EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Liu et al. 2004
Liu, Q., Jackson, M.J., Banerjee, S.K., Maher, B.A., Deng, C., Pan, Y. and Zhu, R. (2004). Mechanism of the magnetic susceptibility enhancements of the Chinese loess. Journal of Geophysical Research 109: doi: 10.1029/2004JB003249. issn: 0148-0227.

Chinese loess/paleosol sequences have been regarded as excellent continental archives for encoding continuous paleoclimatic variations over the past 2.5 Myr. However, the mechanism for magnetic enhancements (especially the low-field mass-specific magnetic susceptibility, χ) of Chinese paleosols is still not completely resolved. This study quantifies contributions of aeolian and pedogenic magnetic particles to the bulk magnetic properties of the Chinese loess/paleosols by using a magnetic extraction technique. Magnetic properties of magnetic separates (extractable) and the corresponding residues (nonextractable) for five characteristic samples covering both loesses and paleosols were comprehensively investigated by hysteresis loops, frequency and low-temperature dependence of magnetic susceptibility, and interparametric ratios. Results show that (1) with moderate degrees of pedogenesis (χ (10--12) ¿ 10-7 m3 kg-1, contributions of pedogenically related fine-grained pseudosingle-domain (PSD, ~100 nm to several microns) particles become significant; (2) pedogenic particles have a narrow grain size distribution concentrated above the SP/SD threshold; and (3) anhysteretic remanent magnetization (ARM) is carried dominantly by SD grains. Moreover, we propose that only the nonextractable fraction of χ, saturation magnetization (Ms) and remanent magnetization (Mrs) show a strong relationship with the degree of pedogenesis. This new interpretation of magnetic enhancements helps us to retrieve more accurate and quantitative paleoclimatic signals recorded by the Chinese loess/paleosol sequences.

BACKGROUND DATA FILES

Abstract

Keywords
Geomagnetism and Paleomagnetism, Environmental magnetism, Geomagnetism and Paleomagnetism, Magnetic mineralogy and petrology, Geomagnetism and Paleomagnetism, Rock and mineral magnetism, Chinese loess, magnetic susceptibility, pedogenesis
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit