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Paleogene to early Neogene calcareous nannoplankton biochronology and evolution (IODP Expedition 390/393)

古近纪到新近纪早期钙质微浮游生物生物年代学和进化（IODP Expedition 390/393）

基本信息

批准号：
NE/W005107/1
负责人：
Paul Bown
金额：
$ 3.59万
依托单位：
University College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FW005107%2F1
关键词：
Paleogene early Neogene calcareous nannoplankton

项目摘要

Calcareous nannoplankton are microscopic marine algae that produce calcite exoskeletons (coccospheres/coccoliths) which can be found in almost all marine sediments in the geological record. By studying the calcareous nannofossils preserved within sediments cored from the sea-floor by the International Ocean Discovery Program (IODP) we can document their evolution through time, including changing number of species (diversity), rates of speciation and extinction, and population compositions. We can use this information to provide accurate ages of the sediments, which is an important task on a deep-sea drilling ship like the IODP JOIDES Resolution, and these results will tell us whether we have achieved our initial objectives. Calcareous nannoplankton are sensitive to changes in ocean environment, particularly sea-surface temperature and nutrient availability, with individual species or groups preferring specific ecological niches. Using the abundance of fossil species, we are able to reconstruct past environmental conditions for a specific location at a given time. IODP Expedition 390 will sail to the South Atlantic Ocean and core deep-sea sediments from the Paleogene to Neogene time interval (around 60 million years ago to present), a key interval in Earth's climate history marking the transition from high CO2, very warm 'greenhouse' climates into a much cooler 'icehouse' world with large Antarctic ice sheets that waxed and waned. This profound interval of climatic change saw dramatic shifts in the environments and ecosystems of the marine and terrestrial realms. A series of rapid warming events, known as hyperthermals, characterise the early Eocene (~56-50 million years ago), followed by long-term cooling through the later Eocene, and then glacial-interglacial cycles through the Oligocene and early Miocene (~33-20 million years ago). Calcareous nannoplankton were the dominant ocean phytoplankton at this time and peaked in diversity in the Eocene but then suffered major decline coinciding with this major climatic change from greenhouse to icehouse. However, the precise timing and speed of this evolutionary change is still poorly known and we plan to better understand this relationship between plankton evolution and palaeoclimatic change in the South Atlantic. A better understanding of this relationship is key to predicting the magnitude and impact of future climate change on the ocean biosphere and ecosystem functions. To answer these research questions, we first have to check that the deep-sea cores that we will drill will be of the right geological age, with continuous records through time, and in sediment types that preserve the fossils we need. This research project will provide the age control for the sites that were drilled by the preliminary IODP Expeditions 390C and 395E and this will be key to the success of the forthcoming expeditions which will sail in 2022.

钙质微型浮游生物是一种能产生方解石外骨骼的微小海藻，在地质记录中几乎所有的海洋沉积物中都能找到。通过研究国际海洋发现计划（IODP）从海底取芯的沉积物中保存的钙质超微化石，我们可以记录它们随时间的演变，包括物种数量（多样性）的变化，物种形成和灭绝的速度，以及人口组成。我们可以利用这些信息来提供沉积物的准确年龄，这是像IODP JOIDES Resolution这样的深海钻探船的重要任务，这些结果将告诉我们是否已经实现了我们的最初目标。钙质微型浮游生物对海洋环境的变化很敏感，特别是海面温度和营养物质的可用性，个别物种或群体更喜欢特定的生态位。利用丰富的化石物种，我们能够重建特定时间特定地点的过去环境条件。IODP Expedition 390将航行到南大西洋，并从古近纪到新近纪的时间间隔（大约6000万年前至今）进行深海沉积物的岩心采集，这是地球气候历史上的一个关键间隔，标志着从高二氧化碳，非常温暖的“温室”气候转变为一个更冷的“冰库”世界，南极冰盖大面积增加和减少。这一深刻的气候变化周期见证了海洋和陆地环境和生态系统的巨大变化。一系列快速变暖事件，称为高温，覆盖了始新世早期（约5600 - 5000万年前），随后是始新世晚期的长期冷却，然后是渐新世和中新世早期（约3300 - 2000万年前）的冰川-间冰期循环。钙质微型浮游生物是当时占主导地位的海洋浮游植物，在始新世达到多样性的顶峰，但随后遭受了重大的下降，与此同时，从温室到冰库的重大气候变化。然而，这种进化变化的精确时间和速度仍然知之甚少，我们计划更好地了解南大西洋浮游生物进化和古气候变化之间的关系。更好地了解这种关系是预测未来气候变化的规模和对海洋生物圈和生态系统功能的影响的关键。为了回答这些研究问题，我们首先必须检查我们将钻探的深海岩心是否具有正确的地质时代，是否有持续的记录，以及是否有保存我们所需化石的沉积物类型。该研究项目将为初步IODP探险队390 C和395 E钻探的地点提供年龄控制，这将是即将于2022年航行的探险队成功的关键。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

South Atlantic Transect

南大西洋横断面

DOI：
发表时间：
2024
期刊：
Proceedings of the International Ocean Discovery Program Expedition reports
影响因子：
0
作者：
Coggon, R.M.;Teagle, D.A.H.;Sylvan, J.B.;Reece, J.;Estes, E.R.;Williams, T.J.;Christeson, G.L.
通讯作者：
Christeson, G.L.

Expedition 393 Preliminary Report: South Atlantic Transect 2