Journal of Asian Earth Sciences最新文献_第8页

Jurassic tectonic activity and geodynamic implications of the eastern segment of the Altyn Tagh Fault, Northwest China 阿尔金断裂带东段侏罗系构造活动及其地球动力学意义

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-12-02 DOI: 10.1016/j.jseaes.2025.106899

Huaiwei Feng , Shumei Xu , Jinduo Wang , Hongzhuang Cui , Xiangfeng Wu

The Altyn Tagh Fault (ATF), forming the northern boundary of the present-day Tibetan Plateau, cuts across multiple structural units of northern Tibetan Plateau and exerts a fundamental control on the framework of the Mesozoic-Cenozoic sedimentary basins. Although numerous studies have investigated the timing and magnitude strike-slip motion along the ATF, its Jurassic evolution remains poorly constrained. In this study, we integrate sedimentological, structural, geophysical, and thermochronological approaches to examine the Jurassic tectonic activity of the eastern segment of the ATF. Analyses of soft-sediment deformation structures indicate that the Altyn Tagh Range experienced incipient, submarine uplift without the development of significant surface topography. The recognition of Jurassic stratigraphic contacts and flower structures in seismic profiles further suggests localized uplift and strike-slip deformation. Detrital zircon U-Pb age spectra exhibit near-source signatures, implying restricted lateral displacement along the fault during the Jurassic. Moreover, aeromagnetic anomaly interpretation combined with low-temperature thermochronology indicates that the ATF operated within a dynamic framework involving pre-Jurassic southward deep subduction of the Tarim Block and northward shallow subduction of the Qaidam Block, mediated by a deep lithosphere-mantle ductile shear zone. Under this tectonic configuration, the fault experienced limited strike-slip motion, segmented activity, and localized uplift during the Jurassic.

尽管许多研究已经调查了沿ATF的走滑运动的时间和规模，但其侏罗纪演化仍然知之甚少。在这项研究中，我们综合了沉积学、构造学、地球物理和热年代学的方法来研究ATF东段的侏罗纪构造活动。软沉积变形构造分析表明，阿尔金山脉经历了早期的海底隆升，没有明显的地表地形发育。地震剖面对侏罗系地层接触和花状构造的识别进一步表明了局部隆升和走滑变形。碎屑锆石U-Pb年龄谱表现出近源特征，表明侏罗纪时期沿断层侧向位移受限。此外，航磁异常解释结合低温热年代学表明，ATF是在塔里木地块前侏罗世向南深俯冲和柴达木地块向北浅俯冲的动力框架内运行的，并以深部岩石圈-地幔韧性剪切带为介质。在这一构造构型下，断层在侏罗纪经历了有限的走滑运动、分段活动和局部隆升。

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引用次数: 0

Tectonic and climate control on the stratigraphic cycles in a Late Paleozoic evaporitic basin in NW China 构造和气候对西北晚古生代蒸发盆地地层旋回的控制

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-12-02 DOI: 10.1016/j.jseaes.2025.106898

Kuanhong Yu , Shuo Du , Yingchang Cao , Zi Wang

The Fengcheng Formation in the Junggar Basin, northwestern China, represents a suite of deposits formed in a hydrologically closed, alkaline saline lake during the Late Paleozoic. This formation hosts high-quality source rocks (oil shales) and significant trona resources. Closed-basin lacustrine systems exhibit stratigraphic architectures that are fundamentally distinct from those of marine or open-lake settings; consequently, conventional sequence stratigraphic models are often inadequate for interpreting the distribution of trona and oil shale resources within such confined depositional systems. Based on integrated analyses of drilling sequences, well logs, and seismic profiles, we identify four key findings: (1) Three third-order sequences can be delineated using lithostratigraphic patterns and seismic-stratigraphic relationships; (2) The Mahu Sag remained predominantly underfilled throughout most of the depositional history, evolving into a balanced-fill basin only at the end of Sequence 3 (SQ3); (3) Trona deposition occurred during arid phases within repeated climatic cycles, with the Fengcheng Formation preserving four long-term cycles, each comprising multiple intermediate- and short-term climatic fluctuations; (4) The highest-quality oil shales accumulated during the transgressive systems tracts (TST) of SQ1 and SQ2, coinciding with periods of rising lake levels. Additional oil shale intervals formed at the onset of individual cycles when lake levels were elevated. These findings offer a comprehensive stratigraphic framework for understanding the spatial and temporal distribution of trona and oil shale resources in a Late Paleozoic alkaline saline lake system characterized by asymmetric basin geometry.

