Yiquan Li - Academia.edu (original) (raw)

Papers by Yiquan Li

Research paper thumbnail of Late Cenozoic east–west crustal shortening in southern Longmen Shan, eastern Tibet: Implications for regional stress field changes

Research paper thumbnail of Figure 1

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Research paper thumbnail of Figure 4

Research paper thumbnail of Forward modeling of oblique-thrust Fault-Related-Folds and instances analysis

Research paper thumbnail of Cenozoic Deformation of the Northwestern Sichuan Basin——Significance for Understanding the Cenozoic Deformation Regime of the Northeastern Tibetan Plateau

Research paper thumbnail of 王天宝, 贾东, 魏东涛 2, 王彦君 2, 李一泉, 张寒 2

Research paper thumbnail of Mesozoic inverted structure analysis of the southern margin of the Junggar Basin

Research paper thumbnail of Deep lithospheric jointing relationship between South Tienshan orogen and West Kunlun (Pamir) orogeny

Research paper thumbnail of Three-dimensional structural geometry of fault-related folds: Examples from 3-D seismic explored blocks in the western Sichuan Province, China

Research paper thumbnail of Cenozoic deformation of the northwestern Sichuan Basin e significance for understanding the cenozoic deformation regime of the northeastern Tibetan Plateau

Research paper thumbnail of Fluid inclusion planes measurement and paleostress field analysis for Cenozoic Gonggashan granite

Research paper thumbnail of The 2013 Lushan earthquake: Implications for seismic hazards posed by the Range Front blind thrust in the Sichuan Basin, China

Research paper thumbnail of Three Dimension Construction and Magnetic Fabric Analysis of the Yanjinggou Fault-propagation Fold in Western Sichuan, China

Recently, there is a transition trend of the research on the fault-related fold from 2D to 3D. Ba... more Recently, there is a transition trend of the research on the fault-related fold from 2D to 3D. Based on ARCGIS, DISCOVERY and GOCAD software platform, we built a 3D geological model of the Yanjinggou anticline using 3D seismic data in the area. It was found that Yanjinggou anticline was a typical trishear fault-propagation fold. Because the structural interpretation of the 3D model only is of non-uniqueness and uncertainty due to geometric constraint, the finite strain analysis was also applied in the structural interpretation. 184 oriented samples have been drilled at 18 sampling sites in Yanjinggou, western Sichuan. AMS of these samples disclosed: (1) that most of the magnetic fabrics were the initial deformation fabric; (2) that deformation in the forelimb was relatively stronger than that in the rearlimb; and (3) that the finite strain was strong within the trishear zone of the fault-propagation fold, in accordance with demonstration in the 3D geometric model. The tectonic stress field indicated by the magnetic fabrics suggested a NW-SE compression and shortening, which was consistent with the prediction of the 3D geometric model.

Research paper thumbnail of Late Holocene activity and historical earthquakes of the Qiongxi thrust fault system in the southern Longmen Shan fold-and-thrust belt, eastern Tibetan Plateau

Tectonophysics, 2013

The 12 May 2008 Wenchuan earthquake (M w 7.9) generated a 285-km-long surface rupture zone along ... more The 12 May 2008 Wenchuan earthquake (M w 7.9) generated a 285-km-long surface rupture zone along the Longmen Shan fold-and-thrust belt (LSFTB) on the eastern margin of Tibetan Plateau. The Wenchuan earthquake did not rupture into the southwestern Longmen Shan, along which there is no evidence for large paleo-or historical earthquakes. Seismic reflection profiles and field investigations reveal that the 50-km-long Qiongxi thrust fault (QTF) of the southern LSFTB is currently active. The QTF consists of three west-dipping ramp segments overlain by fault-bend folds rooted in a regional detachment that transfers shortening from the mountain belt into the Sichuan basin. Trench investigations, coupled with interpretations of seismic reflection profiles and radiocarbon results, show that a recent surface-rupturing earthquake occurred on the QTF during the Late Ming to Qing Dynasty, between AD 1600 and 1800. In addition, seismic reflection profile and topographic analysis indicate the presence of a subtle topographic, produced by kink-band migration folding above a fault bend at about 5 km depth. These findings confirm that the QTF is a significant seismic hazard, and that it should be incorporated into current regional seismic hazard models for the densely populated Sichuan basin.

Research paper thumbnail of Magnetic fabric investigation in the northwestern Sichuan Basin and its regional inference

Physics of the Earth and Planetary Interiors, 2009

... Permissions & Reprints. Magnetic fabric investigation in the northwestern Sic... more ... Permissions & Reprints. Magnetic fabric investigation in the northwestern Sichuan Basin and its regional inference. ... Different types of magnetic fabrics from sedimentary to pencil structure magnetic fabric and sharps of susceptibility ellipsoids from oblate to prolate were observed. ...

Research paper thumbnail of 3-D geomechanical restoration and paleomagnetic analysis of fault-related folds: An example from the Yanjinggou anticline, southern Sichuan Basin

Journal of Structural Geology, 2013

We examine the development of the Yanjinggou anticline, a fault-propagation-fold in the southern ... more We examine the development of the Yanjinggou anticline, a fault-propagation-fold in the southern Longmen Shan, through an integrated study of structural geometry, strain, and paleomagnetism. The 3-D structural and strain restoration models generated in our analysis reveal that the NE-trending Yanjinggou fold has a curved map trace that is convex to the southeast. The fold has three distinct regions characterized by different strain patterns: contraction in the core of the fold, extension in the outer arc, and a forelimb with distributed shear. To further understand the kinematics of the Yanjinggou anticline, we performed paleomagnetic analysis on 184 oriented samples collected across the structure. Anisotropy of magnetic susceptibility (AMS) measurements and stepwise thermal demagnetization were conducted. A strike test was applied to the high temperature component (HTC) in order to identify rotation around the arc. The result indicates that the Yanjinggou anticline is a progressive arc, with a minor initial curvature and a dominant secondary curvature related to vertical-axis rotation synchronous with thrusting. The primary curvature and initial development of the structure correlates with the growth of the southern Longmen Shan in Late Miocene. The secondary curvature correlates with displacement extending since Late Pleistocene toward the southeast into the central basin along the detachments that underlie the structure. Lateral gradients in displacement along this underlying detachment provide a mechanism for producing the vertical rotation of the anticline. AMS results and historical earthquake analysis imply that the fault-propagation fold, along with other NE trending structures in the southern Sichuan basin, are tectonically active and accommodate east-west crustal shortening in the basin. By integrating 3-D structural and strain restoration modeling with systematic AMS and paleomagnetic methods using statistical analysis, we closely constrain how the Yanjinggou anticline developed, and provide insights into the formation of fault-related folds with curved shapes in map view, which are common in other fold-and-thrust belts around the world.

Research paper thumbnail of Structural interpretation of the coseismic faults of the Wenchuan earthquake: Three-dimensional modeling of the Longmen Shan fold-and-thrust belt

Journal of Geophysical Research, 2010

1] The 2008 M w 7.9 Wenchuan earthquake is a result of ongoing India-Tibet collision and reflects... more 1] The 2008 M w 7.9 Wenchuan earthquake is a result of ongoing India-Tibet collision and reflects the growth of the Longmen Shan fold-and-thrust belt. In this paper, we construct a 3-D structural model of the geometry of the coseismic faults and related structures of the Wenchuan earthquake by integrating geological investigations, relocated aftershocks, and seismic reflection profiles. In the 3-D structural model, the differences between the southern and northern segments of the rupture are highlighted. The structural transition zone between the two segments contains a major geometric segment boundary, reflecting differences in the structural configuration of the thrust ramp and the tectonic evolution of the fault system, which appears to have localized significant damage from Anxian to Beichuan. Within the northern segment, we identify a transverse structure across which the Beichuan fault plunges under the Tangwangzhai syncline. This boundary corresponds to a marked change in the nature of the surface rupture and is illuminated by a microearthquake sequence perpendicular to the Longmen Shan thrust belt. In the southern segment, our investigations confirm that uplift due to active faulting and folding is largely responsible for the areas of steepest topography. On the basis of this association, the southwestern segment of the Longmen Shan, south of the Wenchuan earthquake, is likely active and presents a significant earthquake hazard, despite the lack of historical earthquakes in this region. This study illustrates the importance of building 3-D models to study active faulting and folding, as well as to assess earthquake hazard. (2010), Structural interpretation of the coseismic faults of the Wenchuan earthquake: Three-dimensional modeling of the Longmen Shan fold-and-thrust belt,

