COLLABORATIVE RESEARCH: Understanding Climate Change During the Final Stages of Late Paleozoic Gondwanan Glaciation - An Integrated Data-Model Study

摘要合作研究：了解晚古生代贡德瓦纳冰川作用末期的气候变化--一个综合数据模型Isabel Montanez，加州大学，DavisVladimir Davydov，Mark Schmitz，博伊西州立大学Chris Poulsen，密歇根大学Neil塔博尔，&南卫理公会大学最近开发的古气候档案揭示了从晚古生代冈瓦纳冰期到温室世界的转变比以前认为的更加动态-一个以气候和pCO2的相当大的协变为特征的问题。最近记录的短命（1至4百万年）冰川作用的发生似乎与大气pCO2、海洋和大陆温度以及相对海平面的大幅度变化相吻合，这表明了CO2-气候-冰川作用的联系。然而，这种联系并没有受到考验。我们提出了一个跨学科的研究，重点是显着提高我们的理解晚古生代气候系统的演变，以及触发气候变化的机制，在地球的最后一个时期的过渡，从冰室到温室状态。这项研究旨在验证两个假设：（1）大气中二氧化碳的变化是大陆冰盖反复生长和退缩的主要驱动力，反过来，（2）晚古生代冰盖强烈影响全球气候，特别是在热带地区。中欧、东欧和西南极洲的特定盆地已成为目标，因为它们的地层和古地理覆盖范围，存在海洋、沉积物和古土壤陆地沉积物，以及它们现有的生物地层学和进一步放射性测年的潜力（即，多夹层火山凝灰岩）和生物地层学分析。本研究有三个主要目标：* 通过整合新的和现有的生物，旋回和化学地层（87 Sr/86 Sr）数据与火山凝灰岩U/Pb定年，并将这些整合数据应用于多种定量工具（CONOP，RASC，CASP，GraphCor），建立放射性校准的年代地层框架（Gzhelian至中二叠世早期）。*进一步开发和校准高分辨率的古大气二氧化碳分压、古降水量以及海洋和陆地古温度的定量代用记录。这包括新的定量代理的批判性评价和进一步发展，以及直接比较代理记录与冈瓦纳南部继承的冰川和“变暖”的沉积学证据。为晚古生代冰川-间冰期振荡发展一个理论气候框架，使用三维气候模型量化冈瓦纳冰盖对CO2的敏感性，确定冰盖在推动全球气候变化中的作用，并通过与代用记录的比较进行气候预测。更广泛的影响：拟议的研究将为更广泛的科学界提供四个主要贡献：（1）以前所未有的分辨率和精度重建晚古生代气候系统，（2）对pCO2-气候范式在地球历史上的气候演变进行了重要检验，（3）以前所未有的时间分辨率记录了古生代的海洋-陆地气候联系，（4）首次检验了欧亚大陆和北美盆地的旋回演替的相关性，以及与冈瓦纳冰川沉积记录的联系。此外，计划的本科生和研究生的跨学科培训，PI将他们的研究工作整合到三个教育推广计划，旨在提高代表性不足的本科生和高中科学教师的研究和教学机会。我们将通过将我们的数据和模型模拟导入CHRONOS系统（及其合作伙伴网站PaleoStrat），这是一个基于网络的交互式资源，PI Davydov直接参与其中。

ABSTRACTCOLLABORATIVE RESEARCH: UNDERSTANDING CLIMATE CHANGE DURING THE FINAL STAGES OF LATEPALEOZOIC GONDWANAN GLACIATION - AN INTEGRATED DATA-MODEL STUDYIsabel Montanez, University of California, DavisVladimir Davydov & Mark Schmitz, Boise State UniversityChris Poulsen, University of MichiganNeil Tabor, Southern Methodist UniversityRecently developed paleoclimate archives reveal a much more dynamic transition from the latePaleozoic Gondwanan ice age to a greenhouse world than previously considered - one characterized byconsiderable co-variability in climate and pCO2. Recently documented short-lived (1 to 4 m.y.) episodesof glaciation appear to coincide with large magnitude shifts in atmospheric pCO2, marine and continentaltemperatures and relative sea-level suggesting a CO2-climate-glaciation link. This link, however, remainsuntested. We propose an interdisciplinary study focused on significantly improving our understanding ofthe evolution of the late Paleozoic climate system, and the mechanisms that triggered climate changeduring the Earth's last period of transition from icehouse to greenhouse states. The research is designed totest two hypotheses: (1) that atmospheric CO2 variability was the primary driver for repeated growth andretreat of continental ice sheets, and, in turn, (2) that late Paleozoic ice sheets strongly influenced globalclimate, particularly in the tropics. Specific basins in central and eastern Europe and western Argentinahave been targeted given their stratigraphic and paleogeographic coverage, presence of marine, paralicand paleosol-bearing terrestrial deposits, and their existing biostratigraphy and potential for furtherradiometric dating (i.e., multiple intercalated volcanic tuffs) and biostratigraphic analysis. This researchhas three major objectives:* To establish a radiometrically calibrated, chronostratigraphic framework (Gzhelian to early MiddlePermian) through the integration of new and existing bio-, cyclo-, and chemo-stratigraphic (87Sr/86Sr)data with U/Pb dating of volcanic tuffs, and the application of these integrated data to multiplequantitative tools (CONOP, RASC, CASP, GraphCor).* To further develop and calibrate high-resolution, quantitative proxy records of paleo-atmosphericpCO2, paleo-precipitation, and marine and terrestrial paleo-temperatures. This includes criticalevaluation and further development of new quantitative proxies as well as direct comparison of proxyrecords to sedimentologic evidence for glaciations and 'warmings' in southern Gondwanansuccessions.* Development of a theoretical climate framework for the late Paleozoic glacial-interglacial oscillationsusing three-dimensional climate models to quantify the sensitivity of ice sheets on Gondwana topCO2, determine the role of ice sheets in driving global climate change, and make climate predictionsthat can be tested through comparison with the proxy records.Broader Impacts: The proposed research will offer four major contributions to the broader scientificcommunity: (1) a reconstruction of the late Paleozoic climate system at an unprecedented level ofresolution and accuracy, (2) an important test of the pCO2-climate paradigm for climate evolution throughEarth history, (3) documentation of marine-terrestrial climate linkages at unprecedented temporalresolution for the Paleozoic, and (4) the first test of proposed correlations of cyclothemic successions ineastern Euramerican and North American basins, and of linkages to the Gondwanan glaciosedimentaryrecord. In addition, to the planned cross-disciplinary training of undergraduate and graduate students, thePIs will integrate their research efforts into three educational outreach programs designed to enhance theresearch and teaching opportunities of underrepresented undergraduate students and high school scienceteachers. We will make our data and model simulations available to the greater scientific community byimporting them into the CHRONOS System (and its partner website, PaleoStrat), a web-based interactiveresource with which PI Davydov is directly involved.