14 results on '"Peizhen Zhang"'
Search Results
2. 3D geometric modeling for the Yanjinggou anticline in the Longmen Shan fold-and-thrust belt, China: Oblique thrusting kinematic implications
- Author
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Yiquan Li, Chuang Sun, Tao Li, Wenjun Zheng, Peizhen Zhang, Zhigang Li, Dong Jia, R. V. Almeida, and Wei Chen
- Subjects
geography ,Paleomagnetism ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Anticline ,Oblique case ,Geology ,Fold (geology) ,Kinematics ,010502 geochemistry & geophysics ,01 natural sciences ,Fold and thrust belt ,Thrust fault ,Geometric modeling ,Seismology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Three-dimensional (3D) subsurface seismic data acquisition and modeling are rarely undertaken; consequently, the complex effects of oblique thrusting on the 3D morphology and kinematics of folds are still poorly understood. We use 3D seismic data to produce five 3D geometric models and compare our results with structural models of the Yanjinggou anticline in the Longmen Shan fold-and-thrust belt, to investigate the effects of oblique thrusting on 3D fold evolution. 3D geometric modeling results reveal that oblique thrusting may cause fold asymmetry, vertical axis rotation, and a curved fold axis. 3D seismic interpretations and structural modeling suggest that the Yanjinggou anticline developed as a trishear fault-propagation fold and experienced a maximum shortening amount of 1.2 ± 0.1 km. The 3D structural and geometric models are consistent with paleomagnetic results, suggesting that the anticline was affected by oblique thrusting at an angle of 55° above a listric thrust fault with three fault ramps (19°, 30°, and 40°), causing the fold to rotate and develop a curved morphology. The integrated method used in this study to investigate the effects of oblique thrusting on 3D fold morphology and kinematics can be applied to regional oblique thrusting in the Longmen Shan and other fold-and-thrust belts worldwide.
- Published
- 2019
3. Evidence for three Cenozoic phases of upper crustal shortening of the Xiongpo structure in the Longmen Shan fold-and-thrust belt, China: Implications for the eastward growth of the eastern Tibetan Plateau
- Author
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R. V. Almeida, Dong Jia, Tao Li, Peizhen Zhang, Chuang Sun, Wenjun Zheng, Zhigang Li, and Weitao Wang
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Borehole ,Geology ,Fold (geology) ,010502 geochemistry & geophysics ,01 natural sciences ,Thermochronology ,Strain partitioning ,Fold and thrust belt ,Thrust fault ,Longmen shan ,Cenozoic ,Seismology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Cenozoic crustal shortening across the Longmen Shan (LMS) fold-and-thrust belt records the eastward growth of the Tibetan Plateau. Although the structural geometries of individual structures in the region have been studied, the kinematics and rates of deformation across these structures remain unclear. In this study, we construct a geological cross section to derive the subsurface structural architecture of the Xiongpo structure in the LMS piedmont using one seismic reflection profile, and data from two boreholes. The structure displays a superimposed deep fault-bend fold and shallow structural wedge with three splay thrust faults. Using two-dimensional kinematic models, based on fault-bend folding algorithm, we reconstruct three episodes of upper crustal shortening, with 7.0 ± 0.3 km of total shortening. Combining with previously published low-temperature thermochronology data, we further estimate that the structure has experienced an average shortening rate of ∼ 0.2 mm/yr since 40–25 Ma. We infer that the structure acted as the deformation front of the LMS fold-and-thrust belt between 40 and 25 Ma and 15–10 Ma driven by the eastward growth of the Tibetan Plateau. Finally, we review the shortening rates of other five structures within the LMS piedmont, and find that these six structures (including the Xiongpo structure) individually have undergone an average shortening rate
- Published
- 2019
4. The role of the Haiyuan Fault in accelerating incision rate of the Yellow River at the Mijia Shan Area, northeastern Tibetan Plateau, as revealed by in-situ 10Be dating
