Collaborative Research: Developing a multi-proxy approach for reconstructing deep-time silicate weathering

合作研究：开发重建深层硅酸盐风化的多代理方法

• 批准号: 1929593
• 负责人: Justin Strauss
• 金额: $ 24.69万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929593&HistoricalAwards=false
• 关键词: Collaborative; Research; Developing; multi; proxy

Throughout Earth's history the amount of CO2 in the atmosphere has been influenced by reactions with different types of rocks at the surface. The CO2 erodes rocks such as basalt which releases elements into rivers and eventually these elements combine with seawater to form new rocks. The variations in atmospheric CO2 content contribute to variations in the climate over tens or hundreds of millions of years. There is good evidence that 700 million years ago the Earth experienced the longest and most extreme glaciation in our planet's history and ice reached all the way to the equator. Unfortunately, we do not know what caused this glaciation or what the climate was like before the glaciers. This project will investigate the lead-up to the glaciation by examining specific elements in ancient rocks deposited in oceans using new advanced analytical methods. By looking at the chemical composition of rocks that formed in the ancient oceans prior to the glaciation, Earth scientists can trace the changing ocean chemistry and then infer the ancient atmospheric conditions leading up to this glaciation. These investigations will help to train future Earth scientists and provide researchers with opportunities to communicate Earth history and climate science from a novel angle to a variety of audiences. The results from these studies will provide Earth scientists unique insights into the chemical evolution of our planet and oceans during an incredibly fascinating time period.The Neoproterozoic Era (1000-539 Ma) witnessed the assembly and fragmentation of the Rodinia supercontinent, huge swings in geochemical cycles, biological firsts and innovations as well as extreme glaciations known as Snowball Earth events. Recent advances in our understanding of the interplay between these Snowball Earth events and the evolution of complex life have focused on the timing and duration of the glaciations and of the evolutionary events. Despite these advances very little progress has been made in understanding the drivers of the Snowball glaciations. The geology of Svalbard, Norway is host to a thick succession of pristine, low-grade sedimentary rocks that chart the lead-up and aftermath of these global glaciations and represents a unique setting to test a variety of hypotheses related to the causation of the glaciations and their impact on bio/geochemical cycles. This award supports two early-career Assistant Professors, a post-doctoral associate and a Masters student to conduct a detailed geochemical, sedimentological and geochronologic study of these sedimentary units. In particular, this research will couple numerous radiogenic and stable isotope systems tied to a robust stratigraphic and geochronologic framework to elucidate the mechanisms responsible for the Snowball Earth events and trace the chemical evolution of seawater prior to and immediately after the glaciations. Additionally, the project will provide two junior scholars the opportunity to work in the Arctic, gaining exposure to and experience of the logistical and environmental uniqueness of working in these regions. Although the project is specific to the Neoproterozoic, The new approach that couples a wide range of isotope systems will greatly benefit research in the Earth sciences across all timescales. In addition to the scientific research products that will result from this investigation, the PIs will collaborate with the Yale Peabody Museum of Natural History and Yale's pre-college "Pathways to Science" a program that operates within the New Haven public school system with direct opportunities to experience college and learn more about upper-level STEM education. Multiple undergraduate students at Dartmouth and Yale University will also be involved in sample processing, wet-lab chemistry and mass spectrometry as part of senior thesis projects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

纵观地球历史，大气中的二氧化碳含量一直受到地表不同类型岩石反应的影响。二氧化碳侵蚀玄武岩等岩石，将元素释放到河流中，最终这些元素与海水结合形成新的岩石。大气中二氧化碳含量的变化导致了数千万年或数亿年来气候的变化。有很好的证据表明，7亿年前，地球经历了地球历史上最长、最极端的冰川作用，冰一直延伸到赤道。不幸的是，我们不知道是什么导致了这次冰川，也不知道冰川之前的气候是什么样子的。该项目将通过使用新的先进分析方法检查海洋中沉积的古代岩石中的特定元素来调查冰川形成的原因。通过观察冰川之前在古代海洋中形成的岩石的化学成分，地球科学家可以追踪不断变化的海洋化学，然后推断导致这次冰川的古代大气条件。这些调查将有助于培训未来的地球科学家，并为研究人员提供机会，从新的角度向各种受众传播地球历史和气候科学。这些研究的结果将为地球科学家提供独特的见解，了解地球和海洋在令人难以置信的迷人时期的化学演化。新元古代(1000-539 Ma)见证了罗迪尼亚超大陆的组装和碎裂，地球化学循环的巨大波动，生物的第一次和创新，以及被称为雪球地球事件的极端冰川。最近，我们在理解这些雪球地球事件和复杂生命演化之间的相互作用方面取得了进展，重点放在冰川和演化事件的时间和持续时间上。尽管取得了这些进展，但在理解雪球冰川的驱动因素方面进展甚微。挪威斯瓦尔巴特群岛的地质是原始、低品位沉积岩的厚重序列的所在地，这些沉积岩绘制了这些全球冰川的前奏和后遗症，并代表了一个独特的环境，以检验与冰川成因及其对生物/地球化学循环的影响有关的各种假说。该奖项支持两名职业生涯初期的助理教授、一名博士后助理和一名硕士研究生对这些沉积单元进行详细的地球化学、沉积学和地质年代学研究。特别是，这项研究将把许多放射性成因和稳定的同位素系统与强大的地层学和年代学框架联系在一起，以阐明导致Snowball地球事件的机制，并追踪冰川之前和之后海水的化学演化。此外，该项目将为两名初级学者提供在北极工作的机会，获得在这些地区工作的后勤和环境独特性的接触和经验。尽管该项目是专门针对新元古代的，但将多种同位素系统结合在一起的新方法将极大地促进所有时间尺度上的地球科学研究。除了这项调查将产生的科研产品外，私人投资机构还将与耶鲁大学皮博迪自然历史博物馆和耶鲁大学预科课程“科学之路”合作，该项目在纽黑文公立学校系统内运作，有机会直接体验大学并了解更多关于高级STEM教育的知识。达特茅斯大学和耶鲁大学的多名本科生还将参与样品处理、湿法实验室化学和质谱学，作为高级论文项目的一部分。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Tonian deltaic and storm-influenced marine sedimentation on the edge of Laurentia: the Veteranen Group of northeastern Spitsbergen, Svalbard

• DOI: 10.1016/j.sedgeo.2021.106011
• 发表时间: 2021-10
• 期刊: Sedimentary Geology
• 影响因子: 2.8
• 作者: T. Gibson;Alexie E. G. Millikin;Ross P. Anderson;P. Myrow;A. Rooney;J. Strauss

Neoproterozoic stratigraphy of the Southwestern Basement Province, Svalbard (Norway): Constraints on the Proterozoic-Paleozoic evolution of the North Atlantic-Arctic Caledonides

• DOI: 10.1016/j.precamres.2021.106138
• 发表时间: 2021-06
• 期刊: Precambrian Research
• 影响因子: 3.8
• 作者: V. T. Wala;G. Ziemniak;J. Majka;K. Faehnrich;W. McClelland;E. E. Meyer-E.;M. Manecki;J. Bazarnik;J. Strauss