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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

Morphology of crater and caldera lakes in the Far Eastern region of Russia and the features of their development

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Journal of Mountain Science 2024年第4期21卷 1246-1258页

作者： Dmitrii N.KOZLOV Ekaterina V.LEBEDEVA Institute of marine geology and geophysics Far Eastern Branch of the Russian Academy of SciencesYuzhno-Sakhalinsk 693022Russia Institute of Geography Russian Academy of SciencesMoscow 119017Russia

Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data *** authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric *** has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal *** lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric *** was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their *** volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous *** the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were *** observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 *** analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their *** results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying

关键词： Volcanic lakes Echolocation survey Volcanism Gashydrotherms Kamchatka Kuril Islands

Platform Evolution in an Oligo-Miocene Back-arc Basin:An Example from the Central Iran Basin

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 185-206页

作者： Masoud SHARIFI-YAZDI Amirhossein ENAYATI Jamal SALEHI AGHDAM Mohammad BAHREHVAR Seyed Mustafa REZAEI department of geology Faculty of Earth SciencesGeography and AstronomyUniversity of Vienna1090 Vienna.Austria geology and geophysics department Tehran Energy Consultants(TEC Co.)TehranIran School of geology College of ScienceUniversity of TehranTehranIran department of geology Tarbiat Modares UniversityTehranIran

The Qom Formation is the most important hydrocarbon reservoir target in Central *** Qom platform developed in a back-arc basin during the Oligo-Miocene due to the closing of the Tethyan *** formation consists of a variety of carbonate and non-carbonate facies deposited on a platform ranging from supratidal to basin.A combination of tectonic and eustatic events led to some lateral and vertical facies variations in the study *** third-order depositional sequences and related surfaces were identified regarding vertical facies changes in the studied sections of this Oligo-Miocene *** to all results and data,this succession was initially deposited during the Chattian upon a distally steepened ramp of siliciclastic-carbonate composition,including the Bouma ***,from the late Chattian to the Aquitanian,the platform changed into a homoclinal carbonate ramp with a gentle *** respect to tectonic activity,this phase was a calm period during the deposition of the Qom ***,a drowned carbonate platform and a rimmed shelf emerged during the Burdigalian,terminated by the continental deposits of the Upper Red *** all geological characteristics,three main tectono-eustatic evolutionary phases have been recognized in the Qom back-arcbasin.

关键词： carbonate ramp depositional facies submarine fan eustasy basement faults back-arc basin

Geostatistical seismic inversion and 3D modelling of metric flow units,porosity and permeability in Brazilian presalt reservoir

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Petroleum Science 2024年第3期21卷 1699-1718页

作者： Rodrigo Penna Wagner Moreira Lupinacci Exploratory Interpretation and Reservoir Characterization Group(GIECAR) Department of Geology and GeophysicsUniversidade Federal FluminenseNiteroiRJ24210-346Brazil Petrobras Rio de JaneiroRJ20031-912Brazil

Flow units(FU)rock typing is a common technique for characterizing reservoir flow behavior,producing reliable porosity and permeability estimation even in complex geological ***,the lateral extrapolation of FU away from the well into the whole reservoir grid is commonly a difficult task and using the seismic data as constraints is rarely a subject of *** paper proposes a workflow to generate numerous possible 3D volumes of flow units,porosity and permeability below the seismic resolution limit,respecting the available seismic data at larger *** methodology is used in the Mero Field,a Brazilian presalt carbonate reservoir located in the Santos Basin,who presents a complex and heterogenic geological setting with different sedimentological processes and diagenetic *** generated metric flow units using the conventional core analysis and transposed to the well log ***,given a Markov chain Monte Carlo algorithm,the seismic data and the well log statistics,we simulated acoustic impedance,decametric flow units(DFU),metric flow units(MFU),porosity and permeability volumes in the metric *** aim is to estimate a minimum amount of MFU able to calculate realistic scenarios porosity and permeability scenarios,without losing the seismic lateral *** other words,every porosity and permeability volume simulated produces a synthetic seismic that match the real seismic of the area,even in the metric *** achieved 3D results represent a high-resolution fluid flow reservoir modelling considering the lateral control of the seismic during the process and can be directly incorporated in the dynamic characterization workflow.

