New North Atlantic Palaeo-Temperature Reconstruction from Terrestrial Sedimentary Archives: Implications for the Influence of the Icelandic Plume on O

冰岛羽流是目前地球地幔中最活跃的地幔对流细胞。格陵兰-苏格兰脊（GSR）是冰岛羽流的热点路径，是全球环流系统中最重要的门户之一。相对较小（约100米）的GSR高程变化对海洋环流有很强的影响。冰岛羽流的脉动行为驱动了100米尺度的GSR海拔在整个新生代的百万年时间框架内的变化，导致了海洋环流的变化。要了解这些环流变化如何影响气候，就需要北大西洋古温度记录。令人惊讶的是，在GSR附近几乎没有高质量的古温度信息。为数不多的北大西洋古温度重建主要基于海相沉积档案，其温度代用指标已经建立。有机地球化学的最新进展是在富有机质陆地沉积物中使用支链甘油二烷基甘油四醚（br-GDGTs）作为空气温度的代表。这些新工具开启了通过分析含褐煤沉积包体来显著增加北大西洋新生代古温度记录数量的可能性。对冰岛北部厚的、上新世的、含褐煤的Tjörnes沉积序列的初步研究表明，原始的古温度信息被覆盖了，但没有被埋葬所破坏。目前存在几种地理上局部的古温度校准方法。该项目旨在通过结合实验室实验和实地工作，产生一种单一的、广泛适用的校准方法，该校准方法考虑了一系列埋葬条件。在项目合作伙伴的帮助下，新的冰岛上新世古温度记录将利用来自北爱尔兰、挪威和格陵兰岛的褐煤扩展到渐新世。新的新生代古温度记录将根据正在进行的伯明翰环流模式（GCM）对GSR升高对海洋环流影响的研究来解释。该分析将与冰岛南部北大西洋预计的IODP钻井一起工作，并从中受益。通过新生代对气候变化建立更全面的了解，将有助于更好地预测下个世纪人为气候变化可能如何影响世界。

The Icelandic Plume is the most vigorous mantle convection cell currently within Earth's mantle. The Greenland-Scotland Ridge (GSR) is the hotspot track of the Icelandic Plume and forms one of the most important gateways in the global circulation system. Relatively small (c. 100 m) changes in GSR elevation have a strong influence on oceanic circulation. Pulsing behaviour of the Icelandic Plume has driven 100 m-scale changes in GSR elevation on a million-year timeframe throughout Cenozoic time, resulting in variations in oceanic circulation. North Atlantic palaeo-temperature records are required to ask how these circulation changes influence climate. Surprisingly, there is relatively little high quality palaeo-temperature information in the vicinity of the GSR itself. The few available North Atlantic palaeo-temperature reconstructions are predominantly based on marine sedimentary archives, for which temperature proxies are well established. Recent advances in organic geochemistry have developed the use of branched glycerol dialkyl glycerol tetraethers (br-GDGTs) in organic-rich terrestrial sediments as a proxy for air temperature. Such new tools open the possibility of significantly increasing the number of North Atlantic Cenozoic palaeo-temperature records by analysing lignite-bearing sedimentary packages.A pilot study of the thick, Pliocene, lignite-bearing Tjörnes sedimentary succession of northern Iceland shows that original palaeo-temperature information is overprinted, but not destroyed, by burial. Several geographically localised palaeo-temperature calibrations currently exist for br-GDGTs. This project aims to produce a single, widely applicable calibration that accounts for a range of burial conditions by combining lab-based experiments and fieldwork. The new Icelandic Pliocene palaeo-temperature record will then be extended back to the Oligocene using lignites from Northern Ireland, Norway and Greenland, with access aided by project partners. The new Cenozoic palaeotemperature record will be interpreted in the light of an ongoing Birmingham-based General Circulation Model (GCM) study of the effect of GSR elevation on oceanic circulation. This analysis will work alongside and benefit from anticipated IODP drilling in the North Atlantic south of Iceland. Building a more complete understanding of climate change through the Cenozoic will help better predict how anthropogenic climate change might affect the world in the next century.