Research paper thumbnail of Structural deformation and evolution of right-lateral strike-slip tectonics of the Liaohe western depression during the early Cenozoic

Journal of Asian Earth Sciences, 2013

The Tan-Lu fault zone (TLFZ) traverses the Liaohe western depression (LHWD), affords an exception... more The Tan-Lu fault zone (TLFZ) traverses the Liaohe western depression (LHWD), affords an exceptional opportunity to reveal the structural deformation and evolution of a major strike-slip fault of the LHWD using three dimensional seismic data and well data. In this paper, based on structural interpretations of the 3-D seismic data of the LHWD, combined with depth slice and seismic coherency, a variety of structural features in relation to right-lateral strike-slip fault (the western branch of the Tan-Lu fault) have been revealed presence in the depression, such as thrust faults (Xinlongtai, Taian-Dawa, and Chenjia faults), structural wedges, positive flower structures, and en echelon normal faults. Fault cutoffs, growth strata and the Neogene unconformity developed in the LHWD verify that the activity of right-lateral strike-slip from the late Eocene to Neogene (ca. 43-23 Ma). The study indicates that the right-lateral strike-slip played an important role in controlling the structural deformation and evolution of the LHWD in the early Cenozoic. Moreover, the front structural wedge generated the gross morphology of the Xinlongtai anticline and developed the Lengdong faulted anticline during the late Eocene, and the back structural wedge refolded the Lengdong faulted anticline zone in the late Eocene to the early Oligocene. Wrench-related structures (the Chenjia thrust fault and the en echelon normal faults) were developed during the late Oligocene. Uniform subsidence in the Neogene to Quaternary. Furthermore, the driving force of the right-lateral strike-slip deformation was originated from N-S extension stress related to the opening of the Japan Sea and NE-SW compression, as the far-field effect of India-Eurasia convergence.

Research paper thumbnail of Late Cenozoic east–west crustal shortening in southern Longmen Shan, eastern Tibet: Implications for regional stress field changes

Research paper thumbnail of Figure 1

Research paper thumbnail of Figure 3

Research paper thumbnail of Figure 2

Research paper thumbnail of Figure 4

Research paper thumbnail of Forward modeling of oblique-thrust Fault-Related-Folds and instances analysis

Research paper thumbnail of Cenozoic Deformation of the Northwestern Sichuan Basin——Significance for Understanding the Cenozoic Deformation Regime of the Northeastern Tibetan Plateau

Research paper thumbnail of 王天宝, 贾东, 魏东涛 2, 王彦君 2, 李一泉, 张寒 2

Research paper thumbnail of Mesozoic inverted structure analysis of the southern margin of the Junggar Basin

Research paper thumbnail of Deep lithospheric jointing relationship between South Tienshan orogen and West Kunlun (Pamir) orogeny

Research paper thumbnail of Three-dimensional structural geometry of fault-related folds: Examples from 3-D seismic explored blocks in the western Sichuan Province, China

Research paper thumbnail of Cenozoic deformation of the northwestern Sichuan Basin e significance for understanding the cenozoic deformation regime of the northeastern Tibetan Plateau

Research paper thumbnail of Fluid inclusion planes measurement and paleostress field analysis for Cenozoic Gonggashan granite

Research paper thumbnail of The 2013 Lushan earthquake: Implications for seismic hazards posed by the Range Front blind thrust in the Sichuan Basin, China

Research paper thumbnail of Three Dimension Construction and Magnetic Fabric Analysis of the Yanjinggou Fault-propagation Fold in Western Sichuan, China

