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）IODP第318次考察的主要目标之一是从阿德利盆地的钻探中获得全新世的超高分辨率记录。阿德利盆地包含一个190米厚的泥质软泥序列，覆盖在一个年龄约11万年的冰川杂岩上。在站点U1357获得的沉积物揭示了一个超高分辨率的记录，第一个每年解决的海洋和气候变化的时间序列来自南大洋。部位U1357为三芯。在考察期间对孔U1357 A进行了分裂和处理，而孔U1357 B和C则密封在氮气冲洗袋中，仅在取样期间（2010年6月27日至2010年7月3日）进行分裂。U1357A的存档一半的船上测量获得的数据记录了地磁场长期变化（SV）的无与伦比的记录，这不仅保证了前所未有的SV记录，而且将提供关键的约束孔到孔的相关性。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会非常迅速地退化。虽然离散样品已被放置在氮气冲洗袋中进行运输，但迫切需要立即测量。此外，由于磁性矿物学可能是非常不寻常的（例如生物成因的铁硫化物），它也必须在氧化之前和之后进行表征。因此，我们请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古地磁工作的支持。

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.