Generation of a Late Cambrian-Early Carboniferous conodont-based ?18O curve: Paleozoic climates, phosphate ?18O diagenesis, and conodont paleobiology

晚寒武世-早石炭世基于牙形刺的 ?18O 曲线的生成：古生代气候、磷酸盐 ?18O 成岩作用和牙形刺古生物学

• 批准号: 0545799
• 负责人: Kenneth MacLeod
• 金额: $ 12.5万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0545799&HistoricalAwards=false
• 关键词: Generation; Late; Cambrian; Early; Carboniferous; Generation; Late; Cambrian; Early; Carboniferous

Generation of a late Cambrian-Early Carboniferous conodont-based d18O curve: Paleozoic climates, phosphate d18O diagenesis, and conodont paleobiologyKen MacLeod and Raymond L. EthingtonUniversity of MissouriEAR-0545799ABSTRACTExisting temperature estimates for the early Paleozoic have large errors and/or are likely affected by strong diagenetic biases. This uncertainty compromises efforts to use conditions of the early Paleozoic as a natural climate experiment for times when controlling variables (e.g., pCO2, solar luminosity, terrestrial vegetation, paleogeography) differed markedly from the later portions of the Phanerozoic up to the modern. To begin to address this problem, PIs will measure d18O values of up to 1000 early to mid-Paleozoic conodont samples. Because phosphate oxygen, especially in material with relatively high crystallinity like the lamellar hydroxyfluorapatite of conodont elements, is diagenetically more robust than carbonate oxygen, d18O measurements of bioapatite has great potential to advance knowledge of Paleozoic temperatures. Analytical advances have reduced the required sample size and increased sample throughput without compromising accuracy or precision. In addition, for this proposal PIs have access to thousands of samples that are already processed. Coupled with our analytical capabilities, this sample base provides an unparalleled opportunity to efficiently conduct a d18O survey from a range of taxa representing different regions, different times, and different states of preservation. Samples analyzed will come primarily from the University of Missouri conodont collection but will also include specimens from the large collections spanning the Late Ordovician housed at Ohio State University and from those spanning the Cambrian-Ordovician boundary housed at Missouri State University. With these samples PIs will 1) document temporal patterns in conodont d18O across ~160 million years at multiple sites with better than million-year average resolution, 2) compare d18O values with visual (cathodoluminescence, color alteration index, reflected light, and SEM) and geochemical (ICP-MS) observations of preservation to test empirically how robust conodont d18O values are, and 3) compare d18O values of various conodont taxa within multiple samples to search for consistent interspecies differences.

产生的基于寒武纪晚期的石炭纪晚期的D18O曲线：古生代气候，磷酸盐D18O成岩作用和Conodont Pareobiologyken MacLeod MacLeod和Raymond L.Sirsouriear-0545799 Abstressisting温度的强劲估计，或者可能对孔子进行了较大的估计，或者可能受到了较大的估计。这种不确定性损害了在控制变量（例如，PCO2，太阳能发光度，陆地植被，古地理）与后期的phanerokoic pose of Modern of Modern of Modern of Modern to te Modern时，这种不确定性损害了使用早期古生代作为自然气候实验的努力。为了开始解决此问题，PI将测量多达1000个早期至中期牙形牙齿样本的D18O值。因为磷酸盐氧，尤其是在菌根元素的层状羟基氟磷灰石（牙形元素的层状型）的材料中，比碳酸盐氧的氧气更强大，因此生物磷灰石的D18O测量具有巨大的潜力，可以提高对古生代温度的知识。分析进步减少了所需的样本量和增加样品吞吐量，而不会损害准确性或精度。此外，对于此建议，PI可以访问数千个已经处理的样本。再加上我们的分析能力，该样本基础提供了无与伦比的机会，可以从一系列分类单元进行有效进行D18O调查，这些分类单元代表不同的区域，不同时间和不同的保存状态。所分析的样本将主要来自密苏里大学牙能大学系列，但还将包括跨越俄亥俄州立大学的奥多维奇的大型收藏品的标本，以及跨越密苏里州立大学的寒武纪 - ordovician边界的标本。使用这些样品，PIS将1）在多个地点左右的1.6亿年中记录了牙道肌D18O中的时间模式，该站点的平均分辨率高于百万年度，2）将D18O值与视觉发光，降压，颜色改变指数，反射光和SEM和SEM）和地球化学（ICP-MS）和地球化（ICP-MS）的相似之处及38 conodon conodont conodont conodont conodont conodont进行了比较。多个样本中各种牙形类群的值以搜索一致的种间差异。