Collaborative Research: Refining Geothermobarometry in Pyroxenes using In Situ Measurements of Fe3+

合作研究：利用 Fe3 的原位测量改进辉石中的地温气压测量

基本信息

批准号：
1754268
负责人：
Molly McCanta
金额：
$ 14.6万
依托单位：
University of Tennessee Knoxville
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2023-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1754268&HistoricalAwards=false
关键词：
Collaborative Research Refining Geothermobarometry Pyroxenes

项目摘要

This project promotes the progress of science by providing calibrations for use at a national facility, the Advanced Photon Source at Argonne National Laboratory; these results will also be useful for users of other synchrotron facilities worldwide. The calibrations address the scientific question of how much oxygen was present when a mineral crystallized by analyzing a proxy, which is the oxidation state of the multivalent element iron. This understanding has vital importance for understanding how oxygen controls the crystallization path and composition of cooling magmas, also providing insight into processes that may have operated on and in the magma as it moved to the surface. Graduate and undergraduate students at Mount Holyoke College, the University of Tennessee at Knoxville, and the University of Idaho will be supported by this project, including at least three women. The ability to measure redox states at sub-nm and pm scales is a formidable analytical challenges due to the inherent anisotropy of most rock-forming minerals, which causes their crystal structures to interact with photons differently according to crystal orientation. This project studies oriented single crystals to explore the effects of crystallographic orientation on x-ray absorption spectroscopy measurements, focusing on the pyroxene mineral group, one of the most common phases in igneous rocks. The team will use these data to build a universal calibration appropriate for quantifying the partial pressure of oxygen (oxygen fugacity) in pyroxene-bearing samples. This work has the potential to advance knowledge in multiple geological disciplines. It will also enable synchrotrons around the world that use the Athena software package to quickly and easily determine Fe3+ contents of pyroxene minerals with known precision and accuracy. Finally, this project applies machine learning techniques to the study of spectroscopic data. Development of this methodology is exportable to other fields, such as medical, biological, and forensic uses of spectroscopy, where it has the potential for societal impact.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目通过提供国家设施（阿贡国家实验室高级光子源）使用的校准来促进科学进步；这些结果也将对全球其他同步加速器设施的用户有用。通过分析代理（多价元素铁的氧化态），校准解决了矿物结晶时存在多少氧气的科学问题。这种理解对于理解氧气如何控制冷却岩浆的结晶路径和成分至关重要，还可以深入了解当岩浆移动到地表时可能在岩浆上和岩浆中进行的过程。曼荷莲学院、田纳西大学诺克斯维尔分校和爱达荷大学的研究生和本科生将得到该项目的支持，其中至少包括三名女性。由于大多数造岩矿物固有的各向异性，导致其晶体结构根据晶体方向与光子的相互作用不同，因此测量亚纳米和微米尺度的氧化还原态的能力是一项艰巨的分析挑战。该项目研究定向单晶，探讨晶体定向对 X 射线吸收光谱测量的影响，重点关注火成岩中最常见的相之一——辉石矿物组。该团队将利用这些数据建立适合量化含辉石样品中氧分压（氧逸度）的通用校准。这项工作有可能增进多个地质学科的知识。它还将使世界各地使用 Athena 软件包的同步加速器能够以已知的精度和准确度快速、轻松地测定辉石矿物中的 Fe3+ 含量。最后，该项目将机器学习技术应用于光谱数据的研究。这种方法的开发可以输出到其他领域，例如光谱学的医学、生物和法医应用，这些领域具有潜在的社会影响。该奖项反映了 NSF 的法定使命，并通过使用基金会的知识进行评估，被认为值得支持。优点和更广泛的影响审查标准。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Wave vector and field vector orientation dependence of Fe K pre-edge X-ray absorption features in clinopyroxenes

单斜辉石中 Fe K 前边 X 射线吸收特征的波矢量和场矢量方向依赖性

DOI：
10.2138/am-2022-8547
发表时间：
2023-01
期刊：
American Mineralogist
影响因子：
3.1
作者：
Steven, CJ;Dyar, MD;McCanta, MC;Newville, M;Lanzirotti, A
通讯作者：
Lanzirotti, A

The absorption indicatrix as an empirical model to describe anisotropy in X-ray absorption spectra of pyroxenes

吸收指示体作为描述辉石 X 射线吸收光谱各向异性的经验模型

DOI：
10.2138/am-2021-7950
发表时间：
2022-04
期刊：
American Mineralogist
影响因子：
3.1
作者：
Steven, Cody J.;Dyar, M. Darby;McCanta, Molly;Newville, Matthew;Lanzirotti, Antonio
通讯作者：
Lanzirotti, Antonio

Effects of oxidation on pyroxene visible-near infrared and mid-infrared spectra

氧化对辉石可见-近红外和中红外光谱的影响