"Arctic Ocean Paleoceanography (ArcOP)": Pilot research and lead of IODP Expedition 377(ArcOP-Pilot)

《新提案》详细阐述了北冰洋在过去、现在和未来的全球气候/地球系统中是一个关键角色，但北极海洋地球科学研究滞后于世界其他海洋，特别是从古气候的角度来看。在长期气候历史重建方面，北冰洋古气候研究的突破是2004年IODP Exp 302 （ACEX）期间在北冰洋中部永久冰覆盖区进行的首次科学钻探。ACEX的结果是前所未有的，并为从温室到冰窖条件的长期北极气候和海冰历史提供了重要的见解。然而，与早期新生代北冰洋气候历史相关的主要问题仍未得到解答，部分原因是主要的中新生代间歇期（或沉积速率大幅降低），部分原因是ACEX记录恢复不佳。继ACEX及其前沿科学之后，已提出在罗蒙诺索夫海岭进行第二次科学钻探，重点是重建连续完整的新生代北冰洋气候历史，现在重新安排为IODP Exp 377（“北冰洋古海洋学- ArcOP”），时间为2022年8月至9月。在此背景下，该DFG项目的主要重点将是：(1)在2018年PS115/2试验期间，对在潜在的IODP 377钻探地点或附近回收的极地沉积物岩心进行试点研究；(2)为IODP Exp 377的最终规划和实施以及领导做出贡献（作为联合首席科学家之一）。(3)在航行结束后的会议上，以及在报告/出版物中，记录和展示试验研究和IODP考察的初步结果。正如新提案中已经描述的那样，该先导研究与IODP Exp 377具有重要的相关性：-通过结合由最上层未受干扰的约10 m晚第四纪沉积物组成的Polarstern岩心，以及由于水-沉积物界面附近的钻井干扰，最上层经常未被很好地保存的IODP钻孔，将获得一个独特的完整且未受干扰的复合沉积剖面，代表了早新生代至近代。-将使用MSCL-Logging和XRF扫描数据（根据IODP规则在选定的Polarstern岩心上确定）详细地将Polarstern岩心与IODP地点相关联。基于详细的岩石学、旋回学、古地磁学和230钍同位素地层学，建立了极地岩心的年龄模型，并将其纳入IODP Exp 377沉积层序的年龄模型。为了重建第四纪北极气候历史，将对北极星岩心进行多代理方法，包括确定特定生物标志物、矿物组合、粗组分组成、粒度分布和XRF扫描数据。

In the New Proposal, it has been outlined in detail that the Arctic Ocean was/is a key player in the past, present and future global climate/earth system, however, the marine geoscience research in the Arctic lags behind other world oceans, especially from a paleoclimatic perspective. Concerning the reconstruction of the long-term climate history, a breakthrough in Arctic Ocean paleoclimate research was the first scientific drilling in the permanently ice-covered central Arctic Ocean that was carried out during IODP Exp 302 (ACEX) in 2004. The ACEX results were unprecedented and give important insight into the long-term Arctic climate and sea-ice history on its pathway from Greenhouse to Icehouse conditions. However, major questions related to the climate history of the Arctic Ocean during early Cenozoic times remain unanswered, partly due to the major mid-Cenozoic hiatus (or strongly reduced sedimentation rates) and partly to the poor recovery of the ACEX record. Following-up ACEX and its cutting-edge science, a second scientific drilling on Lomonosov Ridge with a focus on the reconstruction of the continuous and complete Cenozoic Arctic Ocean climate history, has been proposed and is now re-scheduled as IODP Exp 377 (“Arctic Ocean Paleoceanography - ArcOP”) for August-September 2022. In this context, the main focus within this DFG project will be (1) to carry out a pilot study on Polarstern sediment cores recovered at or close to the locations of potential IODP 377 drill sites during Exp PS115/2 in 2018, (2) to contribute to the final planning and implementation as well as the lead of IODP Exp 377 (as one of the co-chief scientists), and (3) to document and present first results of the pilot study as well as the IODP expedition during post-cruise meetings and in reports/publications. The pilot study is of major relevance for IODP Exp 377 as already described in the New Proposal:- By combining the Polarstern cores composed of the uppermost undisturbed about 10 m of late Quaternary sediments, and the IODP drill holes in which the uppermost meters are often not well preserved due to drilling disturbances near the water-sediment interface, a unique complete and undisturbed composite sedimentary section representing the early Cenozoic to Recent, will be obtained.- For correlating the Polarstern cores and IODP sites in detail, MSCL-Logging and XRF scanning data (to be determined on selected Polarstern cores following the IODP rules), will be used.- An age model of the Polarstern cores will be developed based on detailed litho-, cyclo-, paleomagneto-, and 230Th-isotope-stratigraphy to be later incorporated into the age model of the IODP Exp 377 sedimentary sequence.- For reconstructing the Quaternary Arctic climate history, a multiproxy approach will be carried out on the Polarstern cores, including the determination of specific biomarkers, mineral assemblages, coarse-fraction composition, grain-size distributions and XRF scanning data.