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RA138 is a new reference material for U-Pb dating of carbonate samples via LA-ICP-MS. RA138 exhibits variable U/Pb ratios and consistent U content, resulting in a precise isochron with low uncertainty. ID-TIMS analyses fix a reference age of 321.99 ± 0.65 Ma. The observed systematic uncertainty challenges previous estimates. This research advances our ability to date carbonate samples accurately, providing deeper insights into geological processes and historical timelines.

We present a new data analysis workflow for thermochronological data based on plots of radiogenic daughter vs. radioactive parent concentration. The daughter-parent relationship helps to identify the sources of age variation. Our workflow classifies the daughter-parent relationship and provides further suggestions, e.g., if a dataset can be described by a sample age and which type of sample age to report.

The age of some geological materials can be estimated from the ratio of certain radiogenic 'daughter' isotopes to their radioactive 'parent'. However, in many cases, the age estimation process is complicated by the presence of an inherited component of nonradiogenic daughter isotopes. This paper presents an improved algorithm to estimate the radiogenic and non-radiogenic components, either separately or jointly.

This note details a development of the (U-Th)/He method for dating apatite crystals in low-temperature thermochronology. Our innovation simplifies analysis protocols for gases (He) and crystals (U, Th, etc.), aiming to expedite data production and enhance study reliability.

We introduce a new statistical method for determining the time of "peak cooling" in thermochronological inversions. Specifically, we focus on the time-temperature paths that intersect the half-maximum cooling isotherm, signifying the zenith or most rapid cooling within a defined interval. The resultant interpolated time distribution provides a systematic metric, particularly applicable for evaluating model cooling characterized by relatively smooth histories featuring a single inflection point.

We have discovered a new way of measuring the three-dimensional distribution of radioactive elements in individual crystals by shining a very bright light on apatite crystals at the Advanced Photon Source at Argonne National Laboratory. This allows us to learn about the rates and timing of geologic processes, and to help resolve problems that previously were unsolvable because we had no way to make this type of measurement.

Establishing an etching procedure for the monazite fission track (MFT) is essential for MFT dating. In this short communication, we have investigated the parameters governing the etching rate of MFT, in particular the effect of radiation damage. Our results show an inverse relationship between MFT etching time and the degree of radiation damage. We show that existing etching recipes may not sufficiently etch MFT of young monazite, advocating the importance of a revision of etching methods.

Decay of U to Pb in the mineral baddeleyite is used for precisely dating mafic rocks, but some daughter Pb atoms can be ejected out of the crystal, resulting in an age that appears too young. Atom Probe Tomography was used to map the distribution of U and Pb atoms in 3 dimensions within a baddeleyite crystal and estimate the average distance that Pb atoms are displaced by decay of U. This allows us to correct the measured age on a baddeleyite crystal knowing its size and shape.

Radiocarbon serves as powerful dating tool, but there remain significant challenges in the calibration of marine radiocarbon dates. This is because the whole surface ocean cannot be represented by a single calibration curve. Here we use climate model outputs to assess a novel method for developing regional marine calibration curves. Our results are encouraging, particularly for the high latitude regions, and point a way forward for solving the marine radiocarbon age calibration problem.

This paper describes how krypton isotopes produced by nuclear fission can be used to determine the age of microscopic particles of used nuclear fuel. This is potentially useful for international safeguards applications aimed at tracking and identifying nuclear materials, as well as geoscience applications involving dating post-1950's sediments or understanding environmental transport of nuclear materials.

We study the use of zircons as dosimeters using modern techniques, highlighting their advantages such as time-invariant dose rates. We explore the correlation between zircon geochemistry and luminescence properties, observe fast zircon optically stimulated luminescence (OSL) bleaching rates, and assess the potential of auto-regeneration. Low OSL sensitivities require combining natural OSL and auto-regenerated thermoluminescence (TL), with the potential to enhance age accuracy and precision.

The Multiple Diffusion Domain (MDD) model quantifies the temperature dependence of noble gas diffusivity in minerals. However, current methods for tuning MDD parameters can yield biased results, leading to underestimates of sample temperatures through geologic time. Our "MDD Tool Kit" software optimizes all MDD parameters simultaneously, overcoming these biases. We then apply this software to a previously published ⁴⁰Ar/³⁹Ar dataset (Wong, 2023) to showcase its efficacy.

The (U-Th)/He dating method helps understand rock’s cooling history. Synthetic modeling experiments were conducted to explore factors affecting in-situ vs. whole-grain (U-Th)/He dates. In-situ dates are often 30 % older than whole-grain dates, whereas very rapid cooling makes helium loss negligible, resulting in similar whole-grain and in-situ dates. In addition, in-situ data can reveal cooling histories even from a single grain by measuring helium distributions.