Stratigraphic Evidence for the Uplift of the Tibetan Plateau between ∼1.1 and ∼0.9 myr Ago

2000 ◽  
Vol 54 (3) ◽  
pp. 309-320 ◽  
Author(s):  
Jimin Sun ◽  
Tungsheng Liu
Keyword(s):  
Tibetan Plateau ◽  
Accumulation Rate ◽  
Qaidam Basin ◽  
Regional Scale ◽  
Middle Pleistocene ◽  
The Tibetan Plateau ◽  
Chinese Loess ◽  
Ice Volume ◽  
Global Ice Volume ◽  
Marginal Region

Uplift of the Tibetan Plateau is manifest not only in widespread denudation, but also by an increased deposition rate of sediment, near or far from the exhumed regions. Our results indicate that the mass accumulation rate (MAR) of eolian dust increased between ∼1.1 and ∼0.9 myr ago. We associate this increase in MAR and median grain size with uplift of the Tibetan Plateau and its adjacent regions during this period. This Middle Pleistocene uplift can also be evidenced by the age of volcanism in the marginal region, the existence of thick conglomerate deposits surrounding the uplifted plateau, and the increased sedimentation rate of lacustrine deposits in the Qaidam Basin (northeastern Tibetan Plateau) between ∼1.1 and ∼0.9 myr ago. The correlation between the loess and marine records indicates that after ∼0.9 myr ago, these two records correlate well. This good correlation probably suggest that the Middle Pleistocene upheaval event not only brought the plateau into the cryosphere, but also enhanced the coupling of regional-scale Chinese loess transportation and deposition to the global ice volume variations through its effects on glacial grinding, rock denudation, and east Asian monsoonal circulation.

scholarly journals Geochronology and Geochemical Properties of Mid-Pleistocene Sediments on the Caiwei Guyot in the Northwest Pacific Imply a Surface-to-Deep Linkage

2021 ◽  
Vol 9 (3) ◽  
pp. 253
Author(s):  
Liang Yi ◽  
Haifeng Wang ◽  
Xiguang Deng ◽  
Haifan Yuan ◽  
Dong Xu ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Western Pacific ◽  
Global Ocean ◽  
Northwest Pacific ◽  
Local Circulation ◽  
Research Attention ◽  
Ice Volume ◽  
Global Ice Volume ◽  
Geochemical Properties ◽  
The Western Pacific

Seamounts are ubiquitous topographic units in the global ocean, and their effects on local circulation have attracted great research attention in physical oceanography; however, fewer relevant efforts were made on geological timescales in previous studies. The Caiwei (Pako) Guyot in the Magellan Seamounts of the western Pacific is a typical seamount and oceanographic characteristics have been well documented. In this study, we investigate a sediment core by geochronological and geochemical studies to reveal a topography-induce surface-to-bottom linkage. The principal results are as follows: (1) Two magnetozones are recognized in core MABC–11, which can be correlated to the Brunhes and Matuyama chrons; (2) Elements Ca, Si, Cl, K, Mn, Ti, and Fe are seven elements with high intensities by geochemical scanning; (3) Ca intensity can be tuned to global ice volume to refine the age model on glacial-interglacial timescales; (4) The averaged sediment accumulation rate is ~0.73 mm/kyr, agreeing with the estimate of the excess 230Th data in the upper part. Based on these results, a proxy of element Mn is derived, whose variability can be correlated with changes in global ice volume and deep-water masses on glacial-interglacial timescales. This record is also characterized by an evident 23-kyr cycle, highlighting a direct influence of solar insolation on deep-sea sedimentary processes. Overall, sedimentary archives of the Caiwei Guyot not only record an intensified abyssal ventilation during interglaciations in the western Pacific, but also provide a unique window for investigating the topography-induced linkage between the upper and bottom ocean on orbital timescales.

