IF 4.2 1区地球科学

Tectonics Pub Date : 2024-09-10 DOI: 10.1029/2024tc008341

Chao Li, Zhongbao Zhao, Marie-Luce Chevalier, Yong Zheng, Dongliang Liu, Haijian Lu, Paul D. Bons, Haibing Li

{"title":"Lancang Fault Assists Block Extrusion in Southeastern Tibet During Early-Middle Miocene","authors":"Chao Li, Zhongbao Zhao, Marie-Luce Chevalier, Yong Zheng, Dongliang Liu, Haijian Lu, Paul D. Bons, Haibing Li","doi":"10.1029/2024tc008341","DOIUrl":"https://doi.org/10.1029/2024tc008341","url":null,"abstract":"The tectonic and topographic evolution of the southeastern Tibetan Plateau based on low-temperature thermochronology data is controversial, especially whether it is tectonically- or climatically-controlled, especially along the Lancang fault (LCF) that links the flat central plateau to the west with the high relief southeastern Tibetan Plateau to the east. To explore the tectonic evolution of the LCF and its role in the tectonic and topographic evolution of the southeastern Tibetan Plateau, we carried out detailed field investigation and low-temperature thermochronology (AHe, AFT, and ZHe) analyses. Field evidence indicate that the northern LCF splits into two branches, the Yangda-Yaxu and Baqing-Leiwuqi faults, the latter striking N50°W and dipping to the SW at ∼55°, exposing >100 m-wide fault rocks composed of a fault damage zone, breccia, and gouge. New thermochronology data and thermo-kinematic modeling results suggest rapid exhumation of the region located between these two fault branches during ∼22–10 Ma at an exhumation rate of ∼1.57 km/Ma, compared to slow cooling prior to 22 Ma and since 10 Ma. We propose that internal anti-clockwise block rotation triggered rapid local exhumation, and that the final merging of different parts of the LCF during the Early-Middle Miocene assisted the southeastward escape of Sundaland, which profoundly affected the evolution of the regional geomorphology.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Surface Rupture of the 2008 Mw 6.6 Nura Earthquake: Triggered Flexural-Slip Faulting in the Pamir-Tien Shan Collision Zone 2008 年 6.6 级努拉地震的地表断裂：帕米尔-天山碰撞带触发的挠性-滑动断层

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-09-05 DOI: 10.1029/2024tc008360

M. Patyniak, A. Landgraf, A. Dzhumabaeva, S. Baikulov, A. M. Williams, F. Preusser, K. E. Abdrakhmatov, J R. Arrowsmith, M. R. Strecker

{"title":"Surface Rupture of the 2008 Mw 6.6 Nura Earthquake: Triggered Flexural-Slip Faulting in the Pamir-Tien Shan Collision Zone","authors":"M. Patyniak, A. Landgraf, A. Dzhumabaeva, S. Baikulov, A. M. Williams, F. Preusser, K. E. Abdrakhmatov, J R. Arrowsmith, M. R. Strecker","doi":"10.1029/2024tc008360","DOIUrl":"https://doi.org/10.1029/2024tc008360","url":null,"abstract":"This study investigates the intricate relationship between earthquake sources and seismogenic surface ruptures in a complex tectonic setting with active faults in the continental collision zone between the southern Tien Shan and the northern Pamir Mountains in Central Asia. The study focuses on the 2008 Mw 6.6 Nura earthquake along the Pamir Frontal Thrust, where the seismogenic surface rupture occurred unexpectedly within the footwall and 10 km away from the source thrust fault. This discrepancy raises questions about the interactions and potential trigger mechanisms between tectonic structures during earthquake rupture. Using unmanned aerial vehicle photography and field inspection, our investigation integrates detailed fault-zone mapping with tectono-geomorphic observations to unravel potential interactions between subsurface structures and surface-deformation phenomena. Our findings suggest that a combination of slip along deep-seated basement faults and remotely triggered flexural slip within folded Paleogene strata led to surface rupture of overlying Quaternary glacial deposits. Geomorphological and geochronological analyses coupled with systematic displacement measurements furthermore reveal evidence of similar past ruptures within the regional fault system, suggesting a recurrence interval of 1.7 kyr and a Holocene vertical offset rate of 0.4 mm/yr. The analysis of the Nura rupture zone contributes significantly to evaluate linkages between surface and subsurface structures regarding fault-zone behavior and seismic hazard assessments. Importantly, our results highlight the critical role of on-site investigations in regions with poorly defined surface ruptures, where misinterpretation may lead to the underestimation of the impact of seismic events and limitations in assessing earthquake history and strain accumulation.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vertical Deformation Along a Strike-Slip Plate Boundary: The Uplifted Marine Terraces of the Gulf of Aqaba and Tiran Island, at the Southern End of the Dead Sea Fault 沿着一个走向-滑动板块边界的垂直变形：死海断层南端亚喀巴湾和蒂朗岛隆起的海洋地层

