Particle size separation and evidence for pedogenesis in samples from the Chinese Loess Plateau spanning the past 22 m.y

Research Article| September 01, 2008 Particle size separation and evidence for pedogenesis in samples from the Chinese Loess Plateau spanning the past 22 m.y. Qingzhen Hao; Qingzhen Hao 11Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 22Department of Geography, University of Liverpool, Liverpool L69 7ZT, UK Search for other works by this author on: GSW Google Scholar Frank Oldfield; Frank Oldfield * 22Department of Geography, University of Liverpool, Liverpool L69 7ZT, UK *E-mail: Oldfield.f@gmail.com. Search for other works by this author on: GSW Google Scholar Jan Bloemendal; Jan Bloemendal 22Department of Geography, University of Liverpool, Liverpool L69 7ZT, UK Search for other works by this author on: GSW Google Scholar Zhengtang Guo Zhengtang Guo 11Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Author and Article Information Qingzhen Hao 11Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 22Department of Geography, University of Liverpool, Liverpool L69 7ZT, UK Frank Oldfield * 22Department of Geography, University of Liverpool, Liverpool L69 7ZT, UK Jan Bloemendal 22Department of Geography, University of Liverpool, Liverpool L69 7ZT, UK Zhengtang Guo 11Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China *E-mail: Oldfield.f@gmail.com. Publisher: Geological Society of America Received: 09 Mar 2008 Revision Received: 29 May 2008 Accepted: 31 May 2008 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2008 Geological Society of America Geology (2008) 36 (9): 727–730. https://doi.org/10.1130/G24940A.1 Article history Received: 09 Mar 2008 Revision Received: 29 May 2008 Accepted: 31 May 2008 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Qingzhen Hao, Frank Oldfield, Jan Bloemendal, Zhengtang Guo; Particle size separation and evidence for pedogenesis in samples from the Chinese Loess Plateau spanning the past 22 m.y.. Geology 2008;; 36 (9): 727–730. doi: https://doi.org/10.1130/G24940A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract A comparison between particle size distributions determined by laser diffraction and the pipette method confirms previous studies that point to a variable underestimate of the clay fraction using laser diffraction, relative to the values obtained by pipette analysis. In order to yield four particle-sized fractions (<2 μm, 2–4 μm, 4–8 μm, >8 μm) for further analysis, the pipette method was used on loess and paleosol samples from sites on the Chinese Loess Plateau spanning the past 22 m.y. In all cases, a subsidiary mode in the <2 μm fraction is identified. The clear separation of this from the coarse mode in the >8 μm fraction provides a basis for evaluating the relative contributions of pedogenic and detrital components. Pretreatment using acetic rather than hydrochloric acid for carbonate removal results in no significant loss of ferrimagnetic minerals and allows magnetic characterization of the separate fractions. This confirms the isolation of almost all the finest, pedogenic ferrimagnetic grains in the clay fraction and their negligible contribution to the magnetic properties of the coarse fractions in all the samples from early Miocene time onward. Because similar conclusions may be drawn from previous studies of late Pleistocene samples from the east-central and extreme western parts of the Chinese Loess Plateau, we conclude that this approach provides a basis for separately characterizing eolian deposition and pedogenesis throughout the region and for the whole time span of loess accumulation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.