Recent  

The work presented here focusses on understanding the nature and lifespan of the Delamerian Orogeny (mountain belt). The results obtained support the hypothesised nature of the long-lived Delamerian Orogeny. The orogen has potential for Cu-Au deposits and the results contribute to the fundamental understanding of the region that will assist in exploring for mineralisation. The aims have been achieved through ⁴⁰Ar/³⁹Ar dating of important structures within the rock units of the orogen.

Radiometric dating methods, involving laser-ablation as sample introduction, require robust calibrations to reference materials with similar ablation properties to the analysed samples. In the case of the Rubidium-Strontium dating method, calibrations are often conducted to a nano-powder with different ablation characteristics than crystalline minerals. We describe the limitations of this approach and recommend an alternative calibration method, involving natural minerals.

We describe a new method of reconstructing the long-term, pre-observational frequency and/or intensity of wildfires in forested landscapes using trace concentrations of the noble gases helium and neon that are formed in soil mineral grains by cosmic-ray bombardment of the Earth's surface.

Developing models that relate stratigraphic position to time are important because they allow the rock record to be understood in terms of absolute time, allowing global comparisons. In this study we developed a novel method for developing these models (called age-depth models) that uses two different types of chronologic information, dated rocks, and records of variations in earths orbit (astrochronology). The resulting models are very precise which can improve understanding of past climates.

Chemical abrasion (CA) is a technique that reduces or eliminates the effects of Pb-loss in zircon U-Pb geochronology. However, CA has yet to be applied to large-n detrital zircon (DZ) analyses. We show that CA does not negatively impact or systematically bias U-Pb dates and improves concordance, precision, and accuracy. When applied to DZ samples prior to laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), CA improves the resolution of DZ age populations.

Chronological information on the evolution of the Namib Desert is scarce. We used U-Pb dating of silcretes formed by pressure-solution during calcrete formation to track paleoclimate variability since the Late Miocene. Calcrete formation took place during the Pliocene with an abrupt cessation at 2.9 Ma. The end took place due to deep canyon incision which we dated using TCN exposure dating. With our data we correct and contribute to the Neogene history of the Namib Desert and its evolution.

Acid leaching is used to remove radiation-damaged portions of zircon crystals prior to U-Pb dating to improve the accuracy of datasets. We test how the temperature and duration of acid leaching affects geochronological and geochemical outcomes. We build a framework that relates radiation damage, zircon solubility, and Pb loss that will ultimately help researchers to tailor their acid leaching approach to different zircon samples.

Sedimentary provenance utilizes the composition of sedimentary rocks to investigate the sources of sediment and the geologic processes controlling it. Common techniques struggle to track mafic igneous and metamorphic rock sources, yet rutile forms in these rock types. We use rutile from ancient sedimentary rocks in Türkiye to present a new workflow for integrating rutile U-Pb ages and chemical composition into an accurate sedimentary provenance reconstruction.

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.

This study tested the application of single-grain feldspar luminescence for dating and reconstructing sediment dynamics of an extreme mass movement event in the Himalayan Mountain range. Our analysis revealed that feldspar signals can be used to estimate the age range of the deposits if the youngest subpopulation from a sample is retrieved. The absence of clear spatial relationships with our bleaching proxies suggests that sediments were transported under extremely limited light exposure.