Synchrotron Data - Uvarova 8992 (Mar 2015) - Uranium speciation in uranium ore minerals from various types of U deposits insight into redox evolution through geologic time

We propose to study natural uraninites and other co-occurring uranium minerals sampled from uranium mineralisation across the globe to better understand early Earth’s oxidation history. Uranium is a redox sensitive element that can record subtle changes in oxygenation over geological time. The redox record is preserved in the U6+/U4+ ratio in
natural uraninite and associated minerals. By measuring the U6+/U4+ ratio in-situ utilizing XANES mapping with the Maia detector on the XFM beamline the proposed experiment will improve our understanding of the redox state of uranium in natural samples, allowing reconstruction of their physio-chemical conditions of formation.

我们拟研究采自全球铀矿化区的天然晶质铀矿及其他共生铀矿物，以深入理解地球早期的氧化历史。铀是一种氧化还原敏感元素（redox-sensitive element），能够记录地质历史时期氧含量的细微变化。该氧化还原记录保存在天然晶质铀矿及伴生矿物中的U6+/U4+比值中。本实验拟利用XFM光束线上配备Maia探测器的X射线吸收近边结构（XANES）成像技术原位测量U6+/U4+比值，以提升我们对天然样品中铀氧化还原状态的理解，进而重建其形成时的物理化学条件。