Collaborative Research: Anatomy of a Greenhouse World: The Early Eocene of the Green River Basin, Wyoming

合作研究：温室世界的解剖：怀俄明州格林河流域的始新世早期

• 批准号: 1813350
• 负责人: Michael Smith
• 金额: $ 19.02万
• 依托单位: Northern Arizona University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1813350&HistoricalAwards=false
• 关键词: Collaborative; Research; Anatomy; Greenhouse; World

The geologic record of past environmental change offers an illuminating glimpse into the behavior of Earth's natural systems. The deposits formed in ancient lakes are particularly useful in this regard for several reasons: they are highly sensitive to climate change; they often contain relatively complete geologic archives with relatively few gaps; and they can potentially be used to document changes that occurred over time scales meaningful to humans. The Green River Formation in the western U.S. offers an especially valuable record of the most geologically recent period of prolonged greenhouse conditions, which occurred approximately 50-53 million years ago during the Eocene Epoch. It is famous for its rich assemblages of fossil vertebrates, insects, and plants, and for containing the world's largest commercial deposits of soda ash and oil shale. This research project will focus on evidence for repeated rapid warming events during this time, by examining how river courses changed, the types of sediment that accumulated within the lake, and variations in ancient soil development and chemistry. Equally important, this study will build a time scale of unprecedented accuracy and precision for these important deposits, based on new radiometric dates of volcanic ash in the lake, the chronology of changes in the Earth's magnetic field, and sedimentation patterns that were driven by periodic oscillations in the Earth's rotation and orbit. Broader impacts of this proposal will include development of local 2-hour field trips for middle and high school students, enhanced through the use of innovative data visualization technology on portable devices. The Early Eocene Climatic Optimum (EECO) was a time of persistent global warmth, of which the cause remains incompletely determined. Lake deposits of the Green River Formation preserve a rich and previously untapped record that complements that contained in marine sediments, and present an opportunity to advance the precision and accuracy of the Early Eocene timescale. This project is an integrated, multidisciplinary investigation focused on one of the world's richest and best studied systems of ancient lake strata. The research will investigate three principal questions: 1. How did the timing of terrestrial warming compare to that inferred from the marine record, and to predicted patterns of the Earth's orbital variations? Recent advances in radioisotopic dating can be used to directly test the relationship of warming events to Earth's orbital changes, and calibrate dynamic gravitational models of the solar system back to ca. 50 million years. 2. How did temperatures, seasonality, hydrologic cycling, and weathering on land evolve during the EECO? One hypothesis is that warming was amplified on continents relative to the oceans and was accompanied by more equable temperatures year-round, whereas precipitation seasonality and intensity increased. 3. How did the complex tectonic and magmatic evolution of western North America impact the preservation of EECO climate signals? The research will test the hypothesis that repeated, stepwise drainage reorganizations within the tectonically-active uplands modified the hydrologic balance and sedimentary deposits of the Eocene lake environment and its response to orbital changes.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.