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-31 DOI: 10.1029/2023tc007977

Matthieu Ribot, Marthe Lefèvre, Yann Klinger, Edwige Pons-Branchu, Arnaud Dapoigny, Sigurjón Jónsson

{"title":"Vertical Deformation Along a Strike-Slip Plate Boundary: The Uplifted Marine Terraces of the Gulf of Aqaba and Tiran Island, at the Southern End of the Dead Sea Fault","authors":"Matthieu Ribot, Marthe Lefèvre, Yann Klinger, Edwige Pons-Branchu, Arnaud Dapoigny, Sigurjón Jónsson","doi":"10.1029/2023tc007977","DOIUrl":"https://doi.org/10.1029/2023tc007977","url":null,"abstract":"Close to its southern end where it connects to the Red Sea rift, the Dead Sea strike-slip fault (DSF) becomes trans-tensional in the Gulf of Aqaba. Details of this transition, however, remain difficult to unravel as most of the active tectonic structures are located off-shore. This study focuses on uplifted marine terraces located in the Gulf of Aqaba and on Tiran Island. Using high-resolution tri-stereo Pleiades satellite imagery, we build a Digital Surface Model (DSM) at a 0.5-m resolution of the eastern coast of the gulf and Tiran Island to map 19 levels of marine terraces. The terraces are preserved at elevations from 1 m to almost 500 m above the current sea level. Correlating laterally U-Th ages obtained along the gulf with the lower levels found on Tiran Island, we build an age model to estimate the ages of the upper terraces on the island. Combining this with the terrace heights from our DSM, we derive the uplift rate affecting the terraces. The geographic extent of the terraces along the gulf suggests that the DSF is responsible for uplift along the entire eastern coastline of the gulf at a rate of about 0.14 ± 0.03 mm/year at least over the Quaternary. The uplift rate of Tiran Island, located closer to the Red Sea rift, is faster at 0.21 ± 0.02 mm/year over the past 2.4 Myr. This faster uplift rate suggests a combined tectonic uplift related to both the Dead Sea strike-slip fault system and the Red Sea rift.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Surface Rupture and Fault Characteristics Associated With the 2020 Magnitude (MW) 6.6 Masbate Earthquake, Masbate Island, Philippines 菲律宾马斯巴特岛 2020 年 6.6 级马斯巴特地震相关的地表破裂和断层特征

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-31 DOI: 10.1029/2023tc008106

D. C. E. Llamas, B. J. Marfito, R. Dela Cruz, M. A. Aurelio

{"title":"Surface Rupture and Fault Characteristics Associated With the 2020 Magnitude (MW) 6.6 Masbate Earthquake, Masbate Island, Philippines","authors":"D. C. E. Llamas, B. J. Marfito, R. Dela Cruz, M. A. Aurelio","doi":"10.1029/2023tc008106","DOIUrl":"https://doi.org/10.1029/2023tc008106","url":null,"abstract":"On 18 August 2020, Masbate Island was struck by a magnitude (MW) 6.6 earthquake. This seismic event represents the second occurrence of a strong earthquake (M > 6) in 17 years, emphasizing the necessity for further investigation into the characteristics of this event. In this study, we employ Interferometric Synthetic Aperture Radar, seismicity analysis, and field investigations to comprehensively characterize the coseismic and postseismic slip associated with the event. Our findings reveal a 50-km-long fault rupture along the Masbate segment of the Philippine Fault, with ∼23 km surface rupture mapped onshore, despite the occurrence of interseismic creep. The slip distribution demonstrates decreasing displacements northwestward toward the creeping section, with a maximum left-lateral displacement of 0.97 m near the epicenter. Toward the southeast offshore, the rupture terminates at a left stepover of a fault. While the surface rupture appears relatively straight and narrowly concentrated, the secondary ruptures and mapped offshore faults reveal a more complex transtensional fault structure in the southeastern part of Masbate Island. This fault complexity represents an asperity that facilitates high-stress accumulation and rupture initiation. Postseismic slip persists for several months along the onshore creeping segment. Based on comprehensive measurements of both cumulative and coseismic slip along the Masbate fault segment, we calculate a slip rate ranging between 2.8 and 3.8 cm/year and a recurrence interval of 16–41 years for earthquakes similar to the 2020 earthquake. Our study highlights how heterogeneity in fault properties, including geometry and coupling state, influences the distribution of slip and magnitude of earthquakes. The 2020 Masbate earthquake provides valuable insights into the rupture dynamics and fault behavior of the Philippine Fault in the Masbate region.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detachment and Transfer Fault Systems in the Northern South China Sea, Insights Into 3D Tectonic Segmentation of Rifted Margins 南海北部的剥离和转移断层系统，对裂谷边缘三维构造划分的启示

