scholarly journals Cenozoic paleostress field of tectonic evolution in Qaidam Basin, northern Tibet

2021 ◽  
Vol 13 (1) ◽  
pp. 736-747
Author(s):  
Shiyang Xu ◽  
Jianming Guo ◽  
Hailong Fan ◽  
Xiang Liu
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Evolution ◽  
Qaidam Basin ◽  
Intermediate Stage ◽  
Stress Fields ◽  
Tectonic Activity ◽  
The Tibetan Plateau ◽  
Northern Boundary ◽  
Southern Boundary ◽  
Compressional Stress

Abstract This article analyzes the stress fields in the Qaidam Basin since the entire Cenozoic using finite element numerical simulations. The stress fields are investigated by analyzing tectonic joints and the GPS velocity field in the basin. The relationship between the stress field patterns and the tectonic activity of the basin was discussed. Based on previous research on the uplift of the Tibetan Plateau, five stages of the tectonic evolution of the Qaidam Basin are modeled. The simulation results show that the stress trajectories in the Oligocence and the Pliocene–Quaternary were similar. In the Oligocence, the stress trajectories in the basin changed significantly and were mainly controlled by the compressional stress on the southern boundary in the initial stage. As the compressional stress on the northern boundary of the basin gradually increased, the compressional stress on the southern and northern boundaries had equal effects in the intermediate stage, and the compressional stress on the northern boundary mainly controlled the stress trajectories in the late stage. During the uplift of the Tibetan Plateau, the stress trajectories in the Qaidam Basin experienced an apparent reversal. The stress trajectories of the internal basin rotated clockwise from NE–SW to NW–SE in the Oligocence and which gradually changed to counterclockwise from NW–SE to NE–SW in the Miocene and recovered to clockwise from NE–SW to NW–SE in the Pliocene–Quaternary.

scholarly journals Extensional Seismogenic Stress and Tectonic Movement on the Central Region of the Tibetan Plateau

2009 ◽  
Vol 2009 ◽  
pp. 1-8
Author(s):  
Jiren Xu ◽  
Zhixin Zhao
Keyword(s):  
Tibetan Plateau ◽  
Normal Fault ◽  
Stress Fields ◽  
Tectonic Activity ◽  
The Tibetan Plateau ◽  
Normal Faulting ◽  
Earthquake Occurrence ◽  
Crustal Movements ◽  
High Plateau ◽  
Central Tibetan Plateau

Various earthquake fault types, mechanism solutions and stress fields, as well as GPS and geothermal data are analyzed for the study of the crustal movements on the Tibetan plateau and their tectonic implications. The results show that a lot of the normal faulting type-event concentrated at altitudes greater than 4000 m on the central Tibetan plateau. The altitudes concentrating normal faulting type-events can be zoned two parts: the western part, the Lhasa block, and the eastern part, the Qiangtang-Changdu region. The azimuths of T-axes are in a general E-W direction in the Lhasa block and NW-SE or NNW-SSE in the Qiangtang-Changdu region at the altitudes of the Tibetan plateau. The tensional stresses in E-W direction and NW-SE direction predominate normal faulting earthquake occurrence in the Lhasa block and the Qiangtang-Changdu region, respectively. The slipping displacements of the normal-faulting-type events have great components in near E-W direction and NW-SE direction in the Lhasa block and the Qiangtang-Changdu region, respectively. The extensions are probably an eastward or southeastward extensional motion, being mainly tectonic activity phenomena in the plateau altitudes. The extensional motions due to normal-fault earthquakes are important tectonic activity regimes on the high altitudes of the plateau. The easterly crustal extensions on the plateau are attributable to the gravitational collapse of the high plateau and eastward extrusion of hotter mantle materials beneath the eastern boundary of the plateau. Numbers of thrust-fault and strike-slip-fault earthquakes with strong compressive stress in a general NNE-SSW direction occur on the edges of the plateau.

Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to global cooling and Paratethys sea incursions

2021 ◽  
Author(s):  
Chengcheng Ye ◽  
Yibo Yang ◽  
Xiaomin Fang ◽  
Weilin Zhang ◽  
Chunhui Song ◽  
...  
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Middle Eocene ◽  
Qaidam Basin ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Driving Mechanism ◽  
The Tibetan Plateau ◽  
Early Oligocene ◽  
Global Cooling

<p>Global cooling, the early uplift of the Tibetan Plateau, and the retreat of the Paratethys are three main factors that regulate long-term climate change in the Asian interior during the Cenozoic. However, the debated elevation history of the Tibetan Plateau and the overlapping climate effects of the Tibetan Plateau uplift and Paratethys retreat makes it difficult to assess the driving mechanism on regional climate change in a particular period. Some recent progress suggests that precisely dated Paratethys transgression/regression cycles appear to have fluctuated over broad regions with low relief in the northern Tibetan Plateau in the middle Eocene–early Oligocene, when the global climate was characterized by generally continuous cooling followed by the rapid Eocene–Oligocene climate transition (EOT). Therefore, a middle Eocene–early Oligocene record from the Asian interior with unambiguous paleoclimatic implications offers an opportunity to distinguish between the climatic effects of the Paratethys retreat and those of global cooling.</p><p>Here, we present a complete paleolake salinity record from middle Eocene to early Miocene (~42-29 Ma) in the Qaidam Basin using detailed clay boron content and clay mineralogical investigations. Two independent paleosalimeters, equivalent boron and Couch’s salinity, collectively present a three-staged salinity evolution, from an oligohaline–mesohaline environment in the middle Eocene (42-~34 Ma) to a mesosaline environment in late Eocene-early Oligocene (~34-~29 Ma). This clay boron-derived salinity evolution is further supported by the published chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin resembles the hydroclimate change in the neighboring Xining Basin, of which both present good agreement with changes of marine benthic oxygen isotope compositions. We thus speculated that the secular trend of clay boron-derived paleolake salinity in ~42-29 Ma is primarily controlled by global cooling, which regulates regional climate change by influencing the evaporation capacity in the moisture source of Qaidam Basin. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.</p>

Tectonic evolution and dynamics of the Tibetan Plateau

2017 ◽  
Vol 41 ◽  
pp. 1-8 ◽  
Author(s):  
Zeming Zhang ◽  
Lin Ding ◽  
Zhidan Zhao ◽  
M. Santosh
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Evolution ◽  
The Tibetan Plateau

scholarly journals Spatio-Temporal Variations of Water Vapor Budget over the Tibetan Plateau in Summer and Its Relationship with the Indo-Pacific Warm Pool

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 828
Author(s):  
Deli Meng ◽  
Qing Dong ◽  
Fanping Kong ◽  
Zi Yin ◽  
Yanyan Li ◽  
...  
Keyword(s):  
Water Vapor ◽  
Indian Ocean ◽  
Tibetan Plateau ◽  
River Basin ◽  
Large Scale ◽  
Warm Pool ◽  
The Tibetan Plateau ◽  
Southern Boundary ◽  
Pacific Warm Pool ◽  
Water Vapor Budget

The water vapor budget (WVB) over the Tibetan Plateau (TP) is closely related to the large-scale atmospheric moisture transportation of the surrounding mainland and oceans, especially for the Indo-Pacific warm pool (IPWP). However, the procession linkage between the WVBs over the TP and its inner basins and IPWP has not been sufficiently elucidated. In this study, the relationship between the summer WVB over the TP and the IPWP was quantitatively investigated using reanalysis datasets and satellite-observed sea surface temperature (SST). The results show that: (1) the mean total summer vapor budget (WVBt) over the TP in the period of 1979–2018 was 72.5 × 106 kg s−1. Additionally, for the 13 basins within the TP, the summer WVB has decreased from southeast to northwest; the Yarlung Zangbo River Basin had the highest WVB (33.7%), followed by the Upper Yangtze River Basin, Ganges River Basin and Qiangtang Plateau. (2) For the past several decades, the WVBt over the TP has experienced an increasing trend (3.81 × 106 kg s−1 decade−1), although the southern boundary budget (WVBs) contributed the most and is most closely related with the WVBt, while the eastern boundary budget (WVBe) experienced a decreasing trend (4.21 × 106 kg s−1 decade−1) which was almost equal to the interdecadal variations of the WVBt. (3) For the IPWP, we defined a new warm pool index of surface latent heat flux (WPI-slhf), and found that an increasing WPI-slhf would cause an anticyclone anomaly in the equatorial western Indian Ocean (near 70° E), resulting in the increased advent of water vapor to the TP. (4) On the interdecadal scale, the correlation coefficients of the variation of the summer WVBt over the TP with the WPI-slhf and Indian Ocean Dipole (IOD) signal were 0.86 and 0.85, respectively (significant at the 0.05% level). Therefore, the warming and the increasing slhf of the IPWP would significantly contribute to the increasing WVB of the TP in recent decades.

Cenozoic tectonic evolution of the Tibetan Plateau - the Nepal Himalaya and the provenance of their foreland basins

2016 ◽  
Vol 52 (4) ◽  
pp. 646-666 ◽  
Author(s):  
Bhupati Neupane ◽  
Yiwen Ju ◽  
Fengqi Tan ◽  
Upendra Baral ◽  
Prakash Das Ulak ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Evolution ◽  
The Tibetan Plateau ◽  
Foreland Basins ◽  
Nepal Himalaya

scholarly journals ESR geochronology of the Minjiang River terraces at Wenchuan, eastern margin of Tibetan Plateau, China

2013 ◽  
Vol 40 (4) ◽  
pp. 360-367 ◽  
Author(s):  
Chun-Ru Liu ◽  
Gong-Ming Yin ◽  
Hui-Ping Zhang ◽  
Wen-Jun Zheng ◽  
Pierre Voinchet ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Activity ◽  
The Tibetan Plateau ◽  
Fluvial Sediments ◽  
River Terrace ◽  
Eastern Margin ◽  
River Terraces ◽  
Quaternary Climate ◽  
Minjiang River ◽  
Longmen Shan Fault

