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Late Paleozoic–Early Mesozoic tectonic evolution of the Zongwulong Shan-Qinghai Nanshan tectonic belt in the northern Qaidam continent， northern Tibet

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Journal of Earth Science 2025年

作者： Yonghui Zhao Chen Wu Jie Li Peter J.Haproff Lin Ding State Key laboratory of tibetan plateau Earth System and Resources environment (TPESRE)， Institute of tibetan plateau Research， Chinese Academy of Sciences University of Chinese Academy of Sciences Chongqing Key laboratory of Complex Oil and Gas Field Exploration and Development， Chongqing University of Science and Technology Department of Earth and Ocean Sciences， University of North Carolina Wilmington

The Zongwulong Shan-Qinghai Nanshan tectonic belt of the northern Tibet plateau experienced a protracted tectonic history， including the openings and closures of the Proto- and Paleo-Tethyan Oceans. Although the tectonic belt has been extensively studied， details regarding the tectonic processes involved in its development remain controversial. To better constrain the tectonic processes of this tectonic belt， we conducted detailed field geological mapping， zircon U-Pb geochronology， and whole-rock geochemical and Sr-Nd isotopic analyses. Our results show that intrusive rocks in the tectonic belt crystallized in ca. 292–233 Ma， perhaps in an arc/subduction setting. Geochemical and Sr-Nd isotopic data suggest that early Permian–late Triassic ultramafic-intermediate intrusions were sourced from the enriched mantle， whereas intermediate-acidic rocks were sourced from mixed crust-mantle. We present the tectonic model that involves: (1) Early Devonian–early Permian intracontinental extension occurred in the northern margin of the Qaidam continent (ca. 416 Ma–292 Ma); (2) Early Permian–late Triassic northward subduction of the Paleo-Tethyan Ocean resulted in arc magmatism (ca. 292 Ma–233 Ma); and (3) subsequent late Triassic intracontinental extension (ca. 233 Ma–215 Ma). Our results suggest that the late Paleozoic–early Mesozoic development of the Zongwulong Shan-Qinghai Nanshan was related to the opening， subduction， and slab retreat of the Paleo-Tethyan Ocean， which has key implications for the tectonic evolution of the northern tibetan plateau.

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Intermolecular reductive coupling of aliphatic ketones with alkynes and alkenes by BCN photocatalysts

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Science China Chemistry 2025年第1期68卷 181-185页

作者： Yanping Xia Luyang Sun Jiajia Cheng Sibo Wang Meifang Zheng Xinchen Wang State Key laboratory of Photocatalysis on Energy and environment College of Chemistry Fuzhou University

A photocatalytic process was developed for intermolecular reductive coupling of aliphatic ketones with alkynes/alkenes to furnish tertiary alcohols. Mechanistic studies support that boron carbonitrides(BCN) promote the single electron reduction of unactivated aliphatic ketones to generate ketyl radicals with visible light irradiation, which then react with alkynes and alkenes to afford the allylic and aliphatic alcohols, respectively. The heterogeneous photocatalytic system is compatible with diverse substrates including pharmaceutical-related molecules(43 examples) with reusability and scale-up experiments, verifying the complementary synthetic utility of this method to the homogeneous catalysts.

关键词： aliphatic ketones ketyl radical intermolecular cross-coupling tertiary alcohols

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Gradient maturation experiment on hairs implies taphonomic changes in fossil hairs

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Science China Earth Sciences 2025年第1期68卷 62-73页

作者： Xin LI Yibo ZHOU Tao ZHAO Xingjian HE Yanhong PAN State Key laboratory for Mineral Deposits Research Center for Critical Earth Material Cycling Centre for Research and Education on Biological Evolution and Environment and Frontiers Science School of Earth Sciences and Engineering Nanjing University Institute of Palaeontology Yunnan Key Laboratory of Earth System Science Yunnan Key Laboratory for PalaeobiologyYunnan University

Mammalian hair, as a key feature related to endothermy, physical protection, and camouflage, has a long geohistorical record that dates back even to the Mesozoic. However, the limited information on the taphonomy of hair hinders the understanding of its evolutionary significance in deep time. To address this, we conducted taphonomic experiments to simulate the transformation process of black hair. The changes in the morphological structure, microscopic characteristics, and chemical composition of hair during the simulated fossilization process were documented by scanning electron microscopy, Fourier transform infrared(FTIR) spectroscopy, and Raman spectroscopy. Our results revealed that damage to the morphology of hair began at a mild temperature(150–175°C), and hair transformed into a fluid-like mass at a relatively high temperature(200°C). In addition, the morphological structure of melanosomes had relatively greater preservation potential than keratins did, and the microscopic features of melanosomes were persistently stable. The Raman and FTIR spectra indicated that the characteristic melanin and keratin peaks changed as the temperature increased. Although the chemical signals were not lost completely, the variations in the characteristic amide bands in the FTIR spectra indicate that the keratins severely degraded at high temperatures(>200°C), whereas the characteristic melanin bands in the Raman spectra suggested that melanin signals were still recognizable, even at high temperatures(>200°C). These results were confirmed by principal component analysis(PCA) and principal component analysis linear discriminant analysis(PCA–LDA). In addition, the Raman signals of all the samples in the simulated experiments were distinguished from the signals of common geological carbonaceous materials(humic acid), which suggested that Raman spectroscopy can be used to detect melanin in fossils.

