DOI: 10.1016/j.gloplacha.2015.05.009
论文题名: Reconstruction of superparamagnetic particle grain size distribution from Romanian loess using frequency dependent magnetic susceptibility and temperature dependent Mössbauer spectroscopy
作者: Necula C. ; Panaiotu C. ; Schinteie G. ; Palade P. ; Kuncser V.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2015
卷: 131 起始页码: 89
结束页码: 103
语种: 英语
英文关键词: Grain size distribution
; Loess-paleosol
; Magnetic enhancement
; Superparamagnetic particles
Scopus关键词: Grain size and shape
; Lithology
; Magnetic susceptibility
; Magnetism
; Sediments
; Size distribution
; Superparamagnetism
; Surface defects
; Frequency dependent
; Grain size distribution
; Loess-paleosol
; Magnetic enhancement
; Ssbauer spectroscopies
; Superparamagnetic particles
; Temperature dependent
; Wide band frequencies
; Magnetic bubbles
; glacial-interglacial cycle
; grain size
; loess
; magnetic property
; magnetic susceptibility
; Mossbauer spectroscopy
; paleosol
; particle size
; pedogenesis
; reconstruction
; size distribution
; Black Sea
; Danube River
; Dobrogea
; Romania
英文摘要: Previous studies have shown that the magnetic parameters of the Romanian loess/paleosol sequences have recorded Quaternary glacial/interglacial cycles over the last 600 kyr. Previous rock magnetic investigations pointed out that the magnetic enhancement in Romanian loess sequences is mainly due to pedogenic magnetite close to superparamagnetic/stable single domain boundary. We report the first reconstruction of grain size distribution (GSD) of the superparamagnetic (SP) particles for two Romanian loess deposits, Costineşti and Mircea Vodă, located in the Dobrogea Plateau between the Danube River and the Black Sea. The GSDs were obtained using both the wide-band frequency spectrum of magnetic susceptibility (FSMS) method and low temperature Mössbauer spectroscopy. The FSMS method shows that the SP particles are present both in loess and paleosols. The GSDs in loess are shifted to slightly higher diameters with respect to paleosols. The concentration of SP particles has an opposite trend. The largest value is reached in the forest paleosol and the lowest in the loess samples. Both loess and paleosols indicated almost the same dominant grain size (about 17. nm in paleosols and 18. nm in loess samples). However the GSD shapes in loess are different than those found in paleosols. In the paleosols, the shape of GSDs seems to be independent of climate and degree of pedogenesis. These factors control only the concentration of SP particles present in each paleosol. Temperature dependent Mössbauer spectroscopy also supports the presence of SP particles both in loess and paleosol with a mean diameter around 13-14. nm. Dispersion of the diameters in the case of Mössbauer spectroscopy varies from sample to sample being probably affected by random surface defects. © 2015 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930227045&doi=10.1016%2fj.gloplacha.2015.05.009&partnerID=40&md5=b43d549334ebfb4b6b908784452a1fe7
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11507
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
There are no files associated with this item.
作者单位: Faculty of Physics, Paleomagnetic Laboratory, University of Bucharest, N. Balcescu 1, Bucharest, Romania
Recommended Citation:
Necula C.,Panaiotu C.,Schinteie G.,et al. Reconstruction of superparamagnetic particle grain size distribution from Romanian loess using frequency dependent magnetic susceptibility and temperature dependent Mössbauer spectroscopy[J]. Global and Planetary Change,2015-01-01,131.