准噶尔盆地丰城组是一套晚古生代水文封闭的碱性盐湖沉积。该地层拥有优质烃源岩（油页岩）和重要的天然气资源。封闭盆地湖泊体系的地层结构与海相或开阔湖泊的地层结构有本质的区别；因此，常规的层序地层学模型往往不足以解释此类封闭沉积体系中地下和油页岩资源的分布。通过对钻井序列、测井曲线和地震剖面的综合分析，得出了四个重要发现：(1)利用岩石地层模式和地震-地层关系圈定了3个三级层序；(2)马湖凹陷在大部分沉积历史中以欠充填为主，仅在层序3 （SQ3）末演化为平衡充填盆地；(3) Trona沉积发生在干旱期，在重复的气候周期中，丰城组保存了4个长期周期，每个周期包含多个中短期气候波动；(4)油页岩质量最高的时期为SQ1和SQ2海侵体系域（TST），与湖泊水位上升时期一致。当湖泊水位升高时，在个别旋回开始时形成额外的油页岩层段。这些发现为认识具有不对称盆地几何特征的晚古生代碱性盐湖体系中烃类和油页岩资源的时空分布提供了一个全面的地层框架。

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引用次数: 0

A refined classification of 3D shape preferred orientation patterns in fault gouges: Insights from the Yangsan and Ulsan Fault Zones, South Korea 断层带中三维形状优选方向模式的精细分类：来自韩国梁山和蔚山断裂带的见解

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-12-02 DOI: 10.1016/j.jseaes.2025.106896

Ho Sim , Seongsik Hong , Yungoo Song , Seung-Ik Park , Changyun Park

Shape preferred orientation (SPO) analysis of rigid clasts in fault rocks is a fundamental tool for understanding grain-scale deformation process. However, the occurrence of anomalous patterns in 3D-SPO data has challenged traditional interpretations that rely solely on clast rotation systems observed in cross-sections. Here, we present a novel classification system for 3D-SPO patterns that accounts for the critical influence of clast morphology. Through integrated analysis of X-ray diffraction patterns, μ-CT imaging, 3D-SPO analysis, and electron microscopy data for three samples from the Yangsan and Ulsan fault zones (southeastern Korean Peninsula), we demonstrate that clast final shape and fabric under shear are primarily controlled by clast morphology, possibly combined with initial orientation. We classified all samples into four types based on clast morphology and identified six distinct SPO patterns associated with these classifications: top-spinning (type-S) and oblate-rolling (type-OR) for oblate type clasts, rotating (type-R) and prolate-rolling (type-PR) for prolate type clasts, and two distinct rotating patterns (types H and V) for bladed type clasts. Natural fault gouge typically exhibits a composite of these patterns, with the dominant pattern reflecting the predominant clast shape population. This refined understanding of the relationship between clast shape and SPO patterns significantly improves the reliability of SPO analysis and enhances our ability to reconstruct fault deformation process.

断裂岩中刚性碎屑的形状优先取向（SPO）分析是理解颗粒级变形过程的基本工具。然而，3D-SPO数据中出现的异常模式对传统的仅依赖于在横截面上观察到的碎屑旋转系统的解释提出了挑战。在这里，我们提出了一种新的3D-SPO模式分类系统，该系统考虑了碎屑形态的关键影响。通过对梁山和Ulsan断裂带3个样品的x射线衍射图、μ-CT成像、3D-SPO分析和电镜数据的综合分析，我们发现剪切作用下碎屑的最终形态和结构主要受碎屑形态的控制，可能与初始取向有关。我们根据碎屑形态将所有样品分为4种类型，并确定了与这些分类相关的6种不同的SPO模式：扁圆型碎屑的顶旋（s型）和扁圆滚动（or型），长圆型碎屑的旋转（r型）和扁圆滚动（pr型），叶片型碎屑的两种不同的旋转模式（H型和V型）。天然断层泥通常表现为这些模式的组合，主要模式反映了主要的碎屑形状种群。这种对碎屑形状与SPO模式之间关系的精细化理解大大提高了SPO分析的可靠性，增强了我们重建断层变形过程的能力。

