Understanding the shallow rupture mechanisms on coseismic faults and assessing the influence of fault area propagation is essential for disaster prevention. Since 2000, Hualien and nearby areas in eastern Taiwan have experienced frequent earthquakes, making it a good area to study the evolution of fault rupture. This study proposes a two-dimensional dynamic discrete element model to simulate the shallow rupture behavior of the Milun Fault. Results indicate that the rupture process proceeds through multiple evolutionary stages, with fractures propagating upward from depth but failing to fully break through to the surface, resulting instead in surface cracking without complete rupture. The second deviatoric stress invariant serves as an effective indicator of stress accumulation and release during rupture progression. For the preferred model, the modeled vertical uplift near the fault reached 0.6 m, consistent with field observations reporting a maximum coseismic uplift of approximately 0.585 m along the Milun Fault. Given the scarcity of near-fault observational constraints, the simulation represents a physically plausible scenario rather than a unique reconstruction. The integration of stress evolution, crack propagation, and near-field displacement provides new insight into the mechanical processes governing shallow thrust fault rupture and can be applied to similar fault systems exhibiting near-surface deformation.

This study develops a MATLAB-based (MathWorks, Natick, MA, USA; version R2024b) first-order probabilistic screening framework for the Shenhu gas hydrate production area, northern South China Sea, to separate the roles of bottom-water warming, geothermal and fluid perturbation, hydrate saturation, excess pore pressure, and slope geometry. The framework integrates methane hydrate phase equilibrium, geothermal profiles, transient heat diffusion, base of gas hydrate stability zone (BGHSZ) migration, conceptual reservoir phase layering, and infinite-slope factor-of-safety (FoS) analysis. The modeled present-day BGHSZ (~271 mbsf) is broadly consistent with reported bottom-simulating-reflector depths. At the baseline thermal diffusivity, conductive potential dissociation thickness stays below 4 m even for +3.0 °C over 1000 years; across the full tested diffusivity–warming–time matrix it ranges 0–19.5 m; geological tests, reported as equilibrium BGHSZ offsets, give larger responses. Monte Carlo analysis under three parallel slope-angle assumptions shows that absolute FoS depends strongly on the slope distribution. Conductive warming reduces the median FoS by about 5.5%, with about 9% of realizations exceeding a 10% reduction, yet low-FoS outcomes remain absent within the tested ranges. Within the adopted parameterization, modeled FoS variability is controlled primarily by slope angle, friction angle, and the prescribed excess pore-pressure ratio, while conductive thermal forcing produces a comparatively modest reduction in relative stability margin.

The Neoproterozoic represents a critical stage in the tectonic evolution of the Tarim Terrane, during which peripheral of the terrane recorded key geodynamic events, including the breakup of the Rodinia supercontinent, the drift of the Tarim Terrane, and the development of the Manjiaer Sag. The Manjiaer Sag exhibits a characteristic two-layer structural architecture, which comprises a Nanhuaian (Cryogenian) rift overlain by a Sinian (Ediacaran) depression. However, its origin remains debated, with proposed mechanisms including mantle plume activity associated with the breakup of Rodinia and subduction of the Paleo-Asian Ocean. The poor quality of seismic data and the paucity of deep borehole data have hindered a comprehensive understanding of its subsurface structural architecture and basin-forming processes. In this study, we apply a multidisciplinary approach to investigate the Neoproterozoic rift-depression system of the Manjiaer Sag. Newly interpreted seismic profiles constrain the structural framework of the rift and its overlying depression, while integrated geochemical and geophysical data place further constraints on the regional geodynamic processes. Our results show that the Nanhuaian rift is characterized by inward-dipping marginal normal faults and an internal array of grabens, horsts, and tilted fault blocks, with syn-rift tectonic activity ceasing in the Sinian. Whole-rock 8Nd(t)- (87Sr/86Sr)i isotopic and zircon 8Hf(t)-age relationships further define three stages of the Paleo-Asian Ocean subduction: an advancing stage (1000-820 Ma), a flat-slab stage (820-700 Ma), and a retreating stage (700-550 Ma). These results suggest that the evolution of the Manjiaer Sag was closely linked to the retreating subduction of the Paleo-Asian Ocean.

