Tectonics最新文献_第2页

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}

引用次数: 0

Single-Stage Synchronous India-Asia Collision Model Revealed by Himalayan High-Pressure Metamorphic Rocks 喜马拉雅高压变质岩揭示的印度-亚洲单级同步碰撞模型

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-14 DOI: 10.1029/2024tc008253

Yanling Zhang, Changqing Yin, Lin Ding, Shun Li, Jiahui Qian, Peng Gao, Wangchao Li

{"title":"Single-Stage Synchronous India-Asia Collision Model Revealed by Himalayan High-Pressure Metamorphic Rocks","authors":"Yanling Zhang, Changqing Yin, Lin Ding, Shun Li, Jiahui Qian, Peng Gao, Wangchao Li","doi":"10.1029/2024tc008253","DOIUrl":"https://doi.org/10.1029/2024tc008253","url":null,"abstract":"Despite a half-century of intense research, the timing and diachroneity of initial collision between India and Asia remain highly debated, largely due to different definitions of “initial collision” and correspondingly different methods adopted. This study focuses on high-pressure pelitic granulites of the Eastern Himalayan Syntaxis (EHS) to elucidate their metamorphic evolution and provide new constraints on the timing of initial India-Asia collision. Petrological examination and phase equilibria modeling show that high-pressure pelitic granulites have undergone four metamorphic stages, with the peak assemblage of garnet + K-feldspar + kyanite + biotite ± plagioclase ± rutile + ilmenite + quartz at P-T conditions of 13.1–15.7 kbar and 790–850°C. Clockwise P-T paths suggest that the Indian continent underwent tectonometamorphic processes of initial collision and subsequent continent subduction. Zircon and monazite dating results indicate that the metamorphic ages of pelitic granulites range from 60 to 15 Ma, with the oldest ones clustered at 60–58 Ma. The oldest metamorphic ages of high- to ultrahigh-pressure Himalayan metamorphic rocks can provide an upper age limit of the initial collision. Therefore, the initial India-Asia collision must have occurred before 60–58 Ma in the EHS, roughly consistent with ca. 57 Ma in the western Himalaya and 63–60 Ma in the central Himalaya. Collectively, we conclude that the northern margin of India most likely underwent a single-stage synchronous collision with the southern margin of Asia initially at around 60 Ma along the entire Yarlung-Tsangpo suture zone.","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":"142209528","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

Slip Distribution Along the Chenghai Fault From Airborne LiDAR and Tectonic Implications for the 1515 Yongsheng Earthquake, China 机载激光雷达显示的澄海断层滑动分布及其对中国 1515 年永胜地震的构造影响

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-10 DOI: 10.1029/2024tc008285

Haomin Ji, Zhikun Ren, Xiaoxiao Zhu, Mingkun Bai, Guodong Bao, Jinrui Liu, Guanghao Ha, Zhongtai He

{"title":"Slip Distribution Along the Chenghai Fault From Airborne LiDAR and Tectonic Implications for the 1515 Yongsheng Earthquake, China","authors":"Haomin Ji, Zhikun Ren, Xiaoxiao Zhu, Mingkun Bai, Guodong Bao, Jinrui Liu, Guanghao Ha, Zhongtai He","doi":"10.1029/2024tc008285","DOIUrl":"https://doi.org/10.1029/2024tc008285","url":null,"abstract":"The tectonic deformation of the southeastern margin of the Tibetan Plateau underwent significant changes before and after the Miocene, which led to the change of the deformation characteristics of the Sichuan-Yunnan block, and some local areas in the block also showed structural patterns inconsistent with the macroscopic clockwise rotation deformation. Moreover, the Chenghai fault (CF) in the Sichuan-Yunnan block was the seismogenic fault of the M 73/4 Yongsheng earthquake in 1515. However, the dense vegetation impeded the acquisition of surface deformation characteristics and small-scale horizontal offsets along the fault, resulting in its misty kinematic properties, roughly determined geometric distribution, and the highly controversial rupture parameters of the Yongsheng earthquake. Therefore, we used airborne light detection and ranging, which can penetrate vegetation to obtain high-resolution surface topography, to map the CF within 120 km. Combined with satellite images and field investigations, we determined that the CF consists of a series of secondary faults with simple geometric structures. Continuous offset linear landforms were preserved along the fault. 102 offsets below 30 m were statistically analyzed and the result revealed that the CF has a characteristic displacement of ∼6 m and it may rupture as a united rupture segment in each large earthquake or its two rupture segments cascade rupture to generate large earthquakes. The magnitude of the Yongsheng earthquake in 1515 was estimated at 7.7. Finally, based on this study, the kinematic characteristics of the Dali terrane and Sichuan-Yunnan block, where the CF is located are discussed.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933222","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

