Low Versus High Latitude Continental Climatic Effects of the Central Atlantic Magmatic Province on the End Triassic Extinction Event

该项目旨在了解三叠纪末的灭绝（大约2.01亿年前的埃特），这是地球历史上五次大规模灭绝之一。埃特的原因仍在调查中，但盘古大陆分裂期间的大规模火山爆发释放了大量温室气体，这反过来又导致了栖息地的变化。 结果，许多动物和植物物种灭绝，使新的动物茁壮成长，特别是恐龙。该项目的重点是两个现场位置：犹他州的Moenave组，在灭绝期间靠近亚热带地区，以及南非和莱索托的Elliot组，靠近南极。通过将时间尺度与化石的出现相结合，可以预测主要气候变化如何导致灭绝，从而为我们提供如何缓解目前物种灭绝水平增加的线索。这项研究具有重要的社会意义。 它解决了地球表面过程研究的一些重大挑战，由国家科学院出版（边缘景观：地球表面研究的新视野）。 例如，这项研究将有助于确定对地球过去的了解如何帮助我们为可持续的未来做好准备。该项目支助的学生将从两个鼓励对少数民族进行科学教育的主要组织中招募：奇卡诺人和美洲土著人科学协会和全国黑人地球科学家协会。该项目将涉及联邦机构通过与圣乔治恐龙发现博物馆和锡安国家公园的合作伙伴关系，特别是通过博物馆和游客中心展示我们的研究成果。学生交流经验将与开普敦大学（UCT）和威特沃特斯兰德大学（UW）的高级人员协调。 来自阿肯色州大学（UA）的学生将在南部非洲度过一个野外季节，学习野外技能并获得文化经验，来自UCT和UW的学生将访问UA，学习地球化学和光谱测定技能并参观野外现场。最后，我们将为正在接受阿肯色州采用的下一代科学标准培训的高中教师开发数据集并与他们合作。该项目将：1）确定美国Moenave地层中的埃特（低纬度）和南部非洲的埃利奥特组（高纬度）使用生物和化学地层学和高分辨率地质年代学; 2）生成古气候代用数据; 3）确定遗迹学和微型动物记录中的生物地层趋势; 4）比较南半球高纬度和低纬度地区的生态系统和气候变化。所采用的方法包括：1）收集两个地层的C同位素（整体和特定化合物）化学地层学和碎屑锆石年代学数据; 2）生物地层学数据（脊椎动物和无脊椎动物的身体和痕迹化石）。CO2浓度、温度和年平均降水量将使用来自古土壤和湖泊沉积物的稳定和聚集同位素、来自古土壤的主要和次要元素浓度以及来自介形虫和脊椎动物化石的O同位素进行计算。这些数据将与来自两大洲的脊椎动物和无脊椎动物遗骸的古生物学事件相关联，以确定CAMP对两个生态系统造成的气候变化的影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project aims to understand the end Triassic extinction (ETE about 201 Million years ago), one of five mass extinctions in Earth's history. The causes of the ETE are still under investigation, but massive volcanic eruptions during the breakup of Pangea emitted large amounts of greenhouse gases, which in turn caused habitat-change. As a result, many animal and plant species went extinct, allowing for new animals to thrive, notably dinosaurs. The project focuses on two field locations: the Moenave Formation of Utah, near the sub-tropics during the time of extinction, and the Elliot Formation of South Africa and Lesotho, near the South Pole. By combining the timescale with the occurrence of fossils, a prediction of how major climatic changes may cause extinction will be developed, thus providing us with clues about how to mitigate the current increased levels of species extinctions. The proposed study has important societal implications. It addresses some of the grand challenges for research on Earth-surface processes, published by the National Academy of Sciences (Landscapes on the Edge: New Horizons for Research on Earth's Surface). For example, the research will help identify how knowledge of our planet's past helps us prepare for a sustainable future. Students supported by this project will be recruited from two major organizations that encourage scientific education for minorities: the Society for Chicanos and Native Americans in Science and the National Association of Black Geoscientists. The project will involve federal agencies through partnerships with the St. George Dinosaur Discovery Museum and Zion National Park, specifically via museum and visitor center displays of our study outcomes. Student exchange experience will be coordinated with Senior Personnel at the University of Cape Town (UCT) and University of the Witwatersrand (UW). Students from the University of Arkansas (UA) will spend a field season in southern Africa learning field skills and gaining cultural experiences, and students from UCT and UW will visit the UA to learn geochemical and spectrometry skills and visit field sites. Finally, we will develop datasets for and work with high school teachers that are training for the Next Generation Science Standards adopted by the state of Arkansas.The project will: 1) identify the ETE in the Moenave Formation, USA (low-latitude) and the Elliot Formation of southern Africa (high-latitude) using bio- and chemostratigraphy and high resolution geochronology; 2) generate paleoclimate proxy data; 3) determine biostratigraphic trends in ichnological and microfaunal record; and 4) compare ecosystem and climatic shifts in high versus low-latitudes in the southern hemisphere. The methods employed include: 1) collection of C-isotope (bulk and compound-specific) chemostratigraphic and detrital zircon geochronologic data from both formations; and 2) biostratigraphic data (body and trace fossils of vertebrates and invertebrates). CO2 concentration, temperature, and mean annual precipitation will be calculated using stable and clumped isotopes from paleosol and lacustrine sediments, major and minor element concentrations from paleosols, and O-isotopes from ostracods and vertebrate fossils. These data will then be correlated to the paleontological occurrences of vertebrate and invertebrate remains from both continents to determine effects of climate change caused by the CAMP on the two ecosystems.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.