Uplift Of Qinghai-Tibet Plateau Research Articles

Phylogeography of Sophora davidii (Leguminosae) across the ‘Tanaka‐Kaiyong Line’, an important phytogeographic boundary in Southwest China

The 'Tanaka-Kaiyong Line' (TKL) is a major phytogeographic boundary in Southwest China, separating East Asia's Sino-Himalayan and Sino-Japanese Floras. However, little is known about the importance of this boundary in promoting intraspecific phylogeographic subdivision and divergence. Using chloroplast (cpDNA) and nuclear-intron (nDNA) sequence data, we reconstructed the population history of Sophora davidii, a drought-tolerant riparian shrub widely distributed on either side of the TKL. Specifically, we aimed at testing two long-standing explanations for possible vicariant events across the TKL: (i) Late Pliocene (c. 3Ma) geological uplift of the eastern Qinghai-Tibetan Plateau (QTP) or (ii) a sharp environmental gradient associated with the establishment of different monsoon regimes on either side of the TKL during the (Late) Pleistocene. Our genealogical analyses detected a major west-east split in cpDNA, geographically largely consistent with the TKL, and dated to c. 1.28Ma (95% HPD: 0.21-2.96Ma), hence postdating the latest phase of eastern QTP uplift. Furthermore, integrating cpDNA phylogeographic patterns with mismatch analyses, we found multiple refugial isolation and long-term demographic stability of populations in the west (Hengduan Mountain Range) compared with extensive range expansions in the east, possibly during the last glacial period(s) and followed by differentiation into regional sublineages (southeast: Yunnan-Guizhou Plateau vs. northeast: Qinling Mts./Loess Plateau). Although nuclear differentiation was less marked, the geographical pattern of nDNA haplotypes provided some further indication of the species' eastward expansion, possibly from source populations located just east of the TKL (lower Jinshajiang region). Overall, the present data reject the geological (tectonic) explanation for the TKL and, instead, provide supportive evidence for its role as a climatically driven barrier to present-day plant dispersal. In addition, our study highlights changing temperatures and vegetation types during the last glacial period(s), along with aspects of regional topography, to be important determinants of the glacial eastward expansion of S.davidii. In consequence, our study lends support to a 'glacial out-of-Hengduan Mts'. hypothesis for the xerophytic-riparian flora of Southwest China, which in turn is inconsistent with the traditional view of the TKL as a 'classical' vicariant-biogeographic boundary.

Definition of the Quaternary Qiangtang Paleolake in Qinghai‐Tibetan Plateau, China

Abstract:Since the Quaternary, many lakes have been present in the Qinghai‐Tibetan Plateau. As peculiar geological processes in the evolution of the uplifting of Qinghai‐Tibetan Plateau, the distributions and evolutions of the Quaternary paleolakes in the Qinghai‐Tibetan Plateau have been the focus of interest among the international geosciences circle. Comparisons of the newly obtained and existing data from field surveys, remote sensing images, characteristics of tectonic landforms and distribution of the lacustrine strata, the author have, for the first time, defined a large‐sized Quaternary Qiangtang Paleolake. The paleolake starts from the east‐westerly direction at Rutog in western Tibet, passing through Gêrzê, and finally ends at Nagqu in eastern Tibet. Its length is approximately 1,200 km; it is about 420 km at its widest point (north‐southerly). The Paleolake forms an E‐W (or NWW) ellipsoid with an estimated area of 354920 km2. The Paleolake is bordered by the Mts. Gangdisê and Nyainqêntanglha to the south and the Karakorum Pass‐Tozê Kangri‐Zangbagangri‐ Tanggula Pass to the north. It generally appears as a basinal landform with low mountains and valleys in the central part (altitudes of 4400 m) and higher altitudes (5000 m) in the peripheries. The formation and development of the Paleolake was controlled by the nearly E‐W trending structures. There are three east‐westerly extending tectonic sutures inside the Paleolake area, from north to south: (1) the Shuanghu Suture; (2) the Bangong Co‐Nujiang River Suture; (3) the Shiquanhe‐Lhari Suture. These three sutures have generally controlled the spreading features of the Paleolake and act as the first grade lake‐controlling structures. In the southern Paleolake basin, there are a series of south‐northerly rift basins, which are controlled by the normal faults and exist as a series of south‐northerly grabens and semi‐graben faulted basins. The south‐northerly rift zones have clearly exerted control over the south margin of the Paleolake as well as the distribution of the residual lake basins after the Paleolake's break up. They are the secondary lake‐controlling tectonics. Discoveries of the lacustrine strata inside the Plateau, especially the successive discoveries of many high‐stand lacustrine strata, are direct evidence supporting the existence of the paleolakes in the Plateau. The dating results of the lake‐eroded travertine in the Dong Co in the hinterland of the Quaternary Qiangtang Paleolake have revealed that the lake‐eroded travertine is of Late Pleistocene sediments. By considering the analysis of the lacustrine strata as well, the researchers have revealed that the Quaternary Qiangtang Paleolake begins its embryonic form in the Early Pleistocene, successively develops till the Middle Pleistocene, and reaches its full blossom in the middle stage of the Late Pleistocene; it further shrinks and separates by the end of the Late Pleistocene, and finally ceases its whole life as the paleolake. After the Holocene, the huge Late Pleistocene Qiangtang Paleolake no longer exists, leaving a series of widely distributed smaller lakes on the Qiangtang Plateau. These smaller, isolated water systems receive the Holocene lacustrine sediments.

