The magnetic properties of Serbian loess and its environmental significance  

作　　者：LIU XiuMing LIU Zhi Lü Bin MARKOVI S B CHEN JiaSheng GUO Hui MA MingMing ZHAO GuoYong FENG Hua 

机构地区：[1]Research School of Arid Environment & Climate Change,Lanzhou University [2]School of Geographical Sciences,Fujian Normal University [3]Department of Environment and Geography,Macquarie University,Sydney NSW 2109,Australia [4]Chair of Physical Geography,Faculty of Sciences,University of Novi Sad,Trg Dositeja Obradovi a 3,21000 Novi Sad,Serbia

出　　处：《Chinese Science Bulletin》2013年第3期353-363,共11页

基　　金：supported by the National Natural Science Foundation of China (40830105,41072124 and 41021091);the Natural Science Foundation of Gansu Province (0710KJZ A024)

摘　　要：This paper reports a loess-paleosol sequence located in the Danube River basin,Serbia,which formed at least since the latest part of the early Pleistocene,and before the paleomagnetic B/M boundary.Various magnetic parameters of the Serbian V-L1-V-S4 loess-paleosol sequence have been measured and analyzed in the Titel Loess Plateau.These parameters show a very similar magnetic behavior compared with that of the Chinese loess.There is a general positive relationship between magnetic susceptibility() and pedogenesis.The main contributors to are the magnetic grains of SP(superparamagnetic) and SD(single domain) magnetic domains,while MD(multi domain) contributes only a small percentage.The difference in between loess and paleosol mainly is caused by pedogenesis.The very fine magnetic minerals increase gradually with increasing soil development(from loess to soil),and they lead to higher.The thermomagnetic curves show thatmagnetic minerals in the loess layers are magnetite and maghemite,both providing a major contribution to.In contrast the paleosol layers mainly are composed of magnetite,with almost no or a very small amount of maghemite,as implied by a reversible thermomagnetic behavior.This indicates that pedogenic conditions during V-S3 and V-S4 strong soil development have resulted in maghemite that is no longer stable,and has been resolved or converted to other stable phase minerals.This likely indicates that soil moisture during V-S3 and V-S4 development exceeded a critical condition of maghemite stability.This paper reports a loess-paleosol sequence located in the Danube River basin, Serbia, which formed at least since the latest part of the early Pleistocene, and before the paleomagnetic B/M boundary. Various magnetic parameters of the Serbian V-L1-V-S4 loess-paleosol sequence have been measured and analyzed in the Titel Loess Plateau. These parameters show a very similar magnetic behavior compared with that of the Chinese loess. There is a general positive relationship between magnetic susceptibility （X） and pedogenesis. The main contributors to Z are the magnetic grains of SP （superparamagnetic） and SD （single domain） magnetic domains, while MD （multi domain） contributes only a small percentage. The difference in Z between loess and paleosol mainly is caused by pedogenesis. The very fine magnetic minerals increase gradually with increasing soil development （from loess to soil）, and they lead to higher Z. The thermomagnetic curves show thatmagnetic minerals in the loess layers are magnetite and ma- ghemite, both providing a major contribution to X. In contrast the paleosol layers mainly are composed of magnetite, with almost no or a very small amount of maghemite, as implied by a reversible thermomagnetic behavior. This indicates that pedogenic conditions during V-S3 and V-S4 strong soil development have resulted in maghemite that is no longer stable, and has been resolved or converted to other stable phase minerals. This likely indicates that soil moisture during V-S3 and V-S4 development exceeded a critical condition of maghemite stability.

关 键 词：黄土高原 塞尔维亚 环境意义 磁学性质 古土壤序列 磁赤铁矿 成土作用 磁性矿物 

分 类 号：P642.131[天文地球—工程地质学]