Study on Environmental Magnetic Characteristics of Loess in Har Keren Desert, Israel
Author:
Affiliation:

State Key Laboratory for Subtropical Mountain Ecology

Clc Number:

Fund Project:

Supported by National Natural Science Foundation of China(41602184), Natural Science Foundation of Fujian Province(2017J01655), Innovation Research Team Fund of Fujian Normal University(IRTL1705)

  • Article
  • |
  • Figures
  • |
  • Metrics
  • |
  • Reference
  • |
  • Related
  • |
  • Cited by
  • |
  • Materials
  • |
  • Comments
    Abstract:

    [Objective] Aeolian loess, widely distributed over the world, is a good carrier for studying paleoclimate change. However, mechanisms of their recording climate change vary as their geographical environments from region to regions. The loess region in the south of Israel borders, a subtropical desert. To explore mechanisms of loess magnetic characteristics responding to the environment of this region, a field survey was conducted in the loess area on the fringe of the Negev Desert to investigate systems environmental magnetism and particle size composition. [Method] This study had soil samples collected from the area and analyzed for types, contents and particle sizes of magnetic domain particles therein by means of the room temperature and high temperature magnetic methods. Through analysis of particle size composition of the samples, transport process and deposition characteristics of loess were determined. [Result] Results show that the magnetic minerals in the HK profile consisted mainly of clastic magnetite and maghemite, quite low in content. The Dearing plot of the sample shows that the magnetic domain particles in the magnetic minerals were quite coarse and mainly of coarse single domain (SD) and multi-domain(MD). Analysis of particle size composition shows that particles in the HK profile varied in size, tended to be coarse, declining from the bottom to the top in the profile, with frequency distribution curve appearing to be of positive skewness and were hard to be fractionated, exhibiting the feature of a mixture of multiple transport modes, which was somewhat different from that of a typical aeolian loess. [Conclusion] (1) Both the room-temperature magnetic parameters and high-temperature thermomagnetic curve of the HK profile show that the magnetic minerals in the HK (Har Keren) profile samples consist mainly of clastic magnetite and maghemite, quite low in content, quite coarse in particle size, and dominated with coarse SD and MD, which reflects that they are clastic magnetic minerals coming from the source area. The loess in the profile is quite similar to that in the arid region of Northwest China in magnetic characteristics. (2) The room-temperature magnetic parameters of the HK profile, as a whole, vary within a quite narrow range and ascend somewhat only in the sub-surface layer, which may be attributed to the impact of the modern soil forming process. And (3) median particle size of the HK profile displays a trend of declining from the bottom to the top, and the particles tend to coarse on the whole. Its frequency distribution curve appears to be of positive skewness and the particles are hard to be fractionated. Besides, in the bottom of the profile mixed are gravel debris layers. All of the above reflect that the process of near-source-wind-driven transport and deposition has been subjected to the fluvial effect of flows.

    Reference
    Related
    Cited by
Get Citation

SHI Yonghui, LIU Xiuming, MAO Xuegang, Lü Bin, LIU Gengyu, CHEN Jinniu. Study on Environmental Magnetic Characteristics of Loess in Har Keren Desert, Israel[J]. Acta Pedologica Sinica,2020,57(5):1177-1185.

Copy
Share
Article Metrics
  • Abstract:
  • PDF:
  • HTML:
  • Cited by:
History
  • Received:April 30,2019
  • Revised:September 14,2019
  • Adopted:November 21,2019
  • Online: June 30,2020
  • Published: