Journal of Geodynamics最新文献

{"title":"Kinematic reconstruction of the Raohe accretionary complex, Northeast China: Integration of onshore geologic evidence and global plate model","authors":"Zaizheng Zhou ,&nbsp;Zuozhen Han ,&nbsp;Sanzhong Li ,&nbsp;Zhaoxia Jiang ,&nbsp;Xiyao Li ,&nbsp;Haoyuan Lan","doi":"10.1016/j.jog.2021.101895","DOIUrl":"10.1016/j.jog.2021.101895","url":null,"abstract":"<div><p><span><span>The Raohe accretionary complex (RHC) is located at the eastern of northeast China and adjacent to Russian Far East. As a part of the Circum-Pacific Orogenic Belt, it is the unique region of the accretionary orogenic belt, which is associated with the subduction process of the Panthalassic-Pacific Plate (PPP). We synthesize the detrital </span>zircon ages of terrigenous </span>clastic rocks<span><span><span> of the RHC and tectonic units along the East Asian Continental Margin (EACM) to clarify its provenance. Then we place the docking position of the RHC adjacent to the South China Block, and determine that the final accretion of the RHC occur during the later </span>Late Jurassic (~150 Ma) according to combination for ages of stitching plutons and terrigenous clastic rock. Integrating with the published global-scale plate kinematic frame, we restored the pre-docking motion path of the RHC using the Gplates software. The reconstructed scenario shows that it is a long distance of at least 1000 km between the proto-RHC and continent margin when the basaltic </span>volcanism occurred subaqueously within the abyssal basin of the PPP. This model also provides a probability that the proto-RHC and the proto-Yuejingshan accretionary complexes have the same drift history, before their simultaneous emplacement into the continental margin.</span></p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"149 ","pages":"Article 101895"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42964298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fractal dimension and area of seismicity in the Baikal Rift System: Implications for modern geodynamics","authors":"A.V. Klyuchevskii ,&nbsp;V.M. Dem'yanovich ,&nbsp;F.L. Zuev ,&nbsp;A.A. Klyuchevskaya ,&nbsp;A.A. Kakourova ,&nbsp;A.A. Golovko","doi":"10.1016/j.jog.2021.101894","DOIUrl":"10.1016/j.jog.2021.101894","url":null,"abstract":"<div><p><span>The fractal geometry and extent of seismicity in the Baikal Rift System (BRS) are estimated from data on 52,700 instrumental events of </span><em>M</em>_LH ≥ 2.5 magnitudes for fifty years (1964–2013). The seismic pattern is characterized by the box-counting Hausdorff dimension <em>D</em>₀, multifractal spectra <em>f</em>(<em>α</em>), and surface area <em>S</em> of seismicity at three scales: the rift system as a whole, its three zones, and six subzones. The multifractal spectra record a self-similar hierarchical structure of the BRS seismicity pattern. The space and time variations in the fractal dimension (<em>D</em>₀) and area of seismicity (<em>S</em><span>), which are mapped and plotted as a function of time, show good correlation. The two parameters depend on three related factors: progressive increase in the amount of instrumental data (dataset size), structure of seismogenic fault network, and geodynamic activity. They increase as ever more data appear with time and acquire high local values at increasing extent and density of quakes. Moreover, the obtained </span><em>D</em>₀ estimates reflect statistical self-similarity of earthquake patterns being in the range ≈ 1.45–1.55 over most of BRS, except one zone and one subzone in the rift flanks. They are the highest in the southwest and the lowest in the northeast of the rift system (<em>D</em>₀ ≈ 1.60 ± 0.02 and <em>D</em>₀ ≈ 1.37 ± 0.02 respectively). This dissimilarity indicates that seismogenic faulting occurs by different mechanisms: distributed failure as a result of superposed global-scale collisional compression and regional rifting in the SW flank and quasi-linear rift propagation in the NE flank. In general, <em>D</em>₀ decreases toward the northeastern part of the BRS, where the pattern of earthquakes becomes localized along lineaments instead of being distributed over an area. The space and time variations of <em>D</em>₀ and <em>S</em><span> revealed in the earthquake data are consistent with the location and activity pulses of rifting attractors and provide a realistic explanation of BRS geodynamics and tectonophysics. The global lithospheric compression and the regional pulse-like activity of rifting attractors control the network of seismogenic faults which, in turn, govern the fractal geometry and 2D structure of seismicity in the region. The obtained results confirm the oscillatory dynamics of the regional seismicity at a decadal period correlated with activity pulses of rifting attractors. The oscillations stand out against the background of decreasing global low-frequency secular cycle of the BRS seismicity. The BRS lithospheric geodynamics fits the model of a nonlinear oscillator with dissipation. The suggested analysis of the fractal geometry and extent of seismicity as proxies of the faulting evolution provides insights into modern geodynamics of the Baikal Rift System a","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"149 ","pages":"Article 101894"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41678175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geodynamic events leading to formation of passive western continental margin of India","authors":"T. Radhakrishna ,&nbsp;B.K. Bansal ,&nbsp;Ch. Ramakrishna","doi":"10.1016/j.jog.2021.101878","DOIUrl":"10.1016/j.jog.2021.101878","url":null,"abstract":"<div><p><span>The geodynamic<span> events of continental breakup<span> and origin of northwest Indian Ocean led to the development of passive continental margin, off western India. However, causal mechanisms and relative chronology of these geodynamic events are not clearly known because of complex regional-scale ridges-basin physiography, multi-stage rifting in a short-time span and thick sediment cover. The Laxmi and adjacent Gop basins constitute key tectonic elements and geophysical investigations on them have come up with sharply divergent explanations of continental rifting and ocean spreading. We present geochemical results of the Laxmi Basin (LB) basement, recovered by the International Ocean Discovery Program Expedition-355 and interpreted in light of existing geophysical results. The basement is identified as continental rift </span></span></span>basalt, different from the Deccan/Madagascan basalts. We suggest the basement eruption at ~75 Ma causing igneous underplating which triggered the extension/rifting in Laxmi and Gop basins. The rifting translated into ocean spreading only in the Gop Basin and not in the Laxmi Basin. The geodynamic events echoed soon with similar relative chronology in western India with Reunion plume impact and the Deccan eruption followed by second extension/rifting that culminated in India-Seychelles breakup.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"148 ","pages":"Article 101878"},"PeriodicalIF":2.3,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46046680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The tectono-stratigraphic and magmatic evolution of conjugate rifted margins: Insights from the NW South China Sea","authors":"Peng Chao ,&nbsp;Gianreto Manatschal ,&nbsp;Pauline Chenin ,&nbsp;Jianye Ren ,&nbsp;Cuimei Zhang ,&nbsp;Xiong Pang ,&nbsp;Jinyun Zheng ,&nbsp;Linlong Yang ,&nbsp;Nick Kusznir","doi":"10.1016/j.jog.2021.101877","DOIUrl":"10.1016/j.jog.2021.101877","url":null,"abstract":"<div><p>This study is based on a careful analysis of high-quality reflection seismic sections located at the tip of the NW South China Sea V-shaped rift basin. Using the CGN-1 section, a seismic line imaging the complete sedimentary and magmatic architecture of conjugate rifted margins, we: (1) provide a detailed description of the crustal architecture; (2) define extensional domains, which we relate to specific deformation phases; and (3) determine the tectono-stratigraphic evolution linked to rifting. Based on these, we propose a kinematic restoration and quantify the amounts of extension and associated strain rates. We discuss the link between the kinematic evolution and the sedimentary and magmatic record and illustrate it in a Wheeler Diagram. Relying on the identification and characterization of distinct stratal patterns and crustal architectures, we propose qualitative and quantitative criteria to interpret two critical rift events that are necking and hyperextension. These two events are linked to the individualization and subsequent dismembering of a so-called keystone, here referred to as H-block. It is the first time such an approach is used to decipher the tectono-stratigraphic evolution of a complete syn-rift mega-sequence across present-day conjugate rifted margins. This study differs from previous interpretations of correlative surfaces in the distinction between: (1) different types of top basement; and (2) syn- and post-tectonic packages within the syn-rift record. It leads to new interpretations of the tectono-stratigraphic evolution of the NW South China Sea and has the potential to be used as a new approach to analyze, quantify and correlate events recorded in seismic sections across rifted margins.