关键词： Mammalian hair Melanin Keratin Fossilization Experimental taphonomy

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Atmospheric Pb variations in Central Asia since 1955 from Muztagata ice core record, eastern Pamirs

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Chinese Science Bulletin 2006年第16期51卷 1996-2000页

作者： LI Zhen YAO Tandong TIAN Lide XU Baiqing LI Yuefang Key laboratory of Cryosphere and environment Chinese Academy of Sciences Lanzhou 730000 China laboratory of environment and process on tibetan plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

A Muztagata ice core recovered at 7010 m altitude in East Pamirs provides a Pb concentration record from 1955 to 2000. The result reveals in- creasing Pb concentrations from 1955 to 1993, with two Pb concentration peaks in 1980 and 1993. After 1993, Pb concentrations in ice core show an obvi- ously declining trend. Analysis shows that the lead in the Muztagata ice core mainly came from anthropo- genic emissions from countries in Central Asia, while the local emission had little contribution.

关键词：冰核慕士塔格山铅大气中亚帕米尔高原

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Relationships between δ ^(18)O in summer precipitation and temperature and moisture trajectories at Muztagata, western China

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Science China Earth Sciences 2006年第1期49卷 27-35页

作者： YU Wusheng1,2, YAO Tandong1,2, TIAN Lide1,2, LI Zhen2, SUN Weizhen2 & WANG Yu2 1. laboratory of environment and process on tibetan plateau, Institute of tibetan plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2. Key laboratory of Cryosphere and environment, Jointly Established by Cold and Arid Regions environmental and Engi-neering Research Institute and Institute of tibetan plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 730000, China laboratory of environment and process on tibetan plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Key laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China

Based on summer observations of stable isotope of precipitation at Muztagata, western China, during 2002―2003, this paper presents the relationship between δ 18O in precipitation and air temperature, and discusses the effect of moisture transport on δ 18O in precipitation. Results show that air temperature correlates positively with δ 18O in precipitation, and the temperature effect controls the δ 18O of precipitation in this area. The Muztagata region exhibits high δ 18O values in summer precipi-tation, similar to those shown at stations in adjacent regions. According to the results of our model set up to trace the moisture trajectories, the westerlies and local moisture circulation contribute to varia-tions of oxygen isotopes in precipitation. In addition, the impacts of the moisture transport distance, the moisture transport level, and the incursion of the polar air mass also influence the variations of δ 18O in precipitation. The moisture origins and transport mechanisms also contribute to the variation of δ 18O in precipitation at Muztagata.

关键词： Muztagata, δ18O, precipitation, temperature, moisture transport.

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Variations of δ^(18)O in precipitation from the Muztagata Glacier, East Pamirs

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Science China Earth Sciences 2006年第1期49卷 36-42页

作者： LI Zhen1, YAO Tandong1,2, TIAN Lide1,2, XU Baiqing1,2 & Wu Guangjian2 1. Key laboratory of Cryosphere and environment, Jointly Established by Cold and Arid Regions environmental and Engi-neering Research Institute and Institute of tibetan plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 730000, China 2. laboratory of environment and process on tibetan plateau, Institute of tibetan plateau Research, Chinese Academy of Sciences, Beijing 100085, China Key laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China laboratory of environment and process on tibetan plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

Expeditions to Muztagata (in the eastern Pamirs) during the summer seasons of2002 and 2003 collected precipitation samples and measured their oxygen isotopes. The δ^(18)O inprecipitation displays a wide range, varying from -17.40per thousand to +1.33per thousand inJune—September 2002 and from -22.31per thousand to +4.59per thousand in May—August 2003. Theδ^(18)O in precipitation correlates with the initial temperature of precipitation during theobserving periods. The positive correlation between δ^(18)O and temperature suggests that δ^(18)Ocan be used as an indicator of temperature in this region. The δ^(18)O values in fresh-snow samplescollected from two snow events at different elevations on the Muztagata Glacier show a strong''altitude effect'', with a ratio of nearly -0.40per thousand per 100 m from 5500 m to 7450 m.

关键词： Muztagata, δ18O, temperature, altitude effect.

