Recent  

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.

Cosmogenic nuclides, such as ¹⁰Be, are rare isotopes produced in rocks when exposed at Earth’s surface and are valuable for understanding surface processes and landscape evolution. However, ¹⁰Be is usually measured in quartz minerals. Here we present advances in efficiently extracting and measuring ¹⁰Be in the pyroxene mineral. These measurements expand the use of ¹⁰Be as a dating tool for new rock types and provide opportunities to understand landscape processes in areas that lack quartz.

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 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.

This study demonstrates the utility of the recently developed laser ablation-based Rb-Sr geochronology methodology to investigate the rates of exhumation and burial in active mountain building systems. It is further demonstrated that additional chemical data collected during spot analyses can be used to determine temperatures recorded in biotite. The method used has advantages over traditional methods in speed, ease of acquisition and the ability to collect additional chemical information.

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.

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.

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 date Laurentide Ice Sheet retreat after the Last Glacial Maximum in western New York, USA. We apply radiocarbon and optically stimulated luminesce dating to glacial features. We find that ice began retreating shortly after 20 ka, but hummocky moraine stabilization is delayed until climate warming at ~15–14 ka.

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.

In this study, we use cosmogenic-sourced ³He to determine the eruption ages of 23 lava flows at Mt. Ruapehu, New Zealand, and we show how this method can help overcome challenges associated with traditional dating methods in young lavas. Comparison with other methods demonstrates the accuracy of our data, and the method's reliability. The new eruption ages allowed us to identify periods of quasi-simultaneous activity from different volcanic vents during the last 20,000 years.

(U-Th)/He chronology relies on accurate measurements of zircon grain dimensions, but the systematic error and uncertainty associated with those measurements have been unquantified, until now. We build on the work of Zeigler et al. (2023) and present the zircon Geometric Correction Method, a simple solution to correcting the error and quantifying the geometric uncertainty in eU and dates. Including this geometric correction and uncertainty matters for data evaluation and interpretation.