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引用次数: 0

Provenance, tectonic setting, weathering patterns, and paleoclimate insight from late Holocene Wainganga River sediments, central India: a geochemical and statistical approach 印度中部晚全新世Wainganga河沉积物的物源、构造背景、风化模式和古气候：地球化学和统计方法

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-12-02 DOI: 10.1016/j.jseaes.2025.106897

Dileep Abdul Kalam T., Samaya S. Humane, Sumedh K. Humane, Shreyash Sayankar

The Geochemical composition of the Holocene sediments of the Wainganga Riverbank near Pauni town, Central India have been probed to understand the localised sedimentary evolution. The provenance of the sediments is of mostly felsic origin suggesting source rocks are granitic gneiss, granite, muscovite schists and gneiss from the adjacent area of the Wainganga River basin (WRB). The paleo weathering conditions plots suggest incipient to moderate chemical weathering. Analysis of tectonic setting discrimination diagrams demonstrate that the sediments are characteristic of a passive margin provenance. The transition from semi-arid to semi-humid climate is evident from the C-value plot and SiO₂ vs Al₂O₃ + K₂O + Na₂O diagram, with multivariate statistical analysis confirming this gradual climatic evolution. The shift in Rb/Sr and Sr/Cu ratios provide additional geochemical evidence supporting the inferred paleoclimatic shift from arid to more humid conditions accompanied by enhanced productivity. Four zones were demarcated based on the significant shifts in the geochemical ratios which are key indicators of climate shifts. The sedimentary record of Zone-I (1100–1300 cm) suggests moderate weathering, with substantial clay formation, potentially attributed to increased precipitation of changes in hydrological regime. Zone- II (800–1100 cm) represents dry period with limited moisture leading to minimal chemical weathering and better drainage or less organic matter accumulation. Zone-III (400–800 cm) shows a slight increase in weathering with more reducing conditions due to either poor drainage or high organic matter content. Zone-Ⅳ (50–400 cm) is characterised by drop in chemical weathering intensity followed by gradual increase, coinciding with a shift towards a more humid.

对印度中部波乌尼镇附近的万安加河岸全新世沉积物的地球化学组成进行了探测，以了解局部沉积演化。沉积物物源以长英质岩为主，表明烃源岩主要为邻近万因甘加河流域的花岗质片麻岩、花岗岩、白云母片岩和片麻岩。古风化条件图显示为早期至中度化学风化。构造环境判别图分析表明，沉积物具有被动边缘物源的特征。c值图和SiO2 / Al2O3 + K2O + Na2O图显示了从半干旱到半湿润气候的转变，多元统计分析证实了这一渐进的气候演变过程。Rb/Sr和Sr/Cu比值的变化提供了额外的地球化学证据，支持推断的古气候从干旱到更湿润的变化伴随着生产力的增强。根据气候变化的关键指标地球化学比值的显著变化，划分了4个带。i区（1100-1300 cm）的沉积记录表明中度风化，具有大量粘土形成，可能归因于降水增加或水文状况的变化。II区（800-1100 cm）为干燥期，水分有限，化学风化作用最小，排水较好，有机质积累较少。iii区（400 ~ 800 cm）由于排水差或有机质含量高，风化作用略有增加，还原条件较多。区域-Ⅳ（50-400厘米）的特征是化学风化强度下降，然后逐渐增加，同时向更潮湿的方向转变。

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引用次数: 0

First quantitative constraints on the Aiyongco Fault: A record of distributed strain in the western Bangong-Nujiang Fault Zone, Tibetan Plateau