Recently, there is a transition trend of the research on the fault-related fold from 2D to 3D. Ba... more Recently, there is a transition trend of the research on the fault-related fold from 2D to 3D. Based on ARCGIS, DISCOVERY and GOCAD software platform, we built a 3D geological model of the Yanjinggou anticline using 3D seismic data in the area. It was found that Yanjinggou anticline was a typical trishear fault-propagation fold. Because the structural interpretation of the 3D model only is of non-uniqueness and uncertainty due to geometric constraint, the finite strain analysis was also applied in the structural interpretation. 184 oriented samples have been drilled at 18 sampling sites in Yanjinggou, western Sichuan. AMS of these samples disclosed: (1) that most of the magnetic fabrics were the initial deformation fabric; (2) that deformation in the forelimb was relatively stronger than that in the rearlimb; and (3) that the finite strain was strong within the trishear zone of the fault-propagation fold, in accordance with demonstration in the 3D geometric model. The tectonic stress field indicated by the magnetic fabrics suggested a NW-SE compression and shortening, which was consistent with the prediction of the 3D geometric model.

Research paper thumbnail of Late Holocene activity and historical earthquakes of the Qiongxi thrust fault system in the southern Longmen Shan fold-and-thrust belt, eastern Tibetan Plateau

Tectonophysics, 2013

The 12 May 2008 Wenchuan earthquake (M w 7.9) generated a 285-km-long surface rupture zone along ... more The 12 May 2008 Wenchuan earthquake (M w 7.9) generated a 285-km-long surface rupture zone along the Longmen Shan fold-and-thrust belt (LSFTB) on the eastern margin of Tibetan Plateau. The Wenchuan earthquake did not rupture into the southwestern Longmen Shan, along which there is no evidence for large paleo-or historical earthquakes. Seismic reflection profiles and field investigations reveal that the 50-km-long Qiongxi thrust fault (QTF) of the southern LSFTB is currently active. The QTF consists of three west-dipping ramp segments overlain by fault-bend folds rooted in a regional detachment that transfers shortening from the mountain belt into the Sichuan basin. Trench investigations, coupled with interpretations of seismic reflection profiles and radiocarbon results, show that a recent surface-rupturing earthquake occurred on the QTF during the Late Ming to Qing Dynasty, between AD 1600 and 1800. In addition, seismic reflection profile and topographic analysis indicate the presence of a subtle topographic, produced by kink-band migration folding above a fault bend at about 5 km depth. These findings confirm that the QTF is a significant seismic hazard, and that it should be incorporated into current regional seismic hazard models for the densely populated Sichuan basin.

Research paper thumbnail of Magnetic fabric investigation in the northwestern Sichuan Basin and its regional inference

Physics of the Earth and Planetary Interiors, 2009

... Permissions & Reprints. Magnetic fabric investigation in the northwestern Sic... more ... Permissions & Reprints. Magnetic fabric investigation in the northwestern Sichuan Basin and its regional inference. ... Different types of magnetic fabrics from sedimentary to pencil structure magnetic fabric and sharps of susceptibility ellipsoids from oblate to prolate were observed. ...

Research paper thumbnail of 3-D geomechanical restoration and paleomagnetic analysis of fault-related folds: An example from the Yanjinggou anticline, southern Sichuan Basin

Journal of Structural Geology, 2013

We examine the development of the Yanjinggou anticline, a fault-propagation-fold in the southern ... more We examine the development of the Yanjinggou anticline, a fault-propagation-fold in the southern Longmen Shan, through an integrated study of structural geometry, strain, and paleomagnetism. The 3-D structural and strain restoration models generated in our analysis reveal that the NE-trending Yanjinggou fold has a curved map trace that is convex to the southeast. The fold has three distinct regions characterized by different strain patterns: contraction in the core of the fold, extension in the outer arc, and a forelimb with distributed shear. To further understand the kinematics of the Yanjinggou anticline, we performed paleomagnetic analysis on 184 oriented samples collected across the structure. Anisotropy of magnetic susceptibility (AMS) measurements and stepwise thermal demagnetization were conducted. A strike test was applied to the high temperature component (HTC) in order to identify rotation around the arc. The result indicates that the Yanjinggou anticline is a progressive arc, with a minor initial curvature and a dominant secondary curvature related to vertical-axis rotation synchronous with thrusting. The primary curvature and initial development of the structure correlates with the growth of the southern Longmen Shan in Late Miocene. The secondary curvature correlates with displacement extending since Late Pleistocene toward the southeast into the central basin along the detachments that underlie the structure. Lateral gradients in displacement along this underlying detachment provide a mechanism for producing the vertical rotation of the anticline. AMS results and historical earthquake analysis imply that the fault-propagation fold, along with other NE trending structures in the southern Sichuan basin, are tectonically active and accommodate east-west crustal shortening in the basin. By integrating 3-D structural and strain restoration modeling with systematic AMS and paleomagnetic methods using statistical analysis, we closely constrain how the Yanjinggou anticline developed, and provide insights into the formation of fault-related folds with curved shapes in map view, which are common in other fold-and-thrust belts around the world.

