Magnetostratigraphy of ODP Leg 178 holes@en

We present revised magnetostratigraphic interpretations for Ocean Drilling Program Sites 1095, 1096, and 1101, cored in sediment drifts located off the Pacific margin of the Antarctic Peninsula. The revised interpretations incorporate a variety of observations and results obtained since the end of Leg 178, of which the most significant are new paleomagnetic measurements from U-channel samples, composite depth scales that allow stratigraphic correlation between multiple holes cored at a site, and revised biostratigraphic interpretations. The U-channel data, which include more than 102,000 paleomagnetic observations from more than 13,400 intervals along U-channel samples, are included as electronic files. The magnetostratigraphic records at all three sites are consistent with sedimentation being continuous over the intervals cored, although the data resolution does not preclude short hiatuses less than a few hundred thousand years in duration. The magnetostratigraphic records start at the termination of Subchron C4Ar.2n (9.580 Ma) at ~515 meters composite depth (mcd) for Site 1095, at the onset of Subchron C3n.2n (4.620 Ma) at ~489.68 mcd for Site 1096, and at the onset of Subchron C2An.1n (3.040 Ma) at 209.38 meters below seafloor for Site 1101. All three sites provide paleomagnetic records that extend upward through the Brunhes Chron.我们针对南极半岛太平洋缘沉积漂移区钻取的大洋钻探计划（Ocean Drilling Program）1095、1096及1101站位，提出了修订后的磁地层学解释。本次修订后的解释整合了178航次结束后获取的各类观测数据与研究结果，其中最具代表性的包括：取自U型岩芯（U-channel）样品的全新古地磁测量数据、可实现站位多钻孔地层对比的综合深度标尺，以及修订后的生物地层学解释。该U型岩芯数据涵盖了超过13400个采样段的102000余条古地磁观测结果，以电子附件形式提供。三个站位的磁地层学记录均表明，取芯段内沉积作用持续进行，但受限于数据分辨率，无法排除时长不足数十万年的短期沉积间断。三个站位的磁地层学记录起始点分别为：1095站位约515米综合深度（meters composite depth, mcd）处的亚时C4Ar.2n（9.580 Ma）终止位置；1096站位约489.68米综合深度处的亚时C3n.2n（4.620 Ma）起始位置；1101站位海底以下209.38米处的亚时C2An.1n（3.040 Ma）起始位置。上述三个站位均获得了延伸至布容正向极性亚时（Brunhes Chron）的古地磁记录。