Neotectonic movement in the southern margin of the Ordos Block inferred from the Qianhe River terraces near the north of the Qinghai-Tibet Plateau

A pioneering rapid and direct measurement of dissolved 222Rn in the field has been used here to explore interaction between surface and groundwater in the source area of the Yellow River (SAYR). The results indicate average 222Rn activity of 2,371 Bq/m3 in surface water and 27,835 Bq/m3 in groundwater. The high 222Rn activity (up to 9,133 Bq/m3) found in the southeast part of the SAYR suggests possible influence of permafrost on the exchange between surface water and groundwater. The remarkable contrast among the different samples of a stream in the Shuangchagou basin, a typical basin in the SAYR, clearly indicates groundwater infiltration along the north tributary and occurrence of groundwater end-member in the south tributary. Considering no 222Rn decay and atmospheric evasion, the daily average fraction of groundwater input to the surface water through the end-member in a location (S1) is estimated at 19%. Despite the up to 40% uncertainty, this is the first estimate of a reference value for groundwater input in this basin and which can be improved in the future with more samples and measurements. 222Rn can be a rapid and easily measured tracer of surface water–groundwater interaction for future investigation in the Qinghai-Tibet Plateau.

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Angular Unconformity of the Late Quaternary Strata in the Hetao Basin, North of the Ordos Block (West China): Timing and Its Tectonic Implications

Frontiers in Earth Science ◽

10.3389/feart.2021.646789 ◽

2021 ◽

Vol 9 ◽

Author(s):

Luanxi Bai ◽

Xiwei Xu ◽

Hao Luo ◽

Kang Li ◽

Xibin Tan ◽

...

Keyword(s):

Late Quaternary ◽

Lacustrine Sediments ◽

Tibet Plateau ◽

Tectonic Activity ◽

West China ◽

The North ◽

Ordos Block ◽

The Pacific ◽

Long Time ◽

Lacustrine Facies

Following the uplift of the Tibet Plateau and the continuous subduction of the Pacific Plate, graben faulting began to appear around the Ordos Block in the Cenozoic. The Hetao Basin is a Cenozoic rift basin between the Ordos Block and the Yinshan Mountains, and Late Quaternary sedimentary strata, which have lacustrine facies, are widely distributed inside this basin. However, the evolution of the Hetao Basin and its related fault systems has been debated for a long time due to the lack of tectonic evidence. In this study, four sections named Haolaigou, Bianqianghao, Huhesala, and Hazigai are selected along the north margin of the Hetao Basin. With the lithology and structural analysis of the Upper Pleistocene series in these sections, two new angular unconformities are found within the 10 m thick sedimentary sequence of the lacustrine sediments. Based on the dating results, we speculate that these two upper and lower angular unconformities are formed between 33 ka BP and 40 ka BP, and 60 ka BP and 80 ka BP, respectively. The angular unconformities also provide tectonic constraints for the latest and ongoing tectonic activity in the Quaternary. This tectonic movement begins at around 80 ka BP and causes two different unconformities of the lower strata with varying degrees of deformation (tilt) but also leads to the final death of the ancient lake.

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Impact of the Qinghai-Tibet Plateau Weather System on the Rainstorm on the North Slope of Kunlun Mountain

10.5194/egusphere-egu2020-4311 ◽

2020 ◽

Author(s):

Zhang junlan

Keyword(s):