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-29 DOI: 10.1016/j.jseaes.2025.106878

Haoxuan Zeng , Dewen Li , Jinzhao Li , Chong Zhang , Yuquan Jiang , Gaojian Miao , Zhenming Liu

The Bangong-Nujiang Fault Zone (BNFZ) separates the Qiangtang terrane to the north from the Lhasa terrane to the south within the Tibetan Plateau. How tectonic strain is accommodated across the western segment of this major suture zone remains a key unresolved question. This study focuses on the Aiyongco Fault, a major NWW-trending structure within the western BNFZ. We employ ground investigations, satellite imagery, UAV photogrammetry, trenching, and geochronological dating (¹⁴C and ¹⁰Be) to constrain its spatial distribution, timing of recent activities, slip rates, and paleoearthquakes. Our study demonstrates that the latest activity on the Aiyongco Fault occurred between 7.8 and 0.47 ka BP, i.e., during the middle to late Holocene, and that the horizontal slip rate ranges from 0.18 ± 0.01 mm/yr to 0.77 ± 0.04 mm/yr, with a vertical slip rate of 0.05 ± 0.01 mm/yr and a single-event horizontal displacement of 1.02 ± 0.17 m. The fault has experienced at least six paleoearthquake events since 21.07 ka, with an average recurrence interval of approximately 4.3–7.0 ka. These findings provide the first quantitative constraints on this active fault, suggesting that tectonic deformation in the western Tibetan Plateau is highly distributed. Our results offer foundational data for regional tectonic models and seismic hazard assessment in this area.

构造应变如何在这个主要缝合带的西段被调节仍然是一个关键的未解决的问题。本文以北北纬向的爱永错断裂为研究对象。我们使用地面调查、卫星图像、无人机摄影测量、沟槽和地质年代测定（14C和1⁰Be）来限制其空间分布、最近活动的时间、滑动率和古地震。研究表明，爱永错断裂的最新活动发生在7.8 ~ 0.47 ka BP之间，即全新世中晚期，水平滑动速率为0.18±0.01 mm/yr ~ 0.77±0.04 mm/yr，垂直滑动速率为0.05±0.01 mm/yr，单次水平位移为1.02±0.17 m。该断裂自21.07 ka以来至少经历了6次古地震事件，平均复发间隔约为4.3 ~ 7.0 ka。研究结果为该区区域构造模型和地震危险性评价提供了基础数据。

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引用次数: 0

Corrigendum to “Indosinian structural geology and tectonics of northern Thailand: A discussion based on new field observation”. [J. Asian Earth Sci. 293 (2025) 1–38/106755] “印支构造地质与泰国北部构造：基于新的野外观测的讨论”的勘误表。[J。地球科学进展，2016 (5):389 - 389 [j]

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-29 DOI: 10.1016/j.jseaes.2025.106876

M. Rozalli , C.K. Morley , N. Mankhemthong

引用次数: 0

Cimmerian tectonostratigraphic events in east-central Iran revealed by a long drill core of the Shemshak Group (Upper Triassic–Middle Jurassic) 上三叠统—中侏罗统Shemshak群长岩心揭示的伊朗中东部辛里纪构造地层事件

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-29 DOI: 10.1016/j.jseaes.2025.106895

