Welcome to the Uranium Isotope Database (UID)
The UID is a comprehensive, freely accessible, updatable, and internally consistent uranium isotope database.
We created it for the benefit of the entire community, so feel free to use it! It contains virtually all published 238U/235U data, and is being updated regularly.
Please reference it as Li H. & Tissot F.L.H. (2023) UID: the uranium isotope database.
Download the UID (xslx, 9.9 MB), updated Mar 31st, 2024 (v2.0.9).Changelog (excel file, 90 KB).If you wish to contribute to the UID, or have questions or corrections, contact uid@caltech.edu.
Motivation
In 1939, Alfred O. Nier reported the first analysis of the isotopic composition of uranium (U), the heaviest primordial element, establishing the 238U/235U ratio as 139 (± 1%). Since this pioneering work, the study of U isotopes has found applications in a wide variety of fields including geo/cosmochronology, oceanic paleoredox reconstruction, magmatic differentiation, environmental remediation, and forensic studies.
Today, tens of new papers every year report collectively more than a thousands new U isotopic data each year. With each new paper, the need for a comprehensive, up to date, U isotope database kept on increasing. The UID is our attempt at addressing this need. It aims to gather all published 238U/235U data, as well as any supporting sample metadata to facilitate data contextualization and interpretation. We hope you will find it useful!
Structure and main features
The UID consists of 10 spreadsheets.
The first six, named Standard, Terrestrial, Meteorites, Experimental, Forensic, and Precision, are subdatabases containing the U isotopic data. These categories were chosen to be as independent and unambiguous as possible, and they are non-overlapping, meaning that no data is duplicated between sub-databases.
The remaining four tabs, named References, Assumptions, Spike, and Constants, provide supplementary information for the database.
Data consistency — All data are normalized to the widely-used CRM-145 standard, and all assumptions used to convert the published data are explicitly detailed in Li & Tissot (2023), and the database itself.
Metadata — For each sample in the database, the UID includes not only the U isotope data, but also all other sample data from the original publications, as well as the relevant metadata and sample information to facilitate further analysis.
Updatable and up-to-date — The be most useful, the UID is being regularly updated. Although we took great care to faithfully incorporate all data as reported in the literature, some typos might have made their way in the UID. Let us know if you find any such issue, or if anything else needs to be modified. and we will correct these rare problems immediately.
Research supported by a FINESST NASA grant 80NSSC20K1398 (PI: F.L.H.T., FI: H.L.), NSF grants EAR-1824002 and MGG-2054892, a Packard Fellowship and start-up funds provided by Caltech.