The slip behavior of the Altyn Tagh Fault (ATF) plays a key role in improving our understanding of the tectonic deformation processes shaping the Tibetan Plateau. In this investigation, a three-dimensional (3D) model representing the central segment of the ATF was constructed using discrete element numerical simulations to examine the main damage zones and stress distribution in the Akato Tagh Bend, AKsay Bend, and Xorkoli segments. The simulation results were then cross-referenced with fault orientation measurements from the northern Qaidam Basin and focal mechanism solutions (FMS) to assess their precision and reliability. The results indicate that the stress environment is stable in the linear strike-slip Xorkoli segment, whereas the stress distribution in the Akato Tagh Bend and AKsay Bend segments exhibits significant heterogeneity, with alternating regions of high and low stress. On the concave side of these bends, compressive stress accumulates, fostering the formation of local thrust faults or folds along the fault plane. Conversely, on the convex side, tensile stress dominates, promoting the development of normal faults or extensional fractures. In the restraining bend region, tensile stress remains horizontal, though its orientation shifts considerably as fault displacement increases. The bend segments also show significant variations in shear stress, which can lead to the creation of secondary fault features like Riedel shears. The intensity and distribution of shear stress are influenced by the curvature and bending angle of the fault, with larger bending angles in the Akato Tagh Bend producing more pronounced shear stress concentrations. Fractures are primarily concentrated at the fault tips, along fault intersections, and within the fault plane, with the fault damage zone being notably wider in the Akato Tagh Bend and AKsay Bend segments. As fault displacement increases, the width of the damage zone and fracture density initially increase rapidly before reaching a plateau. Moreover, the primary damage zone develops earlier in the restraining Akato Tagh Bend and AKsay Bend segments compared to the linear strike-slip Xorkoli segment, which absorbs more strain before the principal displacement zone forms. Therefore, the Akato Tagh Bend exhibits the highest fracture intensity, followed by the AKsay Bend and Xorkoli segment. These findings offer significant insights into the slip behavior and stress distribution along the ATF and enhance our understanding of the tectonic processes in the Tibetan Plateau.

2D discrete element numerical experiments are used to investigate the effect of seamounts subduction on shallow surface tectonic deformation in this paper. It is proved that the interaction between seamounts subduction along the accretionary margins and rough seabed topography give the unique stratigraphic evolution variations: (1) The seamounts develop large offset thrust faults, which are characterized by complex deformation, even with curling in shape; Reversed ridges are located directly above the seamounts, representing the area with the most intense deformation. (2) Seamounts subduction leads to more complex and irregular shapes of the wedge. Seamounts significantly hinder the lateral extension of the wedge. By conducting comparative experiments with different dipping angles, it was proved that the wedge-shaped body with a dipping angle of 35° has a larger dipping angle than the Marianas-type subduction zone. In this case, the subducting plate separates from the overlying plate, and a large amount of ocean sediments is eroded and subducted, thus forming a narrow accretion wedge. In contrast, the accretion wedge formed by the wedge-shaped geometry at a dipping angle of 25° is wider and lower in elevation, with a slope slightly lower than that of the accretion wedge formed by the wedge with a dipping angle of 35° that is composed of oceanic islands. This phenomenon corresponds to the Chile-type subduction zone, where the smaller dipping angle causes the subducting plate and overlying plate to be closely coupled, which is not conducive to the erosion and subduction of ocean sediments, thus allowing for the formation of a wide accretion wedge; (3) Seamounts subduction can lead to the emergence of high-velocity zones at the Earth’s surface and contribute to the upward transport of deep subducted sediments to shallow levels. The resultant variations and related fractures are conducive to enhancing the coupling degree across plate boundaries and augmenting the possibility of major earthquakes in this context. This indicates the necessity of reevaluating the interaction between seamounts and the crustal surface, and holds enlightenment significance for assessing the hazards of seamount subduction in accretionary margins.

At slow-ultraslow spreading mid-ocean ridges, crustal accretion style can vary significantly along and across ridge segments. In magma-poor regions or periods, seafloor spreading can be accommodated largely by tectonic processes. However, the tectonic and magmatic characteristics and formation mechanism of such highly tectonized crust are not fully understood. In this study, we utilized the high-resolution shipboard multibeam bathymetry and gravity data to investigate the tectonic and magmatic crustal accretion of the Southwest Indian Ridge (SWIR) between 49 degrees E and 52 degrees E. The results show that the processes of crustal accretion and magma activity in the study area have undergone significant spatial and temporal changes. Based on the terrain slope, curvature, and roughness characteristics of the study area, three main geomorphic patterns were identified: volcanic, fault, and sedimentary geomorphology, along with three fault types: C-type, E-type, and detachment faults. The proportion of tectonic extension in the entire spreading process, referred to as the strain ratio (T-value), was calculated along the profile perpendicular to the ridge axis, which indirectly provided the value of magma accretion rate (M-value) as (1 - T ). Asymmetric crustal accretion regions exhibit significant differences in terms of water depth, T-value, and geomorphic features on both sides. Furthermore, there is a good correlation between T-value, geomorphic features, and particularly fault types, and the variations in magma supply reflected by the residual mantle Bouguer gravity anomaly (RMBA) in the along-axis direction. In regions with insufficient magma supply, thinner oceanic crust is typically produced, with a larger T-value and detachment faults and E-type faults with large horizontal fault heaves are mostly developed; In regions with sufficient magma supply, thicker oceanic crust is usually produced, with a small T-value and C-type faults with small horizontal fault offsets are mostly developed.

