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Mineral magnetic record of the Miocene-Pliocene climate transition on the Chinese Loess Plateau, North China

Published online by Cambridge University Press:  05 October 2017

Hong Ao ,
Mark J. Dekkers ,
Andrew P. Roberts ,
Eelco J. Rohling ,
Zhisheng An ,
Xiaodong Liu ,
Zhaoxia Jiang ,
Xiaoke Qiang ,
Yong Xu  and
Hong Chang
Hong Ao*
Affiliation:
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA
Mark J. Dekkers
Affiliation:
Paleomagnetic Laboratory ‘Fort Hoofddijk’, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Budapestlaan 17, 3584 CD Utrecht, The Netherlands
Andrew P. Roberts
Affiliation:
Research School of Earth Sciences, The Australian National University, Canberra 2601, Australia
Eelco J. Rohling
Affiliation:
Research School of Earth Sciences, The Australian National University, Canberra 2601, Australia Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, United Kingdom
Zhisheng An
Affiliation:
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
Xiaodong Liu
Affiliation:
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
Zhaoxia Jiang
Affiliation:
State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Xiaoke Qiang
Affiliation:
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
Yong Xu
Affiliation:
Xi’an Center of Geological Survey, China Geological Survey, Xi’an 710054, China
Hong Chang
Affiliation:
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
*
*Corresponding author at: State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China. Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA. E-mail address: [email protected].
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Abstract

Pre-Quaternary terrestrial climate variability is less well understood than that during the Quaternary. The continuous eolian Red Clay sequence underlying the well-known Quaternary loess-paleosol sequence on the Chinese Loess Plateau (CLP) provides an opportunity to study pre-Quaternary terrestrial climate variability in East Asia. Here, we present new mineral magnetic records for a recently found Red Clay succession from Shilou area on the eastern CLP, and demonstrate a marked East Asian climate shift across the Miocene-Pliocene boundary (MPB). Pedogenic fine-grained magnetite populations, ranging from superparamagnetic (SP)/single domain (SD) up to small pseudo-single domain (PSD) sizes (i.e., from <30 nm up to ~1000 nm), dominate the magnetic properties. Importantly, our mineral magnetic results indicate that both pedogenic formation of SP grains and transformation of SP grains to SD and small PSD grains accelerated across the MPB in the Shilou Red Clay, which are indicative of enhanced pedogenesis. We relate this enhanced pedogenesis to increased soil moisture availability on the CLP, associated with stronger Asian Summer Monsoon precipitation during an overall period of global cooling. Our study thus provides new insights into the Miocene-Pliocene climate transition in East Asia.

Keywords

Environmental magnetismChinese Loess PlateauRed clayPaleoclimateAsian Summer MonsoonMiocene-Pliocene transition
Type
Research Article
Information
Quaternary Research , Volume 89 , Issue 3: INQUA LoessFest 2016 , May 2018 , pp. 619 - 628
Copyright
Copyright © University of Washington. Published by Cambridge University Press, 2017 

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