Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.quaint.2009.06.024 |
Magnetic parameters reflecting pedogenesis in Pleistocene loess deposits of Argentina | |
Bidegain, J. C.1; Rico, Y.1; Bartel, A.2; Chaparro, M. A. E.3; Jurado, S.1 | |
通讯作者 | Bidegain, J. C. |
会议名称 | 17th Congress of the International-Union-for-Quaternary-Research |
会议日期 | JUL 28-AUG 03, 2007 |
会议地点 | Cairns, AUSTRALIA |
英文摘要 | Quaternary loess sequences of Argentina, with interbedded loess and buried soils (palaeosols), provide terrestrial records of past climates and environmental conditions. Study of rock magnetic parameters measured over a large area of the Pampean loess seems to indicate that the existing magnetoclimatological models cannot adequately account for the complexities of the Pampean loess. The Chinese loess has been considered as typical, where magnetic properties are largely controlled by pedogenesis. On the other hand, the Siberian loess is an alternative magnetoclimatological model in which palaeosols appear as magnetic lows and the intercalated loess as magnetic highs. Argentine loess is apparently closer to the Siberian model. However, considering the data obtained in Argentina, the situation seems to be more complicated. The higest magnetic values (SIRM and susceptibiliy values) in silty and sandy loess indicate a more efficient entrainment of dense iron oxides particles during stormy dry (glacial) intervals. The parent material shows the highest susceptibility values (> 100 x 10(-8) m(3)/kg) while the waterlogged horizons show the lowest ones (below 20 x 10(-8) m(3)/kg). Pedogenesis resulting in the development of BC and B soil horizons of palaeosols in the parent loess produced decreases in susceptibility values and increases in the F factor. This phenomenon occurs at some degree of humidity in which the process of gleying caused the total depletion of both susceptibility and frequency factor. The magnentic data allows consideration of the relevance of major cycles (arid/humid) separated by discontinuities as the main factor favoring one particular behavior of the magnetic parameters. The B horizons of palaeosols developed during an and cycle will not show a notable difference in the magnetic records from the parent material. In contrast, during humid climate condition the pristine loess can be progresively obliterated by pedogensis through to the extreme situation of gleying. (c) 2009 Elsevier Ltd and INQUA. All rights reserved. |
来源出版物 | QUATERNARY INTERNATIONAL |
ISSN | 1040-6182 |
EISSN | 1873-4553 |
出版年 | 2009 |
卷号 | 209 |
页码 | 175-186 |
出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
类型 | Article;Proceedings Paper |
语种 | 英语 |
国家 | Argentina |
收录类别 | SCI-E ; CPCI-S |
WOS记录号 | WOS:000271693000014 |
WOS关键词 | CHINESE LOESS ; BUENOS-AIRES ; SEDIMENTS ; RECORD ; SUSCEPTIBILITY ; PALEOCLIMATE ; PALEOSOLS |
WOS类目 | Geography, Physical ; Geosciences, Multidisciplinary |
WOS研究方向 | Physical Geography ; Geology |
资源类型 | 会议论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/297912 |
作者单位 | 1.Comis Invest Cient Prov Buenos Aires, PALEOMAGNETISM, LEMIT, RA-1900 La Plata, Buenos Aires, Argentina; 2.ULPam, CONICET, Santa Rosa, La Pampa, Argentina; 3.IFAS, CONICET, Buenos Aires, DF, Argentina |
推荐引用方式 GB/T 7714 | Bidegain, J. C.,Rico, Y.,Bartel, A.,et al. Magnetic parameters reflecting pedogenesis in Pleistocene loess deposits of Argentina[C]:PERGAMON-ELSEVIER SCIENCE LTD,2009:175-186. |
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