NSFGEO-NERC: Collaborative Research: Developing a new Lower Cretaceous time scale: Foundation for the next generation of paleoceanographic and biogeochemical studies

NSFGEO-NERC：合作研究：制定新的下白垩世时间尺度：下一代古海洋学和生物地球化学研究的基础

• 批准号: 1952346
• 负责人: Mark Schmitz
• 金额: $ 19.13万
• 依托单位: Boise State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-11-15 至 2024-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1952346&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Collaborative; Research; Developing

The Cretaceous was a time of global warming during which atmospheric carbon dioxide levels surpassed 800 ppm, similar to those predicted for 2100 by “business-as-usual” emission scenarios. Cretaceous rocks record high sea levels, high biological productivity, massive volcanism, and major perturbations of the carbon cycle during several ocean anoxic events (OAEs). Understanding these phenomena can provide deep-time analogs for future greenhouse scenarios. Marine sediments that record these crises are globally widespread but weaving these records into a common temporal framework is essential if they are to reveal the causes. This project aims to generate a new temporal framework spanning 125 to 93 million years ago during which several major OAEs occurred. This will permit examination of repeated deteriorations of marine ecosystems across the Pacific, Atlantic, and Mediterranean oceans. The team will be involved in novel outreach, international collaboration, and training of future earth science leaders. They will bring deep-time science to the public via presence at the Sturgis Motorcycle Rally. The favored hypothesis for ocean anoxic events involves volcanic initiation leading to a cascade of processes amplifying global marine production; key factors are the nature of volcanism and the source of increased nutrients. Yet geographic differences in proxy records (Carbon and Osmium isotopes) indicate additional complexities, such as sea level and ocean circulation. The goals for the project are to establish: (1) A new time scale for global geochemical and paleobiologic datasets; (2) Chemostratigraphic correlation of the new time scale to European sections using isotope stratigraphy, and (3) A new global time scale for improved understanding of major biogeochemical perturbations. The team will: (i) Determine radioisotopic ages of rhyolitic tuffs in sediments of Japan, (ii) Integrate these new ages with new Osmium and Carbon isotope chemostratigraphy in Europe, (iii) Compile global geochemical proxy data for OAE 1a within a common temporal and stratigraphic framework, and analyze trends and patterns from the Pacific to Europe, (iv) Evaluate the volcanic versus climatic/orbital hypotheses for OAE initiation, and (v) Explore the significance of geography in the timing and magnitude of geochemical signals.This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (UKRI/NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own investigators and component of the work.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.

白垩纪是全球变暖的时期，大气中的二氧化碳含量超过 800 ppm，与“一切照旧”排放情景所预测的 2100 年类似，白垩纪岩石记录了高海平面、高生物生产力、大规模火山活动和火山活动。了解一些海洋缺氧事件（OAE）期间碳循环的主要扰动可以为记录这些危机的未来海洋沉积物提供深度模拟。如果要揭示其原因，将这些记录编入一个共同的时间框架至关重要，该项目旨在生成一个跨越 125 至 9300 万年前的新时间框架，在此期间发生了几次主要的 OAE，这将允许检查海洋的反复恶化。该团队将参与新颖的外展活动、国际合作以及对未来地球科学领导者的培训，他们将通过参加斯特吉斯摩托车拉力赛向公众介绍深度科学。海洋缺氧事件的假设涉及火山喷发，导致一系列放大全球海洋生产的过程；关键因素是火山活动的性质和营养物质增加的来源，但代理记录（碳和锇同位素）的地理差异表明了额外的复杂性，例如。该项目的目标是建立：（1）全球地球化学和古生物学数据集的新时间​​尺度；（2）新时间尺度的化学地层相关性；使用同位素地层学对欧洲剖面进行研究，以及（3）建立新的全球时间尺度，以更好地了解主要的生物地球化学扰动。该团队将：（i）确定日本沉积物中流纹岩凝灰岩的放射性同位素年龄，（ii）将这些新年龄与这些年龄相结合。欧洲新的锇和碳同位素化学地层学，(iii) 在共同的时间和地层框架内编译 OAE 1a 的全球地球化学代理数据，并进行分析从太平洋到欧洲的趋势和模式，(iv) 评估 OAE 启动的火山与气候/轨道假设，以及 (v) 探索地理在地球化学信号的时间和强度方面的重要性。这是一个共同资助的项目由国家科学基金会地球科学理事会 (NSF/GEO) 和英国 (UK) 国家环境研究委员会 (UKRI/NERC) 通过 NSF/GEO-NERC 牵头机构协议本协议允许。单一的美国/英国联合提案将由其研究人员拥有最大预算比例的机构提交并进行同行评审。在成功联合确定资助后，每个机构将资助与其相关的预算和研究人员的比例。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。