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

最近建立的“块状同位素”古温度计是基于碳酸盐矿物中碳13-氧18键的丰度。尽管这项技术正在得到越来越广泛的应用，但关于控制生物矿物和非生物形成矿物中的地球化学特征的潜在过程仍然存在许多问题。该项目将解决其中几个悬而未决的问题。研究人员将把理论计算和实验的结果与观测结果进行比较，包括从魔鬼洞洞穴和各种矿物学的深海珊瑚等缓慢生长的自然发生样本中获得的结果。这项工作将提高在地表和地下系统中使用块状同位素的能力，并确定这项技术的局限性。这项工作将在加州大学洛杉矶分校一年一度的物理科学推广日上得到强调，届时将有2000-3000名公众来到校园，数百人参观展览。该项目的所有参与者还将与在校儿童一起进行矿物沉淀活动，这是国际和平协会开展的定期推广计划的一部分。对这个项目的支持将使一位早期职业PI受益，他正在建立一个由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优秀早期职业科学家，从而促进NSF支持地球科学中代表性不足的群体的目标。

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.