新疆塔克尔莫乎尔沙漠表层沉积物磁化率特征及环境意义

以新疆塔克尔莫乎尔沙漠发育典型的固定半固定沙丘为研究对象,分析了其磁化率变化特征,结果表明:1)研究区表层沉积物低频质量磁化率(χ_lf)和高频质量磁化率(χ_hf)变化趋势相近,χ_lf值总体上略高于χ_hf值。χ_lf与χ_hf含量最大为抛物线型沙丘,其次为灌丛沙堆,相反,χ_fd最高的为灌丛沙堆,其次是抛物线型沙丘。2)频率磁化率(χ_fd)的变化范围为0.02～2.65%,均值为0.76%,表明研究区表层风沙沉积物磁性矿物以多畴MD为主,含有极少量的SP颗粒。3)研究区水分条件相对较好,气候偏湿,表层沉积物磁性矿物来源具有多源性。

Characteristics of magnetic susceptibility of surface sediments and their significance in the Takermohuer Desert of Xinjiang

Typical fixed or semi-fixed dunes developed in Takermohuer desert of Xinjiang were taken as the research object to analyze the magnetization variation characteristics of magnetic susceptibility of surface sediments.The results show that:(1)The trend of low frequency mass susceptibility(χlf)and high frequency mass susceptibility(χhf)of surface sediments in the study area is similar;χlf values generally slightly are higher than the value ofχhf.The maximum content ofχhf andχlf are appeared in parabolic dunes,followed by shrub sands,on the contrary,the highest content ofχfd is appeared in shrub sands,followed by parabola dunes.(2)The frequency of magnetic susceptibility(χfd)changes in the range of 0.02~2.65%,average is 0.76%,showing that surface sand sediment magnetic minerals in the study area is given priority to multiple domain MD,containing very little SP particles.(3)It is found that the moisture conditions in the study area are relatively well and the climate is wet.The research indicates the multi-source of magnetic minerals in the surface sediments of the Takermohuer desert.