Mohammad Ali Salehi , Markus Wilmsen , Ehsan Zamanian , Christoph Heubeck

The Upper Triassic–lower Middle Jurassic tectono-sedimentary megacycle in central Iran is represented by the Shemshak Group, deposited within the central part of the Cimmerian continent (the “Iranian Cimmerides”). It contains key information on the Mesozoic geodynamics of the Middle East during the collision of the Cimmerian terranes with Eurasia. However, detailed insights into the response of depositional systems to the complex contemporaneous tectonics are hampered by poor exposure, in particular of fine-grained strata. A new, 641-m-long core from the northern Tabas Block (east-central Iran) provides an unweathered and continuous subsurface record of the Shemshak Group. Detailed lithofacies and stratigraphic analyses refine previous lithostratigraphic and palaeoenvironmental interpretations, allowing to consider relative sea-level changes caused by Cimmerian tectonic events and/or global sea-level fluctuations. The thick siliciclastic succession of the Rhaetian Qadir Member of the Nayband Subgroup reflects rapid basin subsidence in advance of the Main Cimmerian Event (MCE). It comprises the dominant part of the Shemshak Group. In the aftermath of the MCE at the Triassic–Jurassic boundary, comparatively low subsidence rates and limited accommodation prevailed, resulting in low thicknesses of the Lower–lower Middle Jurassic mixed siliciclastic and carbonate Ab-e-Haji Subgroup. Process and stacking-pattern analyses of eleven clastic and eight carbonate lithofacies indicate a variety of continental and marine depositional environments, ranging from fluvial and deltaic to shallow-marine. Our findings significantly improve the knowledge of the tectono-stratigraphic setting of the Shemshak Group and contribute to a better understanding of the Cimmerian history of central Iran between the Late Triassic and the Jurassic.

伊朗中部上三叠统-下中侏罗统构造-沉积巨旋回以Shemshak群为代表，沉积于西默里亚大陆（“伊朗西默里亚”）中部。它包含了西梅里亚板块与欧亚大陆碰撞期间中东中生代地球动力学的关键信息。然而，由于暴露程度低，特别是细粒地层暴露程度低，很难深入了解沉积体系对复杂同时期构造的响应。来自Tabas地块北部（伊朗中东部）的一个新的641米长的岩心提供了Shemshak群未风化的连续地下记录。详细的岩相和地层分析完善了以前的岩石地层和古环境解释，允许考虑由西merian构造事件和/或全球海平面波动引起的相对海平面变化。Nayband亚群中Rhaetian Qadir段的厚硅-碎屑演替反映了主辛里纪事件（MCE）之前盆地的快速沉降。它是舍姆沙克集团的主要部分。在三叠系-侏罗系边界的MCE之后，相对较低的沉降速率和有限的调节作用占主导地位，导致中侏罗统下-下侏罗统Ab-e-Haji混合硅屑-碳酸盐亚群厚度较低。11个碎屑岩相和8个碳酸盐岩岩相的沉积过程和叠合模式分析表明，该区存在河流三角洲和浅海相等多种陆相和海相沉积环境。我们的发现大大提高了对Shemshak群构造地层背景的认识，有助于更好地理解伊朗中部晚三叠世至侏罗纪之间的辛默纪历史。

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引用次数: 0

Skarn-related sphalerite: Indium enrichment and key controlling factors 矽卡岩型闪锌矿：铟富集及其关键控制因素

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-29 DOI: 10.1016/j.jseaes.2025.106894

Junyi Wang , Guotao Sun , Jia-Xi Zhou , Hui Chen , Bing Yu , Kai Luo , Shiyu Liu , Ruiliang Wang

Indium is a critical metal that can be concentrated in skarn deposits. However, not all skarn deposits exhibit indium mineralization. The controlling factors of indium mineralization in skarn deposits are unclear. We investigate the sphalerite trace element, geological setting, geochemical compositions of related intrusions, and hydrothermal physicochemical conditions of 47 skarn deposits worldwide to unravel the critical factors for indium mineralization. The deposits are classified into four types according to the indium content in sphalerite. The In-rich skarn deposits are predominantly distributed in the intra-continental extension setting. The In-rich skarn deposits show higher SiO₂ values and Rb/δEu ratios, and lower MgO contents than the In-poor deposits, indicating that the evolution process evaluates the indium enrichment in magma. The Sr-Nd-Hf isotopes suggest that In-rich skarns are almost or partly derived from the partial melting of metasedimentary rocks; however, In-poor deposits are dominantly derived from the melting of the mafic lower crust. The similar hydrothermal temperatures (200 to 300 °C), salinities (4 to 12 NaCl wt%), and δ³⁴S (–5 to 10 ‰) between In-rich and In-poor deposits imply that the indium contents in sphalerite may be irrelevant to these conditions. The In and Cu contents define a solubility limit (C_In=C_Cu), indicating that the Cu activity controls the maximum indium contents in sphalerite. The study highlights that the skarn-related indium mineralization is a coupled consequence of the magma sources, evolution, and hydrothermal Cu activity.

