The North American Varve Chronology (NAVC) is a sequence of 5659 annual sedimentary layers that were deposited in proglacial lakes adjacent to the retreating Laurentide Ice Sheet ca. 12 500–18 200 years ago. We attempt to synchronize this record with Greenland ice core and other climate records that cover the same time period by detecting variations in global fallout of atmospherically produced beryllium-10 in NAVC sediments.

This contribution presents a new reference material, ASH-15 flowstone with an age of 2.965 ± 0.011 Ma (95 % CI), to be used for in situ U–Pb dating of carbonate material. The new age analyses include the use of the EARTHTIME isotopic tracers and a large number of sub-samples (n = 37) with small aliquots (1–7 mg) each that are more representative of laser-ablation spot analysis. The new results could improve the propagated uncertainties on the final age with a minimal value of 0.4 %.

In this study, we built a statistical model to determine the initial δ²³⁴U in submerged calcite crusts that coat the walls of Devils Hole 2 (DH2) cave (Nevada, USA) and, using a ²³⁴U–²³⁸U dating method, extended the chronology of the calcite deposition beyond previous well-established ²³⁰Th ages and determined the oldest calcite deposited in this cave, a time marker for cave genesis. The novel method presented here may be used in future speleothem studies in similar hydrogeological settings.

Unetched and etched apatite grains from five samples were dated by U–Pb method using laser ablation inductively coupled plasma mass spectrometry. Our experiment indicates that etching needed for apatite fission track dating has insignificant effects on obtaining accurate U–Pb ages; thus, the laser ablation-based technique may be used for apatite fission track and U–Pb double dating.

A new methodology for the micron-scale uranium–lead dating of carbonate minerals is proposed. It is based on the extraction of ages directly from pixel images (< 1 mm²) obtained by laser ablation coupled to a mass spectrometer. The ages are calculated with a robust linear regression through the pixel values. This methodology is compared to existing approaches.

We present the results of a series of experiments that constrain the temperature sensitivity of fission tracks in monazite over geological time. It is concluded that over a heating duration of 10 million years, the estimated closure temperature is < 50 °C and perhaps not much above ambient surface temperatures. Monazite fission track thermochronology has the potential to understand the thermal history and constrain the timing of geological processes in the Earth’s upper crust (< 1–2 km).

We characterize three natural carbonate samples with elevated uranium/lead (U/Pb) ratios to demonstrate techniques improving the understanding of U incorporation in carbonates for U/Pb dating. With the rapidly accelerating application of laser ablation analyses, there is a great need for well-characterized reference materials that can serve multiple functions. Strontium (Sr) isotope analyses and U XANES demonstrate that these samples could be used as reference materials.

This work presents LA-ICP-MS U–Pb geochronology of epidote in hydrothermal veins. The challenges of epidote dating are addressed, and a protocol is proposed allowing us to obtain epidote U–Pb ages with a precision as good as 5 % in addition to the initial Pb isotopic composition of the epidote-forming fluid. Epidote demonstrates its potential to be used as a U–Pb geochronometer and as a fluid tracer, allowing us to reconstruct the timing of hydrothermal activity and the origin of the fluid(s).

This paper describes geoChronR, an R package that streamlines the process of quantifying age uncertainties, propagating uncertainties through several common analyses, and visualizing the results. In addition to describing the structure and underlying theory of the package, we present five real-world use cases that illustrate common workflows in geoChronR. geoChronR is built on the Linked PaleoData framework, is open and extensible, and we welcome feedback and contributions from the community.

Coastal deposits can help us reconstruct the timing of climate-induced changes in the rates of past landscape evolution. In this study, we show that consistent ages for Holocene beach shorelines can be obtained by dating driftwood deposits. This finding is surprising, as the wood travels long distances through river systems before reaching the Arctic Ocean. The possibility to establish precise age control is a prerequisite to further investigate the regional drivers of long-term coastal change.

We compare two published U–Pb and ⁴⁰Ar / ³⁹Ar geochronologic datasets to produce eruption rate models for the Deccan Traps large igneous province. Applying the same approach to each dataset, the resulting models agree well, but the higher-precision U–Pb dataset results in a more detailed eruption model than the lower-precision ⁴⁰Ar / ³⁹Ar data. We explore sources of geologic uncertainty and reiterate the importance of systematic uncertainties in comparing U–Pb and ⁴⁰Ar / ³⁹Ar datasets.