- Author
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Pichawut Manopkawee, Peizhen Zhang, Zhikun Ren, Huiping Zhang, and Qi Su
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geography ,geography.geographical_feature_category ,Plateau ,Geology ,Structural basin ,Fault (geology) ,Tectonics ,Terrace (geology) ,Tectonic deformation ,River terraces ,Cosmogenic nuclide ,Geomorphology ,Earth-Surface Processes - Abstract
In this study, we employed cosmogenic nuclide 10Be analysis to determine the formation ages of the Yellow River terraces in the Mijia Shan and the Laolongwan Basin at the northeastern periphery of the Tibetan Plateau. The aim of this study is to determine local fluvial incision rates and the effect from tectonic activities. The two sets of terraces were surveyed in field and dated by cosmogenic 10Be exposure dating method. The results show that the best-fitting terrace ages in the Mijia Shan are respective 68.0 - 9.4 + 11.2 ka for T11 and 174.7 - 38.4 + 52 ka for T14. In addition, in the Laolongwan basin, sample S3 constrains an age of 123.9 ± 2.7 ka and S2 yields an age of 45.0 ± 1.8 ka. Combining the strath heights of the sampled terraces, the fluvial incision rates were determined. The results showed that the fluvial incision rate of the Yellow River is ∼1.94 mm/a in the Mijia Shan over the last 175 ka, while a much lower incision rate of ∼0.73 mm/a is yielded in the Laolongwan Basin since the last ∼120 ka. The incision rate in the Mijia Shan is almost twice more than that in the Laolongwan Basin. Considering the same climatic condition in both the Mijia Shan and the Laolongwan Basin, the difference between the two incision rates (∼1.21 mm/a) might be due to local tectonic deformation which is derived from the Haiyuan active strike-slip fault. Consequently, our results showed that the Haiyuan fault plays an important role in accelerating the incision rate in the Mijia Shan. Hence, it is suggested that the role of the main geological structures across the main river should also be considered when studying the evolution of terraces of big rivers.
- Published
- 2019
5. Geomorphic evidence for northeastward expansion of the eastern Qilian Shan, northeastern Tibetan Plateau
- Author
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Pichawut Manopkawee, Hong Xie, Yan Zhan, Daoyang Yuan, Qi Su, Huiping Zhang, and Peizhen Zhang
- Subjects
Hypsometry ,geography ,Plateau ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Geology ,Glacier ,Fault (geology) ,010502 geochemistry & geophysics ,Block (meteorology) ,01 natural sciences ,Snowmelt ,Transition zone ,Glacial period ,Physical geography ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The eastern Qilian Shan is a tectonically-active region consisting of a series of faults with bounded intermountain basins and is located within the transition zone between the mainland Tibetan Plateau and the Alax Block. Active deformation affecting the topography in this region can be quantified based on geomorphic indices. Therefore, we applied the geomorphic indices (hypsometry and stream-power incision model) to evaluate the tectonic deformation pattern of the eastern Qilian Shan. Hypsometric curves and S-A plots of the selected seven rivers were determined. HI values of every single sub-basins were also calculated. The results show that the local topographic evolution of the eastern Qilian Shan is in pre-steady state and will soon reach its equilibrium state. According to the analysis of regional climate condition (e.g., rainfall and glaciers distribution) and fault characteristics, it is suggested that abundant glacial snowmelt water sustains fluvial incision, and tectonic deformation from sustained northeastward expansion of the Tibetan Plateau is the main reason for the landscape growth. Combining the research of the deep electric structure beneath the Gulang Boundary Zone, we claimed that the eastern Qilian Shan (even the northeastern Tibet) has been growing and expanding northeastward since the middle Miocene, and its leading edge now is the Hexibao-Sidaoshan Fault. On the premise of synthetically considering the western and middle parts of the Qilian Shan, it is suggested that the Hexibao-Sidaoshan Fault area will rise into a mountain in 1–2 Ma.
