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  • 學術講座


    發布時間:2024-03-07 打印

    講座1Reconstructing Earth's Ancient Phosphorus Cycle

    講座2Phosphorus Controls on Earth's Early Oxygenation History

    人:Simon Poulton 教授







    Simon Poulton,英國利茲大學教授,歐洲地球化學學會會士、英國皇家學會沃爾夫森優秀科研獎(Royal Society Wolfson Research Merit Award)獲得者。他長期致力于地球生物圈化學演化、營養元素循環以及地球早期大氣和海洋環境演變規律等問題的研究,通過沉積巖的地球化學及非傳統同位素等極具獨創性的手段揭示早期環境與生命協同變化規律,并取得重要成果。發表論文一百余篇,包括Nature、Science、Nature Geoscience、Nature Communications、Science Advances等期刊論文數十篇,SCI引用18000余次。獲得2023年中國科學院國際人才計劃(PIFI)資助。


    Seminar 1: Reconstructing Earth’s Ancient Phosphorus Cycle

    Our understanding of Earth’s oxygenation/deoxygenation history and links to biological evolution and extinction has evolved dramatically over recent years. While there is still much to learn in terms of reconstructing the dynamics of this history, with a broad understanding in place, attention is increasingly focusing on the drivers of intervals of paleoenvironmental change. In this regard, the key major limiting nutrient, phosphorus, plays a key role through its regulation of primary productivity, organic matter production and burial, and hence both regional water column deoxygenation and global oxygenation. However, our understanding of the ancient phosphorus cycle is highly limited, and hence controls on major periods of paleoenvironmental change are often obscured. Here, we will investigate phosphorus cycling in modern redox-sensitive environments, with a focus on ferruginous (Fe-containing) and low ··1= euxinic (sulfidic) water column settings that are analogous to ancient oceans. With this new understanding, we will then explore how new techniques for evaluating the phase partitioning of phosphorus can be used to unravel phosphorus cycling in ancient environments, with a particular focus on the Late Ordovician mass extinction and global ferruginous conditions in the early Neoproterozoic.

    Seminar 2: Phosphorus Controls on Earth’s Early Oxygenation History

    Over the last 20 years, huge progress has been made in terms of our understanding of Earth's oxygenation history. This lecture will start with a general overview and timeline of the advances made, culminating in the most up-to-date reconstruction of atmospheric and oceanic oxygenation. Recent research will then be presented on the role that phosphorus cycling played in priming the Earth for its first major rise in atmospheric oxygen during the Great Oxidation Episode (GOE). Research pertaining to the dynamics of the GOE and links to phosphorus cycling will then be discussed. This work documents a major delay of ~100 million years in the timing of persistent atmospheric oxygenation, with intense fluctuations in atmospheric oxygen levels being linked to major climate perturbations. Finally, we will review how far our understanding of the history of mid-Proterozoic ocean chemistry has evolved over the last 20 years, with an ultimate focus on potential drivers of apparent temporal and spatial variability in this record.


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