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Journal of Desert Research ›› 2023, Vol. 43 ›› Issue (3): 252-263.DOI: 10.7522/j.issn.1000-694X.2022.00149

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Geochemical characteristics of Songnen Sandy Land and its indication of contribution to aeolian dust

Junhe Liu1(), Yunping Chi1,2(), Yuanyun Xie1,2, Chunguo Kang3, Zhenyu Wei1, Peng Wu1, Lei Sun1   

  1. 1.College of Geographic Science /, Harbin Normal University,Harbin 150025,China
    2.Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Harbin Normal University,Harbin 150025,China
    3.School of Geography and Tourism,Harbin University,Harbin 150086,China
  • Received:2022-11-16 Revised:2022-12-28 Online:2023-05-20 Published:2023-05-31
  • Contact: Yunping Chi

Abstract:

As an important part of Asian wind-dust system, desert-sandy land in northern China is one of the important dust sources in Asia, studying the source-sink system of loess deposition in Songnen Sandy Land and the easternmost part of Eurasian loess belt is helpful to understand the relationship between atmospheric circulation model and dust transport path during glacial-interglacial period in Songnen Plain, and provide scientific basis for regional ecological environment and dust weather control. In this study, 47 samples (<63 μm) from Songnen Sandy Land were collected for element geochemical analysis (major elements, trace elements and rare earth elements), and a complete geochemical database of Songnen Sandy Land was established. The provenance quantitative reconstruction was carried out by PCA analysis and Frequentist model, and the contribution degree of Songnen Sandy Land to downwind was discussed in combination with provenance discrimination diagram. The results show that the Songnen Sandy Land is in the primary stage of chemical weathering, and the maturity of the sediment is low, which is composed of a mixture of most primary circulation and a few recycled deposits. According to the results of quantitative reconstruction, Songnen Sandy Land is divided into three regions: Northwest, Southwest-W and Southwest-E, and the contribution degree of Harbin loess is as follows: Southwest-E (Songhua River sediment) 40.5%-66.3%, Southwest-W 24.9%-48.9%,Northwest 1.9%-13.2%. The source discrimination diagram shows that Harbin loess has a similar source area with modern dust storm, and reveals that the dust transmission path in Songnen Plain during the glacial-interglacial period is mainly in the southwest direction, which is different from the circulation mode dominated by northwest wind during the glacial period. High vegetation coverage, small exposed area of sandy land and being blocked by terrain are the main reasons that lead to the limited dust emission in the northwest source area of Harbin (northwest Songnen Sandy Land and Hulun Buir Sandy Land),while low vegetation coverage, large exposed area of sandy land and flat terrain in the southwest source area (mainly the southwest area of Songnen Sandy Land) lead to the continuous increase of dust emission. The control of ecological environment in the southwest of Songnen Sandy Land should be strengthened to improve the frequent dust weather and the increasingly serious air pollution in Harbin. For the prevention and control of regional dust weather, we should pay attention to the ecological environment management of the potential provenance area rather than being limited to the occurrence area itself.

Key words: Songnen Sandy Land, geochemistry, provenance quantitative reconstruction, aeolian dust, dust weather control

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