Magnetostratigraphy of ODP Leg 117 sites

Magnetic measurements were made on discrete samples from the Neogene pelagic and hemipelagic sediments recovered during ODP Leg 117. Polarity zones, usually identified for uppermost 200 m, were correlated to the geomagnetic polarity time scale referring to biostratigraphic datums. Quality and resolution of the magnetostratigraphy was partly limited by the weak and relatively soft magnetic character of almost all intervals, and core disturbance by gas expansion at some Oman Margin sites. Clear polarity records of the Brunhes and Matuyama chrons (C1 to C2r) were observed at Sites 724 and 727 on the Oman continental margin. Extended reversal records of the Pliocene were found at Site 722 on the Owen Ridge and Site 728 on the Oman Margin, and correlated to the Gauss to Gilbert chrons (C2A to C3).本数据集针对大洋钻探计划（Ocean Drilling Program, ODP）第117航次采获的新近纪（Neogene）远洋沉积物（pelagic sediments）与半远洋沉积物（hemipelagic sediments）的离散样品开展了磁性测量。通常针对顶部200米地层所识别出的极性带（polarity zones），参考生物地层基准面（biostratigraphic datums），与地磁极性年表（geomagnetic polarity time scale）开展对比关联。磁性地层学（magnetostratigraphy）的品质与分辨率在一定程度上受到限制：一方面源于几乎所有地层段的磁性均较弱且磁性特征相对松软，另一方面则是部分阿曼陆缘（Oman Margin）站位因气体膨胀引发岩心扰动。阿曼大陆边缘（Oman continental margin）的724与727站位清晰获取了布容极性时（Brunhes chron）与松山极性时（Matuyama chron，C1至C2r）的完整极性记录。欧文海岭（Owen Ridge）722站位与阿曼陆缘728站位则采获了上新世（Pliocene）的完整反转记录，并将其对比关联至高斯极性时（Gauss chron）至吉尔伯特极性时（Gilbert chron，C2A至C3）。