Hostname: page-component-745bb68f8f-b95js Total loading time: 0 Render date: 2025-02-08T17:22:54.477Z Has data issue: false hasContentIssue false
  • English
  • Français

Paleoclimatic Significance of the Mineral Magnetic Record of the Chinese Loess and Paleosols

Published online by Cambridge University Press:  20 January 2017

Barbara A. Maher  and
Roy Thompson
Barbara A. Maher
Affiliation:
School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
Roy Thompson
Affiliation:
Department of Geology and Geophysics, University of Edinburgh, United Kingdom
Get access Rights & Permissions [Opens in a new window]

Abstract

The origins of the magnetic susceptibility variations of the Chinese loess and paleosols are explored by scanning and transmission electron microscopy of magnetic extracts, and by magnetic modeling of magnetic hysteresis data, to provide quantified estimates of the major magnetic components. Microscopy identifies several distinct size and shape characteristics in the magnetic carriers. Lithogenic magnetites, intact and abraded, dominate the coarse-grained magnetic fraction. The smallest of the coarse grains is ∼ 2 μm. The remaining magnetic materal is ultrafine in size, with two types of magnetite particles present. Type A particles strongly resemble soil magnetites produced by inorganic precipitation. Type B particles, which occur rarely, are probably bacterial in origin. Quantitative modeling of these magnetic assemblages shows that over 90% of the susceptibility variations is accounted for by the superparamagnetic magnetite component. Compared to the loess units, the paleosols are richer in magnetite, particularly of superparamagnetic size, and have a threefold higher ratio of magnetite to hematite. We identify pedogenic formation of magnetite as the major contributor to the loess magnetic record. Matching this record against other paleoclimatic records, we find an extremely high correlation with the standard 18O record. The Chinese loess sequences record a very high resolution magnetic stratigraphy directly related to changing climate.