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>

Magnetic parameter variations in the Chaona loess/paleosol sequences in the central Chinese Loess Plateau, and their significance for the middle Pleistocene climate transition

2014 ◽  
Vol 81 (3) ◽  
pp. 433-444 ◽  
Author(s):  
Yougui Song ◽  
Xiaomin Fang ◽  
John W. King ◽  
Jijun Li ◽  
Ishikawa Naoto ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Loess Plateau ◽  
Chinese Loess Plateau ◽  
Middle Pleistocene ◽  
High Coercivity ◽  
The Tibetan Plateau ◽  
Chinese Loess ◽  
Pleistocene Climate ◽  
History Of ◽  
Climate Transition

AbstractA high-resolution rock magnetic investigation was performed on the Chaona Quaternary loess/paleosol sequences in the Central Chinese Loess Plateau. Based on a newly developed independent unturned time scale and magnetic records, we reconstructed the history of the East Asia monsoons during the last 3 Ma and explored the middle Pleistocene climate transition (MPT). Rock magnetic results show that the loess layers are characterized by relatively high coercivity and remanent coercivity, lower magnetic susceptibility (MS), and that the paleosol layers are characterized by relatively high MS, saturation magnetization and remanent saturation magnetization. Spectrum analyses indicate that there are various periods in addition to orbital periodicities. According to the onset and stable appearance of 100 kyr period, we consider that the MPT recorded in this section began at ~ 1.26 Ma and was completed by ~ 0.53 Ma, which differs from previous investigations based on orbitally tuned time scales. The forcing mechanism for the MPT was more complicated than just the orbital forcing. We conclude that the rapid uplift of the Tibetan Plateau may have played an important role in the shift of periodicities during the middle Pleistocene.

Denisovan DNA in Late Pleistocene sediments from Baishiya Karst Cave on the Tibetan Plateau

Science ◽  
2020 ◽  
Vol 370 (6516) ◽  
pp. 584-587
Author(s):  
Dongju Zhang ◽  
Huan Xia ◽  
Fahu Chen ◽  
Bo Li ◽  
Viviane Slon ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Amino Acid ◽  
Tibetan Plateau ◽  
Late Pleistocene ◽  
Amino Acid Substitution ◽  
Middle Pleistocene ◽  
The Tibetan Plateau ◽  
Karst Cave ◽  
Late Middle Pleistocene

A late Middle Pleistocene mandible from Baishiya Karst Cave (BKC) on the Tibetan Plateau has been inferred to be from a Denisovan, an Asian hominin related to Neanderthals, on the basis of an amino acid substitution in its collagen. Here we describe the stratigraphy, chronology, and mitochondrial DNA extracted from the sediments in BKC. We recover Denisovan mitochondrial DNA from sediments deposited ~100 thousand and ~60 thousand years ago (ka) and possibly as recently as ~45 ka. The long-term occupation of BKC by Denisovans suggests that they may have adapted to life at high altitudes and may have contributed such adaptations to modern humans on the Tibetan Plateau.

Water and heat availability are drivers of the aboveground plant carbon accumulation rate in alpine grasslands on the Tibetan Plateau

2019 ◽  
Vol 29 (1) ◽  
pp. 50-64 ◽  
Author(s):  
Jian Sun ◽  
Tian‐Cai Zhou ◽  
Miao Liu ◽  
You‐Chao Chen ◽  
Guo‐Hua Liu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Accumulation Rate ◽  
Carbon Accumulation ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Carbon Accumulation Rate

Qaidam Basin and northern Tibetan Plateau as dust sources for the Chinese Loess Plateau and paleoclimatic implications

Geology ◽  
2011 ◽  
Vol 39 (11) ◽  
pp. 1031-1034 ◽  
Author(s):  
A. Pullen ◽  
P. Kapp ◽  
A. T. McCallister ◽  
H. Chang ◽  
G. E. Gehrels ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Loess Plateau ◽  
Qaidam Basin ◽  
Chinese Loess Plateau ◽  
Chinese Loess ◽  
Northern Tibetan Plateau ◽  
Dust Sources ◽  
The Chinese Loess Plateau

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.

scholarly journals Active Strike-Slip Faulting and Systematic Deflection of Drainage Systems along the Altyn Tagh Fault, Northern Tibetan Plateau

