorithm（in a spherical coordinate system） with a subspace inversion solver to formulate a simultaneous inversion algorithm for triple model parameters updating using direct and later arrival time information.Comparison tests for two sets of data（noise free and added noise） indicate that the new triple-class parameter inversion algorithm is capable of obtaining nearly the same results as the double-class parameter inversion scheme. Furthermore,the proposed multi-parameter type inversion method is not sensitive to a modest level of picking error in the traveltime data, and also performs well with a relatively large uncertainty in earthquake hypocentral locations. This shows it to be a feasible and promising approach in regional or global tomographic applications.

关键词： simultaneous triple model parameten inversion reflector geometry hypocenter location subspace inversion multistage irregular shortest-path ray tracing

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嫦娥五号玄武岩低Ni-Co橄榄石揭秘月球年轻火山成因

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Science Bulletin 2023年第17期68卷 1918-1927页

作者：苏斌张迪陈意杨蔚毛骞李献华吴福元 State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China college of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

对嫦娥五号月球样品研究显示,月球直到20亿年前仍存在岩浆活动.这不仅刷新了人类对月球岩浆活动和热演化历史的认知,也提出了新的科学问题:月球火山活动为什么持续如此之久?本工作对嫦娥五号玄武岩进行橄榄石微量元素研究,发现与阿波罗... 详细信息

对嫦娥五号月球样品研究显示,月球直到20亿年前仍存在岩浆活动.这不仅刷新了人类对月球岩浆活动和热演化历史的认知,也提出了新的科学问题:月球火山活动为什么持续如此之久?本工作对嫦娥五号玄武岩进行橄榄石微量元素研究,发现与阿波罗低钛玄武岩相比,嫦娥五号玄武岩的橄榄石Ni和Co含量较低.结合一系列岩浆结晶模拟,恢复了嫦娥五号和阿波罗玄武岩的初始岩浆Ni和Co含量,揭示嫦娥五号玄武岩的源区含有更多低镁、富铁的岩浆洋晚期堆晶体,它们加入会降低月幔熔点,进而抑制Ni和Co在月幔熔融过程中进入熔体.本研究表明,尽管月球内部在持续缓慢冷却,但岩浆洋晚期堆晶体翻转引起的月幔混合作用可以有效降低月幔源区的熔点,抵消月幔逐渐缓慢变冷的大趋势,引发长期持续的月球火山作用.

关键词：火山作用火山活动混合作用橄榄石岩浆活动玄武岩月幔岩浆洋

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Nonlinear amplitude inversion using a hybrid quantum genetic algorithm and the exact zoeppritz equation

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Petroleum Science 2022年第3期19卷 1048-1064页

作者： Ji-Wei Cheng Feng Zhang Xiang-Yang Li College of Geophysics State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Beijing102249China British Geological Survey EdinburghUK

The amplitude versus offset/angle(AVO/AVA)inversion which recovers elastic properties of subsurface media is an essential tool in oil and gas exploration.In general,the exact Zoeppritz equation has a relatively high accuracy in modelling the reflection coefficients.However,amplitude inversion based on it is highly nonlinear,thus,requires nonlinear inversion techniques like the genetic algorithm(GA)which has been widely applied in seismology.The quantum genetic algorithm(QGA)is a variant of the GA that enjoys the advantages of quantum computing,such as qubits and superposition of states.It,however,suffers from limitations in the areas of convergence rate and escaping local minima.To address these shortcomings,in this study,we propose a hybrid quantum genetic algorithm(HQGA)that combines a self-adaptive rotating strategy,and operations of quantum mutation and catastrophe.While the selfadaptive rotating strategy improves the flexibility and efficiency of a quantum rotating gate,the operations of quantum mutation and catastrophe enhance the local and global search abilities,respectively.Using the exact Zoeppritz equation,the HQGA was applied to both synthetic and field seismic data inversion and the results were compared to those of the GA and QGA.A number of the synthetic tests show that the HQGA requires fewer searches to converge to the global solution and the inversion results have generally higher accuracy.The application to field data reveals a good agreement between the inverted parameters and real logs.

关键词： Nonlinear inversion AVO/AVA inversion Hybrid quantum genetic algorithm(HQGA)

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