Towards understanding the Behaviour of the Clumped Isotope Signal During Marine Diagenesis; Implication for Reading the Ancient Record

旨在了解海洋成岩作用期间聚集同位素信号的行为；

• 批准号: 1635874
• 负责人: Peter Swart
• 金额: $ 39.95万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1635874&HistoricalAwards=false
• 关键词: Towards; understanding; Behaviour; Clumped; Isotope

Reconstruction of the chemical and physical conditions of Earth's early history is often accomplished by analyzing the chemical composition of shallow water sediments. A critical assumption made in such studies is that there have been no significant modifications of the sediments/rocks after they were deposited, and that whatever is measured represents the original conditions present when the sediments were formed. This project aims to test this critical assumption through the use of a relative new and novel geochemical technique, namely the clumped isotope method. Clumped isotopes are combinations of two or more of the rare isotopes of an element. This project will use the clumped isotope method to investigate modern marine sediments and the conditions under which these modern sediments are changed to rock. This will allow previously unavailable information to be obtained from the system under study, namely the temperature of formation. It will also allow an assessment of the chemical records that are used to interpret the early history of Earth. This project provides training for a graduate student as well as research opportunities for undergraduate and high schools students.Specifically, the researchers will measure clumping of C and O isotopes (delta47) in a variety of different types of modern carbonate sediments and trace this signature through recrystallization in the marine burial realm. Significant headway has already been made into characterizing the clumped isotopic signal in modern carbonate sediments of differing types, and preliminary data suggest a difference between skeletal and non-skeletal dominated sediments. The goals of this work are to: (i) examine in more detail the difference in the delta47 of various type of modern allochems and how these control the delta47 of the bulk sediments, and (ii) study the diagenetic behaviour using delta47 along transects at two different carbonate margins, one dominated by non-skeletal production (ODP Sites 1003, 1005, and 1006) located off the western margin of the Bahamas), and one dominated by skeletal sediments (Maldives (IODP Sites U1466-68) and/or the Great Barrier Reef (Sites 819- 823). These data will be compared with a pelagic site (Site 807). The rates of diagenesis using the delta47 will be modelled and compared with rates determined from other geochemical proxies, including Sr, Ca, and O isotopes. This work will build on 30 years of ODP cruises (Legs 101-359) and interactions and collaborations with young scientists using other novel tracers of diagenesis.

重建地球早期历史的化学和物理条件通常是通过分析浅水沉积物的化学成分来完成的。 此类研究中做出的一个关键假设是，沉积物/岩石在沉积后没有发生重大变化，并且无论测量到什么，都代表沉积物形成时存在的原始条件。该项目旨在通过使用相对较新的地球化学技术（即簇同位素方法）来测试这一关键假设。 簇同位素是一种元素的两种或多种稀有同位素的组合。 该项目将使用团块同位素方法来研究现代海洋沉积物以及这些现代沉积物转变为岩石的条件。这将允许从所研究的系统中获得以前无法获得的信息，即地层温度。 它还将允许对用于解释地球早期历史的化学记录进行评估。该项目为研究生提供培训，并为本科生和高中生提供研究机会。具体来说，研究人员将测量各种不同类型的现代碳酸盐沉积物中 C 和 O 同位素 (delta47) 的聚集，并通过以下方式追踪这一特征：海葬领域的再结晶。 在表征不同类型的现代碳酸盐沉积物中的聚集同位素信号方面已经取得了重大进展，初步数据表明骨骼和非骨骼主导沉积物之间存在差异。 这项工作的目标是：(i) 更详细地研究各种类型现代合金的 delta47 差异以及它们如何控制大块沉积物的 delta47，以及 (ii) 使用 delta47 沿横断面研究成岩行为两个不同的碳酸盐岩边缘，其中一个以非骨架生产为主（ODP 站点 1003、1005 和 1006），位于碳酸盐岩西部边缘巴哈马），以及以骨骼沉积物为主的一个（马尔代夫（IODP 站点 U1466-68）和/或大堡礁（站点 819-823）。这些数据将与远洋站点（站点 807）进行比较。成岩作用速率使用 delta47 进行建模并与其他地球化学替代物（包括 Sr、Ca 和 O）确定的速率进行比较这项工作将建立在 30 年的 ODP 航行（第 101-359 段）以及与年轻科学家使用其他新型成岩作用示踪剂的互动和合作的基础上。

项目成果

Oxygen Isotopic Exchange Between CO 2 and Phosphoric Acid: Implications for the Measurement of Clumped Isotopes in Carbonates

CO 2 和磷酸之间的氧同位素交换：对碳酸盐中聚集同位素测量的影响

• DOI: 10.1029/2019gc008209
• 发表时间: 2019-07
• 期刊: Geosystems
• 作者: Swart, Peter K.;Murray, Sean T.;Staudigel, Philip T.;Hodell, David A.
• 通讯作者: Hodell, David A.

Geochemical fingerprints of dolomitization in Bahamian carbonates: Evidence from sulphur, calcium, magnesium and clumped isotopes

巴哈马碳酸盐白云石化的地球化学指纹：来自硫、钙、镁和团块同位素的证据

• DOI: 10.1111/sed.12775
• 发表时间: 2020-08-13
• 期刊: Sedimentology
• 影响因子: 3.5
• 作者: S. Murray;J. Higgins;C. Holmden;Chaojin Lu;P. Swart
• 通讯作者: P. Swart

Cryogenic brines as diagenetic fluids: Reconstructing the diagenetic history of the Victoria Land Basin using clumped isotopes

低温盐水作为成岩流体：利用聚集同位素重建维多利亚陆地盆地的成岩历史

• DOI: 10.1016/j.gca.2018.01.002
• 发表时间: 2018-03-01
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: P. Staudigel;S. Murray;D. Dunham;T. Frank;C. Fielding;P. Swart
• 通讯作者: P. Swart

An abrupt Middle-Miocene increase in fluid flow into the Leeward Margin Great Bahama Bank, constraints from δ44Ca and Δ47 values

中中新世流入背风边缘大巴哈马浅滩的流体流量突然增加，受到 44Ca 和 47 值的限制

• DOI: 10.1016/j.epsl.2020.116625
• 发表时间: 2021-01
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Staudigel, Philip T.;Higgins, John A.;Swart, Peter K.
• 通讯作者: Swart, Peter K.

A diagenetic origin for isotopic variability of sediments deposited on the margin of Great Bahama Bank, insights from clumped isotopes

大巴哈马浅滩边缘沉积物同位素变异的成岩起源，来自团块同位素的见解

• DOI: 10.1016/j.gca.2019.05.002
• 发表时间: 2019-08-01
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: P. Staudigel;P. Swart
• 通讯作者: P. Swart