Intense uplift of the Qinghai-Tibetan Plateau triggered rapid diversification of Phyllolobium (Leguminosae) in the Late Cenozoic

Background: Phyllolobium, a recently established genus from subgenus Pogonophace of Astragalus, contains about 20 species and four sections, mostly endemic to the Qinghai-Tibetan Plateau (QTP). The uplift of the QTP undoubtedly affected organismic evolution in the region, but further molecular dating in a phylogenetic context is required to test whether diversification is linked in particular to the intense uplift 3.6 million years ago (Ma). Aims: Based on molecular dating of Phyllolobium, we attempted to identify a relationship between diversification and speciation of Phyllolobium and the geological event of this intense uplift. Methods: Internal transcribed spacer (ITS) sequence data of Phyllolobium were used for the study. Outgroup genera selected were Astragalus, Oxytropis, Caragana, Calophaca, Hamilodendron, Hedysarum, Sphaerophysa, Swainsona and Colutea, as well as Dalbergia and Pueraria. Both of the latter genera have fossil records, enabling their use in constraint calibrations for dating. Phylogenetic analysis employed maximum parsimony and Bayesian inference, and phylogenetic datings were conducted by using three approaches implemented in the programs r8s, PAML and BEAST. Results: The estimated crown age of Phyllolobium was dated to 3.62 Ma in PL-r8s (3.96 in BEAST, 3.48 in PAML, listed similarly in the following), and sections within the genus had ages ranging between 3.60 and 2.55 Ma. These dates coincide with, or follow soon after, the intense uplift of the QTP in the Late Pliocene. By contrast, diversification of sections Bibracteolati and Oliganthum began at estimated ages of 1.95 Ma (2.24, 1.94) and 1.83 Ma (1.53, 1.62), respectively, and may therefore have been triggered by the ‘Qingzang’ plateau uplift (2.5–1.7 Ma). P. tribulifolium had a dated crown age of 0.63 Ma (0.58, 0.42), suggesting that the ‘Kunhuang’ uplift and/or glaciation (occurring between 1.1/0.8 and 0.6 Ma) facilitated diversification. Conclusions: The estimated crown ages of Phyllolobium and of sections within it indicate that rapid diversification was likely triggered by consecutive phases of QTP uplift in the Late Pliocene and the Early-to-Mid Pleistocene. However, the diversification of at least some Phyllolobium species can be explained by Late Pleistocene glaciation and/or geological events. In sum, these findings characterise Phyllolobium as a recently diversified genus adapted to the cold and dry habitats of the QTP and its environs.