Mantle plume is an essential component of the mantle convection system, and its influence on the geodynamics of continental rifts is of great significance for understanding the crust–mantle interaction. The East African Rift System, as the largest continental rift in the Cenozoic and in the initial stage, provides an excellent option for studying the interaction between the mantle plume and the continental crust. Based on the data such as GPS, seismic tomography, and global crustal model, a viscoelastic-plastic 2D thermodynamic numerical model is established to reconstruct the evolution of the Afar depression, Ethiopian Rift, and Kenyan Rift. By comparing the differences between the models of the Afar depression, Ethiopian Rift, and Kenyan Rift, the relationship between the mantle plume and pre-existing structures and their influence on the evolution of continental rifts are discussed. The results show that the mantle plume can increase the depth of the rift faults, concentrate the distribution of the faults, and strengthen the control of main faults on the rifts, allowing the possibility of narrow rifts. Pre-existing structures control the fault styles and symmetry of the rifts and also the morphology of the mantle plume.

The turbidite channel of South China Sea has been highly concerned. Influenced by the complex fault and the rapid phase change of lithofacies, predicting the channel through conventional seismic attributes is not accurate enough. In response to this disadvantage, this study used a method combining grey relational analysis (GRA) and support vector machine (SVM) and established a set of prediction technical procedures suitable for reservoirs with complex geological conditions. In the case study of the Huangliu Formation in Qiongdongnan Basin, South China Sea, this study first dimensionalized the conventional seismic attributes of Gas Layer Group I and then used the GRA method to obtain the main relational factors. A higher relational degree indicates a higher probability of responding to the attributes of the turbidite channel. This study then accumulated the optimized attributes with the highest relational factors to obtain a first-order accumulated sequence, which was used as the input training sample of the SVM model, thus successfully constructing the SVM turbidite channel model. Drilling results prove that the GRA-SVM method has a high drilling coincidence rate. Utilizing the core and logging data and taking full use of the advantages of seismic inversion in predicting the sand boundary of water channels, this study divides the sedimentary microfacies of the Huangliu Formation in the Lingshui 17-2 Gas Field. This comprehensive study has shown that the GRA-SVM method has high accuracy for predicting turbidite channels and can be used as a superior turbidite channel prediction method under complex geological conditions.

The South China Sea is in the convergence zone of the Pacific plate, the Indo-Australian plate, and the Eurasian plate. Its formation and tectonic evolution were influenced by continental margin spreading and plate interaction between the three plates and their microcontinents. It has a complex geodynamic background. To understand how continents break up to form ocean basins, the South China Sea Basin is taken as an example to study the dynamic mechanism of its formation and evolution and the driving force of seafloor spreading, so as to understand the relationship between oceanic–continental lithosphere plates. The South China Sea basin’s opening mechanism and its principal factors of control remain controversial. To explore the influence of different extension rates, we summarized the different genesis mechanisms of the South China Sea, and combined with the tectonic section of the basin, the numerical simulation was obtained based on the finite difference method. The results obtained from numerical simulations show that the rapid extension rate was one of the important factors in the asymmetric expansion of the model, with other factors such as the thickness and rheological properties of the lithosphere held constant. The lithospheric mantle continued thinning in the stress concentration area, with the crust being pulled apart before the lithospheric mantle, eventually forming an ocean basin corresponding to the east sub-basin. However, when the extension rate was low, the model expanded almost symmetrically, and the lithosphere thinning occurred at a slow rate. The simulation results confirm that, compared with the southwest sub-basin of the South China Sea, the spreading rate of the east sub-basin was even higher. We believe that the subduction of the proto-South China Sea played a crucial role in the opening of the South China Sea, providing a more reasonable mechanism. The opposite movement of the Indo-Australian plate and Kalimantan may have inhibited the formation of the southwest sub-basin of the South China Sea, resulting in a later spreading of the southwest sub-basin than the east sub-basin, as well as a lower rate of spreading than the east sub-basin.