关键词： Flowunits Geostatistical inversion Presalt reservoir 3D reservoir modelling Petrophysical modelling

MAVEN observation of magnetosonic waves in the Martian magnetotail region

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Earth and Planetary Physics 2024年第2期8卷 317-325页

作者： ShangChun Teng JiCheng Sun JiaWei Gao Y.Harada Markus Fraenz DeSheng Han State Key Laboratory of marine geology School of Ocean and Earth ScienceTongji UniversityShanghai 200092China MNR Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai 200136China 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 department of geophysics Kyoto UniversityKyotoJapan Max-Planck-Institute for Solar System Research GoettingenGermany

Magnetosonic waves are an important medium for energy transfer in collisionless space *** waves have been widely investigated in the upstream of the bow shock at *** waves are believed to originate from pickup ions or reflected *** utilizing MAVEN spacecraft data,we have observed the occurrence of quasi-perpendicularly propagating magnetosonic emissions near the proton gyrofrequency in the Martian magnetotail *** plasma waves are associated with a significant enhancement of proton and oxygen *** excited magnetosonic waves could possibly heat the protons through resonance and facilitate the ionospheric plasma *** results could be helpful to better understand the Mars’magnetospheric dynamics and offer insights into possible energy redistribution between waves and plasma in the Martian nightside magnetosphere.

关键词： Martian magnetotail region magnetosonic waves proton escape

Stochastic seismic inversion and Bayesian facies classification applied to porosity modeling and igneous rock identification

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Petroleum Science 2024年第2期21卷 918-935页

作者： Fábio Júnior Damasceno Fernandes Leonardo Teixeira Antonio Fernando Menezes Freire Wagner Moreira Lupinacci Exploratory Interpretation and Reservoir Characterization Group(GIECAR) Department of Geology and GeophysicsFederal Fluminense UniversityNiter oiRJ24210-346Brazil Petrobras Rio de JaneiroRJ20231-030Brazil National Institute of Science and Technology of Petroleum geophysics(INCT-GP/CNPQ) Niter oiRJ24210-346Brazil

We apply stochastic seismic inversion and Bayesian facies classification for porosity modeling and igneous rock identification in the presalt interval of the Santos Basin. This integration of seismic and well-derived information enhances reservoir characterization. Stochastic inversion and Bayesian classification are powerful tools because they permit addressing the uncertainties in the model. We used the ES-MDA algorithm to achieve the realizations equivalent to the percentiles P10, P50, and P90 of acoustic impedance, a novel method for acoustic inversion in presalt. The facies were divided into five: reservoir 1,reservoir 2, tight carbonates, clayey rocks, and igneous rocks. To deal with the overlaps in acoustic impedance values of facies, we included geological information using a priori probability, indicating that structural highs are reservoir-dominated. To illustrate our approach, we conducted porosity modeling using facies-related rock-physics models for rock-physics inversion in an area with a well drilled in a coquina bank and evaluated the thickness and extension of an igneous intrusion near the carbonate-salt interface. The modeled porosity and the classified seismic facies are in good agreement with the ones observed in the wells. Notably, the coquinas bank presents an improvement in the porosity towards the top. The a priori probability model was crucial for limiting the clayey rocks to the structural lows. In Well B, the hit rate of the igneous rock in the three scenarios is higher than 60%, showing an excellent thickness-prediction capability.