Abstract The Minjiang River terrace along the Longmen Shan fault zone near Wenchuan, at the eastern margin of the Tibetan Plateau, China, provides archives for tectonic activity and quaternary climate change. However, previous studies were not able to provide ages older than 100 ka due to the limitations of dating material or/and methods applied to date the fluvial sediments. In this study, we used the ESR signal of the Ti-Li center in quartz to obtain the ages of four higher terraces (T3–T6). According to the results, the terraces T3 to T6 were formed at 64±19 ka, 101±15 ka, 153±33 ka, and 423±115 ka, respectively. Combined with previous studies, these results indicate that the formations of all terraces correspond to glacial/interglacial transition periods, such as, T1-T5 being correlated to MIS2/1, MIS4/3, MIS5d/5c, and MIS6/5e respectively, while T6 probably to MIS12/11. According to these data, it is found that the average incision rate was significantly higher over the last 150 ka than that previous 100 ka (250 to 150 ka). As both tectonics and climate have affected the formation of these terraces, in addition to the overall uplifting of Tibetan Plateau, the regional uplift due to isostasy would be an additional tectonic factor in the formation of river terraces in the eastern margin of Tibetan plateau.

Late Mesozoic tectonic evolution and growth of the Tibetan plateau prior to the Indo-Asian collision

2012 ◽  
Vol 114 (3-4) ◽  
pp. 236-249 ◽  
Author(s):  
Kai-Jun Zhang ◽  
Yu-Xiu Zhang ◽  
Xian-Chun Tang ◽  
Bin Xia
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Evolution ◽  
The Tibetan Plateau ◽  
Late Mesozoic

scholarly journals Interannual Variation of Summer Atmospheric Heat Source over the Tibetan Plateau and the Role of Convection around the Western Maritime Continent

2015 ◽  
Vol 29 (1) ◽  
pp. 121-138 ◽  
Author(s):  
Xingwen Jiang ◽  
Yueqing Li ◽  
Song Yang ◽  
Kun Yang ◽  
Junwen Chen
Keyword(s):  
Water Vapor ◽  
Tibetan Plateau ◽  
Heat Source ◽  
Interannual Variation ◽  
The Tibetan Plateau ◽  
The South ◽  
Maritime Continent ◽  
Southern Boundary ◽  
Atmospheric Heat Source ◽  
Atmospheric Heat

Abstract The impacts of summer atmospheric heat source over the Tibetan Plateau (TP) on regional climate variation have attracted extensive attention. However, few studies have focused on possible causes of the interannual variation of atmospheric heat source over the TP. Total heat (TH) is generally composed of three components: surface sensible heat, latent heat release of condensation (LH), and radiative convergence. In this study, it is found that interannual variation of summer TH is dominated by LH in the central and eastern TP. The atmospheric circulation patterns associated with the TH over the TP in June are different from those in July and August. Large TH is accompanied by a cyclone centered over the South China Sea in June, which is replaced by an anticyclone in July and August. The interannual variation of July–August TH over the central and eastern TP is significantly affected by convection around the western Maritime Continent (WMC) that modulates the LH over the southeastern TP. Enhanced WMC convection induces an anticyclone to the south of the TP, which favors water vapor transport to the southeastern TP and thus an increase in precipitation. Enhanced convection over the southeastern TP may exert a positive feedback on local precipitation through pumping more water vapor from the southern boundary. Both observations and model simulations indicate that the enhanced WMC convection can induce the anticyclone to the south of the TP and convection–circulation is important for maintenance of the anticyclone.

scholarly journals Late Cenozoic continuous aridification in the western Qaidam Basin: evidence from sporopollen records

2013 ◽  
Vol 9 (2) ◽  
pp. 1485-1508 ◽  
Author(s):  
Y. F. Miao ◽  
X. M. Fang ◽  
F. L. Wu ◽  
M. T. Cai ◽  
C. H. Song ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Middle Miocene ◽  
Qaidam Basin ◽  
East Asian ◽  
The Tibetan Plateau ◽  
Late Cenozoic ◽  
Plateau Uplift ◽  
Western Qaidam Basin ◽  
Global Cooling ◽  
Tibetan Plateau Uplift

Abstract. Cenozoic climate changes in inner Asia provide a basis for understanding linkages between global cooling, the Tibetan Plateau uplift, and possibly the development of the East Asian monsoon. Based on the compiled palynological results from the western Qaidam Basin, this study reconstructed an 18 Ma record of changing vegetation and paleoclimates since the middle Miocene. Thermophilic taxa percentages were highest between 18 and 14 Ma and decreased after 14 Ma, corresponding closely with the Middle Miocene Climatic Optimum (MMCO) between 18 and 14 Ma and the following global climatic cooling. After 3.6 Ma, the thermophilic taxa percentages further decreased, showing the inevitable relations with the ice-sheets enlargement in the North Hemisphere. During the same period of time, the increase in xerophytic taxa percentages and decrease in conifers percentages imply aridification in both the basin and surrounding mountains since 18 Ma. These results indicate that global cooling mainly controlled the climate change from a relative warm-wet stage to a cold-dry stage during the late Cenozoic at the western Qaidam Basin, and that the Tibetan Plateau uplift also contributed in contrast to the East Asian summer monsoon.

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