Resolving the enigmatic Precambrian-Cambrian boundary event (BACE)

解决神秘的前寒武纪-寒武纪边界事件（BACE）

• 批准号: NE/T008458/1
• 负责人: Rachel Wood
• 金额: $ 78.34万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FT008458%2F1
• 关键词: Resolving; enigmatic; Precambrian; Cambrian; boundary

Charles Darwin's 'great dilemma' was why complex life in the form of fossil animals seemed to appear so abruptly in rocks around 540 million years ago (Ma), in what is widely known as the Cambrian Explosion. Although we now know that many fossils are found in slightly older rocks, nonetheless the triggers and drivers of the Cambrian Explosion remain highly enigmatic. This revolutionary event follows immediately after a perturbation in the carbon cycle as revealed by carbon isotopes. This is known as the BAsal Cambrian carbon isotope Excursion (the BACE), and although has long been known, this event remains highly enigmatic. This is because there is no single stratigraphic section that allows us to create an integrated picture, which needs to include where and at what time the key fossils are found, the geochemistry that can tell us about how the Earth's environment may have changed at this time, and finally absolute ages (dates) of the rocks so that we can reconstruct the exact order of events. This means that our understanding of this profound evolutionary transition remains very uncertain.In this project we will use unique and new archives of sedimentary rocks derived from drilled, subsurface cores. This enables us to construct a much higher resolution, four-dimensional (temporal-spatial) picture of the evolutionary history of the earliest animals and their environment. These cores are from three diverse locations: Namibia, Brazil and South China, so that we can compare local to global patterns. Such cores are unweathered, so will preserve the most accurate geochemical signatures possible. We have also assembled a very multidisciplinary team, which combines complementary expertise in: 1) geochronology - the dating of rocks; 2) geochemistry - for reconstructing nutrient and biogeochemical cycles; 3) palaeontology - the record of life and evolution; and 4) mathematical modelling, which will enable us to capture geological information, in such a way as to test key hypotheses about the effects of animal evolution on environmental stability. Our project aims to address three central scientific questions: Q1: Is the BACE local or global, diagenetic or primary? Q2: What were the causes of the BACE? and Q3: What role did the BACE play in the evolution of metazoans? We will consider environmental factors, such as changes in oxygen levels, as the drivers of evolutionary change. By distinguishing physical, extrinsic drivers we can address a fundamental and motivating question: what caused animals to evolve and radiate when they did? This unique dataset is likely to be transformative as it will resolve the key processes fundamental to the coupled evolution of the Earth System and the rise of complex life.This study has relevance to today's biosphere, as the modern Earth system and its stabilising feedbacks arose during this key interval. By studying it in more detail, and establishing temporal relationships and causality between key events, we can find out how the modern Earth system and the unique life it carries, is structured.

查尔斯·达尔文的“巨大困境”是，为什么以动物化石形式存在的复杂生命似乎突然出现在大约 5.4 亿年前（Ma）的岩石中，也就是众所周知的寒武纪大爆发。尽管我们现在知道许多化石是在稍微古老的岩石中发现的，但寒武纪大爆发的触发因素和驱动因素仍然非常神秘。这一革命性事件紧随碳同位素揭示的碳循环扰动之后发生。这被称为BAsal寒武纪碳同位素偏移（BACE），尽管早已为人所知，但这一事件仍然高度神秘。这是因为没有单一的地层剖面可以让我们创建一个完整的图景，其中需要包括关键化石的发现地点和时间，以及可以告诉我们此时地球环境可能发生了怎样变化的地球化学信息。 ，最后是岩石的绝对年龄（日期），以便我们可以重建事件的确切顺序。这意味着我们对这一深刻的进化转变的理解仍然非常不确定。在这个项目中，我们将使用来自钻探的地下岩心的独特且新的沉积岩档案。这使我们能够构建一幅更高分辨率的四维（时空）最早动物及其环境的进化史图景。这些核心来自三个不同的地点：纳米比亚、巴西和华南地区，以便我们可以比较当地与全球的模式。此类岩心未经风化，因此将保留最准确的地球化学特征。我们还组建了一支多学科团队，结合了以下领域的互补专业知识：1) 地质年代学 - 岩石测年； 2）地球化学——重建养分和生物地球化学循环； 3）古生物学——生命和进化的记录； 4）数学模型，这将使​​我们能够捕获地质信息，从而测试有关动物进化对环境稳定性影响的关键假设。我们的项目旨在解决三个核心科学问题： Q1：BACE 是局部的还是全球的、成岩的还是原生的？ Q2：BACE的原因是什么？ Q3：BACE 在后生动物的进化中发挥什么作用？我们将把环境因素（例如氧气水平的变化）视为进化变化的驱动因素。通过区分物理的、外在的驱动因素，我们可以解决一个基本的、激励性的问题：是什么导致动物进化和辐射？这个独特的数据集可能具有变革性，因为它将解决地球系统耦合演化和复杂生命兴起的关键过程。这项研究与当今的生物圈相关，因为现代地球系统及其稳定反馈是在这个关键区间。通过更详细地研究它，并建立关键事件之间的时间关系和因果关系，我们可以找出现代地球系统及其所承载的独特生命的结构。

项目成果

Enhanced clay formation key in sustaining the Middle Eocene Climatic Optimum.

• DOI: 10.1038/s41561-023-01234-y
• 发表时间: 2023
• 期刊: NATURE GEOSCIENCE
• 影响因子: 18.3
• 作者: Krause, Alexander J. J.;Sluijs, Appy;van der Ploeg, Robin;Lenton, Timothy M.;von Strandmann, Philip A. E. Pogge
• 通讯作者: von Strandmann, Philip A. E. Pogge

Constraining the onset and environmental setting of metazoan biomineralization: The Ediacaran Nama Group of the Tsaus Mountains, Namibia

• DOI: 10.1016/j.epsl.2023.118336
• 发表时间: 2023-08-17
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Bowyer, Fred T.;Uahengo, Collen-Issia;Wood, Rachel A.
• 通讯作者: Wood, Rachel A.

Modelling Ediacaran metazoan-microbial reef growth

模拟埃迪卡拉后生动物-微生物礁的生长

• DOI: 10.1111/sed.12832
• 发表时间: 2020
• 期刊: Sedimentology
• 影响因子: 3.5
• 作者: Curtis A

Implications of an integrated late Ediacaran to early Cambrian stratigraphy of the Siberian Platform, Russia

• DOI: 10.1130/b36534.1
• 发表时间: 2023-09-01
• 期刊: GEOLOGICAL SOCIETY OF AMERICA BULLETIN
• 影响因子: 4.9
• 作者: Bowyer, Fred T.;Zhuravlev, Andrey Yu;Zhu, Maoyan
• 通讯作者: Zhu, Maoyan

Insights Into the Terminal Ediacaran Marine Carbonate Record From Shale-Hosted Carbonate Carbon Isotopes

• DOI: 10.2475/001c.88082
• 发表时间: 2023-11
• 期刊: American Journal of Science
• 影响因子: 2.9
• 作者: F. Bowyer;Mariana Yilales;Rachel Wood;S. Poulton