Ice sheet mass loss is adding to sea-level rise, and is expected to increase, but by how much and how fast remains uncertain. Isotopes produced in rock at the Earth’s surface provide records of past ice sheet thinning which help predict future change but are more effective if they are precise enough to determine past changes to the nearest thousand years. The precision of carbon-14, an isotope which is guaranteed to record past change since the last ice age, can be improved.

Conventional (U-Th)/He thermochronology requires accurate calculation of mineral grain volumes, often based on approximations to an ideal geometry. However, there are many instances where knowingly altering the geometry through polishing mineral grains for additional in situ data collection is desirable. This contribution provides a new method to calculate polished grain volume and other derived data for zircon (U-Th)/He thermochronology using no-added-cost modifications of existing workflows.

The uranium-thorium and uranium-lead radiometric dating methods are both capable of dating carbonate samples ranging in age from about 400,000 to 650,000 years.  Here we test agreement between the two methods by 'double dating' speleothems (i.e. secondary cave mineral deposits) that grew within this age range. We demonstrate excellent agreement between the two dating methods and discuss their relative strengths and weaknesses.

OCTOPUS v2.3 updates CRN Denudation datasets, adding 1,311 new river basins to the CRN International and Australia collections, totalling 5,611 basins with recalculated beryllium-10 denudation rates and 561 with aluminium-26 rates. New fields include basin centroid latitude, effective atmospheric pressure, glacier extent, and quartz-bearing lithology percentages, improving data quality and interoperability with online erosion calculators.

Accurate readings on the environmental gamma dose rate are important. Portable gamma-ray detectors, such as NaI or LaBr₃-based, are easy to handle and affordable. Limited information on alternatives, like CZT (Cadmium Zinc Telluride) detectors is available. We tested CZT detectors and found them suitable for in-field deployment. We used simulations and field tests to evaluate the optimal energy threshold for direct dose rate readings, making the CZT system a reliable alternative.

In this contribution we demonstrate in situ monazite Lu–Hf dating and compare results with U–Th–Pb dating. We present data from monazite reference materials and complex samples to demonstrate the viability of this method. We show that in situ Lu–Hf dating of monazite can resolve multiple age populations and may find use where the U–Th–Pb system is compromised by Pb-loss, non-radiogenic Pb contamination, excess 206 Pb, low U contents, or a combination of these factors.

This manuscript presents a new method to date geological events affecting sedimentary rocks. This method relies on the potential for the zircon U-Pb system to be disturbed during fluid-flow, alteration, and metamorphic events in sedimentary rocks. This manuscript presents synthetic datasets for testing the accuracy and precision of the discordance dating method, as well as data from detrital zircons found in the contact metamorphic aureole surround the Alta Stock.

Laser-based dating of rocks and minerals is invaluable in geoscience. This study presents a significant advancement in our ability to model and correct for a process called downhole fractionation (DHF) that can impact the accuracy and uncertainty of dates. We develop an algorithm that quantitatively models DHF patterns. The implications are far-reaching: improved accuracy, reduced uncertainty, and easier comparisons between different samples and laboratories.

We present the first new image-based study to reveal how choices made by different analysts affect the results obtained by fission-track analysis. Participants analyzed an identical image data set with varying grain quality. Experienced analysts tend to select lower rates of unsuitable grains and conduct lower rates of invalid length measurements. Fission-track studies need image data repositories, teaching modules, guidelines, an open science culture, and new approaches for calibration.

We use a method called cosmogenic nuclide dating on bedrock surfaces and moraine boulders to determine the relative length of time an alpine glacier was larger or smaller than its current extent over the past 15 thousand years. We also discuss several important limitations to this method. This method gives information on the duration of past ice advances and is useful in areas without other materials that can be dated.

We present a set of six standardized time-temperature histories, which we call benchmark paths, that can be used by the low-temperature thermochronology community to evaluate and visualize the sensitivity of thermochronologic systems to the variables inherent in the interpretation of thermochronologic data. As an example, we present a method for “tuning” each benchmark path to eleven published kinetics models (for the apatite (U-Th-Sm)/He, apatite fission-track, and zircon (U-Th)/He systems).

Age-depth models assign ages to sampling locations (e.g., in drill cores), making them crucial to determined timing and pace of past changes. We present two methods to estimate age-depth models from sedimentological and stratigraphic information, resulting in richer and more empirically realistic age-depth models. As a use case, we determine (1) the timing of the Frasnian-Famennian extinction and (2) examine the duration of PETM, an potential deep time analogue for anthropogenic climate change.

We performed a statistical analysis of high precision U-Pb zircon age distributions. This reveals that volcanic and porphyry zircon age distributions are skewed to younger ages, whereas plutonic age distributions are skewed to older ages. We show that this is caused  by truncation of zircon crystallisation by magma evacuation, rather than differences in magmatic flux. Our contribution has key implications for modelling of magma dynamics and eruption ages using zircon age distributions.

The timing of an ancient gravity slide that originated in the Marysvale volcanic field (Utah) is constrained using ⁴⁰Ar/³⁹Ar dating of pseudotachylyte, a friction-induced glass that is generated during slide movement, and the volcanic tuffs that were displaced by the slide and those that overly the slide mass. Our results suggest that the Sevier gravity slide occurred at 25.25 Ma. The removal of such a large volume of material likely allowed for the eruption of the Antimony Tuff at 25.19 Ma. 

The equatorial Pacific is an important region that helps determine Earth's climate. This work presents new age models for two sediment core sites located in that region, spanning the last 280 ka. Our age models are based on new radiocarbon dates and oxygen isotope measurements. We also use the oxygen isotope data to infer changes in sea surface salinity patterns, finding evidence for a change in the position of the Intertropical Convergence Zone (ITCZ) on glacial/interglacial timescales.