Biogeographical Origin and Speciation of theAnthocoris nemorumGroup

The Anthocoris nemorum group belongs to the Anthocoridae (Hemiptera), and is an important group of predators of agricultural pests. A phylogeny was constructed in conjunction with dispersal-vicariance analysis of the Anthocoris nemorum group species in order to discern the relationships between the phylogeographical structuring of A. nemorum group species, and the effects of the Qinghai-Tibet plateau uplift. The divergence times were estimated using Bayesian inference as implemented in BEAST. A portion of the mitochondrial COI gene (1406 bp) and 16S rDNA (932 bp) were chosen as molecular markers to reconstruct evolutionary relationships among 10 species in this group. The combined approach, based on phylogeny, estimation of node dates, and dispersal-vicariance analyses, indicated that the phylogeographical structuring of A. nemorum has been primarily shaped by the two main periods of the Qinghai-Tibet plateau uplift. The DIVA optimal reconstructions suggest that A. nemorum diversified from the Miocene to the Pleistocene from a center of origin in the Hengduan Mountains. The rapid uplift of Mountain ranges associated with the uplift of the entire Qinghai-Tibet plateau may have promoted rapid divergence in the A. nemorum group. Vicariance and dispersal were both essential in shaping the present distribution patterns of A. nemorum.

Study of Qinghai-Tibet Plateau Uplift Response to Eco-geological Environment Based on Remote Sensing

The rapid uplift of the Qinghai-Tibet Plateau has changed the morphologic units,the tectonic frameworks,the rivers strike,the Asian monsoon and the climate.On the basis of the survey and monitoring results of eco-geological environment and from the angle of the uplift of the Qinghai-Tibet Plateau,this paper systematically describes the eco-geological environment features,the response of eco-geological environment and its regularity in the Qinghai-Tibet Plateau.The results show that the geological environment of the Qinghai-Tibet Plateau is the foundation controlling the formation,development and evolution of ecological environment of the Qinghai-Tibet Plateau and its surrounding areas.The rapid uplift of the Qinghai-Tibet Plateau has provided external factors for modern glaciers,desertification and geological disasters.Besides,the climatic environment of the Qinghai-Tibet Plateau is the power source of ecological environment change in China.Human activities have played a catalytic role in ecological environment change in the Qinghai-Tibet Plateau and its surrounding areas.

Sedimentary Evolution in the Northern Slope of the South China Sea Since the Oligocene and Its Response to Tectonics

AbstractThe sedimentary evolution of the South China Sea (SCS) since the Oligocene and its response to tectonics was reconstructed based on a multi‐proxies approach including monomineralic quartz oxygen isotope ratios (δ18O), terrigenous grain‐size and accumulation rate, and scanning electron microscopy (SEM) observation of isolated quartz in sediments from Ocean Drilling Program (ODP) Site 1148 in the northern SCS. The sedimentary evolution of SCS could be divided into five stages: initial expansion (34~28.5 Ma), intense tectonic activity (28.5~23 Ma), reduced tectonic activity (23~16.5 Ma), thermal subsidence (16.5~3.5 Ma), and Taiwan uplift (3.5 Ma to present). Significant variations of the composition of terrigenous minerals and oxygen isotope values of quartz between 28.5 Ma and 23 Ma suggest a change in sediments provenance, which may be related to the strongest tectonic activity of the SCS in the Oligocene. Terrigenous materials at the study site were mainly originated from the southern source (presumptively from Palawan) during the early spreading period of the SCS. With the extensive spreading of the SCS, especially when the spreading axis of the SCS jumped southwards during 25~23 Ma, the Palawan continental block moved away from the study site. Moreover, the northern sources (South China) were not significant because of low topography at that time. Therefore, the terrigenous mass accumulation rate (MAR) was very low. Because of the rapid uplift of the Qinghai‐Tibet Plateau, Pearl River developed gradually and thus South China became the main source of ODP Site 1148. With the formation of the Taiwan island since 3.5 Ma, Taiwan contributed significant terrigenous materials to the northern SCS. The hiatus in sediments at ODP Site 1148 in the late Oligocene possibly resulted from the influence of low terrigenous materials supply, rising sea level and relatively stronger currents during provenance change.

