Expedition 378: Planktonic foraminiferal biostratigraphy, biogeography and climatic evolution of the Southern Ocean

IODP 378考察队将首次在西南太平洋中纬度海域进行钻探。此次考察的主要目的是恢复5500万至3000万年前（始新世至渐新世）适合古海洋学和古气候重建的开放海洋沉积物。在这段时间内，地球经历了过去6500万年以来大气中二氧化碳含量最高的时期，随后逐渐变冷，导致了南极冰期（3400万年前）的开始，气候状态更类似于现代。通过回收西南太平洋的沉积物，我们可以近距离观察始新世到渐新世早期，这个海洋地区的气候演变，当时是地球上最广阔的亚极地地区。研究人员弗拉维亚·博斯科洛-加拉佐博士将作为专门研究浮游有孔虫的船上生物地层学家乘坐Exp 378号航行。她在船上的主要任务是通过分析沉积物的化石含量，对回收沉积物的年龄进行初步评估，这对继续钻探作业至关重要。特别是，她将研究浮游有孔虫化石物种，这是一个广泛使用的工具，以确定海洋沉积物的年龄。在提出的研究中，我们的目标是通过分析更多的样本和对浮游有孔虫化石的形态（分类）进行详细的研究，来确定（通常是繁忙的）船上活动期间提供的沉积物的年龄。这对于任何旨在重建钻探区域古气候和古地理的后续研究都是至关重要的，并且可以与来自不同海洋盆地的同期记录进行比较。此外，通过分析更多的样本，我们将能够研究气候对浮游有孔虫进化的影响，特别是测试该地区的降温是否伴随着物种组成和物种起源速度的变化。这与评估气候变化对海洋生态系统的长期影响极为相关。

IODP Expedition 378 will drill for the first time in the middle latitude south-west Pacific ocean. Main aim of the expedition is to recover open ocean sediments suitable for paleoceanographic and paleoclimatic reconstructions dating between 55 to 30 million years ago (Eocene to Oligocene Epochs). During this time interval Earth experienced the highest atmospheric carbon dioxide levels of the last 65 million years, and afterwards a gradual cooling which led to the inception of the Antarctic glaciation (34 million years ago) and of a climate state more similar to the modern. By recovering south-west Pacific sediments we will have a close-up view of the long term, Eocene to early Oligocene, climate evolution in this oceanic area which was, at that time, the widest sub-polar region on Earth.The researcher, Dr Flavia Boscolo-Galazzo, will sail on Exp 378 as ship-board biostratigrapher specializing in planktonic foraminifera. Her primary duty on board will be to contribute to preliminary assessments of the age of the recovered sediments by analysing their fossil content, essential to continue the drilling operations. In particular, she will study fossil planktonic foraminiferal species, which are a widely employed tool to define the age of ocean sediments.With the proposed research we aim to refine the age of the sediments provided during the (often hectic) shipboard activity, by analysing a greater number of samples and by performing detailed studies on the morphology (taxonomy) of fossil planktonic foraminifera. This will be essential for any subsequent study aiming at reconstructing the paleoclimate and paleocenography in the drilled region, and to allow comparisons with coeval records from different ocean basins. Further, by analysing a larger number of samples, we will be able to study the influence of climate on planktonic foraminifera evolution through time, and specifically to test whether cooling in this region was accompanied by changes in species composition and in the rate of species origination. This is extremely relevant to assess long term impacts of climate change on marine ecosystems.