Block Rotations in NW Iran in Response to the Arabia-Eurasia Collision Constrained by Paleomagnetism 古地磁学制约的伊朗西北部地块旋转与阿拉伯-欧亚大陆碰撞的关系

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-07 DOI: 10.1029/2023tc008139

Ali Niknam, Annique van der Boon, Mahnaz Rezaeian, Nuretdin Kaymakcı, Cor Langereis

{"title":"Block Rotations in NW Iran in Response to the Arabia-Eurasia Collision Constrained by Paleomagnetism","authors":"Ali Niknam, Annique van der Boon, Mahnaz Rezaeian, Nuretdin Kaymakcı, Cor Langereis","doi":"10.1029/2023tc008139","DOIUrl":"https://doi.org/10.1029/2023tc008139","url":null,"abstract":"Northwest Iran is a seismically active region dominated by NW-SE trending strike-slip faults, such as the North Tabriz and Qosha Dagh faults, and smaller NNE-SSW striking faults. The Bozgush Mountains are shaped by these faults and divided into two domains that show a difference in strike. To quantify rotational tectonic deformation in NW Iran, we performed a paleomagnetic study along three transects of the Bozgush and Qosha Dagh Mountains with 127 sites. Our large new paleomagnetic data set shows that the Bozgush Mountains did not rotate as a single rigid block. In the western domain of the Bozgush Mountains, we find evidence for clockwise vertical axis rotations of ∼40°, while the eastern domain has rotated up to ∼80° clockwise. Declinations of the western Bozgush domain fit well with observed declinations in the Qosha Dagh Mountains. Fault patterns show that the eastern domain of the Bozgush Mountains is divided by a set of NNE-SSW striking sinistral strike-slip faults, which created domino-style blocks that accommodated the additional 40° of rotation. We estimate that these extra rotations have resulted in around 4 km of N-S shortening and more than 1.5 km of differential uplift.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933224","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

Kinematics Along the Qingchuan Fault and Deformation Pattern in the Eastern Tibetan Plateau 青藏高原东部青川断层运动学与变形模式

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-06 DOI: 10.1029/2023tc008075

Haoyue Sun, Honglin He, Yasutaka Ikeda, Ken'ichi Kano, Wei Gao, Wen Sun, Feng Shi, Peng Su, Tomoo Echigo, Shinsuke Okada, Yoshiki Shirahama

{"title":"Kinematics Along the Qingchuan Fault and Deformation Pattern in the Eastern Tibetan Plateau","authors":"Haoyue Sun, Honglin He, Yasutaka Ikeda, Ken'ichi Kano, Wei Gao, Wen Sun, Feng Shi, Peng Su, Tomoo Echigo, Shinsuke Okada, Yoshiki Shirahama","doi":"10.1029/2023tc008075","DOIUrl":"https://doi.org/10.1029/2023tc008075","url":null,"abstract":"The accommodation of the substantial eastward crustal motion of the Bayan Har block characterizes the dynamics of faults located at the eastern Tibetan Plateau. However, uncertainties persist concerning the manner and amount of deformation distributed on these faults, with slip senses and rates constituting critical factors. In the northeastern segment of the Longmenshan thrust zone, the contentious activity and the unknown geologic slip rate present challenges. This study, focusing on the Qingchuan fault, the predominant fault within the northeastern Longmenshan, employed satellite imagery interpretation, displaced fluvial terraces surveying, displacement measurements, and chronological analysis to comprehensively characterize its fault activity. Our investigation robustly demonstrates the Qingchuan fault has been active since the late Quaternary, and is primarily marked with a pronounced dextral slip at a rate of 0.6–1.0 mm/year. By quantitatively assessing the deformation rates of the faults at the eastern Tibetan Plateau, we propose that they sufficiently accommodate the entire eastward crustal movement of the Bayan Har block; thereby no additional deformation propagates beyond the Qingchuan fault. Furthermore, we introduce a subblock model to elucidate the regional crustal deformation pattern, wherein the eastward movement of the Bayan Har block transfers to the northeastward movement of the Bikou subblock. This movement results in reverse slip patterns for the Minjiang and Huya faults, while the Beichuan and Qingchuan faults predominantly experience dextral displacements. The complex strain partitioning within the northern Longmenshan range underscores the observed variations in slip patterns across different segments of the Longmenshan thrust zone, advancing our understanding of fault behavior and the orchestration of crustal deformation in this intricate tectonic framework.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933165","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

