Geologic dating methods generally do not directly measure ages. Instead, interpreting a geochemical measurement as an age requires a middle layer of calculations and supporting data, and the fact that this layer continually improves is an obstacle to synoptic analysis of geochronological data. This paper describes a prototype data management and analysis system that addresses this obstacle by making the middle-layer calculations transparent and dynamic to the user.

The generation of highly precise and accurate ages requires crushing of the original sample so that individual mineral grains may be separated out for dating. Here, we use a focused ion beam to extract grains directly from a subset of a sample, effectively performing microsurgery to isolate individual crystals from the rock itself. This approach opens the door to high-precision dating for a variety of precious planetary materials that have previously been challenging to date.

Baddeleyite is commonly used for U–Pb dating, but textural complexities, alteration features and discordance often make age interpretation difficult. Based on this case study, we discuss strategies for obtaining more accurate baddeleyite ages by high-precision and high spatial resolution methods, including analytical challenges and discordance interpretation. An evaluation of microtextures allows us to distinguish among seven different types of baddeleyite–zircon intergrowths.

The integration of zircon geochemistry and U–Pb geochronology (petrochronology) allows us to improve our understanding of magmatic processes. Here we could reconstruct the ~300 kyr evolution of the magma reservoir that sourced the magmas, fluids and metals to form the Batu Hijau porphyry Cu–Au deposit. The application of in situ LA-ICP-MS and high-precision CA–ID–TIMS geochronology to the same zircons further allowed an assessment of the strengths and limitations of the different techniques.

We show results from a new type of ion detector technology for mass spectrometry that allows us to measure ion beams more precisely. This technology expands the range of ages we can measure using a single instrument and makes it possible to measure those ages – including all required corrections and adjustments – with more confidence. We show measurements of widely used standard materials for Ar / Ar, including air and synthetic standard gas, to illustrate the capabilities of the new detectors.

We investigate the timing and rate of retreat for three alpine glaciers in the southern Rocky Mountains to test whether they followed the pattern of global climate change or were majorly influenced by regional forcing mechanisms. We find that the latter is most likely for these glaciers. Our conclusions are based on a new ¹⁰Be chronology of alpine glacier retreat. We quantify retreat rates for each valley using the BACON program in R, which may be of interest for the audience of Geochronology.

U–Pb ages of zircon crystals are used to determine the provenance and depositional age of strata of the Triassic Chinle and Moenkopi formations and the Permian Coconino Sandstone of northern Arizona. Primary source regions include the Ouachita orogen, local Precambrian basement rocks, and Permian–Triassic magmatic arcs to the south and west. Ages from fine-grained strata provide reliable depositional ages, whereas ages from sandstones are compromised by zircon grains recycled from older strata.

Using a relatively new dating technique, in situ Rb–Sr geochronology, we constrain the ages of two generations of mineral assemblages from the Tropicana Zone, Western Australia. The first, dated at ca. 2535 Ma, is associated with exhumation of an Archean craton margin and gold mineralization. The second, dated at ca. 1210 Ma, has not been previously documented in the Tropicana Zone. It is probably associated with Stage II of the Albany–Fraser Orogeny and additional gold mineralization.

Luminescence properties of samples from the Rinikerfeld, northern Switzerland, are assessed. Reader-specific low preheat temperatures are invesigated to ensure suitable measurement conditions. While quartz is found to be dominated by stable fast components, signal loss is observed for feldspar and polymineral. In general, the ages of the fading corrected feldspar and the fine-grained polymineral fractions are in agreement with coarse-grained quartz, and ages indicate sedimentation during MIS6.

The standard approach to isochron calculation assumes that the distribution of uncertainties on the data arising from isotopic analysis is strictly Gaussian. This excludes datasets that have more scatter, even though many appear to have age significance. Our new approach requires only that the central part of the uncertainty distribution of the data defines a "spine" in the trend of the data. A robust statistics approach is used to locate the spine, and an implementation in Python is given.

This paper serves as a guide to those interested in dating calcite by laser ablation. Within it are theoretical and practical limits of U and Pb concentrations (and U / Pb ratios), which would allow viable extraction of ages from calcite (and other minerals with moderate U / Pb ratios), and which type of instrumentation would be appropriate for any given sample. The method described uses a new detector array, allowing for lower detection limits and thereby expanding the range of viable samples.

⁴⁰K is an isotope of potassium that undergoes several different modes of radioactive decay. We use the decay of ⁴⁰K to determine the ages of geologic materials that contain potassium but doing this requires us to know the rate at which ⁴⁰K decays by its different decay modes. Here, we investigate one decay mode of ⁴⁰K that has previously been overlooked. We demonstrate that this decay mode exists, estimate its rate, and evaluate its significance for geochronology.

Orakei Basin – a former maar lake in Auckland, New Zealand – provides an outstanding sediment record over the last ca. 130 000 years, but an age model is required to allow the reconstruction of climate change and volcanic eruptions contained in the sequence. To construct a relationship between depth in the sediment core and age of deposition, we combined tephrochronology, radiocarbon dating, luminescence dating, and the relative intensity of the paleomagnetic field in a Bayesian age–depth model.

Meteoric beryllium-10 concentrations in soil profiles have great capacity to quantify Earth surface processes, such as erosion rates and landform ages. However, determining these requires an accurate estimate of the delivery rate of this isotope to local sites. Here, we present a new method to constrain the long-term delivery rate to an eroding western US site, compare it against existing delivery rate estimates (revealing considerable disagreement between methods), and suggest best practices.

Cassiterite is the primary tin ore mineral and is associated with other elements needed for green technology. The mineral is deposited from hydrothermal fluids released from magmas. Because it is extremely acid resistant, there has been difficulty dissolving the mineral for isotopic analysis. To improve the understanding of the timing and models of formation processes, we use a novel method to dissolve and extract radiogenic isotopes of the uranium-to-lead decay scheme from cassiterite.