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-31 DOI: 10.1029/2023tc008172

Shihao Hao, Lianfu Mei, Jinyun Zheng, César R. Ranero

{"title":"Detachment and Transfer Fault Systems in the Northern South China Sea, Insights Into 3D Tectonic Segmentation of Rifted Margins","authors":"Shihao Hao, Lianfu Mei, Jinyun Zheng, César R. Ranero","doi":"10.1029/2023tc008172","DOIUrl":"https://doi.org/10.1029/2023tc008172","url":null,"abstract":"The 2D rifting modes interpreted in traditional “magma-poor” and “magma-rich” margins cannot explain the crustal structure and inferred rifting processes in the northern South China Sea (SCS) rifted margin. The “intermediate-type” terminology has been therefore applied to the mid-northern SCS, where a “wide-rift” model has been widely accepted. However, the tectono-magmatic processes of the SCS are still debated and at least five contrasting models exist. We present a compilation of 3-D seismic volumes and regional 2-D seismic surveys covering the entire Baiyun and Liwan Sub-basins to investigate their tectonic structure and faulting style in this “wide-rift” region. We interpret two segments with contrasting tectonic styles separated by a volcanic lineament and steep transfer faults. The Baiyun Sub-basin was controlled by a landward-dipping detachment system. The Liwan Sub-basin, however, was formed by a ∼100 km-long oceanward-dipping, concave-up detachment fault working at a low angle of <10°. The lateral boundaries of the detachment system were mechanically decoupled from surrounding tectonics by a volcanic lineament/transfer zone to the west and a > 190 km-long N-S-trending left-lateral strike-slip fault to the east. The planar low-angle detachment does not resemble classical metamorphic core complex domes interpreted previously. Our results indicate a 60-80 km-wavelength segmentation within a single “wide-rift” system, indicating complex 3D rifting during crustal extension. This study supports that the intermediate SCS margin had a kinematically complex deformation style locally dominated by the interaction between detachment and transfer fault systems that might be yet unrecognized in other margins.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Crustal Structure of the Northeast South China Sea Rifted Margin 中国南海东北部裂陷边缘的地壳结构

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-23 DOI: 10.1029/2024tc008399

Mateus Rodrigues de Vargas, Julie Tugend, Geoffroy Mohn, Nick Kusznir, Lin Liang-Fu

{"title":"Crustal Structure of the Northeast South China Sea Rifted Margin","authors":"Mateus Rodrigues de Vargas, Julie Tugend, Geoffroy Mohn, Nick Kusznir, Lin Liang-Fu","doi":"10.1029/2024tc008399","DOIUrl":"https://doi.org/10.1029/2024tc008399","url":null,"abstract":"We investigate the crustal structure of the Northeastern (NE) South China Sea (SCS) rifted margin to constrain its crustal thickness and basement nature with implications for the Mesozoic and Cenozoic evolution of the SCS. First-order interfaces interpreted from seismic reflection data were integrated into a 3D gravity inversion scheme to determine Moho depth and crustal thickness variations. A joint inversion of seismic and gravity data allowed us to determine crustal density variations along 2D profiles. The distal margin of the NE SCS is divided into two distinct crustal domains: the Southern Rift System (SRS), and the Southern High (SH). The SRS shows an extremely thinned crust on top of which thick Cenozoic sequences are observed. It is separated from the oceanic crust (∼6–8 km thick) by the SH, a comparatively thicker crustal domain (∼10–15 km thick) with significant magmatic additions. The distal NE SCS margin formed during the Cenozoic rifting of the SCS. The SH likely corresponds to a polygenic piece of crust, recording polyphase magmatic activity since the Mesozoic, with potentially significant activity during Cenozoic post-rift time. The NE SCS margin is conjugate to Palawan whose basement is considered to be part of the exotic Luconia microcontinent that collided with Eurasia during the Late Cretaceous. Basement similarities between Palawan and the SH are highlighted, suggesting that the latter might also be part of Luconia. Our results suggest that the docking/suture zone between Eurasia and Luconia might have acted as a preferred zone for the Cenozoic rift development.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Time Constraints on the Late Cenozoic Fault Evolution Along the Northern Margin of the Iranian Plateau in the Arabia-Eurasia Collision Zone 阿拉伯-欧亚大陆碰撞带伊朗高原北缘晚新生代断层演化的时间制约因素