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"148 ","pages":"Article 101877"},"PeriodicalIF":2.3,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42711791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ca. 835–823 Ma doming extensional tectonics in the west Jiangnan accretionary orogenic belt, South China: Implication for a slab roll-back event","authors":"Jinlong Yao ,&nbsp;Liangshu Shu ,&nbsp;Guochun Zhao ,&nbsp;Yigui Han ,&nbsp;Qian Liu","doi":"10.1016/j.jog.2021.101879","DOIUrl":"10.1016/j.jog.2021.101879","url":null,"abstract":"<div><p><span>The Neoproterozoic Jiangnan accretionary orogenic belt recorded the accretion and collision of the Yangtze and Cathaysia blocks to form a stablized South China Block, but related geometry and kinematics is poorly constrained, leading to largely varied tectonic models. Here, we present detailed field investigation and kinematic analysis of the plutonic-metamorphic complexes in the Yuanbaoshan and Sanfang areas of the west Jiangnan orogenic belt, which enables identification of extensional granite-cored domes. In the dome margins, down-dipping </span>lineations<span><span> display a radial pattern and dome dominated foliations are extensively developed. The shearing structures within the plutonic-metamorphic complexes display extensional shearing surrounding the Yuanbaoshan and Sanfang granitic dome cores. Gneissic granites and massive ones from both the Yuanbaoshan and Sanfang plutons yield comparable crystallization ages of ca. 835–823 Ma that are within age errors of each other, as are the sheared recrystallized asymmetric quartz veins and mylonites dated at 831 Ma. Overall ages of the deformed Sibao Group and the undeformed overlying Danzhou Group, along with those of the granite plutons and mylonites, suggest formation of the granite-cored domes at ca. 835–823 Ma, coeval to the timing of emplacement of the granitic plutons. Locally, top-to-the-E thrusting structures are also observed in the west Yuanbaoshan and Sanfang areas and are inferred as at ca. 860–835 Ma, coinciding well with E- or SE- directed structures developed elsewhere in the Jiangnan orogenic belt, but in contrast with doming extensional shearing structures. Therefore, overall geometry and kinematics in the west Jiangnan belt indicate development of granitic dome related extensional ductile shearing deformation dated at ca. 835–823 Ma and a possible top-to-the-E compressional ductile thrusting deformation within 860–835 Ma. Given the previously inferred </span>regional geology<span><span> observations, along with age and chemical data across the Jiangnan orogenic belt, the dominant extensional shearing deformation in the region argue for a slab roll-back event within an accretionary belt, typical of domes-and-basins structures formed in accretionary convergent continental margin. The top-to-the-E thrusting is here interpreted as corresponding to compressional regime generated by the west directed subduction of </span>oceanic crust beneath the northern Guangxi continental margin arc in the west Jiangnan orogenic belt.</span></span></p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"148 ","pages":"Article 101879"},"PeriodicalIF":2.3,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42341284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithosphere ionosphere coupling associated with three earthquakes in Pakistan from GPS and GIM TEC","authors":"M. Arslan Tariq ,&nbsp;Munawar Shah ,&nbsp;Zishen Li ,&nbsp;Ningbo Wang ,&nbsp;M. Ali Shah ,&nbsp;Talat Iqbal ,&nbsp;Libo Liu","doi":"10.1016/j.jog.2021.101860","DOIUrl":"10.1016/j.jog.2021.101860","url":null,"abstract":"<div><p><span><span>Total Electron Content (TEC) derived from satellite-based measurements has been widely used for the detection of </span>ionospheric<span><span> perturbations associated with earthquakes. In this paper, we analyze Pre-Earthquake Ionospheric Anomalies (PEIAs) with TEC data from Global Positioning System (GPS) stations in two Pakistani regions, Islamabad (33.74°N, 73.16°E) and Multan (30.26°N, 71.50°E). These stations operate within seismogenic zones of three earthquakes in Pakistan and Tajikistan. We implement a statistical technique on daily TEC for the detection of PEIA. The results show that PEIAs appear in the form of enhancement during 08:00–12:00 UT (LT = UT+5 h) within 5–10 days before the mainshock. Global Ionospheric Maps (GIMs) over the </span>epicentre are examined on abnormal TEC days. Dense electron enhancements occur during 08:00−12:00 UT, i.e. before three M</span></span><em>_w</em>&gt; 5.0 earthquakes. Diurnal mean TEC deviates on the suspected days. It supports the anomalous signatures observed in the temporal and spatial distributions during the particular days. The geomagnetic and solar indices show no activity. These results endorse the existence of Lithosphere Atmosphere Ionospheric Coupling (LAIC) mechanism within the earthquake preparation period associated with the Pakistan and Tajikistan earthquakes.