Recent  

Cosmogenic nuclide exposure dating is an exceptional tool for reconstructing glacier histories, but reconstructions based on common target nuclides (e.g., ¹⁰Be) can be costly and time consuming to generate. Here, we present a low-cost proof-of-concept ²¹Ne exposure age chronology from Lassen Volcanic National Park, CA, USA that broadly agrees with nearby ¹⁰Be chronologies but at lower precision.

A standalone data analysis application for Th/U dating on multi-collector inductively coupled plasma mass spectrometers features a Python-based algorithm with a graphical user interface. It handles data treatment, corrections, age calculus, and error estimation and supports various detector layouts including Faraday and electron multiplier detectors. Key features include reproducibility, user-friendly reanalysis, and automated data storage. A case study demonstrated the software’s performance.

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.

Understanding how volcanic landscapes, such as Iceland, grow and evolve through time is important for constraining the role volcanism plays in driving variations in geography, climate, and ocean circulation. Here we provide a new method for determining the timescales of volcanic terrain construction using argon geochronology on individual grains of Icelandic sand. This allows us to determine the timing of volcanic eruptions along drainage basins using a small number of strategic sampling sites.

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.

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.

Goethite is one of the most common Fe- (oxy)hydroxide minerals which is formed during hydrolyzation of the rocks, implying it is a desired mineral for dating various surface and subsurface geological processes. Nowadays (U-Th)/He dating of goethite is widely used in geochronological studies. Here, on the example of goethite from the Chukchi Borderland, we introduce a new simple methodological approach for accurate (U-Th)/He dating of goethite.

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.

Cosmogenic nuclide geochronology requires accurately scaling production rates with altitude. The energy spectrum of cosmic radiation changes with altitude and reactions that are sensitive to different energies may have different scaling behavior. Here, we model the altitude scaling of ³⁶Cl production from Fe and evaluate this model against calibration data. The data are broadly consistent with the prediction of larger altitude scaling factors for ³⁶Cl from Fe than for other reactions.

We present an improved workflow for extracting and measuring chlorine isotopes in rocks and minerals. Experiments on seven geologic samples demonstrate that our workflow provides reliable results while offering several distinct advantages over traditional methods. Most notably, our workflow reduces the amount of isotopically enriched chlorine spike used per rock sample by up to 95 %, which will allow researchers to analyze more samples using their existing laboratory supplies.