Type
Research Article
Information
Quaternary Research , Volume 37 , Issue 2 , March 1992 , pp. 155 - 170
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Begét, J.E. Stone, D.B. Hawkins, D.B., (1990). Paleoclimatic forcing of magnetic susceptibility variations in Alaskan loess during the late Quaternary Geology 18, 40–43 Google Scholar
Blakemore, R.P., (1982). Magnetotactic bacteria Annual Review of Microbiology 36, 217–238 Google Scholar
Bloemendal, J. de Menocal, P., (1989). Evidence for a shift in the climatic variability of the African and Asian monsoons at 2.5 Ma: An application of whole-core magnetic susceptibility measurements to palaeoclimatology Nature 342, 897–900 CrossRefGoogle Scholar
Clemens, S.C. Prell, W.L., (1990). Late Pleistocene variability of Arabian Sea summer monsoon winds and continental ardity: Eolian records from the lithogenic component of deep-sea sediments Palaeoceanography 5, 109–145 CrossRefGoogle Scholar
Fassbinder, J.W.E. Stanjek, H. Vali, H., (1990). Occurrence of magnetic bacteria in soil Nature 343, 161–163 CrossRefGoogle ScholarPubMed
Freeman, R., (1986). Magnetic mineralogy of pelagic limestones Geophysical Journal of the Royal Astronomical Society 85, 433–452 Google Scholar
Heller, F. Liu, T.S., (1982). Magnetostratigraphical dating of loess deposits in China Nature 300, 431–433 CrossRefGoogle Scholar
Heller, F. Liu, T.S., (1984). Magnetism of Chinese loess deposits Journal of Geophysical Research 77, 125–141 CrossRefGoogle Scholar
Heller, F. Liu, T.S., (1986). Palaeoclimatic and sedimentary history from magnetic susceptibility of loess in China Geophysical Research Letters 13, 1169–1172 Google Scholar
Heller, F. Liu, X. Wu, T.S. Xu, T.C., (1991). Magnetic susceptibility of loess in China Earth and Planetary Science Letters 103, 301–310 Google Scholar
Hovan, S.A. Rea, D.K. Pisias, N.G. Shackleton, N.J., (1989). A direct link between the China loess and marine 180 records: Aeolian flux to the north Pacific Nature 340, 296–298 Google Scholar
Imbrie, J. Hayes, J.D. Martinson, D.G. McIntyre, A. Mix, A.C. Morley, J.H. Pisias, N.G. Prell, W.L. Shackleton, N.J., (1984). The orbital theory of Pleistocene climate: Support from a revised chronology of the marine delta 18O record Berger, A.L. et al. Milankovitch and Climate Part I: Boston Reidel Dordrecht 169–395 Google Scholar
Kent, D.V., (1982). Apparent correlations of palaeomagnetic intensity and climatic records in deep-sea sediments Nature 299, 538–539 Google Scholar
Kukla, G., (1987). Loess stratigraphy in Central China Quaternary Science Reviews 6, 191–219 Google Scholar
Kukla, G. Heller, F. Liu, X.M. Xu, T.C. Liu, T.S. An, Z.A., (1988). Pleistocene climates in China dated by magnetic susceptibility Geology 16, 811–814 Google Scholar
Lovley, D.R. Stolz, J.F. Nord, G.L. Phillips, E.J.P., (1987). Anaerobic production of magnetite by a dissimilatory iron-reducing microorganism Nature 330, 252–254 Google Scholar
Maher, B.A., (1988). Magnetic properties of some synthetic sub-micron magnetites Geophysical Journal of the Royal Astronomical Society 94, 83–96 CrossRefGoogle Scholar
Maher, B.A. Taylor, R.M., (1988). Formation of ultrafine-grained magnetite in soils Nature 336, 368–370 Google Scholar
Maher, B.A. Thompson, R., (1991). Mineral magnetic record of the Chinese loess and paleosols Geology 19, 1 3–6 Google Scholar
Murray, J.M., (1876). On the distribution of volcanic debris over the floor of the oceans—Its character, source and some products of its disintegration and decomposition Proceedings of the Royal Society of Edinburgh 9, 247–261 Google Scholar
Opdyke, N.D., (1972). Palaeomagnetism of deep-sea cores Review of Geophysics and Space Physics 10, 213–249 Google Scholar
Ozdemir, O. Banerjee, S.K., (1982). A preliminary magnetic study of soil samples from westcentral Minnesota Earth and Planetary Science Letters 59, 383–403 Google Scholar
Petersen, N. von Dobeneck, T. Vali, H., (1986). Fossil bacterial magnetite in deep-sea sediments from the S. Atlantic Ocean Nature 320, 611–615 Google Scholar
Prell, W.L. Niitsuma, N. et al. One Million Year Record of Summer Monsoon Winds and Continental Aridity from the Owen Ridge (Site 722), Northwest Arabian Sea (1991). Ocean Drilling Program College Station, TX 365–388 Proceedings of ODP Scientific Results 117 Google Scholar
Radhakrishnamurty, C. Deutsch, E.R., (1974). Magnetic techniques for ascertaining the nature of iron oxide grains in basalts Journal of Geophysics 40, 453–465 Google Scholar
Robinson, S.G., (1986). The late Pleistocene palaeoclimatic record of N. Atlantic deep-sea sediments revealed by mineral magnetic measurements Physics of the Earth and Planetary Interiors 42, 22–48 CrossRefGoogle Scholar
Stacey, F.D., (1963). The Physical Theory of Rock Magnetism Advances in Physics 12, 45–133 Google Scholar
Taylor, R.M. Maher, B.A. Self, P.G., (1988). Magnetite in soils. I. The synthesis of superparamagnetic and single domain magnetite Clay Minerals 1987 22, 411–422 CrossRefGoogle Scholar
Thompson, R., (1986). Modelling magnetization data using SIMPLEX Physics of the Earth and Planetary Interiors 42, 113–127 Google Scholar
Thompson, R. Berglund, B., (1976). Late Weichselian geomagnetic “reversal” as a possible example of the reinforcement syndrome Nature 263, 490–491 Google Scholar
Thompson, R. Oldfield, F., (1986). Environmental Magnetism Allen and Unwin London Google Scholar
Thompson, R. Clark, R.M., (1989). Sequence slotting for stratigraphic correlation between cores: Theory and practice Journal of Paleolimnology 2, 173–184 CrossRefGoogle Scholar
Tite, M.S. Linington, R.C., (1975). Effect of climate on the magnetic susceptibility of soils Nature 256, 565–566 Google Scholar
Zhou, L.P. Oldfield, F. Wintle, A.G. Robinson, S.G. Wang, J.T., (1990). Partly pedogenic origin of magnetic variations in Chinese loess Nature 346, 737–739 CrossRefGoogle Scholar