Chloroplast phylogeny and phylogeography of Stellera chamaejasme on the Qinghai-Tibet Plateau and in adjacent regions

Historic events such as the uplift of Qinghai-Tibet Plateau (Q-T Plateau) and climatic oscillations in the Quaternary period greatly affected the evolution and modern distribution of Sino-Tibetan flora. Stellera chamaejasme, a perennial herb with flower color polymorphism that is distributed from the mountainous southeastern Q-T Plateau (Hengduan Mountains, H-D Mountains) to the vast platform of the Q-T Plateau and the adjacent plain of northern China, provides an excellent model to explore the effects of historic events on the origination and variation of species. In this study, we conducted a phylogenetic and phylogeographical study using three chloroplast sequences ( trnT-L, trnL-F and rpL16) in 26 populations of S. chamaejasme and 12 outgroups from the Thymeleaceae. Phylogenetic analysis and molecular clock estimation revealed that the monophyletic origin of S. chamaejasme occurred ca. 6.5892 Ma, which is consistent with the radical environment changes caused by the rapid uplift of the Q-T Plateau ca. 7 Ma. Intra-specific differentiation of S. chamaejasme is estimated to have occurred after ca. 2.1 Ma. Twelve haplotypes were revealed from combined trnL-F and rpL16 sequences. High genetic diversity ( h T = 0.834) and population differentiation ( N ST = 0.997 and G ST = 0.982) imply restricted gene flow among populations and significant geographical or environmental isolation. All populations from the vast plain of northern China were dominated by one haplotype (H1), and the same haplotype was fixed in most populations from the high elevation platform of the western and northern Q-T Plateau. In contrast, the majority of the haplotypes were found in the relatively narrow area of the H-D Mountains, in the southeastern distribution of S. chamaejasme. The contrasting haplotype distribution patterns suggested that the H-D Mountains were either a refugium for S. chamaejasme during the Quaternary climatic oscillations or a diversification center of this species. The present wide distribution of this species on the Q-T Plateau platform and in northern China is likely to have resulted from a rapid post-glacial population expansion from the southeastern refugium involving founder effects, facilitated by the adjacent geographic range with a similar grassland habitat.

Evolutionary response of Caragana (Fabaceae) to Qinghai–Tibetan Plateau uplift and Asian interior aridification

Caragana is endemic to temperate Asia, with most species distributed on the Qinghai–Tibetan Plateau (QTP) and in Northwestern China. Consequently its biogeography should be hypothesized to have been affected by QTP uplift. To examine the biogeography of Caragana in relation to QTP uplift and consequent interior aridification, we conducted molecular dating analyses based on three genes (ITS, cpDNA trnS-trnG and rbcL). Results from relaxed Bayesian BEAST, relaxed Bayesian Multidivtime, and PL (penalized likelihood) indicate that QTP uplift, especially the onset of Himalayan motion at 21–17 Ma, triggered the origin of Caragana (with estimated ages 16–14 Ma). The subsequent QTP rapid uplift at 8 Ma is inferred to have driven the evolution and diversification of the three major clades of Caragana: section Caragana (northern China and the Junggar–Altai–Sayan region), section Frutescentes (Central Asia), and sections Bracteolatae and Jubatae, centered in the QTP. A rapid and active speciation process occurring in the QTP intense uplift at 3.4–1.8 Ma, is indicated by the chronogram.

Phylogeography of the ring-necked pheasant ( Phasianus colchicus) in China

The ring-necked pheasants ( Phasianus colchicus) are widely distributed in China. We used mitochondrial DNA control-region data to investigate the origin and past demographic changes in 139 ring-necked pheasants ( P. colchicus) sampled from the species’ distribution range. A total of 1078 nucleotides from the control region of mitochondrial DNA were sequenced, and 88 polymorphic positions defined 102 haplotypes. High level of genetic diversity was detected in all populations studied which could be associated with the wide ecological distributions and niche variation. Phylogenetic analyses of all haplotypes identified five major clades. The haplotypes of Gray-rumped Pheasants existed in the three clades: A (western clade), B (eastern clade) and C (Sichuan Basin clade). Two haplotypes of Kirghiz Pheasants were in the clade B, and the rest haplotype of Kirghiz Pheasants formed the clade D. Only one haplotype from White-winged Pheasants made up clade E. The results of AMOVA showed a low gene flow (Nm = 0.44) and significant genetic differentiation (Fst = 0.31, P < 0.001) among all populations. Based on the divergence time, we speculate that the divergence of the ring-necked pheasant occurring in the late Pleistocene may have resulted from three events: (1) the uplift of Qinghai-Tibet Plateau, (2) the existence of Qinling Mountains and Liupan Mountains, (3) the isolation of Sichuan Basin. Demographic population expansion was strongly confirmed by the non-significant mismatch distribution analysis. The described subspecies of the ring-necked pheasant could not be supported by the phylogeographical structuring.