铟是一种重要的金属，可以在矽卡岩矿床中富集。然而，并非所有矽卡岩矿床都表现出铟矿化。矽卡岩矿床中铟矿化的控制因素尚不清楚。通过对全球47个矽卡岩矿床闪锌矿微量元素、地质背景、侵入体地球化学组成及热液物化条件的研究，揭示了铟成矿的关键因素。根据闪锌矿中铟的含量，将矿床划分为4种类型。富铟夕卡岩矿床主要分布在陆内伸展构造中。富in夕卡岩矿床的SiO2值和Rb/δEu比值高于贫in夕卡岩矿床，MgO含量低于贫in夕卡岩矿床，表明演化过程评价了岩浆中铟的富集。Sr-Nd-Hf同位素表明富in夕卡岩几乎或部分来源于变质沉积岩的部分熔融作用；贫铟矿床主要来源于基性下地壳的熔融作用。富铟矿和贫铟矿的热液温度（200 ~ 300℃）、盐度（4 ~ 12 NaCl wt%）和δ34S（-5 ~ 10‰）相似，表明闪锌矿中的铟含量可能与这些条件无关。In和Cu的含量决定了闪锌矿的溶解度极限（CIn=CCu），表明Cu的活性控制着闪锌矿中铟的最大含量。强调夕卡岩相关的铟成矿作用是岩浆来源、演化和热液Cu活动的耦合结果。

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引用次数: 0

Dolomitization mechanism for thick bedded dolostones of the Ordovician Majiagou Formation (Member 5) in the eastern Ordos Basin, China 鄂尔多斯盆地东部奥陶系马家沟组（五段）厚层状白云岩白云化机制

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-28 DOI: 10.1016/j.jseaes.2025.106889

Zhenmeng Sun, Xiangjie Cui, Huan Liu, Jian Cao, Xiancai Lu

The genesis of thick bedded dolostones is considered closely related to the “Dolomite Problem”. This study investigates the mineralogical, sedimentological, and geochemical characteristics of thick bedded dolostones of the Ordovician Majiagou Formation (Member 5) in the eastern Ordos Basin, China. These dolostones consist of stacked meter to submeter scale thin bedded cycles, characterized by three key facies: cryptocrystalline dolostone with spherical gypsum molds, microcrystalline dolostone with nonplanar crystal boundaries and lath shaped gypsum pseudomorphs, and fine crystalline dolostone with planar boundaries lacking gypsum. The vertical distribution of these facies correlates with sea level cyclicity and geochemical variations in dolomite stoichiometry, indicating that dolomitization was controlled by high frequency sea level oscillations. The preservation of horizontal gypsum pseudomorphs, together with diagnostic Th/U ratios and bell-shaped REE patterns, supports a low energy, restricted cratonic setting. We apply a syndepositional model wherein evaporative concentration in a warm, shallow greenhouse sea led to calcite and gypsum precipitation, elevating the Mg/Ca ratio and triggering dolomitization. The resulting dense brine percolated downward, replacing unconsolidated calcareous precursors to form the observed dolostone types. This case demonstrates that high frequency sea level oscillations and their resultant thin bedded cycle stacking can constitute an efficient formation mechanism for thick bedded dolostones in cratonic basins.

