High resolution hematite/goethite records from Chinese loess sequences for the last glacial-interglacial cycle: Rapid climatic response of the East Asian Monsoon to the tropical Pacific

In order to study the variability of dry versus humid conditions resulting from the East Asian monsoon (EAM) we analyzed hematite and goethite from two high-resolution Chinese loess sections by diffuse reflectance spectroscopy. The hematite and goethite concentrations are higher in interglacial pale...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Ji, JF, Chen, J, Balsam, W, Lu, HY, Sun, YB, Xu, HF
Format: Article in Journal/Newspaper
Language:English
Published: AMER GEOPHYSICAL UNION 2004
Subjects:
hematite and goethite
humid and dry
Chinese loess
Geology
SURFACE MAGNETIC-SUSCEPTIBILITY
DUST ACCUMULATION RATE
PALEOSOL SEQUENCES
NORTH-ATLANTIC
PLATEAU
ICE
PRECIPITATION
TEMPERATURE
DEPENDENCE
GOETHITE
Geosciences
Multidisciplinary
Pacific
North Atlantic
Online Access:http://ir.ieecas.cn/handle/361006/11936
https://doi.org/10.1029/2003GL018975
Description
Summary:In order to study the variability of dry versus humid conditions resulting from the East Asian monsoon (EAM) we analyzed hematite and goethite from two high-resolution Chinese loess sections by diffuse reflectance spectroscopy. The hematite and goethite concentrations are higher in interglacial paleosols than in glacial loess sediments, whereas the hematite/goethite (Hm/Gt) ratios are lower in paleosols than in loess. Such changes are consistent with higher precipitation and temperature and increased pedogenesis during interglaciation and lower precipitation and temperature and decreased pedogenesis during glaciation. The Hm/Gt ratio can be employed as a tool to assess short-term variations in humidity and aridity of the EAM. The Hm/Gt ratios of the last glacial loess displays millennial-scale abrupt climate oscillations, revealing a pattern of significantly reduced and enhanced summer monsoon moisture. Our results indicate that the EAM responded to tropical Pacific climate by millennial-scale changes in precipitation during the last glaciation.

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