南中国海位于三大板块的汇聚地带,分布范围广、地球动力学背景复杂,因此其成因及动力学模式仍然存在争议.根据南中国海的地质和重磁资料对南中国海进行平面和剖面构造特征分析,在此基础上进行了数值模拟.模拟结果表明较弱的下地壳使得壳幔脱耦,裂谷向一侧迁移,由于后续岩浆热供给不足,上涌地幔冷却而停滞;新的岩浆供给跃迁至相反方向,形成新的扩张中心,流变性弱的下地壳和区域高伸展速率共同控制了洋脊的向西迁移.结合构造解译和数值模拟结果分析,认为南中国海的形成主要受印澳板块与欧亚板块的碰撞、古南海的俯冲拖曳和深部地幔上涌3个因素的影响,印澳板块与欧亚板块的碰撞及古南海的俯冲拖曳控制了南中国海的构造应力场,深部地幔上涌控制岩浆迁移.

Rifted margins in the central South Atlantic portray spatial variability in terms of preserved width and thickness,which relates to complex rift-related fault activities.However,there is still a lack of systematic and quantitative explanations for the causes of the variations that are observed along the paired rifts.To elucidate this issue,2D viscous-plastic thermomechanical numerical models are applied to capture the behavior of deformation,in which we investigate the effects of extensional rate,crustal strength and thickness on crust-mantle coupling,and timing of transition from rifting to breakup.Our numerical experiments demonstrate that crust-mantle decoupling accounts for crustal hyperextension,and that incorporating moderate-intensity rheology into lower crust may yield insights into the hyper-extended crust and asymmetric architecture observed in the central South Atlantic.The results also suggest that undulations in lithospheric basement cause asymmetric mantle upwelling.The lower crust of fold belts takes priority to be thermally weakened over craton and induces rift migration simultaneously.A new mechanism for the formation of failed rift is described,where the mechanical decoupling derived from thermally weakened lower crust gives access to dual rift migration.These results reinforce the interpretation on how crustal rheology shapes margins architectures and highlight the first-order effects of crust-mantle coupling.

贝加尔裂谷位于全球最大的大陆板块中心,远离任何活跃板块边界,却是地球上现今构造活动最为活跃和复杂的地区之一,其形成演化的主控因素是地球科学界广泛讨论的问题之一并一直存在争议.文章通过物理实验模拟手段,研究了裂谷区在局部拉张背景下,岩石圈形变过程.贝加尔裂谷区位于较强的西伯利亚克拉通与较弱的萨彦—贝加尔造山带结合部位.克拉通一侧下地壳强度大,壳幔机械耦合程度高,实验结果显示,当区域遭受局部拉张时,应力易在克拉通一侧聚集,最先于克拉通与造山带薄弱缝合处的靠近克拉通边缘一侧发育深大断裂.随着岩石圈不断伸展,应力向造山带一侧传递,断裂也随之向造山带一侧发生迁移,呈现雁列式排列.古老克拉通相比于年轻造山带下地壳流变性质差异,决定了贝加尔裂谷窄且深凹陷的发育特征及发育结构的不对称性.

Efficient exploration and development of oil and gas resources in complex geological environments continue to pose significant challenges for the energy industry. The localization and extraction of reservoirs in basins with complex structures, developed faults, and scattered sedimentary sand bodies are topics of international interest. One such basin, the Hailar Basin in northeastern China, represents a complex geological environment with heterogeneous distributions of oil and gas reserves, along with variable reservoir conditions, leading to challenges in hydrocarbon exploration and extraction. The Sudeert oil field, situated within this basin, is known for its high productivity; nevertheless, the underlying factors responsible for its success are not yet fully comprehended. Based on seismic, logging, and core data from the Sudeert oil field, as well as previous research, this study comprehensively analyzed the sedimentary environment, sedimentary facies characteristics, sand body distribution patterns, vertical stacking relationships of sand bodies, and hydrocarbon accumulation potential of the oil reservoirs in the Lower Cretaceous Xing’anling Formation in the Sudeert oil field. The Xing’anling Formation I and II oil reservoirs are deposited in a fan-delta front sedimentary environment, and the sedimentary microfacies that are conducive to the development of reservoir sand bodies include underwater distributary channels, underwater natural levees, estuary dams, front silt beds, and turbidite sands. Among them, the underwater distributary channel microfacies is the main depositional facies for the development of reservoir sand bodies. Three major depositional patterns of fan lobes can be identified within this depositional system: 1) isolated, 2) contact, and 3) superimposed lobes. Different combinations of lobes developed in different blocks and resulted in different sand body depositional patterns. The isolated lobes mainly developed in the western oil-producing (B28 block) due to the scarcity of sand and slowly increasing accommodation space. The contact lobes mainly developed in the central oil-producing block (B14 block) due to sufficient sediment supply and steadily increasing accommodation space across a wide area. The superimposed lobes mainly developed in the southeast oil-producing block (B16 block) due to sufficient sediment input and steadily increasing accommodation space within a restricted area. In the whole study area, the superimposed lobe pattern is the most favorable depositional pattern and forms the highest-quality reservoirs because of the high degree of sand body connectivity. These results also highlight the utility of sedimentary patterns and sand body assemblage studies for the oil exploration and development of similar rifted basins.