关键词： Stochastic inversion Bayesian classification Porosity modeling Carbonate reservoirs Igneous rocks

A Numerical Calculation Algorithm of the Inclination Function Based on the Representation of SO(3) Group

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 137-148页

作者： Yu-xiao Wei Wen-lin Tang department of geophysics School of Geology Engineering and GeomaticsChang’An UniversityXi’an710064China Key Laboratory of Electronics and Information Technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing100190China

In the determination of the Earth gravity field in satellite geodesy, the inclination functions represent the projection of data observed along the orbital plane of a satellite orbit into the sphere in the terrestial reference frame. The inclination functions in this work is studied from a group theoretical perspective. The inclination functions are proved to generate a representation of the SO(3) group. An orthogonal relation of the inclination functions is derived and some recurrence relations for the inclination functions are given, based on which an algorithm to calculate the inclination functions is proposed.

关键词： SO(3)group inclination function satellite geodesy representation of SO(3)

Stratigraphy of the Alveolina elliptica group from the Middle Eocene of Iran:Calibration with calcareous nannofossils biozones and description of Alveolina ozcani n. sp.

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Journal of Palaeogeography 2024年第1期13卷 54-79页

作者： Mehdi Hadi Lorenzo Consorti Ali Bahrami Mohammad Parandavar Saeed Khorramdel department of geology Faculty of SciencesUniversity of IsfahanIsfahanIran Institute of marine Sciences(ISMAR-CNR) Area Science ParkBasovizza34149 TriesteItaly National Iranian Oil Company Exploration DirectorateSheikh Bahaei SquareTehranIran department of geology Faculty of ScienceFerdowsi University of MashhadMashhadIran

Precise taxonomy and the chronostratigraphic calibration of the Middle Eocene Alveolina from Central Iran is here undertaken from the Chah-Talkh section of the southern Sabzevar region(Central Iran). We have identified Alveolina kieli, Alveolina stercusmuris and Alveolina nuttalli along with the new species Alveolina ozcani n. sp. that we include into the Alveolina elliptica group. We have also found Nummulites uroniensis, Nummulites obesus and Nummulites cf. verneuili and associated calcareous nannofossils that look reliable to make thoughtful correlations with the Shallow Benthic Zones(SBZ). The foraminiferal biostratigraphy suggests an assignment to the upper part of the lower Lutetian-lower part of the middle Lutetian,SBZ13(Middle Eocene), further strengthened through the identification of the calcareous nannofossil NP14b-NP15b or CNE8-CNE10 biozones, providing a solid correlation with the global stratigraphic standards.

关键词： Alveolina Calcareous nannofossil Central neo-tethys Central Iran Middle Eocene Biostratigraphy

An improved reverse time migration for subsurface imaging over complex geological structures:A numerical study

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Energy Geoscience

Energy Geoscience 2024年第2期5卷 290-297页

作者： Alok Kumar Routa Priya Ranjan Monahty department of Applied geophysics IIT(ISM)DhanbadJharkhandIndia

In seismic exploration,it is a critical task to image and interpret different seismic signatures over complex geology due to strong lateral velocity contrast,steep reflectors,overburden strata and dipping *** understand the behavior of these seismic signatures,nowadays Reverse Time Migration(RTM)technique is used extensively by the oil&gas *** the extrapolation phase of RTM,the source wavefield needs to be saved,which needs high storage memory and large computing *** two are the main obstacles of RTM for production *** order to overcome these disadvantages,in this study,a second-generation improved RTM technique is *** this improved form,a shift operator is introduced at the time of imaging condition of RTM algorithm which is performed automatically both in space and time *** effort is made to produce a better-quality image by minimizing the computational time as well as numerical *** proposed method is applied over various benchmark models and validated by implementing over one field data set from the Jaisalmer Basin,*** the analysis,it is observed that the method consumes a minimum of 45%less storage space and reduce the execution time by 20%,as compared to conventional *** proposed RTM is found to work efficiently in comparison to the conventional RTM both in terms of imaging quality and minimization of numerical artefacts for all the benchmark models as well as field data.

关键词： Imaging condition Reverse time migration(RTM) Seismic imaging Velocity-depth model Wave propagation