High Pressure ◽

Water Vapor ◽

Tarim Basin ◽

Bay Of Bengal ◽

Tibet Plateau ◽

Weather System ◽

Shear Line ◽

The North ◽

Qinghai Tibet Plateau ◽

Southern Xinjiang

Based on the encryption automatic station data, the conventional ground and high altitude observation data, the FY2 static satellite data, and the initial field data of the ECMWF fine grid forecast model (spatial resolution 0.125 &#176;&#215; 0.125 &#176;) in Tarim Basin in the southern Xinjiang, the rare rainstorm process occurred on the north slope of Kunlun Mountains from 24-26 June 2019 is analyzed. Aiming at the circulation situation, the weather system and the configuration of the high and low altitude systems, the plateau weather systems such as the Qinghai-Tibet high pressure, the plateau low vortex and shear line, and the jet stream south of the plateau were analyzed. Their important effects of the formation of Rainstorm on the northern slope of Kunlun Mountain is concluded as follows:(1) The development and maintenance of the Qinghai-Tibet Plateau weather system are generated during favorable weather-scale dynamic and thermal processes, which are mainly manifested in the following three aspects: First of all, the South Asian High pressure changed from a double type to Qinghai-Tibet high pressure at 100hPa. At 200 to 300hPa, the southwestern jet stream lifted northward from the plateau and strengthened in the Tarim Basin in the southern Xinjiang. Suction effect can promote the ascending movement over the rainstorm area; Secondly, the low value system of the shear line nearly in the north-south direction between the Qinghai-Tibet high, the plateau vortex, the shear line and the Indian low is stable in 500hPa. The southerly flow prevails in the periphery of the West Pacific subtropical high, which runs through the Qinghai-Tibet Plateau and the South Xinjiang basin from the Bay of Bengal. The positive vorticity advection and warm advection on the southerly flow over the Qinghai-Tibet Plateau are conducive to the large-scale uplift movement over the rainstorm area and the western part of South Xinjiang, forming water vapor channel from south to north. While warm air transporting to the north, the North-South cold and warm air convergence is enhanced. Thirdly, the coupling between strong high-level divergence and middle-level convergence during heavy rains can result in enhanced mid-level water vapor convergence and vertical water vapor transport.&#160;(2) Weather systems below 600hPa have positive feedback on the maintenance and development of plateau weather systems. Easterly airflow was in the Tarim Basin in the southern Xinjiang between 600hPa and 700Pa&#65292;and the airflow at 600hPa was stronger than 700hPa. The easterly airflow carried part of the cold air into the Tarim Basin in the southern Xinjiang. A cold pad was formed in the lower layer below 600hPa in the southern Xinjiang basin, which facilitated the transfer of warm and humid air northward by the 500hPa middle-south wind and the 500 to 200hPa ascent movement development and maintain, while exacerbating the vertical cold and warm exchanges.&#160;(3) Water vapor mainly comes from the Bay of Bengal, the Caspian Sea and the Aral Sea, but the water vapor contribution from the Bay of Bengal is even greater.

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Taxonomic consideration of eight Chinese bisexual Artemia populations, based on the morphology of frontal knob and gonopod and the result of cross-breeding tests

Zootaxa ◽

10.11646/zootaxa.1919.1.2 ◽

2008 ◽

Vol 1919 (1) ◽

pp. 25-44 ◽

Cited By ~ 2

Author(s):

BO ZHENG ◽

SHI-CHUN SUN

Keyword(s):