This paper proposes a new research method for braided river sedimentation on the beach shore based on the action of tidal currents. This study conducts a statistical analysis of the length and width of a single braided river and channel bar sand body, and establishes the relationship function model of the quantitative scale of a single braided river and the channel bar. According to the core and logging data of the Nanwu area of the target oilfield, a quantitative methodology based on the calculation of a single accretion scale is established from three perspectives: the architecture interface identification of the accretion, the occurrence and scale calculation of the interlayer, and the scale calculation of the single accretion. In the Nanwu area, the inclination angle of the accretion interface in the direction of the long axis is 0.78–1.32°, and the inclination angle of the accretion interface in the direction of the short axis is 2.02–3.78°. The density of a single well group is generally 2–3 per well. The length of the single accretion in the channel bar is 700–1500 m. Based on these findings, this paper completes the construction of the architecture of the channel bar, and establishes the quantitative scale calculation method for architecture elements for different levels of braided river reservoirs. The research results provide support for the prediction of the braided river reservoir architecture and the remaining oil in similar blocks.

黑龙江兴凯湖国家级自然保护区是许多濒危物种的主要栖息地,几乎容纳了三江平原的所有重要物种.保护区位于Global 200优先生态区俄罗斯远东江河湿地之内,是东亚—澳大利西亚迁飞区的重要廊道,位列全球重要鸟类和生物多样性关键地区,地理位置独特,具有国际重要意义,在生物多样性保护和科研方面具有突出价值.文章从自然资源概况、突出普遍价值、完整性及国际对比角度分析兴凯湖自然保护区的世界自然遗产潜力价值,认为其是我国东北地区的重要申遗潜力区.

随着巴西和西非海上巨型油气田的不断发现,盐相关勘探技术进步和数据资料快速积累,深入开展南大西洋被动陆缘盆地下白垩统盐岩成因环境及盐构造变形机理的研究,对于基础地质理论发展及海洋油气勘探开发具有重要的现实意义.南大西洋两岸被动陆缘盆地下白垩统阿普特阶盐岩构造具有明显的分带性特征,显示了从伸展构造到挤压构造连续过渡特点.巴西一侧,出现连续分布厚层盐岩,盐上和盐下地层协调变形.盐岩构造变形开始于洋壳出现的阿尔比期,漂移期新海底负地形空间的增长,触发了沉积载荷作用下的盐岩构造变形.随着被动陆缘沉积沉降,两侧陆地抬升(地幔作用),以及板块边界上构造应力的远程传递作用(南美),到新近纪持续发生重力作用下的构造变形.物理模拟实验以及在力学上实现正演再现的离散元数值模拟,表明南大西洋盐构造变形为重力构造作用成因,斜坡上的重力作用形成被动陆缘盆地的伸展—过渡—挤压的盐构造分带.局部高地抬升(被动陆缘断块抬升)扰动盐岩流动,盐岩颗粒具有较大的向上速度分量,形成盐株、盐底辟构造.而前缘构造阻挡(大洋地壳、SDRs形成、过渡型伸展地壳、出露的超镁铁质地幔等抬升造成)、盐上地层压力(载荷)则是坡下盐岩运动速率降低,出现聚集增厚现象的主要原因.南大西洋两岸的盐构造经历多期构造变形改造,主要涉及两期(阿尔比期和新生代)盐构造变形流动及其向大洋盆地的前展式扩张.沿着盐层滑动过程中重力滑动及重力扩展的混合作用模式,可以解释本区主体的盐构造样式.

