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

合作研究：了解拉特帕洛佐克冈德瓦南冰川末期的气候变化--综合数据模型研究伊莎贝尔·蒙塔内兹，加州大学戴维斯分校Vladimir Davydov&Amp；Mark Schmitz，博伊西州立大学克里斯·鲍尔森，密歇根大学尼尔·塔博尔，南卫理公会大学最近开发的古气候档案显示，从晚古生代冈德旺冰川时代到温室世界的转变比以前认为的要动态得多--一个以气候和二氧化碳的显著共同变化为特征的转变。最近记录的短命(1至4英里)冰川事件似乎与大气二氧化碳浓度、海洋和大陆温度以及相对海平面的巨大变化相吻合，表明二氧化碳-气候-冰川作用之间存在联系。然而，这种联系仍未得到检验。我们建议进行一项跨学科的研究，重点是显著提高我们对晚古生代气候系统演化的理解，以及在地球从冰库向温室状态过渡的最后一段时间内触发气候变化的机制。这项研究旨在检验两个假设：(1)大气中二氧化碳的可变性是大陆冰盖反复消长的主要驱动力，而反过来，(2)晚古生代冰盖强烈影响全球气候，特别是热带地区。中欧和东欧以及阿根廷西部的特定盆地由于其地层和古地理覆盖范围、海洋、近海和古土壤陆相沉积的存在、其现有的生物地层学和进一步进行放射性测年(即多个夹层火山凝灰岩)和生物地层学分析的可能性而成为目标。这项研究有三个主要目标：*通过将新的和现有的生物、旋回和化学地层学(87Sr/86Sr)数据与火山凝灰岩的U/Pb测年相结合，并将这些综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格架(Gzhelian至中二叠世早期)。*进一步开发和校准古大气pCO2、古降水、海洋和陆地古温度的高分辨率、定量的替代记录。这包括关键的评估和进一步开发新的定量指标，以及将代理记录与冈萨斯南部冰川和“变暖”的沉积学证据进行直接比较。*开发晚古生代冰川-间冰川振荡的理论气候框架，使用三维气候模型量化冰盖对冈瓦那二氧化碳的敏感性，确定冰盖在推动全球气候变化中的作用，并做出气候预测，通过与代理记录的比较进行检验。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准确性重建晚古生代气候系统(2)对二氧化碳-气候范式在地球历史上的气候演变进行了一次重要的检验；(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)首次对所提出的欧亚大陆和北美盆地旋回序列的相关性以及与冈德瓦南冰川沉积记录的联系进行了检验。此外，除了计划对本科生和研究生进行的跨学科培训外，私营部门还将把他们的研究工作整合到三个教育推广方案中，旨在增加未被充分代表的本科生和高中理科教师的研究和教学机会。我们将把我们的数据和模型模拟输入Chronos系统(及其合作网站PaleoStrat)，向更大的科学界提供这些数据和模型模拟，这是一个皮伊·达维多夫直接参与的基于网络的互动资源。

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.