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文中对新疆罗布泊北部21个风积物样品和56个冲洪积物样品进行了磁性特征和粒度的分析,初步探讨了罗布泊风积物与冲洪积物磁性变化的差异性。结果表明:1)风积物与冲洪积样品中对磁化率起主要贡献的是磁铁矿和磁赤铁矿;2)风积物的磁化率与百分比频率磁化率呈负相关,与粗粒(>63μm)组分呈正相关,与细粒(<5μm)组分呈负相关关系,说明风积物磁化率与非成土风积粗粒组分密切相关;3)冲洪积物1.25m~1.90m之间的磁化率和百分比频率磁化率呈正相关关系,和SIRM/χ呈反相关关系,和粒度呈反相关关系,揭示了后期的化学风化可能主导着磁化率的变化。
In this paper, the magnetic characteristics and grain size of 21 aeolian samples and 56 alluvial sediment samples from northern Lop Nur in Xinjiang Autonomous Region were analyzed. The differences between the magnetic changes of the Lop Nur and the alluvial sediments were discussed. The results show that: 1) magnetite and maghemite are the major contributors to the susceptibility of the aeolian and alluvial samples; 2) the susceptibility of the aeolian is negatively correlated with the percentage frequency susceptibility, (> 63μm), but negatively correlated with the fraction of fine particles (<5μm), indicating that the susceptibility of aeolian is closely related to the non-soil aeolian coarse fraction. 3) There is a positive correlation between magnetic susceptibility and percentage magnetic susceptibility (m ~ 1.90m), inversely related to SIRM / χ and inversely related to grain size, revealing that the later chemical weathering may dominate the magnetic susceptibility.