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Variations of near-surface atmospheric CO_(2)and H_(2)O concentrations during summer on Muztagata

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Science China Earth Sciences 2006年第1期49卷 18-26页

作者： XU Baiqing1,2, YAO Tandong1,2, LU Anxin2, GUO Xuejun, LIU Xianqin2 & LI Zhen2 1. laboratory of environment and process on tibetan plateau, Institute of tibetan plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2. Key laboratory of Cryosphere and environment, Jointly Established by Cold and Arid Regions environmental and Engi-neering Research Institute and Institute of tibetan plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, Lanzhou 730000, China laboratory of environment and process on tibetan plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Key laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China

Expeditions during the summers of 2002 and 2003 implemented continuous monitoring of near-surface (2 m height) atmospheric CO2 and H2O concentrations at the 4500 m elevation on Muztagata. The resultant data sets reveal a slight decrease of CO2 concentrations (of about 5 μmol·mol?1) and changes in the diurnal variations from the end of June to the middle August. The daily maximum CO2 concentrations occur between 02:30―05:30 AM (local time) and the minimum levels occur between 12:00―15:30 PM. The atmospheric CO2 concentrations in the summer of 2002 were around 5 μmol·mol?1 lower than those during the same period of 2003, whereas the diurnal amplitude was higher. In contrast, we found that the daily mean atmospheric H2O content in 2003 was much lower than that in 2002 and there exists a striking negative correlation between CO2 and H2O con-centrations. We therefore suggest that the near-surface atmospheric CO2 concentration is affected not only by photosynthesis and respiration, but also by the air H2O content in the glaciated region around Muztagata.

关键词： atmospheric CO2 and H2O concentration, continuous monitoring, glaciation region, Muztagata.

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Grain size record of microparticles in the Muztagata ice core

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Science China Earth Sciences 2006年第1期49卷 10-17页

作者： WU Guangjian1,2, YAO Tandong1,2, XU Baiqin1,2, LI Zheng2, TIAN Lide1,2, DUAN Keqin2 & WEN Linke2 1. laboratory of environment and process on tibetan plateau, Institute of tibetan plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2. Key laboratory of Cryosphere and environment, Jointly Established by Cold and Arid Regions environmental and Engi-neering Research Institute and Institute of tibetan plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, Lanzhou 730000, China laboratory of environment and process on tibetan plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Key laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China

The dust transport and sediment characteristics are discussed based onanalysis of mi-croparticle size and size distribution in the Muztagata ice core at 6350 m a.s.I. Thefiner particles with diameter of 1—5 μm are the dominant fraction in number, while middle andcoarse particles mainly contribute to the total volume. The lognormal distribution characteristicscan be seen for some high concentration samples, showing that model size and standard variation aregreater than that in the Greenland ice cores. However, size-volume distribution of some lowconcentration samples is abnormal. Those distributions reflect the dust deposit process in highmountain glaciers at mid-low latitudes and show differences from those in polar ice sheet.

关键词： Muztagata, ice core, microparticle, dust, size distribution.

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environmental significance of levoglucosan records in a central tibetan ice core

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Science Bulletin 2019年第2期64卷 122-127页

作者： Chao You Tandong Yao Chao Xu Key laboratory of tibetan environment Changes and Land Surface processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Center for Excellence in tibetan plateau Earth Sciences Chinese Academy of Sciences

The environmental significance of levoglucosan(LEV) records in tibetan glacier ice layers on sub-annual to annual scales, in particular their suitability as a specific biomarker for indicating past fire changes, is poorly understood at present. In this work, a continuous LEV record was reconstructed in a central tibetan ice core for the period 1990–2012. The LEV record was classified into two categories based on its LEV concentrations: background levels and extreme events. Annually-resolved LEV records and background levels in the ice core were strongly correlated with satellite observations of fire occurrence frequency over the northern Indian peninsula between 2003 and 2012, especially for strong fire events during the pre-monsoon season(March–May). In addition, peaks in LEV concentrations may represent extreme fire events in regions around the tibetan plateau. LEV records in the ice core reflect a longterm increasing trend in fire background and also an increase in fire extreme events, across the tibetan plateau and its surroundings. We therefore conclude that LEV records in tibetan ice cores can be used as a powerful tool for calibrating and reconstructing past fire changes over subtropical Asia.

关键词： Fire variation Levoglucosan Ice core tibetan plateau Subtropical Asia

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Seasonal variations of dust record in the Muztagata ice cores

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Chinese Science Bulletin 2008年第16期53卷 2506-2512页

作者： WU GuangJian YAO TanDong XU BaiQing TIAN LiDe LI Zhen DUAN KeQin laboratory of environment and process on tibetan plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China State Key laboratory of Cryospheric Science Chinese Academy of Sciences Lanzhou 730000 China

Based on the oxygen isotope ratio and microparticle record in ice cores recovered at Mt. Muztagata, Eastern Pamirs, the seasonal variations of atmospheric dust have been reconstructed for the past four decades. High dust concentrations and coarser particle grains have the similar trend with oxygen iso- tope value. Our statistical results indicate that 50%―60% high dust concentration samples occur dur- ing the season with high oxygen isotope values (summer), while low dust storm frequency during spring and winter. Back-trajectory analysis shows that the air mass hitting Muztagata predominately came from West Asia (such as Iran-Afghanistan plateau) and Central Asia, which are the main dust source area for Muztagata. Dust storms in those source areas most frequently occur during summer (from May to August), while frequent dust storm events in northern China mainly occur during spring (March to May). Regions in the path of Asian dust transport, such as in Japan, the North Pacific, and Greenland, also show high dust concentrations during spring (from March to May). Our results indicate that dust storms have different seasonality in different regions within Asia.

关键词：灰尘季节变化冰层氧同位素

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