Investigating effects of aqueous speciation in 13C-18O clumping and its implications for paleothermometry

最近建立的“团块同位素”古温度表是基于碳酸盐矿物中的碳13 -氧18键丰度。尽管这一技术的应用越来越广泛，但控制生物矿物和非生物形成矿物地球化学特征的潜在过程仍然存在许多问题。本项目将解决其中几个悬而未决的问题。研究人员将比较理论计算和实验结果与观察结果，包括缓慢生长的自然样本，如魔鬼洞洞穴和不同矿物学的深海珊瑚。这项工作将提高在地表和地下系统中使用团块同位素的能力，并确定该技术的局限性。这项工作将在加州大学洛杉矶分校的年度物理科学推广日上得到强调，该日将吸引2000-3000名公众来到校园，并吸引数百人参加展览。该项目的所有参与者还将与学校儿童一起开展矿物沉淀活动，作为PI运行的常规外展计划的一部分。该项目的支持将有利于早期职业PI，他正在建立一个NSF支持的最先进的同位素实验室，并致力于招募，指导和支持来自不同背景的杰出早期职业科学家，从而进一步推动NSF支持地球科学中代表性不足群体的目标。

The recently established "clumped isotope" paleothermometer is based on the Carbon 13 - Oxygen 18 bond abundance in carbonate minerals. Although this technique is becoming more widely used, there are still many questions about the underlying processes that control geochemical signatures in bio-minerals and non-biologically formed minerals. This project will address several of these outstanding questions. Investigators will compare results from theoretical calculations and experiments to observations, including from slowly-grown naturally occurring samples such as the Devils Hole speleothem and deep-sea corals of variable mineralogy. This work should improve the ability to employ clumped isotopes in surface and subsurface systems, and identify the limitations of this technique. This work will be highlighted in UCLA's annual Physical Sciences Outreach Day that brings 2000-3000 members of the public to the campus and a few hundred people to the exhibits. All of the participants in this project will also conduct a mineral precipitation activity with school children as part of a regular outreach program the PI runs. Support of this project will benefit an early career PI who is establishing a NSF-supported state-of-the-art isotope lab and is committed to recruiting, mentoring, and supporting outstanding early career scientists from diverse backgrounds, thus furthering NSF's goals to support underrepresented groups in the Earth Sciences.