To explore the U–Pb geochronometer in fluorite, the spatial distribution of uranium and other substituted elements in natural crystals is investigated using induced fission-track and synchrotron radiation X-ray fluorescence mapping. LA-ICP-MS U–Pb dating on four crystals, which preserve micrometer-scale variations in U concentrations, yields identical ages within analytical uncertainty. Our results show that fluorite U–Pb geochronology has potential for dating distinct crystal growth stages.

This paper demonstrates how to model optically stimulated luminescence (OSL) and radiocarbon ages in a Bayesian framework, using a dedicated software tool called BayLum. We show the effect of stratigraphic constraints, of modelling the covariance of ages when the same equipment is used for a series of OSL samples, and of including independent ages on a chronological inference. The improvement in chronological resolution is significant.

This paper shows that the current practice of filtering discordant U–Pb data based on the relative difference between the ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²⁰⁶Pb ages is just one of several possible approaches to the problem and demonstrably not the best one. An alternative approach is to define discordance in terms of isotopic composition, as a log ratio distance between the measurement and the concordia line. Application to real data indicates that this reduces the positive bias of filtered age spectra.

We carried out thermal annealing experiments between 500 and 1000 °C to determine the closure temperature of radiation-damage annealing in zircon (ZrSiO₄). Our results show that the different Raman bands of zircon respond differently to annealing. The repair is highest for the external rotation Raman band near 356.6 cm⁻¹. The closure temperature estimates range from 250 to 370 °C for different bands. The differences in closure temperatures offer the prospect of multi-T zircon Raman dating.

High-resolution geochronology is one of the key factors to predict volcanic eruptions. To build up a high-resolution geochronological framework, we reported 21 new high-precision eruption ages (⁴⁰Ar / ³⁹Ar) for a ~ 3.3 × 10⁶-year-old volcanic field: Milos (Greece). In combination with geochemical information and eruption volumes from the volcanoes of Milos, the long-lived volcanic history could provide important clues for the prediction of volcanic eruptions.

Our contribution enhances the infrared radiofluorescence dating technique, used to determine the last sunlight exposure of potassium feldspars in a range of about 600 to 600 000 years backwards. We recorded radiofluorescence images of fine sands and processed them with tailored open-source software to obtain ages from single grains. Finally, we tested our new method successfully on two natural sediment samples. Studies in Earth science will benefit from improved age accuracy and new insights.

We generated a synthetic dataset applying published kinetic models and distinct annealing kinetics for the apatite fission track and (U–Th)/He methods using a predetermined thermal history. We then tested how well the true thermal history could be recovered under different data interpretation schemes and geologic constraint assumptions using the Bayesian QTQt software. Our results demonstrate that multikinetic data increase time–temperature resolution and can constrain complex thermal histories.

Distinguishing between different dolomitization processes is challenging yet critical for resolving some of the issues and ambiguities related to the formation of dolomitic rocks. Accurate U–Pb absolute dating of dolomite by LA-ICP-MS could contribute to a better understanding of the dolomitization process by placing syngenetic, early diagenetic, and/or epigenetic events in the proper geological context.

Apatite and zircon (U–Th) / He thermochronology is now a mainstream tool to reconstruct Earth's evolution through the history of cooling and exhumation over the first dozen kilometers. The geological implications of these data rely on the precision of measurements of He, U, Th, and Sm contents in crystals. This technical note documents the methods for He thermochronology developed at the GEOPS laboratory, Paris-Saclay University, that allow (U–Th) / He data to be obtained with precision.

Luminescence dating requires irradiating the sample in the laboratory. Here, we address some concerns about the reliability of the calibration procedure that have been published recently. We found that the interplay between geometrical parameters such as grain size and aliquot size impacts the calibration value more than previously thought. The results of our study are robust and allow us to recommend an improved calibration procedure in order to enhance the reliability of the calibration value.

Artificial intelligence techniques are capable of automatically detecting fission tracks in minerals. The AI-Track-tive software presented here can be used to automatically determine fission track densities for apatite fission track dating studies. Apatite fission track dating is mainly applied to tectonic research on exhumation rates in orogens. Time-consuming manual track counting can be replaced by deep neural networks capable of automatically finding the large majority of tracks.