摘要
利用沉降离心法将老虎山黄土-古土壤的酸不溶相分离成<2μm、2～45μm和>45μm三个粒级组分,并分别测定了这些组分和全岩的磁化率。结果表明,无论是全岩,还是三个不同粒级组分,它们的磁化率都可以单独作为长江中下游地区古气候演变的参考指标。其中,<2μm粒级的质量磁化率明显大于全岩和2～45μm、>45μm两粒级,而且其分辨率也明显高于2～45μm和>45μm这两个粒级组分。本实验结果还显示,虽然<2μum的质量磁化率最大,但对全岩质量磁化率的贡献率与2～45μm粒级相当,>45μm粒级的贡献率较低。
In this paper, separation of <2μm, 2-45μm and >45μm particle size fractions of acetic-acid insoluble residues from a loess-paleosol sequence in a Laohushan depth Profile in the south of the lower Yangtze Basin were conducted and magnetic susceptibility of the different fractions as well as of the bulk sample were tested. The results indicated that both magnetic susceptibility of these size fractions and of the bulk samples could be a useful proxy recorder for paleo-climatic fluctuations. However, the magnetic susceptibility of the <2μm size fraction was greater than that of the larger fractions and the bulk sample, and the resolution as a proxy of this fraction was also better than the other fractions. From the finding we also found that though the magnetic susceptibility of <2μm fraction was largest, the contribution of this fine fraction to the bulk magnetic susceptibility was not larger than the 2-45μm fraction, while the contribution of the >45μm fraction was smallest.
出处
《土壤通报》
CAS
CSCD
北大核心
2004年第2期159-162,共4页
Chinese Journal of Soil Science
基金
中国博士后科学基金(第30批)资助
关键词
南京市
老虎山
黄土-古土壤
剖面
粒级组分
磁化率
古气候
Loess-paleosol sequence
Grain-size fractions
Magnetic susceptibility
Partial contribution
Laohushan profile