Cenozoic sedimentary records and geochronological constraints of differential uplift of the Qinghai-Tibet Plateau

Geological mapping data (1:250000) in the Qinghai-Tibet Plateau and its adjacent regions reveal the sediment sequences, distribution and tectonic evolution of the 92 Tertiary remnant basins. Southern Tibet and the Yecheng area in Xinjiang, located at southern and northwestern margins of the Qinghai-Tibet Plateau, respectively, were parts of the Neo-Tethys remnant sea in the Paleogene. In southern Tibet, both the subabyssal and abyssal sequences occur at the Gyangze, Saga, Guoyala, and Sangmai areas. The deep-water facies successions outcrop in the west, whereas the shallow-water facies sequences in the east, indicating the east to the west retreat of the Neo-Tethys Ocean. The retreat of the Neo-Tethys Ocean in the east was contributed to the earlier tectonic uplift of the eastern Qinghai-Tibet Plateau. The uplift process of the Plateau from the Late Cretaceous to Pliocene is described as follows: During the Late Cretaceous, tectonic uplift of the Qinghai-Tibet Plateau occurred in the northeastern part and the configuration of the Qinghai-Tibet Plateau was characterized by rise in the northeast and depression in the west. In the Paleocene-Eocene interval, the Tengchong-Baingoin and Kuyake-Golmud areas experienced local tectonic uplifting, the West Kunlun uplift zone broadened easterly, the Qilian uplift zone broadened southerly, and the Songpan-Garze uplift zone shrank easterly. The Oligocene configuration of the Qinghai-Tibet Plateau was characterized by mountain chains rising along its margins and sedimentary basins in the central part because of tectonic uplifts of the Gangdise and the Himalaya blocks. Meanwhile, the Kunlun-Altyn-Qilian uplift zones have also broadened southerly and northerly. In contrast, the great uplift zones of the Gangdise, the Himalaya, the Karakorum, and the Kunlun blocks characterize the paleogeographic contours of the Qinghai-Tibet Plateau during the Miocene-Pliocene. Additionally, the thermochronological data on tectonic uplift events in southern Tibet, West Kunlun Mountains, Altyn Tagh, eastern Tibet, and western Sichuan all suggest that the most intense deformation occurred at 13-8 Ma and since 5 Ma, respectively, corresponding to two great uplift periods in Neogene. As a result, turnover of paleogeographic configuration of the Qinghai-Tibet Plateau occurred during the Neogene, experiencing a change from high contours in the east in the pre-Oligocene to high contours in the west at the end-Pliocene. The uplift of the Qinghai-Tibet Plateau during the Cenozoic was episodic, and the uplifts of various blocks within the Plateau were spatially and chronologically different.

Sedimentary features of XK&lt;sub&gt;1&lt;/sub&gt;, core and paleaoenvironment in Gaxun Niir of Inner Mongolia since late Quaternary

通过对嘎顺淖尔XK₁孔沉积岩芯的岩性特征及多种环境代用指标的综合分析,初步认为:中更新世早中期,29.6-42.5m(推测时代为距今218.3 kaBP以前),气候温凉偏干,滨湖与洪积相交替;距今218.3-172.8 kaBP气候温凉偏湿, 湖泊面积扩大,以滨浅湖-浅湖沉积为主,并-度出现半深湖环境;距今172.8-93.4 kaBP,沉积环境为湖滨相与洪积相交替,气候特点是冷凉干旱;距今93.4-67.4 kaBP,沉积环境以淡水浅湖为主,夹湖滨相.气候温偏湿;距今67.4-54.0 kaBP,湖滨相沉积为主,气候温凉偏干;距今54-48.9 kaBP,气候暖湿的浅湖环境,气温较高;距今48.9-42.6 kaBP,凉而且干旱的气候特点,沉积相为湖滨相;42.6-0 kaBP,气候暖湿、凉干交替,浅湖相为主.;Ejinaqi is far from ocean and located in Asian hinterland where the atmospheric circulation is hindered by high mountains. Ejinaqi is controlled by this geographic setting, especially the rapid uplift of Qinghai-Tibet Plateau since the late Quaternary, which undoubtedly influences the climate and environment in Ejinaqi. One of our objectivcs is to establish the palaeoclimatic evolution sequence and to reveal the character of palaeoclimatic changes since the late Quaternary through comprehensively analyzing physical, chemical and biological proxy of sediment in Juyanhai lake. The sediment character, pollen and ostracode assemblage, minerals, and geochemical elements of 42.5m long core in middle-west of Gaxun Nur and of JYH-E section in Quyanhai indicate that there are 8 climate stages and the climate was mainly warmer and cool or warmer with obvious fluctuating from dry to wet since middle-Pleis-tocene. It was cooler and relative wet before 218. 3 kaBP; From172. 8 kaBP to 218. 3 kaBP, the climate was cooler and relative wetter and the lake expanded to a deeper lake; the climate turned to be colder or cooler an dry from 172. 8 to 93.4 kaBP; from 93. 4 kaBP to 67. 4 kaBP, the lake shrank to be a shallow lake, showing the climate probably was mild with little humidity; from 67.4 to 5.4 kaBP, the salinity of the lake increased and the climate was cooler and relative dry; from 54 kaBP to 48. 9 kaBP, the climate was warmer and wetter; the climate was cool and dry from 48. 9 kaBP to 42. 6 kaBP; after 42. 6 kaBP, the climate alternated with warmer-wetter and cooler-dry.