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"147 ","pages":"Article 101860"},"PeriodicalIF":2.3,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jog.2021.101860","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41293327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A black hole particle swarm optimization method for the source parameters inversion: application to the 2015 Calbuco eruption, Chile","authors":"Leyang Wang ,&nbsp;Xibo Jin ,&nbsp;Wenbin Xu ,&nbsp;Guangyu Xu","doi":"10.1016/j.jog.2021.101849","DOIUrl":"10.1016/j.jog.2021.101849","url":null,"abstract":"<div><p><span>The traditional genetic algorithm and simulated annealing methods have been widely used in geophysical modeling. However, these nonlinear inversion methods require a lot of calculations, many control parameters and are unstable. In this paper, a particle swarm optimization algorithm combined with black hole strategy (BH-PSO) is proposed to solve these problems. The comprehensive experiments show that the BH-PSO method consumes less time than the simulated annealing (SA) method and has a higher accuracy than the genetic algorithm (GA). It is more applicable to the inversion of parameters of volcanic magma chamber, and easier to be generalized to other kinematic source parameters inversion. Based on BH-PSO method, Sentinel-1 data, composite dislocation model (CDM), Yang model and Mogi model, the magma chamber parameters of Calbuco eruption in 2015 were retrieved. The results show that the RMSE of CDM model is 1.1 cm, which can better fit the surface deformation than the Mogi model and Yang model. The final results show that the magma chamber is located about 0.8 km northeast of the crater, about 9 km below the surface, and the total volume of the erupted volcanic material obtained with the CDM Model is of 0.209 km</span>³, without considering dense rock equivalent.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"146 ","pages":"Article 101849"},"PeriodicalIF":2.3,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jog.2021.101849","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43522358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress changes associated with the significant first subevent of the 2008 Wenchuan earthquake and implications for the rupture behavior transition","authors":"Yujiang Li ,&nbsp;Lianwang Chen ,&nbsp;Hong Li ,&nbsp;Yuanzhong Lu","doi":"10.1016/j.jog.2021.101859","DOIUrl":"10.1016/j.jog.2021.101859","url":null,"abstract":"<div><p>The rupture process of the Wenchuan earthquake demonstrated a transition from thrust-dominated slip to northeastward strike-slip motion along the Longmen Shan Fault Zone. The initial stress has been reported as playing a critical role in this process; however, the stress changes, especially those caused by the significant first subevent of the Wenchuan earthquake are not well understood. Here, we employ a three-dimensional finite element model of the Sichuan-Yunnan region to analyze the stress change caused by the significant first subevent and explore the possible influence on the following ruptures. The results indicate that the auxiliary maximum principal compressive stress (S_H) associated with the significant first subevent was horizontal and that the auxiliary stress regime was S_H&gt;S_h&gt;S_v, supporting the ongoing regional thrust motion near the southwestern segment of the rupture plane. However, in the northeastern segment, the auxiliary stress regime transitioned to S_H&gt;S_v&gt;S_h, demonstrating that the stress changes promoted the transition of the rupture behavior from predominantly thrust motion in the southwest to right-lateral strike-slip motion in the northeastern segment, which was also supported by the dominant shear stress change and the subtle normal stress change along the fault plane in the northeastern segment. In addition, our modeled results also indicate that the orientation of the maximum principal compressive stress changed from SEE to northeastward NEE along the strike of Longmen Shan Fault Zone. This anticlockwise rotation hastened the rupture behavior transition, suggesting that both the initial stress and the stress changes associated with the first subevent jointly controlled the following northeastward rupture of the Mw7.9 Wenchuan earthquake.