RAPID: Collaborative Research: Paleomagnetic and Rock Magnetic Investigation of IODP Expedition 318 Site U1357 Sediments

2010年1月至3月（惠灵顿至霍巴特）的IODP 318考察的主要目标之一是通过在阿德利盆地钻探获得全新世的超高分辨率记录。阿德利盆地包含190米厚的硅藻软泥层序，覆盖在年龄约为11 ka的冰川上。U1357站点获得的沉积物显示了来自南大洋的海洋和气候变化的超高分辨率记录，这是第一个每年分辨率的时间序列。站点U1357为三芯。U1357A孔在考察期间被拆分和处理，而U1357B孔和C孔被密封在氮气冲洗袋中，仅在采样期间（2010年6月27日至2010年7月3日）才被拆分。从船上对U1357A一半存档的测量数据中获得的数据记录了无与伦比的地磁场长期变化（SV）记录，这不仅保证了前所未有的SV记录，而且将为孔间相关性提供关键约束。在巡航后的采样过程中，我们增强了对这一独特记录可靠性的信心，但也发现磁性矿物学在暴露于空气后降解得非常快。虽然离散样品已放置在氮气冲洗袋中运输，但迫切需要立即进行测量。此外，由于磁性矿物学可能非常不寻常（例如生物硫化铁），它也必须在氧化之前和之后进行表征。因此，我们要求通过快速供资机制提供资金。将使用通常的EOR机制请求对剩余的远征318古磁学工作的支持。

One of the prime objectives of IODP Expedition 318, January to March 2010 (Wellington to Hobart) was to obtain an ultra high resolution record of the Holocene from drilling in the Adelie Basin. The Adelie Basin contains a 190 m thick sequence of diatomaceous ooze overlying a glacial diamict with an age of about 11 ka. Sediments obtained at Site U1357 reveal an ultra-high resolution record with the first annually resolved time series of oceanographic and climatic variability derived from the Southern ocean. Site U1357 was triple cored. Hole U1357A was split and processed during the expedition while Holes U1357B and C were sealed in nitrogen flushed bags and only split during the sampling party (June 27, 2010 - July 3, 2010). Data obtained from shipboard measurements of the archive half of U1357A documented an unrivaled record of secular variation (SV) of the geomagnetic field, which promises not only an unprecedented SV record but also will provide critical constraints for hole to hole correlation. During post-cruise sampling we bolstered our confidence in the reliability of this unique record, but also discovered that the magnetic mineralogy degrades extremely rapidly after exposure to air. While the discrete samples have been placed in nitrogen flushed bags for transport, immediate measurement is urgently required. Also, because the magnetic mineralogy is likely to be quite unusual (for example biogenic iron sulfides), it must also be characterized prior to as well as after oxidation. We therefore request funding via the RAPID funding mechanism. Support for the remaining Expedition 318 paleomagnetic efforts will be requested using the usual EOR mechanism.