厚层白云岩的成因被认为与“白云岩问题”密切相关。研究了鄂尔多斯盆地东部奥陶系马家沟组（五段）厚层状白云岩的矿物学、沉积学和地球化学特征。这些白云岩由米级至亚米级的薄层旋回堆积而成，具有3个关键相：具有球形石膏模的隐晶白云岩、具有非平面晶界和板条状石膏假晶的微晶白云岩和具有平面晶界但不含石膏的细晶白云岩。这些相的垂向分布与海平面旋回性和白云岩化学计量学的地球化学变化有关，表明白云化受海平面高频振荡的控制。水平石膏伪晶的保存，以及诊断Th/U比率和钟形REE模式，支持低能量，受限制的克拉通环境。我们采用了一个同沉积模型，其中温暖的浅温室海的蒸发浓度导致方解石和石膏沉淀，升高Mg/Ca比并引发白云化。由此产生的浓盐水向下渗透，取代未固结的钙质前体，形成观察到的白云岩类型。该实例表明，高频海平面振荡及其形成的薄层旋回叠加是克拉通盆地厚层白云岩的有效形成机制。

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引用次数: 0

Different types of lobes and autogenous circulation phenomena in alluvial fans based on flume simulation experiments: A case study of the Baiyanghe alluvial fan in China 基于水槽模拟实验的冲积扇不同叶型及自循环现象——以中国白洋河冲积扇为例

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-27 DOI: 10.1016/j.jseaes.2025.106880

Fukang Ma, Ye Tao

Although extensive research has been done on alluvial fans, the quantitative relationships between lobe-scale characteristics and internal spatial structures within alluvial fans remain unclear. This study adopt the Baiyang River alluvial fan in China as basic conceptual model and use a flume to simulate to quantitatively analyze differences in lobe types and autogenic cycles in stable period of benchmark. The study reveals that: (1) Based on differences in sedimentary processes, geometric scale, and internal superposition styles, the lobes can be classified into four types: A, B, C, and D, with lobe D exhibiting the highest number; (2) The internal superposition styles of the different lobe types vary significantly, the internal sand body superposition styles of the four lobe types A, B, C, and D are respectively progradation, regression, aggradation, and lateral accumulation; (3) The study introduces four indicators to measure the internal superposition of the sand bodies, analyzing the scale characteristics of the lobes, including dimensionless length, width, area, and distribution angle. The dimensionless length, width, area, and distribution angle of lobes A and D are relatively large, while those of lobes C and B are comparatively smaller. (4) The evolution of alluvial fans involves autogenetic cycles process corresponding to different types of lobe evolution, namely: channel incision, lobe proaccretion (lobe A), lobe lateral migration (lobe D), lobe aggradation (lobe C), lobe retrograde regression (lobe B), and channel incision again. The four lobe types reflect dynamic changes in the sedimentary characteristics and environment of the alluvial fan at various developmental stages. This research will provide a scientific basis for the prediction of alluvial fan oil and gas reservoirs in similar regions in northwest China, and also contribute to the in-depth study of the sedimentary dynamics of alluvial fans and the coupling mechanism of the “source-sink” system under stable base level conditions.

虽然对冲积扇进行了大量的研究，但冲积扇的叶尺度特征与内部空间结构之间的定量关系尚不清楚。本研究以中国白杨河冲积扇为基本概念模型，采用水槽模拟，定量分析基准稳定期叶型和自生旋回的差异。研究表明：(1)根据沉积过程、几何尺度和内部叠合样式的不同，裂片可分为A、B、C、D 4类，其中D类数量最多；(2)不同叶片类型砂体内部叠加样式差异明显，A、B、C、D四种叶片类型砂体内部叠加样式分别为进积、退积、堆积和侧向堆积；(3)引入了无量纲长度、宽度、面积、分布角度等4个指标衡量砂体内部叠加性，分析了砂体叶片的尺度特征。叶片A和D的无因次长度、宽度、面积和分布角较大，而叶片C和B的无因次长度、宽度、面积和分布角较小。(4)冲积扇的演化涉及自生旋回过程，对应不同类型的裂片演化，即：河道切割、裂片增生（裂片A）、裂片侧向迁移（裂片D）、裂片沉积（裂片C）、裂片逆退（裂片B）和河道再次切割。四种叶型反映了冲积扇在不同发育阶段沉积特征和沉积环境的动态变化。该研究将为西北类似地区冲积扇油气储层预测提供科学依据，并有助于深入研究稳定基准面条件下冲积扇沉积动力学和“源-汇”系统耦合机制。

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