Magnetic susceptibility parameters as proxies for desert sediment provenance
Magnetic susceptibility parameters as proxies for desert sediment provenance
复制标题
DOI：
10.1016/j.aeolia.2020.100615
复制
发表时间：
2020-10-01
期刊：
影响因子：
3.3
通讯作者：
Lin, Zeng
中科院分区：
文献类型：
--
作者：
Hallberg, Lars Petter;Stevens, Thomas;Lin, Zeng
在过去的几十年中，沉积物的磁化率作为古环境指标得到了深入的研究。然而，磁化率变化在多大程度上也是不同沉积物来源的一个诊断，这是未知的。在这里，我们调查，如果多个磁磁化率为基础的参数可以有效地用作沉积物源指标。将中国毛乌素和腾格里沙漠的新的磁性数据与以前已知的沉积物来源进行了比较，这些沉积物来源是基于其他成熟的代理。为了评估这些沙漠的磁性，磁化率及其异相分量，其依赖于频率，温度和低场振幅进行了分析。我们的研究结果表明，西部毛乌素沙漠和腾格里沙漠和东部毛乌素的一个独特的来源，与以前假设的种源模式相似。然而，腾格里沙漠沉积物的磁性是均匀的，这可能表明整个腾格里沙漠的物源是一致的，沉积物被大大改造，或在潜在的多个源区相似的磁性。磁铁矿是研究区的主要磁性矿物，磁性矿物富集和磁畴状态是导致磁性差异的主要原因。这里的结果，特别是从毛乌素，建议相当大的承诺，使用磁化率参数在沙漠沉积物的物源研究。
Magnetic susceptibility in sediments has been thoroughly studied as a paleoenvironmental proxy over the last decades. However, it is unknown to what extent magnetic susceptibility variation is also a diagnostic of different sediment sources. Here we investigate if multiple magnetic susceptibility-based parameters can effectively be used as sediment source indicators. New magnetic property data from the Mu Us and Tengger Deserts in China are compared to previously known sediment provenance based on other well-established proxies. To assess the magnetic properties of these deserts, magnetic susceptibility and its out-of-phase component, its dependence on frequency, temperature and low-field amplitude are analyzed. Our results indicate similar sources for the western Mu Us Desert and the Tengger Desert and a distinct source for the eastern Mu Us, in-line with previously hypothesized provenance patterns. However, magnetic properties within the Tengger Desert sediments are homogenous, which may suggest a uniform provenance for the entire Tengger Desert, that the sediments are greatly reworked, or similar magnetic properties in potential multiple source regions. Magnetite is the major magnetic mineral in the study area and the dominant causes for divergence in magnetic properties are the magnetic mineral concentration and domain state. The results here, in particular from the Mu Us, suggest considerable promise for using magnetic susceptibility parameters in desert sediment provenance research.