Abstract
West Kunlun Mountains have continuous loess deposits. However, very few papers have explored the rock magnetic characteristics of loess deposited there. Thus, although Kunlun Mountains loess is one of the useful paleoclimate archives, its importance has not been emphasized. Here we present detailed rock magnetic and bulk grain‐size studies on a 207 m loess core on the northern slope of the West Kunlun Mountains. We find that magnetic susceptibility of loess from the northern slope of the West Kunlun Mountains is not controlled by changes in the concentration of ultrafine pedogenic magnetite and maghemite, but instead controlled by changes in the concentration of aeolian multidomain magnetite and maghemite. This is unsurprising given the low rainfall of the Kunlun region and the lack of postdepositional weathering and soil formation in these aeolian sequences. In addition, we find that magnetic susceptibility values increase dramatically at 111 m corresponding to an age of ∼0.5 Ma. The magnetic susceptibility increase is accompanied by coarsening of both bulk and magnetic grain size and softening of magnetic mineralogy. We tentatively tie these changes in rock magnetic and grain‐size parameter records to an expansion of desert environment.
Published Version
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