Testing for high-frequency (104-105 yr) glacio-and thermo-eustasy in greenhouse and transtional climates using oxygen isotopes of conodont apatite

使用牙形磷灰石氧同位素测试温室和过渡气候中的高频（104-105 年）冰川和热稳定

• 批准号: 0920830
• 负责人: Maya Elrick
• 金额: $ 29.84万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0920830&HistoricalAwards=false
• 关键词: Testing; frequency; 104; 105; yr

Testing for high-frequency glacio- and/or thermo-eustasy during greenhouse and transitional climates using oxygen isotopes of conodont apatite.Maya Elrick and Zachary SharpUniversity of New MexicoEAR-0920830ABSTRACTHigh-frequency (104-105 years) upward-shallowing carbonate cycles are common sedimentary features and are generally attributed to orbitally driven glacio-eustasy (changes in ice volume). But in warm, greenhouse conditions, glacial ice is thought not to have been significant, making this interpretation for high frequency carbonate cycles less compelling. We will evaluate the possibility that glacio-eustasy did occur in warm climates by analyzing oxygen isotope ratios of conodonts, a common fossil composed of diagenetically-resistant phosphate. Glacial ice strongly incorporates the light stable isotope of oxygen. Therefore, when large ice volumes are present (low sea level), the oxygen isotope ratio of the ocean becomes measurably heavier. The diagenetically resistant conodonts will allow us to search for this signal and address the long-debated origin of temporally persistent and widespread meter-scale carbonate cycles/parasequences, specifically whether the controversial proposal that transient ice sheets can form even in warm climatic periods is reasonable and supported by geochemical evidence. Our study will center on three greenhouse (Late Silurian, Early Devonian and Early Triassic) and one transitional (Early Mississippian) climatic mode. We plan to incorporate local middle and high school science teachers into our research project to help bring scientific inquiry into the classroom. This will be accomplished through collaboration with the Science Education Institute of the Southwest (SEIS), and by conducting a series of week-long summer workshops for professional teacher development in the sciences.

Testing for high-frequency glacio- and/or thermo-eustasy during greenhouse and transitional climates using oxygen isotopes of conodont apatite.Maya Elrick and Zachary SharpUniversity of New MexicoEAR-0920830ABSTRACTHigh-frequency (104-105 years) upward-shallowing carbonate cycles are common sedimentary features and are generally attributed to orbitally driven斜晶状体（冰量的变化）。 但是在温暖的温室条件下，人们认为冰川冰并不重要，这使得对高频碳酸盐循环的这种解释降低了。 我们将通过分析由肌肌的氧同位素比（一种由浓度耐氧化磷酸盐组成的常见化石）来评估在温暖气候中确实发生冰川化的可能性。 冰川冰强烈结合了氧气的轻稳定同位素。 因此，当存在较大的冰量（低海平面）时，海洋的氧同位素比变得更重。 可基核抗性的牙能力将使我们能够搜索此信号，并解决时间持续且广泛的仪表尺度碳酸盐循环/parasequences的长期来源的起源，即使在温暖的气候期间，瞬态冰片是否可以合理，并得到地球化学证据，即使在温暖的气候期间也可以形成。 我们的研究将集中在三个温室（已故的志留纪，早期的泥盆纪和早期三叠纪）和一个过渡（密西西比州早期）的气候模式。 我们计划将当地的中学和高中科学教师纳入我们的研究项目，以帮助将科学调查带入课堂。 这将通过与西南科学教育学院（SEIS）合作，并通过一系列为期一周的夏季讲习班，以供科学专业的教师发展。