权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Paul Bown - IODP Expedition 320 participation

Paul Bown - IODP Expedition 320 参与

基本信息

批准号：
NE/I000011/1
负责人：
Paul Bown
金额：
$ 1.13万
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：
2010
资助国家：
英国
起止时间：
2010 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FI000011%2F1
关键词：
Paul Bown IODP Expedition 320

项目摘要

1. Intercalibration of stratigraphic datums from the Paleogene PEAT splice Undertake shipboard and post-cruise calcareous nannofossil biostratigraphy for the Eocene-Miocene interval and integrate these data with those from other PEAT stratigraphers. The completion of a astronomically calibrated Paleogene stratigraphic 'mega-splice' is an Expeditions 320/321 primary objective. 2. Calcareous nannofossil evolution through Eocene hyperthermals and the Eocene climatic optimum The early to middle Eocene saw a rise in nannofossil diversity to a Cenozoic maximum. I will investigate the timing and structure of this increase and examine whether climatic shifts played a significant role in the evolution of the oceanic plankton at this time. If early Eocene hyperthermal intervals are recovered I will investigate the nannofossil response at high resolution to test for the forcing effects of temperature and/or ocean chemistry changes (e.g. acidification) on nannofossil abundance, diversity and evolutionary rates. 3. Climate, carbonate accumulation and nannofossil evolution through the middle to late Eocene Carbonate and silica accumulation events have been identified in previous records from the equatorial Pacific and linked to changes in planktonic productivity and global climate shifts. This time interval also saw a precipitous decline in the diversity of nannofossils from which the group has arguably never completely recovered. I will generate quantitative nannofossil abundance and diversity records on short and long timescales in order to examine the relationships between nannofossil productivity and evolution, carbonate accumulation and paleoclimate/paleoceanography. In detail, I am interested in the nannofossil record across the Middle Eocene climatic optimum (MECO; 42Ma) and the biogenic accumulation and carbonate compensation depth (CCD) events that follow, and precede the Eocene/Oligocene transition (48-34Ma). I will also investigate the nature of nannofossil preservation as sites approach the CCD, in particular its influence on preserved diversity and proxy records. 4. Eocene-Oligocene transition (EOT) - investigating links between ocean chemistry and plankton evolution A major restructuring in plankton ecosystems across the EOT suggests that the expansion of Antarctic ice sheets is coincident with a significant perturbation in low-latitude surface ocean environments. Evidence from calcareous nannofossil assemblages indicates that this may be due to a widespread increase in nutrient availability. A marked shoaling of the CCD immediately prior to the EOT has hampered the production of a comparable record from deep-sea sediments. We propose to measure absolute nannofossil species abundances and, combined with the cyclostratigraphic age model, quantify nannofossil accumulation rates across the EOT. We would also actively collaborate with PEAT scientists in the production of the full range of carbonate, silica, nannofossil and foraminiferal accumulation rates. 5. Early Miocene glaciation (Mi-1) and the plankton ecosystem The relatively short but significant early Miocene glacial episode, Mi-1, is in some ways similar to the EOT climate event. There has, however, been little observed response within planktonic ecosystems to Mi-1. We would apply the methodology used in objective 4 to Mi-1 (PEAT-6C). This is an extension of objective 4 and we will collaborate with PEAT nannofossil biostratigraphers who have this interval as a primary objective.

1.古近系泥炭拼接地层数据的相互校准承担始新世-中新世间隔的船上和巡航后钙质超微化石生物地层学，并将这些数据与其他泥炭地层学家的数据相结合。完成天文校准的古近纪地层“巨型拼接”是320/321远征队的主要目标。2.通过始新世高温和始新世气候最佳的钙质超微化石演化始新世早期至中期超微化石多样性上升到新生代最大。我将调查这种增加的时间和结构，并研究气候变化是否在这个时候海洋浮游生物的进化中发挥了重要作用。如果早始新世超温区间恢复，我将调查nannofosfite响应在高分辨率测试温度和/或海洋化学变化（如酸化）对nannofosfite丰度，多样性和进化速率的强迫效应。3.气候，碳酸盐积累和超微化石的演变，通过中到晚始新世碳酸盐和二氧化硅积累事件已被确定在以前的记录从赤道太平洋，并与南极洲生产力和全球气候变化的变化。这段时间也见证了超微化石多样性的急剧下降，而这一群体可以说从未完全恢复。我将产生定量的超微化石丰度和多样性记录的短期和长期的时间尺度，以研究超微化石生产力和演化，碳酸盐积累和古气候/古海洋学之间的关系。详细地说，我感兴趣的是中始新世气候最佳时期（MECO; 42 Ma）的超微化石记录，以及始新世/渐新世过渡时期（48- 34 Ma）之前的生物积累和碳酸盐补偿深度（CCD）事件。我还将调查的性质nannofosal保存的网站接近CCD，特别是其对保存的多样性和代理记录的影响。4.始新世-渐新世过渡（EOT）-调查海洋化学和浮游生物进化之间的联系贯穿EOT的浮游生物生态系统的重大重组表明，南极冰盖的扩张与低纬度表层海洋环境的重大扰动一致。来自钙质超微化石组合的证据表明，这可能是由于养分供应的广泛增加。就在EOT之前，CCD的显著变浅阻碍了从深海沉积物中产生可比较的记录。我们建议测量绝对的超微化石物种丰度，并结合循环地层年龄模型，量化整个EOT的超微化石积累率。我们还将积极与PEAT科学家合作，以生产碳酸盐，二氧化硅，超微化石和有孔虫积累率的全方位数据。5.早中新世冰期（Mi-1）和浮游生物生态系统相对较短但重要的早中新世冰期（Mi-1）在某些方面与EOT气候事件相似。然而，很少有观察到的反应在南极生态系统Mi-1。我们将对Mi-1（PEAT-6C）采用目标4中使用的方法。这是目标4的延伸，我们将与PEAT超微化石生物地层学家合作，他们将此间隔作为主要目标。