COLLABORATIVE RESEARCH: Investigating Early Triassic Ocean Chemistry, Stratigraphy, and Paleobiology During the Protracted Biotic Recovery from the Permo-Triassic Mass Extinction

合作研究：在二叠纪-三叠纪大规模灭绝的长期生物恢复过程中调查早期三叠世海洋化学、地层学和古生物学

• 批准号: 0446580
• 负责人: Alan Kaufman
• 金额: $ 8万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0446580&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Investigating; Early; Triassic

ABSTRACTThe most devastating mass extinction since the origin of animals occurred at the end of the Permian Period (c. 251 million years ago) when over 80% of all marine species went extinct. The marine realm remained perturbed into the subsequent Triassic Period for several million years after the extinction events, but the details are poorly known and may help us more completely understand the extinction. Unusual geologic features reminiscent of earlier times in Earth's history, such as seafloor precipitated aragonite fans, subtidal stromatolites, and remarkable excursions in seawater d13C and d34S, indicate that atypical ocean chemistries and environments persisted into the Early Triassic, but their exact nature is not well-understood, given the boundary-centric nature of previous studies. We will investigate connections between unusual biotas, anachronistic lithofacies, strong isotopic shifts (d13C, d34S) and the protracted animal recovery in the Early Triassic (the geologic period following the mass extinctions). The western U.S., our proposed study area, resided on the eastern margin of the giant Panthalassic Ocean during this geologic time and thus provides a global comparison with ongoing research elsewhere (China, Europe, etc.). Our preliminary 87Sr/86Sr work in the western US demonstrates that samples are well preserved and that 87Sr/86Sr provides sub-stage time correlation potential. Sulfur-rich deposits that reflect seawater conditions are rare in the rock record. We will surmount this problem by using a new technique to extract sulfur isotopic information from normal marine limestones (the so-called "carbonate associated sulfate" or CAS), which are common around the world. The assembled dataset will likely be the first of its kind and reveal features that may give insight into the mass extinction not previously recognized.

自动物起源以来，最具破坏性的大规模灭绝发生在二叠纪末期（约公元前200年）。2.51亿年前，超过80%的海洋物种灭绝。 在灭绝事件发生后的几百万年里，海洋领域仍然受到干扰，进入随后的三叠纪时期，但细节知之甚少，可能有助于我们更全面地了解灭绝。 不寻常的地质特征让人想起地球历史上的早期，如海底沉淀的文石扇，潮下层积，以及海水d13 C和d34 S的显着漂移，表明非典型的海洋化学和环境持续到早三叠世，但它们的确切性质并不清楚，因为以前的研究具有边界中心的性质。 我们将研究不寻常的bioburden，时代错误的岩相，强烈的同位素变化（d13 C，d34 S）和延长动物恢复在早三叠世（地质时期后的大规模灭绝）之间的联系。美国西部，我们建议的研究区域，在这个地质时期居住在巨大的Panthalassic Ocean的东部边缘，因此提供了与其他地方（中国，欧洲等）正在进行的研究的全球比较。 我们在美国西部进行的初步87 Sr/86 Sr工作表明，样本保存完好，并且87 Sr/86 Sr提供了子阶段时间相关潜力。反映海水条件的富硫矿床在岩石记录中很少见。 我们将通过使用一种新技术来克服这个问题，从正常的海洋石灰岩（所谓的“碳酸盐缔合硫酸盐”或CAS）中提取硫同位素信息，这在世界各地都很常见。 组装的数据集可能是同类中的第一个，并揭示了可能让我们深入了解以前未被认识到的大规模灭绝的特征。