Magnetic Susceptibility and Influencing Factors of Loess From Bole,Xinjiang Province
0
Citation
0
Reference
20
Related Paper
Abstract:
Bole is a major area with loess sediments in Xinjiang Province.On the basis of a 11 m loess section from bole,a series of indices consisting of magnetic susceptibility,grain size,TOC and CaCO3 in the laboratory.And the results show that the average value of the magnetic susceptibility is far below than that of typical loess on loess plateau,the changing process is also different from that of the typical loess on loess plateau.Coarse silt(63-10 μm) is the dominant component of the section,and there are only a small amount of clay(5 μm),silt(63 μm) and fine silt(5-10 μm) in the section.There is a negative correlation between clay,fine silt and magnetic susceptibility.Clay and fine silt contain little magnetic minerals,so their impacts on magnetic susceptibility is limit,while the contribution of sand is relatively large;The section carries a small quantity of TOC,so TOC makes only a small contribution for magnetic susceptibility;The correlation between magnetic susceptibility and CaCO3 is weak.Thus,the factors influencing magnetic susceptibility in this area are very complex.More climatic indicators in combination with magnetic susceptibility are needed to restore the ancient climate and paleo-environment of the area.And then we can carry out multi-index analysis and synthesis to get more reliable and accurate explanations.Keywords:
Silt
Loess plateau
Cite
Paleosol
Loess plateau
Cite
Citations (111)
Paleosol
Environmental Magnetism
Cite
Citations (742)
We analyze high-resolution anisotropy of magnetic susceptibility (AMS) of the loess-paleosol successions at Luochuan, central Chinese Loess Plateau, in order to investigate the AMS characteristics and their climatic implications. Our results indicate a normal sedimentary magnetic fabric for almost of all samples, characterized by minimum susceptibility axes grouped in an almost vertical direction. Magnetic foliation and anisotropy degree show upwards decreasing trend due to decreasing post-depositional compaction. Magnetic lineations show no preferred directions and thus cannot indicate paleowind patterns. AMS parameters at Luochuan are controlled by particle size, pedogenesis, and sedimentary compaction. The high peaks of magnetic foliation and anisotropy degree of L2, L3, L6, L9, and L15 correspond to the coarse particle sizes of these loess beds, indicating the grain-size dependence of AMS.
Lineation
Loess plateau
Paleosol
Cite
Citations (0)
Research Article| January 01, 1991 Mineral magnetic record of the Chinese loess and paleosols Barbara A. Maher; Barbara A. Maher 1School of Environmental Sciences, University of East Anglia, Norwich, England Search for other works by this author on: GSW Google Scholar Roy Thompson Roy Thompson 2Department of Geology and Geophysics, University of Edinburgh, Edinburgh, Scotland Search for other works by this author on: GSW Google Scholar Author and Article Information Barbara A. Maher 1School of Environmental Sciences, University of East Anglia, Norwich, England Roy Thompson 2Department of Geology and Geophysics, University of Edinburgh, Edinburgh, Scotland Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1991) 19 (1): 3–6. https://doi.org/10.1130/0091-7613(1991)019<0003:MMROTC>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Barbara A. Maher, Roy Thompson; Mineral magnetic record of the Chinese loess and paleosols. Geology 1991;; 19 (1): 3–6. doi: https://doi.org/10.1130/0091-7613(1991)019<0003:MMROTC>2.3.CO;2 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 Variations in the magnetic susceptibility of the Chinese loess and its interbedded paleosols correlate strikingly well with the deep-sea oxygen isotope record. Low susceptibility values are found for the loess layers, and high values are found for the soil horizons. Two interpretative models have been advanced to account for these magnetic variations. Both of these models discount any significant in situ formation of magnetite during soil-forming periods. Instead, they infer relative concentration of detrital or atmospheric magnetite at these times. We critically examine the assumptions made in these models and, on the basis of some new mineral magnetic data and formalized magnetic flux calculations, offer an alternative explanation of the loess magnetic record. Our model identifies pedogenic formation of magnetite as the major contributor to the high magnetic susceptibility of the paleosols. The formation and preservation of this pedogenic magnetite is dependent on soil-forming conditions and hence reflects the regional climate. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Icon
Paleosol
Cite
Citations (394)
[1] Little is known about the mechanisms of magnetic susceptibility (χ) enhancement for the red-clay sequence on the Chinese Loess Plateau (CLP), in comparison to the overlying loess-paleosol sequence. Here we present a rock magnetic study of the red-clay sediments from the central CLP. Our results show that frequency dependence of χ (χfd = χlf − χhf, where χlf and χhf are χ measured at 470 Hz and 4700 Hz, respectively), χlf, and susceptibility of anhysteretic-remanent-magnetization (χARM) are linearly correlated within the red-clay sequence. This linear correlation indicates that the pedogenic magnetic minerals of the red-clay have a rather uniform grain size distribution as in the loess-paleosol sequence, and the grain size is independent of the degree of pedogenesis. Nevertheless, red-clay sediments are slightly more enriched in superparamagnetic magnetic particles than the overlying loess-paleosol sediments as indicated by the higher slope of the regression line between χfd and χlf.
Paleosol
Sequence (biology)
Superparamagnetism
Loess plateau
Cite
Citations (0)
Environmental Magnetism
Topsoil
Ferrimagnetism
Cite
Citations (61)
Maghemite
Environmental Magnetism
Archaeomagnetic dating
Magnetic mineralogy
Rock magnetism
Cite
Citations (5)
Paleosol
Environmental Magnetism
Cite
Citations (14)
Central Asia
Cite
Citations (8)