为探明龙门山构造带隆升变形的主要控制因素,基于龙门山构造带东西两侧下地壳物质层属性差异巨大的特征,进行3组PFC2D离散元数值模拟对比实验,将深度扩大至下地壳,记录颗粒运动状态,实现定量化分析.实验得到的变形结果及模型颗粒运动矢量图显示,在下地壳物质属性无明显差异的条件下,板块碰撞挤压应力及地壳厚度的差异不会在龙门山构造带形成巨大的地形高差.当下地壳黏度系数存在明显差异时,软弱下地壳物质层颗粒相对运动速率为1.5～2.94 m/s,平均运动速率为1.62 m/s,大约是坚硬下地壳层颗粒平均运动速率的54倍.模型中部(龙门山构造带)出现隆升变形,纵向影响范围为94.74％,隆升幅度为19.85％.软弱下地壳上覆的中地壳和上地壳颗粒具有较大的向上速度分量,上地壳物质层上涌趋势明显.巴颜喀拉块体和四川盆地地壳存在20 km的厚度差异,使得龙门山构造带隆升幅度由14.79％ 增至19.85％.综合分析3组离散元模拟实验结果,得出巴颜喀拉地块下地壳物质层与四川盆地下地块物质层的黏度差异是龙门山构造带垂向隆升变形最关键控制因素的结论,在下地壳黏度结构存在明显差异的前提下,巴颜喀拉块体和四川盆地的地壳厚度差异对龙门山构造带纵向上逆冲隆升幅度有明显的促进作用.

The oceanic crustal thickness of mid-ocean ridges and adjacent ocean basins can well reflect the characteristics of melt accretion of the mid-ocean ridges, which is of great significance for the study of magmatic activities and tectonic evolution along the mid-ocean ridges and their surroundings. As a typical slow-spreading mid-ocean ridge, the spreading patterns of the Northwest Indian Ocean Ridge (NWIR) has a strong spatio-temporal relationship with tectonic patterns. In this paper, oceanic crustal thickness model derived from gravity shows the distribution of oceanic crustal thickness and melt accretion characteristics of NWIR. It is found that the average thickness of the oceanic crust within Northwest Indian Ocean is 7. 8 km, and the thickness distribution of oceanic crust is different. According to the statistical distribution characteristics of oceanic crustal thickness, the crust is divided into three types: thin oceanic crust (<4. 5 km), normal oceanic crust (4.5-6. 5 km) and thick oceanic crust (>6. 5 km). The NWIR is divided into five segments within 40 Ma, in that case, oceanic crustal thickness around ridge segment is controlled by regional tectonic processes and mantle temperature. The thin oceanic crust is mainly influenced by transform faults which make regional oceanic crust thickness thinning, while thick oceanic crust is affected by the mantle temperature and hot spot. S4 ridge segment shows a strong interaction between hot spot and mid-ocean ridge. Besides, cracking and drift of micro-continents may also be one of the causes of oceanic crust thickness variation.

借助世界自然遗产数据库(UNESCO),从全球尺度对遗产的地域分布、类型类别、入选标准进行综合分析,提出在现有世界自然遗产发展框架下所存在的问题并提出建议,参考世界自然保护联盟(IUCN)对全球世界自然遗产地保护前景评估报告《世界遗产展望3》,总结分析遗产地保护现状及所面临的潜在威胁,以期为全球自然遗产的发展与保护工作提供帮助,同时为我国今后世界自然遗产申报和遗产地的保护管理等工作提供理论参考.

海底热液系统是地球热量平衡的重要组成,也是地球化学循环和成矿作用发生的主要场所,与洋中脊系统在空间上具有很强的联系.慢速-超慢速扩张洋中脊中确认的活跃热液喷口数量约占全球总数量的三分之一,查明热液发育位置及发育岩性与岩浆-构造活动的耦合关系,对于研究海底热液活动演化过程和海底找矿具有很好的指示意义.本文将全球慢速-超慢速扩张洋中脊中已确认的活跃热液活动进行统计分类,其中受岩浆活动控制的热液活动有29处,而受构造活动控制的热液活动有15处,相对于快速-中速扩张洋中脊显示出较强的构造相关性.研究发现,岩浆作用控制下的热液活动集中在洋中脊轴部中央裂谷内,而构造主控型热液活动常发育在非转换不连续间断和拆离断层系统内.随着大洋核杂岩成熟,热液活动位置向着离轴方向迁移,并且热液类型由高温"黑烟囱"型向低温弥散流型转变.