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.

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.

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.

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 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.

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. 

We present an approach to U-Pb dating of carbonates using isotopic image maps. The maps are divided into squares called virtual spots. For each virtual spot, statistical values (mean, uncertainty) are used to determine the age. The user can modify the size and location of the virtual spots and select those that give the most robust age. This approach, applied to high spatial resolution images, makes it possible for the first time to obtain satisfactory ages on images as small as 100 µm x 100 µm.

Sediment generation on hillslopes and transport through river networks are complex processes that influence landscape evolution. In this study compiled sand from over 600 river basins and measured its (very subtle) radioactivity to unravel timelines of sediment routing around the world. With this data we empirically confirm that sediment from large lowland basins in tectonically stable regions typically experiences long periods of burial, while sediment moves rapidly through small upland basins.

We apply luminescence dating of feldspars to establish a geochronological framework for the sequence of accretionary hillslope deposition at Jojosi, which contain important archaeological artefacts. We test and evaluate four different dose models and their applicability to single grain and multi-grain data sets containing up to 67 % saturated grains. Our results constrain erosional and depositional processes from 100–700 ka, and human occupation of the area in the early MIS 5 and late MIS 6.

This article presents a non-destructive method for studying laminated sediments with X-ray computed tomography (μCT). It aims to study the possibility of using μCT as an analytical tool to analyse varved sediments in the context of paleoclimatic studies. As results, µCT offers the possibility of to do fasts analysis and constitutes a powerful tool to improve the quality of results through the access of a 3D view allowing choosing the most representative part of varved record.

We have built a database of (U-Th)/He ages and U and Th contents of goethites from various weathering environments. The database contains 2597 (U-Th)/He ages of goethites from 10 countries. The findings presented in this manuscript contribute insights onto the distribution of dated goethites from different environments globally and into the Earth's Cenozoic weathering history.

Sedimentary rocks are typically dated indirectly, by comparing the fossil content of basins with the geological timescale. In this study, we employed an absolute dating approach to date 19 million year old sediments in the Paris Basin, using uranium-lead dating of calcite nodules associated with soil formation. The precision of our new ages enable more accurate comparisons (independent of their fossil contents) between the Paris Basin and other basins of similar age.

To investigate the Laurentide Ice Sheet’s erosivity before and during the Last Glacial Maximum, we sampled sand deposited by ice in eastern Canada before final deglaciation. We also sampled modern river sand. The ²⁶Al and ¹⁰Be measured in glacial deposited sediments suggests that ice remained during some Pleistocene warm periods and was an inefficient eroder. Similar concentrations of ²⁶Al and ¹⁰Be in modern sand suggests that most modern river sediment is sourced from glacial deposits. 

We obtained a cosmogenic ³He (³He_c) exposure age of 10.9 ka ± 1.1 ka for the youngest lava flow at Volcano Mountain (VM) in Yukon, Canada. Initially, olivine grains from the flow were crushed to release mantle He from fluid inclusions and subsequently fused to release ³He_c from the matrix. However, mantle He was significantly retained in fusions. We circumvented this problem by step-heating powdered olivine at three temperature steps, where the lowest temperature step successfully isolated ³He_c.

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.

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.

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.

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.

We investigate the relationship between damage trails from uranium fission in apatite and the etched tracks measured with an optical microscope. We aim to understand sampling biases and to improve etching, selection and measurement protocols. The track orientation and length, apatite and track etch rate, and effective etch time co-determine whether a track is suitable for measurement. Reliable data are attainable because the specific sample properties have but a limited effect on these factors.

As a result of increasing precision and accuracy in geochronology, interpreting complicated age spectra has become increasingly important, since individual mineral ages often do not directly date the actual geologic process of interest. Here we propose a method for estimating the age of eruption or deposition of a set of minerals dated by the U-Pb system which, in contrast to previous approaches, remains accurate even when the dated minerals have experienced loss of the daughter product Pb.

Volcanic ash layers are a common tool to synchronize records of past climate, and their estimated age relies on external dating methods. Here, we show that the chemical composition of the well-known, 12000 year-old Vedde Ash is indistinguishable with several other ash layers in Iceland that are ~1000 years younger. Therefore, chemical composition alone cannot be used to identify the Vedde Ash in sedimentary records.

The Great Unconformity represents an enormous amount of time lost from the sedimentary record. Its origin is debated, in part, due to different approaches used to interpret zircon (U–Th)/He ages. This thermochronometric system is ideal for this problem because the temperature sensitivity varies according to radiation damage. Here we explore the uncertainty associated with the radiation damage model and show how this limits our ability to resolve the origin of the Great Unconformity.

We proposed a new non-destructive mineralogical methodology on inframilimetric grains that allows to quantify the hematite and goethite content and hematite/goethite ratio of grains prior to (U-Th)/He geochronological analysis. (U-Th)/He data performed on different aliquots with different acquisition time shows no remarkable differences in age, opening a new way to investigate the (U-Th)/He data evolution in supergene lateritic duricrusts.

Paleomagnetic data from Cascade Lake (Brooks Range, Alaska) extend the radiometric-based age model of the sedimentary sequence extending back 21 kyr. Correlated ages based on prominent features in paleomagnetic secular variations (PSV) diverge from the radiometric ages in the upper 1.6 m, by up to about 2000 years at around 4 ka. Four late Holocene cryptotephra in this section support the PSV chronology and suggest the influence of hard water or aged organic material.

Prehistoric volcanic eruptions are often dated by wiggle matching series of radiocarbon ages on tree rings to standard calibration curves, ignoring potential contamination by 'old' carbon given off by the volcano. We modeled the effects of low amounts of contamination on wiggle match dates for the 10th century Changbaishan eruption and found evidence of contamination in all. We propose a new protocol to identify the presence of contamination, and provide more secure dates for major eruptions.

The timing and duration of fluid activity within a gold deposit enables a greater understanding of how the deposit evolved and thus help future mineral exploration. This research uses high resolution dating methods to unravel the overprinting fluid activity at the Martabe gold field in Sumatra. Methods outline in this report can be applied to deposits globally.

Potassium-based geochronology, including the ⁴⁰Ar/³⁹Ar and K-Ar methods, provides critical constraints on the timing and duration of many events and processes in earth history. These methods assume that a key parameter, the fraction of potassium with a mass of 40, does not vary in some relevant materials. Some recent work has identified some variability in these materials. This work examines the effects of this variability on calculated K-Ar and ⁴⁰Ar/³⁹Ar ages.