- Published
- 2019
6. Cretaceous Tethyan subduction in SE Borneo: Geochronological and geochemical constraints from the igneous rocks in the Meratus Complex
- Author
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Yuejun Wang, Xin Qian, Peter A. Cawood, Azman Ghani, Chengshi Gan, Sainan Wu, Yuzhi Zhang, Yang Wang, and Peizhen Zhang
- Subjects
Geology ,Earth-Surface Processes - Published
- 2022
7. Paleoseismology and slip rate of the western Tianjingshan fault of NE Tibet, China
- Author
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Wenjun Zheng, Chuanyou Li, Xinnan Li, Peizhen Zhang, Xuguang Wang, Steven G. Wesnousky, and Ian Pierce
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geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Deformation (mechanics) ,Geology ,Paleoseismology ,Active fault ,Fault (geology) ,010502 geochemistry & geophysics ,01 natural sciences ,Sinistral and dextral ,Quaternary ,Seismology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Slip rate - Abstract
We present results from a detailed investigation of the horizontal displacement distribution, timing of paleoearthquakes and left-lateral slip rate on the western Tianjingshan fault. Measurements of 240 offset streams and ridges confirm that the fault is left-lateral and record evidence of repeated ∼3–4 m coseismic offsets along the 60–km–long fault. This suggests that ∼6 earthquakes may have occurred along the entire western Tianjingshan fault with repeated occurrence of earthquakes of Mw 7.2–7.5. Structural and stratigraphic relationships exposed in our five trenches in combination with previously reported studies further indicate that the fault has ruptured in as many as six paleoearthquakes since the late Quaternary. Paleoseismic data show that the average recurrence interval for Holocene earthquakes is approximately 5,000 yr. The most recent earthquake along the western Tianjingshan fault occurred ∼1.2 ± 0.1 kyr BP, indicating that this fault segment did not rupture in the M 7.5 historical earthquake of 1709 that ruptured the central Tianjingshan fault. We estimate that the Holocene slip rate of the western Tianjingshan fault is ∼1.1–1.2 mm/yr based on measurements of the age and offset of stream channels. Compared with the relatively fast slip rate of the Haiyuan fault (∼4–6 mm/yr), we suggest that the Tianjingshan fault acts as an essential active fault accommodating the sinistral displacement and crustal shortening deformation in NE Tibet.
- Published
- 2017
8. Triassic two-stage intra-continental orogensis of the South China Block, driven by Paleotethyan closure and interactions with adjoining blocks
- Author
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Chengshi Gan, Yang Wang, Peizhen Zhang, Yuejun Wang, Xin Qian, Feifei Zhang, Yuzhi Zhang, and Peter A. Cawood
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Metamorphic zone ,010504 meteorology & atmospheric sciences ,Subduction ,Early Triassic ,Geology ,010502 geochemistry & geophysics ,01 natural sciences ,Transpression ,Nappe ,Paleontology ,Sinistral and dextral ,Basement (geology) ,Clockwise ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The South China Block (SCB) is tectonically bounded by the Tethyan and Pacific subduction zones and the Qinling-Dabie HP-UHP metamorphic zone. Triassic tectonic activity was a key phase in the tectonic history of the SCB and in creating the fundamental framework of East Asia. The geometry and kinematics of the Triassic deformation sheds light on the mechanism driving intra-continental orogenesis in the SCB. Our new field- and mapped- based structural analysis, along with thermo-chronological dating results, reveal two-stage distinct Triassic deformations in the southern SCB involving top-to-north dextral thrusting at ~250–225 Ma and NE-trending sinistral transpression at ~230–190 Ma. Early Triassic dextral transpression is marked by WNW-trending high-strain zones and thrust nappes/sheets, which might have been rooted beneath the Hainan-Yunkai basement along a low angle, middle-upper crustal basal detachment. It transformed from a thick-skinned fold-and-thrust belt to thin-skinned Jura-like patterns with northerly-propagating deformation. Late Triassic NE-trending sinistral transpression was accompanied by a series of the parallel folds and thrusts in the SCB interior, resulting in the development of the regional positive-flower geometry and reactivation of the pre-existing structures. Such signatures, in combination with the available geological, geochronological, and paleogeographic observations, suggest two-stage (early-middle and late Triassic) intra-continental orogenesis in the SCB, were controlled by the clockwise scissor-like closure of the Paleotethyan Ocean and its interactions with the adjoining blocks including deep-subduction beneath the North China Block and limited lateral extrusion due to the obstructing paleo-Pacific plate.
- Published
- 2021
9. On the evolution of seismogenic faults in the Longmen Shan, eastern Tibet
- Author
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Guixi Yi, Huiping Zhang, Eric Kirby, and Peizhen Zhang
- Subjects
Seismic hazard ,Sichuan basin ,Geology ,Thrust fault ,Slip (materials science) ,Longmen shan ,Aftershock ,Seismology ,Earth-Surface Processes - Abstract
A fundamental debate exists regarding the geometry and depth extent of seismogenic faults in eastern Tibet. Along the Longmen Shan, geologic and seismic reflection data reveal a belt of low to moderate angle thrust faults, some of which may have been activated in devastating earthquakes in 2008 (Mw ∼7.9, Wenchuan) and 2013 (Mw ∼6.6, Lushan). However, geologic and geodetic constraints on these ruptures suggest rupture along relatively high-angle listric reverse faults. Here, we use a combination of focal mechanisms determined from 276 aftershocks (Ms > 4.0) with well-determined waveforms and aftershock distributions from the 2008 event to determine subsurface fault geometry. Our results imply that seismogenic slip occurred along relatively high-angle structures that cross-cut low-angle imbricate faults imaged in reflection seismic data. Thus, we suggest that current geometric models of seismogenic faults may not fully represent the distribution of subsurface seismic hazard along the heavily-populated Sichuan Basin.