North China ◽

Type Locality ◽

Tibet Plateau ◽

Taxonomic Assignment ◽

Cross Breeding ◽

Chinese Populations ◽

The North ◽

Xizang Plateau ◽

Qinghai Tibet Plateau ◽

Taxonomic Consideration

The taxonomic assignment of the Artemia from Qinghai-Xizang Plateau has been argued. In the present paper, the morphology of frontal knobs and gonopods of five Artemia populations from Qinghai-Xizang Plateau (Lagkor Co, Cam Co, Dagdong Co and Jibu Caka, Tibet; Jingyu Hu, Xinjiang) and three populations from North China (Badain Jaran and Yimeng, Inner Mongolia; Xiechi Lake, Shanxi) is described and compared with four non-Chinese species, the results of cross-breeding tests between the eight Chinese populations are documented and the taxonomic assignment of these Artemia populations is discussed. Morphological observations show that gonopods of the Chinese populations are significantly longer than those of the other species; distal gonopods of the Chinese populations possess spines that can be classified into three groups (posterior spines, exolateral spines and orthostichous spines). In the four non-Chinese species, however, orthostichous spines are absent (thus providing a morphological separation between A. urmiana and A. tibetiana) and the number of spines is much smaller than those of the Chinese populations. Discriminant analysis on numerical characters showed that three North China populations were divergent from four Tibetan populations, with Jingyu Hu population intermediate. Compared with the North China populations, the Tibetan populations possess a longer gonopod (longer gonopod, longer distal gonopod and longer finger-like tip), larger basal gonopod spine, larger percent of frontal knob spines that emerge by 2 spines from the same region and smaller percent of frontal knob spines that emerge by 4 and 5 spines from the same region. The Artemia from Jingyu Hu is morphometrically close to the Tibetan populations by possessing a larger basal gonopod spine, larger percent of frontal knob spines emerging by 2 spines from the same region and smaller percent of frontal knob spines emerging by 4 and 5 spines from the same region, but different from the latter by having a shorter gonopod (shorter gonopod, shorter distal gonopod and shorter finger-like tip), fewer frontal knob spines, more distal gonopod spines and more posterior spines. The results of cross-breeding tests showed that isolating barrier did not exist among the three North China populations or among the five Qinghai-Xizang Plateau populations, while they might exist between A. urmiana and the populations of Xiechi Lake (type locality of A. sinica) and Lagkor Co (type locality of A. tibetiana) and between the Qinghai-Xizang Plateau populations and A. sinica. The present results thus support the validity of A. tibetiana. Among the eight Chinese populations, the five populations from Qinghai-Tibet Plateau belong in A. tibetiana, whereas three populations from North China belong in A. sinica.

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High Diversity of Small Insectivorous Mammals on Qinghai-Tibet Plateau and First Description of Karyotype for four Endemics of China

10.21203/rs.3.rs-793070/v1 ◽

2021 ◽

Author(s):

Svetlana V. Pavlova ◽

Vladimir S. Lebedev ◽

Vasily D. Yakushov ◽

Yongke Zhu ◽

Yun Fang ◽

...

Keyword(s):

Molecular Genetic ◽

B Chromosome ◽

Central China ◽

Western China ◽

Tibet Plateau ◽

Phylogenetic Groups ◽

The North ◽

Molecular Genetic Data ◽

Distribution Ranges ◽

Qinghai Tibet Plateau

Abstract Among seven species of the order Eulipotyphla (from southern Gansu and northern Sichuan Provinces, Central China) studied cytogenetically, karyotypes of one talpid species, Uropsilus aff. soricipes (2n = 36, NFa = 54), and three soricid species, Chodsigoa hypsibia (2n = 65, NFa = 66), Sorex cansulus (2n = 42, NFa = 64) and Sorex thibetanus (2n = 42, NFa = 60), are described cytogenetically for the first time. All four species are endemic to China with distribution ranges restricted to the Qinghai-Tibet Plateau and adjacent mountain ranges. The Ch. hypsibia karyotype consists of mostly acrocentric autosomes and one metacentric pair of autosomes; besides, a B chromosome was identified. No polymorphism was detected among karyotypes of other species, including shrews Sorex bedfordiae (2n = 26, NFa = 44), Anourosorex squamipes (2n = 48, NFa = 92) and Crocidura suaveolens (2n = 40, NFa = 44). The Chinese shrew mole U. aff. soricipes and three shrew species (S. bedfordiae, Ch. hypsibia and A. squamipes) represent autochthonous fauna of Central/Western China, whereas S. thibetanus, S. cansulus and C. suaveolens belong to phylogenetic groups occurring mostly to the north and west from China; therefore, they should be considered relatively recent colonisers. Thus, considering the relationships of the species within phylogenetic groups, our results on karyotypes are in good agreement with molecular genetic data.

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