Research paper thumbnail of Structural interpretation of the coseismic faults of the Wenchuan earthquake: Three-dimensional modeling of the Longmen Shan fold-and-thrust belt

Journal of Geophysical Research, 2010

1] The 2008 M w 7.9 Wenchuan earthquake is a result of ongoing India-Tibet collision and reflects... more 1] The 2008 M w 7.9 Wenchuan earthquake is a result of ongoing India-Tibet collision and reflects the growth of the Longmen Shan fold-and-thrust belt. In this paper, we construct a 3-D structural model of the geometry of the coseismic faults and related structures of the Wenchuan earthquake by integrating geological investigations, relocated aftershocks, and seismic reflection profiles. In the 3-D structural model, the differences between the southern and northern segments of the rupture are highlighted. The structural transition zone between the two segments contains a major geometric segment boundary, reflecting differences in the structural configuration of the thrust ramp and the tectonic evolution of the fault system, which appears to have localized significant damage from Anxian to Beichuan. Within the northern segment, we identify a transverse structure across which the Beichuan fault plunges under the Tangwangzhai syncline. This boundary corresponds to a marked change in the nature of the surface rupture and is illuminated by a microearthquake sequence perpendicular to the Longmen Shan thrust belt. In the southern segment, our investigations confirm that uplift due to active faulting and folding is largely responsible for the areas of steepest topography. On the basis of this association, the southwestern segment of the Longmen Shan, south of the Wenchuan earthquake, is likely active and presents a significant earthquake hazard, despite the lack of historical earthquakes in this region. This study illustrates the importance of building 3-D models to study active faulting and folding, as well as to assess earthquake hazard. (2010), Structural interpretation of the coseismic faults of the Wenchuan earthquake: Three-dimensional modeling of the Longmen Shan fold-and-thrust belt,

Research paper thumbnail of Structural deformation and evolution of right-lateral strike-slip tectonics of the Liaohe western depression during the early Cenozoic

Journal of Asian Earth Sciences, 2013

The Tan-Lu fault zone (TLFZ) traverses the Liaohe western depression (LHWD), affords an exception... more The Tan-Lu fault zone (TLFZ) traverses the Liaohe western depression (LHWD), affords an exceptional opportunity to reveal the structural deformation and evolution of a major strike-slip fault of the LHWD using three dimensional seismic data and well data. In this paper, based on structural interpretations of the 3-D seismic data of the LHWD, combined with depth slice and seismic coherency, a variety of structural features in relation to right-lateral strike-slip fault (the western branch of the Tan-Lu fault) have been revealed presence in the depression, such as thrust faults (Xinlongtai, Taian-Dawa, and Chenjia faults), structural wedges, positive flower structures, and en echelon normal faults. Fault cutoffs, growth strata and the Neogene unconformity developed in the LHWD verify that the activity of right-lateral strike-slip from the late Eocene to Neogene (ca. 43-23 Ma). The study indicates that the right-lateral strike-slip played an important role in controlling the structural deformation and evolution of the LHWD in the early Cenozoic. Moreover, the front structural wedge generated the gross morphology of the Xinlongtai anticline and developed the Lengdong faulted anticline during the late Eocene, and the back structural wedge refolded the Lengdong faulted anticline zone in the late Eocene to the early Oligocene. Wrench-related structures (the Chenjia thrust fault and the en echelon normal faults) were developed during the late Oligocene. Uniform subsidence in the Neogene to Quaternary. Furthermore, the driving force of the right-lateral strike-slip deformation was originated from N-S extension stress related to the opening of the Japan Sea and NE-SW compression, as the far-field effect of India-Eurasia convergence.