- Published
- 2015
10. Exhumation and landscape evolution in eastern South China since the Cretaceous: New insights from fission-track thermochronology
- Author
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Shubo Li, E. G. Seagren, Xin Qian, Yuzhi Zhang, Yuejun Wang, Yang Wang, and Peizhen Zhang
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010504 meteorology & atmospheric sciences ,Geology ,010502 geochemistry & geophysics ,Neogene ,Fission track dating ,01 natural sciences ,Cretaceous ,Graben ,Thermochronology ,Peneplain ,Paleontology ,Plate tectonics ,Paleogene ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Widespread extensional half-/grabens with red bed sedimentation, dome structures, and magma intrusions/eruptions with polymetallic mineralization within South China during the Cretaceous-Cenozoic provide a natural laboratory to understand intracontinental deformation and plate tectonics. In order to decipher the tectonic and landscape evolution of eastern South China, this study presents new low-temperature thermochronology from a broad region covering major tectonic units including the Xuefeng, Jiuling, Nanling, and Wuyi mountains. Zircon and apatite fission track dates, length distribution, and thermal history modeling reveal a prominent and rapid cooling phase during ~125–80 Ma across the paleo-highland in eastern South China. A synthesis of existing thermochronologic data and geological observations suggests that NE/NNE-striking syn-sedimentary faults system with half-/graben basins, rapid exhumation of Cretaceous magma and pre-Cretaceous basement, and final extension of dome structures were all initiated in a back-arc setting during this period (~80-125 Ma). Eastern South China during the Paleogene was characterized by a tectonic quiescence during which insignificant exhumation, peneplanation, and local sedimentation occurred, forming regional low-amplitude, long-wavelength topography. Accelerated regional cooling commenced in the late Oligocene or early Miocene in response to the far-field effect of the India-Asia continental convergence. Additionally, the termination of red-colored gypsum-salt-bearing sediment in the Neogene suggests a paleo-environmental change within South China, from an arid to a monsoonal climate; such change was likely the result of the topographic uplift of the Tibetan Plateau and its margins.
- Published
- 2020
11. 3D geometry of range front blind ramp and its effects on structural segmentation of the southern Longmen Shan front, eastern Tibet
- Author
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Peizhen Zhang, Xiaogen Fan, Zhigang Li, Dong Jia, Dongli Zhang, Chuang Sun, and Wenjun Zheng
- Subjects
Seismic gap ,geography ,geography.geographical_feature_category ,business.product_category ,Plateau ,010504 meteorology & atmospheric sciences ,Front (oceanography) ,Geology ,Fracture zone ,Deformation (meteorology) ,Fault (geology) ,010502 geochemistry & geophysics ,01 natural sciences ,Wedge (mechanical device) ,Shear stress ,business ,Seismology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
A 3D fault morphology model has been constructed from seismic profiles covering the piedmont of the southern Longmen Shan (LMS), eastern margin of the Tibetan Plateau. It reveals a spatial correlation between an ∼3.5 km-high geometrical bump on the range front blind ramp (RFBR) and the gap between the 2008 M w 7.9 Wenchuan and 2013 M w 6.6 Lushan earthquakes. Sandbox modeling is then used to probe the effects of the geometrical irregularity of the RFBR on fault behaviors and the LMS range front deformation. Sand wedges are designed to thrust over artificial blind ramps, analogous to the thrusting of the LMS orogenic wedge toward the Sichuan Basin through the RFBR. The experiments reproduce the first-order deformation features presented in the southern LMS range front, confirming that along-strike geometrical variations of the RFBR have induced the segmentation of both fault motion and the range front deformation. Their results also suggest that the gap between the Wenchuan and Lushan earthquakes is located directly within the structural transition zone originating from the geometrical bump on the RFBR. Additionally, there is a duplex structure occurring in the hanging wall of the geometrical bump, which localizes significant shear strain with progressive shortening and represents a fracture zone corresponding to the observed geophysical anomaly (low seismic velocity) underneath the seismic gap. It is likely that this fractured body protected the gap from the ruptures of the Wenchuan and Lushan earthquakes.