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"146 ","pages":"Article 101859"},"PeriodicalIF":2.3,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jog.2021.101859","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42232309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simple picture of mantle wedge flow patterns and temperature variation","authors":"Ikuko Wada","doi":"10.1016/j.jog.2021.101848","DOIUrl":"10.1016/j.jog.2021.101848","url":null,"abstract":"<div><p>The solid-state mantle flow is an important factor that controls the mass and heat transfer in the solid Earth. This study aims to provide a simple picture of three-dimensional (3-D) mantle flow patterns in the sub-arc region of subduction zones<span> based on the results of 3-D steady-state numerical models with varying subduction parameters. Here, the mantle wedge flow pattern is evaluated based on the azimuthal directions of the mantle inflow from the back-arc and the down-dip outflow. The outflow direction generally parallels the subduction direction, but the inflow direction relative to the outflow direction depends on the local subduction obliquity – the angle between the subduction direction and the strike-normal axis of the subducting slab. A change in the strike of the slab leads to a change in the obliquity and thus the inflow direction. Such change is common along curved margins as the strike of the slab tends to follow that of the margin, or vice versa. Along convex-arc-ward margins, the mantle inflow is deflected towards the region of lowest obliquity but with reduced vigor due to lower dynamic pressure gradients that partly drive the flow, resulting in a cooler mantle wedge. Along concave-arc-ward margins, the mantle inflow is deflected away from the region of lowest obliquity but with increased vigor, resulting in a hotter mantle wedge. These effects increase with decreasing radius of curvature. Along-margin change in the dip of the subducting slab also affects the inflow direction through its impact on the strike of the slab, but its effect is relatively small. We express the azimuthal inner angle between the inflow and outflow directions as a function of obliquity and apply the function to predict sub-arc mantle inflow directions in the circum-Pacific and neighboring regions. Within and among these margins, the inner angle varies over its full range of 0–180°. Most of the margins that are 1000s of kilometers in length are either straight or curved concave-arc-ward with large radii of curvature, for which small or gradual along-margin changes in the mantle inflow direction and the mantle wedge temperature are predicted. A large drop in the mantle wedge temperature by up to a couple of hundred degrees is predicted at short convex-arc-ward segments, such as at the Kuril-Japan and Bonin-Mariana junctions. The fringes of flat slab segments are curved with small radii of curvature, likely resulting in sharp lateral changes in the inflow direction and the mantle wedge temperature.</span></p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"146 ","pages":"Article 101848"},"PeriodicalIF":2.3,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jog.2021.101848","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44272939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of multi-seamount subduction on accretionary wedge deformation: Insights from analogue modelling","authors":"Chunyang Wang ,&nbsp;Weiwei Ding ,&nbsp;Wouter P. Schellart ,&nbsp;Jiabiao Li ,&nbsp;Chongzhi Dong ,&nbsp;Yinxia Fang ,&nbsp;Tianyao Hao ,&nbsp;Zhengyi Tong","doi":"10.1016/j.jog.2021.101842","DOIUrl":"10.1016/j.jog.2021.101842","url":null,"abstract":"<div><p>Deformation patterns caused by the subduction of a single seamount or aseismic ridge have been well studied in analogue and numerical models. However, the effects of sequential multi-seamount subduction on accretionary wedge deformation have rarely been investigated in details. We performed a series of analogue modelling experiments of sequential subduction involving two seamounts of variable shape, spacing and rheological properties of strata to better understand the deformation mechanisms of an accretionary wedge with multi-seamount subduction. The results demonstrate that a seamount significantly hinders the seaward propagation of the accretionary wedge and facilitates lateral propagation. Two structural quiet zones form at the leading and trailing edges of the subducted seamount in the early stage of collision. As the seamount deeply penetrates into the wedge, the structural quiet zone in the leading edge is remoulded by a duplex structure, which may help the upward transport of deep subducted sediments back into the shallow area. Comparatively, the structural quiet zone in the trailing edge remains undeformed because it is situated in the stress shadow of the seamount. Deformation of the strata between two subducting seamounts may occur by thrusts laterally propagating into the seamount gap, which is facilitated by the décollement layer. The modelling results provide insights into the complex deformation mechanisms related to seamounts collision observed in the accretionary wedge offshore from the Costa Rica margin.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":"145 ","pages":"Article 101842"},"PeriodicalIF":2.3,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jog.2021.101842","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46097490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}