过去环境变化的地质记录为地球自然系统的行为带来了启发性的瞥见。 由于几个原因，在古代湖泊中形成的沉积物在这方面特别有用：它们对气候变化高度敏感；它们通常包含相对完整的地质档案，差距相对较少。它们有可能用于记录对人类有意义的随时间尺度发生的变化。 美国西部的绿河构造提供了最有价值的记录，这是最近期的延长温室条件的最新记录，这发生在始新世时期的大约500-53亿年前。 它以丰富的化石脊椎动物，昆虫和植物的浓度而闻名，并包含世界上最大的苏打灰和油页岩商业矿床。 该研究项目将通过研究河流课程的变化，湖泊内积累的沉积物类型以及古代土壤发育和化学的变化来重点介绍反复快速变暖事件的证据。 同样重要的是，这项研究将基于湖中火山灰的新辐射日期，地球磁场变化的年代学以及由地球周期性振荡驱动的，基于湖中火山灰的新辐射日期，建立前所未有的准确性和精确度。 该建议的更广泛的影响将包括开发中学和高中生的本地2小时实地考察，并通过在便携式设备上使用创新的数据可视化技术来增强。 始新世的早期气候最佳（EECO）是一个持续的全球温暖时期，其原因仍未完全确定。 绿河层的湖泊沉积物保留了一份富裕且未开发的记录，该记录与海洋沉积物中包含的补充，并提供了提高始新世早期时间尺度的精确性和准确性的机会。 该项目是一项综合，多学科的调查，旨在介绍世界上最丰富，最好的古湖区系统之一。该研究将研究三个主要问题：1。陆地变暖的时机与从海洋记录中推断出的时间相比以及预测地球轨道变化的模式？ 放射性分析的最新进展可用于直接测试变暖事件与地球轨道变化的关系，并将太阳系的动态重力模型校准回到CA。 5000万年。 2。在EECO期间，在土地上的温度，季节性，水文循环和风化如何？一个假设是，相对于海洋，大陆放大了变暖，并且伴随着全年更平等的温度，而降水季节性和强度增加。 3。北美西部的复杂构造和岩浆演变如何影响EECO气候信号的保存？ 这项研究将检验以下假设，即在构造活跃的高地内重复进行逐步排水的重组修改了始新世湖环境的水文平衡和沉积沉积物及其对轨道变化的反应。这奖反映了NSF的立法任务，并被认为是通过基金会的智力评估和广泛的范围来评估的，因此值得通过评估来进行评估。

项目成果

The Aspen paleoriver: Linking Eocene magmatism to the world's largest Na-carbonate evaporite (Wyoming, USA)

阿斯彭古河：将始新世岩浆作用与世界上最大的钠碳酸盐蒸发岩联系起来（美国怀俄明州）

• DOI: 10.1130/g46419.1
• 发表时间: 2019
• 期刊: Geology
• 影响因子: 5.8
• 作者: Hammond, A. P.

Watershed-scale provenance heterogeneity within Eocene nonmarine basin fill: Southern Greater Green River Basin, western USA

始新世非海洋盆地填充物内的流域规模物源异质性：美国西部大格林河流域南部

• DOI: 10.1130/b36822.1
• 发表时间: 2023
• 期刊: Geological Society of America Bulletin
• 影响因子: 4.9
• 作者: Parrish, Ethan C.;Carroll, Alan R.;Gregorich, Holly;Smith, M. Elliot;Schwaderer, Colby
• 通讯作者: Schwaderer, Colby

Simulating the source waters for the Wilkins Peak Member evaporite sequence with modern soda spring analogues

使用现代苏打泉类似物模拟威尔金斯峰成员蒸发岩序列的源水

• DOI: 10.1016/j.apgeochem.2023.105597
• 发表时间: 2023
• 期刊: Applied Geochemistry
• 影响因子: 3.4
• 作者: Arnuk, William D.;Lowenstein, Tim K.;Klonowski, Elizabeth M.;Carroll, Alan R.;Smith, M. Elliot
• 通讯作者: Smith, M. Elliot

Climate and ecology in the Rocky Mountain interior after the early Eocene Climatic Optimum

• DOI: 10.5194/cp-17-2515-2021
• 发表时间: 2021-12
• 期刊: Climate of the Past
• 影响因子: 4.3
• 作者: Rebekah A. Stein;N. Sheldon;S. E. Allen;Michael E. Smith;Rebecca M. Dzombak;B. Jicha

High-resolution X-ray fluorescence-based provenance mapping of Eocene fluvial distributary fans that fed ancient Gosiute Lake, Wyoming, USA

基于高分辨率 X 射线荧光的始新世河流分流扇的物源图，这些分流扇为美国怀俄明州古戈休特湖提供水源

• 发表时间: 2023
• 期刊: Geological Society of America bulletin
• 影响因子: 4.9
• 作者: Smith, M.E.