ABSTRACT The participants of the 12 th International Atomic Energy Agency (IAEA) meeting on stable isotope reference materials reached a consensus, acknowledging the existence and use of two carbon isotope delta scales: the VPDB (Vienna Peedee belemnite) scale and the VPDB‐LSVEC (LSVEC ‐ lithium carbonate prepared by H. J. Svec). Conversion models between the two scales can be established and used but introduce uncertainty. A format for isotope delta scale definition was agreed upon and was used to define the two …

Due to legal requirements on international imports, it is important for law enforcement and regulatory agencies to identify the geographical provenance of timber. Current methods for geographic identification utilize data generated by direct analysis in real time time-of-flight mass spectrometry (DART TOFMS), genetics, and isotope-ratio mass spectrometry (IRMS), but identification methods based on genetics and IRMS data require months to years to create usable databases. This study used machine learning algorithms…

This data publication contains analytical data from direct analysis in real time time-of-flight mass spectrometry (DART TOFMS), inductively coupled plasma mass spectrometry (ICP-MS), and handheld laser-induced breakdown spectroscopy (LIBS) collected from five populations of Pinus ponderosa located 14 to 72 kilometers apart in Oregon between October 2021 and February 2025. These data were generated to assess the effectiveness of these techniques paired with machine learning models in determining the geographical pr…

Rationale Vein calcite in Devils Hole has been precipitating continuously in oxygen‐isotope equilibrium at a constant temperature for over 500 000 years, providing an unmatched δ 18 O paleoclimate time series. A substantial issue is that coeval calcite (based on matching δ 18 O values) has uranium‐series ages differing by 12 000 years. Methods An unparalleled high‐accuracy δ 18 O chronology series from continuously submerged calcite was used to correct the published uranium‐series ages of non‐continuously formed c…

Abstract Following the reviews of atomic-weight determinations and other cognate data in 2015, 2017, 2019 and 2021, the IUPAC (International Union of Pure and Applied Chemistry) Commission on Isotopic Abundances and Atomic Weights (CIAAW) reports changes of standard atomic weights. The symbol A r °(E) was selected for standard atomic weight of an element to distinguish it from the atomic weight of an element E in a specific substance P, designated A r (E, P). The CIAAW has changed the values of the standard atomic…