Collaborative Research: Illuminating the characteristics, causes, and paleoclimatic importance of the Mid-Cenozoic Loess in the Western USA

合作研究：阐明美国西部中新生代黄土的特征、成因和古气候重要性

• 批准号: 2114204
• 负责人: Ran Feng
• 金额: $ 26.08万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2114204&HistoricalAwards=false
• 关键词: Collaborative; Research; Illuminating; characteristics; causes; Collaborative; Research; Illuminating; characteristics; causes

Loess deposits consist of fine-grained, windblown sediments and contain critical information about continental aridification processes that are key to understanding biotic evolution and climate change. This project integrates field data collected from loess deposited ~37-30 million years ago in Wyoming, Nebraska and Montana, laboratory analyses, and paleoclimate simulations to understand the nature, causes, and paleoclimatic importance of these loess deposits. The research will advance STEM diversity by supporting a two-day GEOCAMP for historically underrepresented high-school students from east Texas. In addition, this project will promote further development of the high-resolution Community Earth System Model to be used to better understand ancient climate changes. This project will include field sedimentological observation and lab analyses of bulk sediment and quartz grain-size, quartz surface morphology, detrital and high-precision zircon U-Pb geochronology to study the ancient loess deposits in Wyoming, Nebraska and Montana, USA. These proxy data will constrain the extent, timing, pattern and characteristics of the loess; and determine sediment provenance and sediment recycling mechanisms. These proxy data will be integrated with a coupled atmosphere-land model to simulate changes of regional climate and vegetation induced by topography changes, global climate cooling, glaciation and shoreline regression to understand the cause and climate significance of the loess. In additional to gaining fundamental understanding of the loess deposits, the project will shed light on 1) the influence of climate change on biotic evolution at the Eocene-Oligocene transition (~34 million years ago); 2) the validity of different models of surface uplift in the western USA; and 3) the potential positive climate feedback of enhanced mineral dust emissions on global cooling at the transition.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.

黄土沉积物由细粒度，风吹沉积物组成，并包含有关大陆干旱化过程的关键信息，这些信息是理解生物进化和气候变化的关键。该项目集成了从怀俄明州，内布拉斯加州和蒙大拿州，实验室分析和古气候模拟中收集的现场数据，以了解这些黄土沉积物的性质，原因和古气候重要性。这项研究将通过支持为期两天的地理领域来推动STEM多样性，以供历史上代表性不足的来自东德克萨斯州的高中生。此外，该项目将促进高分辨率社区地球系统模型的进一步发展，以更好地了解古老的气候变化。该项目将包括现场沉积学观察以及散装沉积物和石英晶粒大小，石英表面形态，碎屑和高精度锆石U-PB地球人类学的实验室分析，以研究怀俄明州，内布拉斯加州和美国蒙大拿州Wyoming的古老loess矿床。这些代理数据将限制黄土的程度，时机，模式和特征。并确定沉积物出处和沉积物回收机制。这些代理数据将与耦合的大气层模型集成，以模拟由地形变化，全球气候冷却，冰川和海岸线回归引起的区域气候和植被的变化，以了解黄土的原因和气候意义。除了对黄土沉积物的基本了解之外，该项目还将阐明1）气候变化对始新世 - 新世过渡过渡时生物进化的影响（约3400万年前）； 2）美国西部不同模型的表面隆升模型的有效性； 3）在过渡期间，增强矿物灰尘排放的积极气候反馈。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为是值得通过评估来支持的。