- Published
- 2019
12. Magnetostratigraphy and depositional history of the Miocene Wushan basin on the NE Tibetan plateau, China: Implications for middle Miocene tectonics of the West Qinling fault zone
- Author
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Jianhui Liu, Daoyang Yuan, Carmala N. Garzione, Dewen Zheng, Chuanyou Li, Guang-Liang Zhang, Richard O. Lease, Zhicai Wang, Brian G. Hough, Peizhen Zhang, and Qinglong Wu
- Subjects
geography ,geography.geographical_feature_category ,Geology ,Structural basin ,Fault (geology) ,Transpression ,Sedimentary depositional environment ,Tectonics ,Paleontology ,Sedimentary rock ,Paleogene ,Geomorphology ,Magnetostratigraphy ,Earth-Surface Processes - Abstract
Based on field mapping, section measurement and magnetostratigraphy, ∼1700 m of sedimentary rocks have accumulated in the Wushan basin between ∼16 Ma and ∼6 Ma. Basin geometry, sedimentation characteristics and the early syn-depositional deformation along the northern margin of the basin indicate that formation of the Wushan basin was related to tectonic deformation along the West Qinling fault zone during the middle Miocene. A series of basins of similar age to the Wushan basin were generated along and to the south of the West Qinling fault zone while basalts also erupted in this region at this time. We suggest that the middle Miocene (∼16 Ma) may represent a change in kinematics and deformation style in the region along and to the south of the West Qinling fault zone. At this time, there was a transition from NNE–SSW compressional deformation, that dominated the region since the late Paleogene, to the development of WNW–ESE and/or E–W trending strike-slip movement and associated transpressional and transtensional activity that continues today. The Miocene Wushan basin may have developed in association with transpression along the West Qinling fault zone. Whether this transition was related to the onset of strike-slip along the east Kunlun fault and related deformation transfer, lower crustal flow, or removal of mantle lithosphere, the middle Miocene provides direct evidence for a change in the kinematic style along the plateau margin.
- Published
- 2012
13. Along-strike topographic variation of the Longmen Shan and its significance for landscape evolution along the eastern Tibetan Plateau
- Author
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Gui-hua Yu, Chunru Liu, Eric Kirby, Jinhui Yin, Huiping Zhang, and Peizhen Zhang
- Subjects
Single fault ,Topographic relief ,Mountain formation ,Sichuan basin ,Geology ,Slip (materials science) ,Longmen shan ,Seismic cycle ,Geomorphology ,Earth-Surface Processes - Abstract
Regional topographic and geomorphic analyses reveal first-order topographic variations from high-elevation and low-relief interior plateau to the relatively low elevation, high-relief marginal plateau in eastern Tibet. Field investigation and slip distribution modeling after 2008 Ms. 8.0 Wenchuan earthquake indicate significant along-strike variability during the rupture that appears to correspond to different segments of a single fault system. This observation motivates a more careful examination of topographic features along the Longmen Shan to explore the connection between the seismic cycle and mountain building. Analyses of topographic relief, hillslope gradient, and channel gradient indices reveal significant differences in the character of topography along the Longmen Shan mountain front. The central portion of the range exhibits the highest slope, relief and steepness of river longitudinal profiles. Whereas the southern Longmen Shan exhibits only subtle differences associated with slightly lower hillslope and channel gradients, the northern Longmen Shan is characterized by topography of significantly lower relief, lessened hillslope gradients, and low-gradient channels. We consider two explanations for these topographic differences; first, that the differences in topographic development along the Longmen Shan reflect different stages of an evolutionary history. Alternatively, these may reflect differences in the rate of differential rock uplift relative to the stable Sichuan Basin.
- Published
- 2011
14. Late Cenozoic deformation of the Da’an-Dedu Fault Zone and its implications for the earthquake activities in the Songliao basin, NE China
- Author
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Zhongyuan, Yu, primary, Peizhen, Zhang, additional, Wei, Min, additional, Qinghai, Wei, additional, Limei, Wang, additional, Bin, Zhao, additional, Shuang, Liu, additional, and Jian, Kang, additional
- Published
- 2015
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