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-21 DOI: 10.1029/2023tc008034

Sedigheh Khodaparast, Saeed Madanipour, Eva Enkelmann, Khaled Hessami, Reza Nozaem

{"title":"Time Constraints on the Late Cenozoic Fault Evolution Along the Northern Margin of the Iranian Plateau in the Arabia-Eurasia Collision Zone","authors":"Sedigheh Khodaparast, Saeed Madanipour, Eva Enkelmann, Khaled Hessami, Reza Nozaem","doi":"10.1029/2023tc008034","DOIUrl":"https://doi.org/10.1029/2023tc008034","url":null,"abstract":"The collisional Iranian Plateau and its recent kinematic evolution represent a natural example to study the intraplate response to the transferred deformation from an active convergent plate margin. The late Cenozoic deformation and structural evolution of the Plateau is not well understood. Here, we integrate structural, tectonostratigraphic, and morphotectonic field observations with low-temperature thermochronometric data along the NW-SE trending Kushk-e-Nosrat (KN) Fault to unravel the exhumation history and the kinematic change at the northwestern boundary of the Iranian Plateau. We found different sets of strike-slip related structures along the KN Fault zone, which are classified into four categories based on their cross-cutting relations and the superimposition of kinematic indicators. These include dextral transtension, dextral, dextral transpression, and sinistral kinematics. The unreset zircon (U-Th)/He and apatite fission track results and the reset apatite (U-Th)/He data from the restraining area along the KN Fault suggest 80–60°C of cooling during the early Miocene (∼20–18 Ma) and late Miocene–early Pliocene (∼7–5 Ma) due to dextral and dextral transpressional kinematics along the KN Fault zone, respectively. The dextral transtentional faulting was recorded as deposition of the Qom Formation within the releasing overlap areas along the KN Fault at >20–18 Ma. The kinematics of the KN Fault changed to sinistral during Pliocene–Quaternary times presumably triggered by the simultaneous clockwise rotation of central Iran, Alborz Mountains, and the South Caspian block. Our study proposes that the morphological and tectonostratigraphic evolution of the northern margin of the Iranian Plateau has mainly been controlled through local uplift and exhumation in restraining areas and local thick deposition in releasing areas of the major strike-slip faults during the late Cenozoic time.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring Uplift Mechanisms Across the Forearc of a Subduction System: Karpathos Island as a Natural Transect Across the Eastern Hellenic Margin 探索俯冲系统前弧的上升机制：将卡尔帕索斯岛作为横跨东希腊边缘的自然横断面

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-21 DOI: 10.1029/2023tc008156

Violeta Veliz-Borel, Vasiliki Mouslopoulou, Johannes Glodny, John Begg, Sabrina Metzger, Dimitris Sakellariou, Onno Oncken

{"title":"Exploring Uplift Mechanisms Across the Forearc of a Subduction System: Karpathos Island as a Natural Transect Across the Eastern Hellenic Margin","authors":"Violeta Veliz-Borel, Vasiliki Mouslopoulou, Johannes Glodny, John Begg, Sabrina Metzger, Dimitris Sakellariou, Onno Oncken","doi":"10.1029/2023tc008156","DOIUrl":"https://doi.org/10.1029/2023tc008156","url":null,"abstract":"Sets of marine terraces, sediments, and paleoshorelines are commonly found in forearc regions worldwide. A common assumption holds that crustal uplift prevents these features from littoral erosion. Here, we study the vertical deformation of Karpathos, a forearc island in the eastern Mediterranean, whose long axis extends at a high angle to the strike of the Hellenic Subduction System (HSS). We target three key coastal localities along the island to discuss spatial and temporal variability of vertical motion. We mapped sets of up to 19 marine terraces per locality, with elevations ranging from 1.5 to ∼350 masl. Ages for terraces and sediments are constrained by radiocarbon (<31 masl) and Sr-isotope (2–310 masl) dating, and range from 2.4 ka to ∼4.3 Ma. Data analysis shows that average uplift rates are up to two orders of magnitude faster over shorter (⪅100 ka) than longer (⪆100 ka) timescales, in agreement with other local and global data sets. Further, we find evidence for multiple marine reoccupations of late Pleistocene terraces, indicating that carbonate beachrock is often resistant to multiple interactions with sea-level. Neogene marine sequences that witness longer periods (∼4 Ma) show signs of alternating vertical motion. Using this novel data set, we explore the effects of various mechanisms (i.e., upper-plate normal faulting, splay-thrust faulting, basal underplating) on the spatial and temporal patterns of vertical deformation. Although the contribution of each mechanism to the net vertical deformation cannot be isolated with certainty, our results show that none alone could account for the observations.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Serpentinization and Magmatic Distribution in a Hyperextended Rift Suture: Implication for Natural Hydrogen Exploration (Mauléon Basin, Pyrenees) 超延伸裂谷断裂中的蛇纹石化和岩浆分布：对天然氢勘探的影响（比利牛斯山脉莫莱昂盆地）

