Collaborative Research: Testing the Early Late Ordovician Cool Water Hypothesis

合作研究：检验早奥陶世晚期冷水假说

• 批准号: 1323444
• 负责人: Kenneth MacLeod
• 金额: $ 18万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1323444&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; Early; Late; Collaborative; Research; Testing; Early; Late

Collaborative Research: Testing the Early Late Ordovician Cool Water Hypothesisby Achim Herrmann, Louisiana State UniversityKenneth MacLeod, University of MissouriStephen Leslie, James Madison UniversityEAR-1324954, -1323444, -1324577ABSTRACTThe Late Ordovician glaciation (LOG) is associated with the second largest mass extinction event of the Phanerozoic. It marks the end of the global warm conditions of the early Paleozoic that lasted ~150my and occurred under elevated pCO2 conditions. Considerable doubt has recently been raised with regard to the duration of the LOG, its potential driving mechanisms, and pre-glacial, long-term temperature variations. For instance approximately 15 Ma prior to LOG the North American continental plate was situated in tropical to subtropical latitudes, but sedimentological and paleontological evidence suggest a shift from deposition of warm water carbonates to deposition of cool water carbonates. It is not clear whether this sedimentological change reflects global cooling (indicating significant perturbation to the global climate system well before the Late Ordovician glaciation) or physical responses to tectonic activity with no requisite climatic implications. The projects will test competing hypotheses that try to explain this event through an extensive geochemical study. In particular, PIs will use the geochemical archive of conodont apatite (delta18O and epsilonNd) and carbonates (DELTA48, delta18O, and delta13C) to address questions about paleoceanographic conditions during the Early Late Ordovician. They expect that this research will lead 1) to clarification of potential causes for the paleontological/sedimentological changes during this interval, 2) to a better understanding of epicontinental sea circulation and an improved facies model for epicontinental low latitude carbonate platforms (for which no modern-day analogues exist), and 3) to better documentation of the temperature history of the Ordovician greenhouse interval.This research project will have active participation by undergraduate students, graduate students, and a secondary school science teacher. Therefore, the project will not only impact present university students and researchers, it will also impact future generations of students through enhancing an earth science secondary educations teacher¡¦s knowledge base and science curriculum. Data will be contributed to publicly accessible databases making them available for further research and general education in the fields of paleoclimate and paleoceanography.

合作研究：测试由路易斯安那州立大学的阿奇·赫尔曼（Achim State Kenneth Macleod），密苏里斯坦大学麦克劳德（University of Missouristephen Leslie），詹姆斯·麦迪逊大学1324954，-1323444，-132324577ABSTRACTTHE LOGOVICIAN LOGITIS（LOGAN）与第二名的Eventries（logan）相关的测试，测试了路易斯安那州立大学Kenneth Macleod，路易斯安那州立大学Kenneth Macleod的假设测试。它标志着持续约150my的早期古生素的全球温暖条件的终结，发生在升高的PCO2条件下。最近，关于原木的持续时间，其潜在的驾驶机制以及冰期前的长期温度变化提出了很大的怀疑。例如，在登录前约15 mA北美大陆板位于热带纬度上，但是沉积和古生物学证据表明，从温水碳酸盐的沉积转移到冷水碳酸盐的沉积。目前尚不清楚这种沉积学变化是反映全球冷却（表明在晚期奥托维奇冰川冰川之前对全球气候系统的明显扰动）还是对构造活动的物理反应，而没有必要的杂交含义。这些项目将测试竞争假设，试图通过广泛的地球化学研究来解释这一事件。特别是，PIS将使用Conodont Apatite（Delta18o和Epsilonnd）和碳酸盐（Delta48，delta18o和delta13c）的地球化学档案库解决有关晚期天道早期的古疗法的问题。他们希望这项研究将导致1）在此间隔期间阐明对古生物学/沉积学变化的潜在原因，2）更好地理解上层海洋循环以及改进的面对面模型，用于上皮大陆较低的碳酸盐平台的模型（不存在现代的类似物），以及3）在不中间的研究中，不适合进行了不中间的研究，使得不中间的整体疗法是在不中间的研究，使得不中间的整体疗法，使得不中等温度的整体化，使得众所周知的温度有限。研究生和中学科学老师。因此，该项目不仅会影响当前的大学生和研究人员，还将通过增强地球来影响子孙后代。科学中学教育教师的知识库和科学课程。数据将有助于公开访问的数据库，使其可以在古气候和古群学领域进行进一步的研究和通识教育。