The Bend on the Haiyuan Strike-Slip Fault Leads to Segmented Activity of the Minle-Damaying Thrust Fault in the Qilian Shan, the Northeastern Tibetan Plateau 海原走向滑动断层弯曲导致青藏高原东北部祁连山民乐-大麦营推断断层分段活动

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-04 DOI: 10.1029/2023tc008239

Qingri Liu, Jianguo Xiong, Peizhen Zhang, Wei Tao, Luyuan Huang, Xuhang Yang, Yihui Zhang, Feipeng Huang, Xiuli Zhang, Huiping Zhang, Chuanyou Li, Youli Li

{"title":"The Bend on the Haiyuan Strike-Slip Fault Leads to Segmented Activity of the Minle-Damaying Thrust Fault in the Qilian Shan, the Northeastern Tibetan Plateau","authors":"Qingri Liu, Jianguo Xiong, Peizhen Zhang, Wei Tao, Luyuan Huang, Xuhang Yang, Yihui Zhang, Feipeng Huang, Xiuli Zhang, Huiping Zhang, Chuanyou Li, Youli Li","doi":"10.1029/2023tc008239","DOIUrl":"https://doi.org/10.1029/2023tc008239","url":null,"abstract":"The present tectonic regime of the Qilian Shan is dominated by large northeast and northwest striking strike-slip faults and northwest striking thrust faults. Deformation distribution between the subparallel Haiyuan Strike-slip Fault and the Minle-Damaying Thrust Fault (MDF) is crucial for understanding the orogenic mechanism of the northeastern Tibetan Plateau. However, the uncertain kinematics of the MDF and the stress variation along the strike-varying Haiyuan Fault inhibit further discussion of their relationship. Five key sites along the MDF were selected for analysis of terrace abandonment ages and vertical offsets to determine the slip rates. Two finite element models were constructed to calculate the stress-strain relationship between the Haiyuan Fault and MDF. We find that the activity of the MDF can be divided into two segments by a stepover with less activity and lower terrain at the Xida River site. Shortening rates of the MDF vary between 0.2 and 2.4 mm/a since the late Pleistocene with trapezoidal trends on both fault segments. The two finite element models and GPS data reveal that the strain rates are lower at the Xida River site but higher at the Menyuan Bend on the Haiyuan Fault. We infer that long-term strain accumulation at the Menyuan Bend may have mitigated the tectonic activity northeast to the bend under the northeastward stress field, including the activity of the MDF at the Xida River site, and resulted in the segmentation of the MDF.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933223","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

Cenozoic Pulsed Rise and Growth of the Chinese South Tianshan Revealed by Zircon and Apatite Provenance Analyses: Implications for Stepwise Aridification in the Tarim Basin 锆石和磷灰石产状分析揭示的中国南天山新生代脉冲式上升和增长：塔里木盆地逐步干旱化的影响

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-02 DOI: 10.1029/2023tc008211

Dunfeng Xiang, Zhiyong Zhang, David Chew, Marc Jolivet, Marco G. Malusà, Thomas Zack, Lin Wu, Chao Guo, Nan Wang, Wenjiao Xiao

{"title":"Cenozoic Pulsed Rise and Growth of the Chinese South Tianshan Revealed by Zircon and Apatite Provenance Analyses: Implications for Stepwise Aridification in the Tarim Basin","authors":"Dunfeng Xiang, Zhiyong Zhang, David Chew, Marc Jolivet, Marco G. Malusà, Thomas Zack, Lin Wu, Chao Guo, Nan Wang, Wenjiao Xiao","doi":"10.1029/2023tc008211","DOIUrl":"https://doi.org/10.1029/2023tc008211","url":null,"abstract":"Cenozoic uplift in the Tianshan played an important role in driving Proto-Paratethys Sea retreat and Asian aridification. However, most paleoclimate studies have focused on the Pamir-Tianshan corridor, and frequently overlook the role of the entire Tianshan range in modifying the Central Asian climate during Cenozoic uplift. When and how Cenozoic deformation of Tianshan was initiated and propagated are intensively debated which makes its role in contributing to climate change in Central Asia more ambiguous. To address this issue, this study presents new detrital zircon U-Pb and detrital apatite U-Pb and fission track age data from Cenozoic sedimentary successions (54–0 Ma) in the northern margin of the Tarim Basin and integrates these data with published provenance data from adjacent regions. Our results show that deformation/uplift of the Baicheng-Kuqa Depression and the South Tianshan occurred at ∼41–37 Ma and ∼24 Ma, when topographic growth of South Tianshan began to block the flow of sediment from the north. Continued uplift of the South Tianshan completely blocked fluvial transport from the Central Tianshan-Yili Block by ∼10 Ma, as shown by the paucity of 380–310 Ma detrital zircons/apatites. Far-field, north-directed compressive stress resulting from the India-Asia collision began to propagate toward the South Tianshan and its foreland during the Late Eocene, and continued to propagate into the South Tianshan and northward at the ∼24 Ma and 10 Ma. Finally, we suggest a two-stage of aridification in the Tarim Basin which can be linked to two stages (∼24 and 10 Ma) of growth of the Tianshan.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884574","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