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-15 DOI: 10.1029/2024tc008385

N. Saspiturry, C. Allanic, A. Peyrefitte

{"title":"Serpentinization and Magmatic Distribution in a Hyperextended Rift Suture: Implication for Natural Hydrogen Exploration (Mauléon Basin, Pyrenees)","authors":"N. Saspiturry, C. Allanic, A. Peyrefitte","doi":"10.1029/2024tc008385","DOIUrl":"https://doi.org/10.1029/2024tc008385","url":null,"abstract":"The Mauléon basin is a world-class example of hyperextended rift suture. The basin possesses key attributes of an optimal hydrogen target, namely mantle, at shallow depth with tectonic structures rooted into it. Natural H2 seepages have been recognized at the surface in the foothills. Yet distribution and quantification of serpentinization within the mantel piece representing the potential H2 source has not been addressed while this aspect is crucial to consider further exploration. We discuss these aspects using joint gravimetric and magnetic 2D forward modeling along two orthogonal transects. 2D forward modeling shows that serpentinization gradually increases from bottom (20 km depth) to top reaching a maximum amount of nearly 76% (8 km depth). The N-S transect evidence that serpentinization fronts are northward inclined, suggesting a N-S serpentinization gradient responsible for the long wavelength gravity and magnetic anomalies. This orientation matches that of detachment within the former hyperextended domain, which exhumed the mantle during the Cretaceous. The W-E transect shows that serpentinization also increase toward the east reaching its maximum amount against the Barlanès lithospheric structure. The latter also coincides with the main short wavelength magnetic anomaly recognized in the basin. Forward geophysical modeling reveals that this anomaly could be linked to the presence, at shallow depth, of an alkaline magmatic body or a shallower piece of highly serpentinized subcontinental mantle both attesting for the paroxysm of the Cretaceous rifting phase. Finally, we propose a conceptual model of the H2 life cycle in the Mauléon basin and discuss the implications for H2 exploration.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deformation Mechanisms During the Syn-Orogenic Extrusion of the High-Pressure Phyllites-Quartzites Unit in the Central and Northern Peloponnese, Greece 希腊伯罗奔尼撒半岛中部和北部高压辉绿岩-石英岩单元同步造山挤压过程中的变形机制

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-14 DOI: 10.1029/2023tc008116

Vincent Wicker, Simon Bufféral

{"title":"Deformation Mechanisms During the Syn-Orogenic Extrusion of the High-Pressure Phyllites-Quartzites Unit in the Central and Northern Peloponnese, Greece","authors":"Vincent Wicker, Simon Bufféral","doi":"10.1029/2023tc008116","DOIUrl":"https://doi.org/10.1029/2023tc008116","url":null,"abstract":"The High-Pressure Phyllites-Quartzites (PQ) unit of the External Hellenides is exposed in tectonic windows in the central and northern Peloponnese (Greece). Understanding the deformation history of this unit is essential to interpreting the Oligo-Miocene evolution of the External Hellenides belt and its associated exhumation events. This study integrates new field observations and microtectonic analyses with previous studies to offer a comprehensive deformation model of the PQ unit since the Late Oligocene. The first deformation phase (D1), captures the progressive incorporation of the PQ into an orogenic wedge. This phase is largely overprinted and only preserved as relict features. The second phase (D2) displays coeval top-to-the-ENE and top-to-the-WSW localized ductile shear. A transition is observed from top-to-the-ENE non-coaxial deformation at the upper parts of the nappe to intense isoclinal folding (refolding S1) at the lower structural levels. We associate D2 with the ductile syn-orogenic exhumation of the PQ within an extrusion wedge, accompanied by greenschist-facies retrogression. In the third phase (D3), semi-brittle to brittle extensional fault planes cut through the previous ductile structures. D3 faults exhibit extensional kinematics in all directions on the flanks of exhumation domes. This phase correlates with a late-orogenic doming event, marking the final exhumation stage of the PQ unit in the upper crust. The exhumation of high-pressure units results from the interplay between ductile syn-orogenic extrusion and continuous underplating within the subduction zone. This underplating maintains vertical movements and uplift of the units, initiating a 3D upper-crustal extensional collapse along low-angle normal faults.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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