天山北麓典型黄土磁学特征及其控制因素

MAGNETIC PROPERTY AND DOMINATING FACTORS OF THE LOESS AT NORTHERN PIEDMONT OF TIANSHAN, XINJIANG

摘要: 选取新疆天山北麓地区的典型黄土钟梁剖面,进行了系统的环境磁学和粒度特征研究。结果显示其磁性特征主要由磁铁矿控制,同时含有磁赤铁矿、赤铁矿;磁性矿物磁晶粒度以假单畴和多畴为主。与黄土高原地区黄土磁化率变化模式不同,钟梁剖面黄土层的磁化率高于古土壤层,磁化率受控于原生亚铁磁性矿物的含量,增强模式以风速论模式为主,黄土高原超细颗粒成壤模式不显著。

Abstract: We carried out systemic rock-magnetic investigations on the loess/paleosol sequence at the northern piedmont of the Tianshan Mountain, Xinjiang. Results show that the main magnetic minerals of this sequence are magnetite, maghaemite, haematite, and the main magnetic grain size of magnetic minerals are PSD and MD. The magnetic susceptibility of the loess layer in the Tianshan Mountains is higher than that of paleosoil, which is different from the loess in Loess Plateau. Magnetic susceptibility of the sediments is controlled by native ferrimagnetic minerals from source. Fine grain magnetic materials produced by pedogenic progress make limited contribution to magnetic susceptibility of the loess.