The Role of Lower Crustal Rheology on Surface Deformation During Oblique Extension: Insights From Sandbox Modeling 下地壳流变对斜向延伸过程中地表变形的作用：沙箱建模的启示

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-02 DOI: 10.1029/2024tc008365

Yuqiong Mao, Yiquan Li, Dong Jia, Xianyan Wang, Yingying Chen, Qin Li, Rui Li

{"title":"The Role of Lower Crustal Rheology on Surface Deformation During Oblique Extension: Insights From Sandbox Modeling","authors":"Yuqiong Mao, Yiquan Li, Dong Jia, Xianyan Wang, Yingying Chen, Qin Li, Rui Li","doi":"10.1029/2024tc008365","DOIUrl":"https://doi.org/10.1029/2024tc008365","url":null,"abstract":"Extensive researches have been conducted on the relationship between surface deformation and the properties of upper crust. However, the link between surface deformation and lower crustal rheology, especially in a three-dimensional context, remains unclear. In this study, we utilize sandbox modeling to investigate the impact of lower crustal rheology on surface deformation during oblique extension. Under the same conditions, six models with different lower crustal viscosities, both with and without syn-kinematic deposits, are conducted. The results indicate that a decrease in lower crustal viscosity may contribute to an increase in: (a) graben width, (b) graben length, (c) graben spacing, (d) the number of isolated rifts and (e) topographic relief of oblique extensional systems, while also leading to a reduction in the total number of grabens. Notably, there exists a negative linear correlation between graben spacing and lower crustal viscosity. In map view, the angle between fault strike and the direction of pre-existing discontinuities increases as the viscosity of the lower crust decreases. Furthermore, the frequency of large rakes (>50°) decreases with decreasing lower crustal viscosity. These findings align with natural examples such as the East African Rift System, Weihe Graben and the South Tibetan Rift in terms of geomorphology, tectonics, and crustal rheology. Through a comprehensive comparison of the graben width, spacing, and the angle between fault strike and the direction of pre-existing discontinuities, our study provides valuable insights into the rheology of the lower crust in natural settings.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884576","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

Transient Aseismic Vertical Deformation Across the Steeply-Dipping Pisia-Skinos Normal Fault (Gulf of Corinth, Greece) 穿越陡倾皮西亚-斯基诺斯正断层的瞬态地震垂直变形（希腊科林斯湾）

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-02 DOI: 10.1029/2024tc008276

Zoë K. Mildon, Manuel Diercks, Gerald P. Roberts, Joanna P. Faure Walker, Athanassios Ganas, Ioannis Papanikolaou, Vassilis Sakas, Jenni Robertson, Claudia Sgambato, Sam Mitchell

{"title":"Transient Aseismic Vertical Deformation Across the Steeply-Dipping Pisia-Skinos Normal Fault (Gulf of Corinth, Greece)","authors":"Zoë K. Mildon, Manuel Diercks, Gerald P. Roberts, Joanna P. Faure Walker, Athanassios Ganas, Ioannis Papanikolaou, Vassilis Sakas, Jenni Robertson, Claudia Sgambato, Sam Mitchell","doi":"10.1029/2024tc008276","DOIUrl":"https://doi.org/10.1029/2024tc008276","url":null,"abstract":"Geodetically-derived deformation rates are sometimes used to infer seismic hazard, implicitly assuming that short-term (annual-decadal) deformation is representative of longer-term deformation. This is despite geological observations indicating that deformation/slip rates are variable over a range of timescales. Using geodetic data from 2016 to 2021, we observe an up to 7-fold increase in vertical deformation rate in mid-2019 across the Pisia-Skinos normal fault in Greece. We hypothesize that this deformation is aseismic as there is no temporally correlated increase in the earthquake activity (M > 1). We explore four possible physical mechanisms, and our preferred hypothesis is that the transient deformation is caused by centimeter-scale slip in the upper 5 km of the Pisia fault zone. This is the first observation of shallow tectonic (i.e., not related to human activities) aseismic deformation on a normal fault globally. Our results suggest that continental normal faults can exhibit variable deformation over shorter timescales than previously observed, and thus care should be taken when utilizing geodetic rates to quantify seismic hazard.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884575","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