Susceptibility, magnetization and S-ratio of ODP Sites 201-1225 and 201-1227@en

Samples were collected at Sites 1225 and 1227 to investigate the occurrence of fine-grained, biogenic magnetic particles (magnetosomes). Several magnetic methods, including anhysteretic remanent magnetization and isothermal remanent magnetization, were used to characterize the main magnetic carriers in the samples. Extracts were made to isolate the fine-grained fraction, which was then examined under a transmission electron microscope. Grains with the unique characteristics of magnetosomes were found in samples from regions in the core with both high and low concentrations of magnetic minerals. This suggests they have the potential to be a persistent proxy of paleoredox conditions.本研究于1225号与1227号站位采集样品，旨在探究细粒生物成因磁性颗粒（磁小体，magnetosomes）的赋存特征。研究采用包括非滞后剩磁（anhysteretic remanent magnetization）与等温剩磁（isothermal remanent magnetization）在内的多种磁性测试手段，对样品中的主要磁性载体进行表征。通过萃取分离得到细粒级组分，随后借助透射电子显微镜（transmission electron microscope）对该组分展开观测。在岩心磁性矿物浓度高低各异的区域的样品中，均发现了具备磁小体独特特征的颗粒。该结果表明，磁小体有望成为古氧化还原条件（paleoredox conditions）的持续性代用指标。