The upper mantle anisotropy in Yunnan area, China

Shear wave phase SKS of 11 earthquakes, collected from 23 stations of Yunnan Digital Seismic Network, is analyzed by fitting the theoretical transverse component with the observed one for determining the orientation and extent of polarization seismic anisotropy of upper mantle. Shear wave splitting is obviously observed in all stations except Heqing station (HQ). The results show that the polarization of fast split S-wave of upper mantle in Yunnan area is north-northeast in general and the time delay between fast and slow split shear waves is 0.5–2.0 s. It suggests that the influence of faults upon anisotropy analysis could not be neglected in such a geologically complex area. As the transitional zone between Qinghai-Tibetan plateau and the block of southern China, in Yunnan area the orientation of fast shear wave polarization indicating the subduction of Indian plate into Eurasian plate is the fundamental background of earth dynamics. While the southeast or south-southeast movement of Sichuan-Yunnan rhomb block, formed by the uplift of Qinghai-Tibetan plateau, plays an important role in the composition of complicated structural and stress environment of Yunnan area. The divergence between the fast direction and the movement of upper mantle indicates in Yunnan area there exists complex coupling effect between lower velocity layer or asthenosphere and crustal block. The distribution of structure driving force looks like a palm extending to northeast. According to the time delay between fast and slow shear waves, it is deduced that the thickness of anisotropy layer is 60–225 km with variation range roughly equal to that of 104–260 km of the buried depth of lower velocity layer of the earth in Yunnan area. So it suggests the top of anisotropy zone starts from the bottom of crust or from the lower velocity layer varying with specific locations related to the tremendous variation of the Moho discontinuity in Yunnan area. Furthermore, it is deduced that the anisotropy of the upper mantle is mainly from the lithosphere rather than the whole upper mantle.

Eco-environmental effects of the Qinghai-Tibet Plateau uplift during the Quaternary in China

The Qinghai–Tibet Plateau uplifted >3000 m in the Quaternary period. The average rate of uplift was 1–1.1 mm/year. The uplifting has remolded the geomorphology of China. The landform in China was changed from west-low and east-high to west-high and east-low in three steps. The Qinghai-Tibet Plateau uplift is an important factor that affected the climate and the environment of China in the Quaternary period. It controls atmospheric circulation and climatic change in Asia and even the northern hemisphere, by dividing the westerlies into two branches: south and north. The plateau gradually became a heat source in summer and a cold source in winter. The uplift had a decisive effect on the formation of the East-Asia monsoon, which increased the climatic differences between the glacial period and the interglacial period. The climate and environment of China are characterized by the influences of the plateau uplift. The east of China became the south-east monsoon area, whereas the south-west became the south-west monsoon area and the north-west turned into an arid inland region. The Gobi and large-scale deserts that formed in the inland basins are ceaselessly extending. The climate of northern China became more arid as the Qinghai-Tibet Plateau continued to uplift. The Plateau uplift affected glacial evolvement and loess formation, and propelled the migration of cold- and warm-blooded animals, which differed from other regions of the world at the same latitude.