SCIENTIA GEOGRAPHICA SINICA ›› 2015, Vol. 35 ›› Issue (11): 1475-1481.doi: 10.13249/j.cnki.sgs.2015.011.1475

• Orginal Article • Previous Articles     Next Articles

The Magnetic Characteristics Comparison of Sedimentary Red Clay and Laterite Weathering Crust in Subtropical China

Li-hui YANG1,2(), Wei YE3(), Xiang-min ZHENG2, Li-min ZHOU2, You SU1   

  1. 1.Anhui Key Laboratory of Natural Disaster Process and Protection Research, Anhui Normal University, Wuhu, Anhui 241003, China
    2. School of Geographic Sciences, East China Normal University, Shanghai, 200241, China
    3.College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, Zhejiang 321004, China
  • Received:2014-08-10 Revised:2014-11-09 Online:2015-11-20 Published:2015-11-20

Abstract:

Kind of red, loose or semi-cemented sediment was widely distributed in tropical and subtropical regions of China, called Quaternary Red Clay (QRC). The causes and definitions of QRC were argued intensely. Depends on matrix, the QRC can be broadly divided into two types, Sedimentary Red Clay (SRC) and Laterite Weathering Crust (LWC). The SRC, development on all kinds of Quaternary sediments, always got similar profile configuration. The layer of SRC profile, from top to bottom, was Homogeneous Red Clay (HRC) or Yellow-Brown Earth (YBE), Vermicular Red Clay (VRC) and weathered gravel or bedrock; LWC was a kind of residual soil, formed by different types of bedrock weathering and widely distributed in tropical and subtropical regions. Representative LWC profile was generally contained weathered red soil, semi-weathered layer and bedrock. In this article, magnetic characteristics of basalt and granite weathering crust in Xinchang, Zhejiang Province, Quaternary SRC in Nanchang, Jiangxi Province were analyzed. The main characteristics of LWC are that, magnetic characteristics distinction of two kinds of weathering crust in the same climate zone was relatively large and the magnetic characteristics were determined by the matrix; Magnetisability of basalt weathering crust increased after a small decrease with the increasing weathering intensity; Magnetisability of granite weathering crust increased with increasing weathering intensity. Intense weathering made mineral particles tapering and antiferromagnetic minerals reduce in these two kinds of weathering crust. The main characteristics of sedimentary red clay were that, magnetisability of HRC was greater than VRC at least one order of magnitude. The content of antiferromagnetic mineral in VRC was much greater than the HRC. The content of Pseudo-Single Domain and Multidomain grain in VRC was much greater than the HRC. The magnetic characteristics change rule in SRC did not meet with the weathering rule prove that maybe HRC and VRC got different provenance in Quaternary sedimentary red clay profile.

Key words: Laterite weathering crust, sedimentary red clay, quaternary, magnetic characteristics

CLC Number: 

  • P318