2021 ◽  
Vol 13 (16) ◽  
pp. 3109
Author(s):  
Peng Chen ◽  
Bing Yan ◽  
Yuan Liu
Keyword(s):  
Tibetan Plateau ◽  
Large Scale ◽  
Regional Scale ◽  
Strike Slip ◽  
The Tibetan Plateau ◽  
Stream Channels ◽  
Altyn Tagh Fault ◽  
Drainage Systems ◽  
Northern Tibetan Plateau ◽  
Altyn Tagh

Systematic deflection of drainage systems along strike-slip faults is the combination of repeated faulting slipping and continuous headward erosion accumulated on the stream channels. The measurement and analysis of systematically deflected stream channels will enhance our understanding on the deformational behaviors of strike-slip faults and the relationship between topographic response and active strike-slip faulting. In this study, detailed interpretation and analysis of remote sensing images and DEM data were carried out along the Altyn Tagh Fault, one typical large-scale strike-slip fault in the northern Tibetan Plateau, and together with the statistical results of offset amounts of 153 stream channels, revealed that (i) the drainage systems have been systematically deflected and/or offset in sinistral along the active Altyn Tagh Fault; (ii) The offset amounts recorded by stream channels vary in the range of 7 m to 72 km, and indicate a positively related linear relationship between the upstream length L and the offset amount D, the channel with bedrock upstream generally has a better correlation between L and D than that of non-bedrock upstream; (iii) River capture and abandonment are commonly developed along the Altyn Tagh Fault, which probably disturbed the continuous accumulation of offset recorded on individual stream channel, suggesting that the real maximum cumulative displacement recorded by stream channels might be larger than 72 km (lower bound) along the Altyn Tagh Fault. Along with the cumulative displacements recorded by other regional-scale strike-slip faults in the Tibetan Plateau, these results demonstrate that the magnitude of tectonic extrusion along these first-order strike-slip faults after the collision of India–Asia plates might be limited.

scholarly journals Community assembly and functional leaf traits mediate precipitation use efficiency of alpine grasslands along environmental gradients on the Tibetan Plateau

2016 ◽  
Author(s):  
Shaowei Li ◽  
Jianshuang Wu
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Community Assembly ◽  
Environmental Gradients ◽  
Diversity Index ◽  
Regional Scale ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Moisture Index ◽  
Use Efficiency

The alpine grasslands on the Tibetan Plateau are sensitive and vulnerable to climate change. However, it is still unknown how precipitation use efficiency (PUE), the ratio of ANPP to precipitation, is related to community assembly of plant species, functional groups or traits for the Tibetan alpine grasslands along actual environmental gradients. We conducted a multi-site field survey at grazing-excluded pastures across meadow, steppe and desert-steppe to measure aboveground biomass in August, 2010. We used species richness, the Shannon diversity index, and cover-weighted functional group composition (FGC) of 1-xerophytes, 2-mesophytes, and 3-hygrophytes to describe community assembly at the species level; and chose community-level leaf area index (LAIc ), specific leaf area (SLAc ), and species-mixed foliar δ13C to quantify community assembly at the functional trait level. Our results showed that PUE decreased with increasing accumulated active temperatures (AccT) when daily temperature average is higher than 5°C, but increased with increasing climatic moisture index, which was demined as the ratio of growing season precipitation (GSP) to AccT. We also found that PUE increased with increasing species richness, the Shannon diversity index, FGC and LAIc ,decreased with increasing foliar δ13C, and had no relation with SLAc at the regional scale. Neither soil total nitrogen nor organic carbon has no influence on PUE at the regional scale. The community assembly of the Shannon index, LAIc and SLAc together accounted for 46.3 % of variance in PUE, whilst climatic moisture index accounted for 47.9 % of variance in PUE at the regional scale. This implies that community structural properties and plant functional traits can mediate the sensitivity of alpine grassland productivity in response to climate change. Thus, a long-term observation on community structural and functional changes is recommended for better understanding the response of alpine ecosystems to regional climate change on the Tibetan Plateau.

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