Estimation of the sources of pelagic sediments by sedimentation age

通过沉积年龄估算远洋沉积物的来源

基本信息

批准号：
20810007
负责人：
SHOZUGAWA Katsumi
金额：
$ 1.88万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (Start-up)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2009
项目状态：
已结题

项目摘要

Our study in 2008 is, in order to estimate the source in pelagic sediments, principal components analysis (PCA) was applied to the data matrix which was made by chemical compositions of sediments measured by instrumental neutron activation analysis and prompt gamma-ray analysis. The results of PCA represented 3-factor models in each sediment, explaining 58-98% of the total variations in the sediments. A comparison of eigenvectors of terrigenous elements indicated the existence of 2 sources. Group 1 is suggested to be continental dust, whereas Group 2 is suggested to be volcanic rock. Variation of K/Ti ratio and Eu anomaly of sediments supported the above results. In 2009, to elucidate the environment of sedimentation in the Scotia and Ross Seas in the Antarctic Ocean during the period from upper Pleistocene to the present, sediments from the seas were investigated by ^<57>Fe Mossbauer spectroscopy, instrumental neutron activation analysis and X-ray absorption near-edge structure. In Mossbauer spectra of Scotia Sea sediment, a specific doublet peak (isomer shifts of 0.57-0.59mms^<-1>, quadrupole splitting of 1.70-1.83mms^<-1>) was observed, suggesting the generation of primary glauconite by detailed speciation. In contrast, sediment cores from the Ross Sea and another sea area around Antarctica had no specific peak in Mossbauer spectra. Concentrations of iron and other elements in both sediments hardly fluctuated, that is, sedimentation matter in the Scotia Sea sediments containing iron species was not affected by the origin of specific iron species but by factors such as early-stage diagenesis.

为了估计层层沉积物中的源，我们在2008年的研究将主成分分析（PCA）应用于数据矩阵，该数据矩阵是由通过仪器中子激活分析和迅速伽马射线分析测量的化学成分制成的。 PCA的结果代表每个沉积物中的3个因子模型，解释了沉积物总变化的58-98％。对陆元元素的特征向量的比较表明存在2个来源。建议第1组是大陆尘埃，而第2组则是火山岩。沉积物的K/Ti比和欧盟异常的变化支持上述结果。 2009年，为了阐明从上更新世到现在的南极海洋中的斯科舍省和罗斯海的沉积环境，通过 ^<57> fe mossbauer镜头，仪器中子激活分析和X射线吸收接近距离的距离结构，研究了海洋的沉积物。在Scotia Sea Seement的Mossbauer光谱中，观察到了一个特定的双线峰（异构体峰值为0.57-0.59mms^<-1>，Quadrupole分裂为1.70-1.83mmms^<-1>），表明通过详细的概况表明，主要的glauconite的产生。相比之下，来自罗斯海和南极周围另一个海洋地区的沉积物岩心在Mossbauer光谱中没有具体的峰值。在两个沉积物中，铁和其他元素的浓度几乎没有波动，也就是说，斯科舍省海洋沉积物中含有铁物种的沉积物不受特定铁物种的起源的影响，而是受早期成岩作用等因素的影响。