Alexandru T. Codilean

To quantify the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses, we analysed a suite of liquid and quartz reference materials, together with duplicate preparations of unknown research samples. Comparison among these materials allows us to constrain uncertainties associated with AMS measurement, chemical extraction, and quartz purification, and to assess whether additional variability is introduced at successive stages of the analytical process. Samples were prepared in three chemistry laboratories at the Australian Nuclear Science and Technology Organisation (ANSTO), the University of Wollongong (UOW), and Imperial College London, and subsequently analysed by accelerator mass spectrometry (AMS) using the 6 MV SIRIUS accelerator at ANSTO. All three laboratories showed intra-laboratory variability below the routine 2% analytical uncertainty, while measured values were consistent with the nominal values of the reference materials. These results indicate that both methodological reproducibility and inter-laboratory variability are also within the analytical uncertainty, and provide no evidence for additional uncertainty associated with processing quartz relative to liquid reference materials. The implications for cosmogenic-nuclide research are that: (1) the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses are typically 2–3% when sufficient counting statistics are achieved; (2) at lower isotope concentrations, counting statistics and/or background corrections may limit the achievable measurement uncertainty, although the resulting variability remains consistent with the reported analytical precision; and (3) precision of approximately 1% is achievable for high-concentration liquid reference materials, as demonstrated by Be-KN-5-4 and Al-KN-4-3, but has not yet been demonstrated for quartz samples.

To quantify the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses, we analysed a suite of liquid and quartz reference materials, together with duplicate preparations of unknown research samples. Comparison among these materials allows us to constrain uncertainties associated with AMS measurement, chemical extraction, and quartz purification, and to assess whether additional variability is introduced at successive stages of the analytical process. Samples were prepared in three chemistry laboratories at the Australian Nuclear Science and Technology Organisation (ANSTO), the University of Wollongong (UOW), and Imperial College London, and subsequently analysed by accelerator mass spectrometry (AMS) using the 6 MV SIRIUS accelerator at ANSTO. All three laboratories showed intra-laboratory variability below the routine 2% analytical uncertainty, while measured values were consistent with the nominal values of the reference materials. These results indicate that both methodological reproducibility and inter-laboratory variability are also within the analytical uncertainty, and provide no evidence for additional uncertainty associated with processing quartz relative to liquid reference materials. The implications for cosmogenic-nuclide research are that: (1) the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses are typically 2–3% when sufficient counting statistics are achieved; (2) at lower isotope concentrations, counting statistics and/or background corrections may limit the achievable measurement uncertainty, although the resulting variability remains consistent with the reported analytical precision; and (3) precision of approximately 1% is achievable for high-concentration liquid reference materials, as demonstrated by Be-KN-5-4 and Al-KN-4-3, but has not yet been demonstrated for quartz samples.

Lake Woods, Jurrkulu, is northern Australia's largest freshwater lake filled today in strong Indo–Australian summer monsoons (IASM) to maximum depths of ~5 m. On the western margins of the lake, two large arcuate ridges occur 20 to 40 m above the lake floor and inset within these are other mid‐elevation lake deposits, such as depositional ridges, which suggest past filling events much higher than the modern maximum. We have undertaken the analysis of 20 samples for single‐grain optically stimulated luminescence (OSL) from shoreline and lake‐floor deposits and supplemented this chronology with an analysis of the basin hypsometry, basin‐wide erosion rates and rare earth elements to ascertain the dominant source of the large source‐bordering ridges. The outer and inner arcuate ridges represent both aeolian accumulation and inferred lake‐level highstands due to the presence of fine gravel facies and gastropods contained within them. We document two lake highstands at 195 ± 16 ka and at 98 ± 7 ka (20 and 15 m above the lake floor, respectively; the lake floor is 197 m Australian Height Datum, AHD). We also present a third but undated filling event 18.5 m above the lake floor (215.5 m AHD) but that is bracketed by two OSL ages of 91 ± 5 and 52 ± 3 ka, with a Bayesian modelled boundary age for lake filling of 95.9 to 53.8 ka (95% credible interval; C.I.). We find no evidence of the previously reported late Marine Isotope Stage [MIS] 3 highstand deposits and the prevalence of gully‐filled structureless sediments, dated to the mid to late Holocene, many of which contain archaeological artefacts that do not allow for the quantification of any accurate Holocene lake‐filling episodes. The lake floor is characterised by deeply cracking silts and clays, with single‐grain OSL results supporting significant post‐depositional mixing (maximum ages are <143 ka). Denudation rate data from detrital stream sediment samples indicate some of the lowest rates of denudation in northern Australia, of between 2.05 ± 0.51 and 0.83 ± 0.23 m/Myr, with the latter rate stemming from the dominant catchment area in the Barkly Tablelands. Sediment provenance data indicate that the slowly eroding Barkly Tablelands is the dominant source for the clays and silts in the lake basin. Despite being the largest lake in northern Australia, the slow rates of catchment‐wide erosion coupled with the intermittent filling have only produced a discontinuous record of the IASM, but one that shows exceptional episodic filling in MIS 5 to 4.

To quantify the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses, we analysed a suite of liquid and quartz reference materials, together with duplicate preparations of unknown research samples. Comparison among these materials allows us to constrain uncertainties associated with AMS measurement, chemical extraction, and quartz purification, and to assess whether additional variability is introduced at successive stages of the analytical process. Samples were prepared in three chemistry laboratories at the Australian Nuclear Science and Technology Organisation (ANSTO), the University of Wollongong (UOW), and Imperial College London, and subsequently analysed by accelerator mass spectrometry (AMS) using the 6 MV SIRIUS accelerator at ANSTO. All three laboratories showed intra-laboratory variability below the routine 2% analytical uncertainty, while measured values were consistent with the nominal values of the reference materials. These results indicate that both methodological reproducibility and inter-laboratory variability are also within the analytical uncertainty, and provide no evidence for additional uncertainty associated with processing quartz relative to liquid reference materials. The implications for cosmogenic-nuclide research are that: (1) the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses are typically 2–3% when sufficient counting statistics are achieved; (2) at lower isotope concentrations, counting statistics and/or background corrections may limit the achievable measurement uncertainty, although the resulting variability remains consistent with the reported analytical precision; and (3) precision of approximately 1% is achievable for high-concentration liquid reference materials, as demonstrated by Be-KN-5-4 and Al-KN-4-3, but has not yet been demonstrated for quartz samples.

To quantify the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses, we analysed a suite of liquid and quartz reference materials, together with duplicate preparations of unknown research samples. Comparison among these materials allows us to constrain uncertainties associated with AMS measurement, chemical extraction, and quartz purification, and to assess whether additional variability is introduced at successive stages of the analytical process. Samples were prepared in three chemistry laboratories at the Australian Nuclear Science and Technology Organisation (ANSTO), the University of Wollongong (UOW), and Imperial College London, and subsequently analysed by accelerator mass spectrometry (AMS) using the 6 MV SIRIUS accelerator at ANSTO. All three laboratories showed intra-laboratory variability below the routine 2% analytical uncertainty, while measured values were consistent with the nominal values of the reference materials. These results indicate that both methodological reproducibility and inter-laboratory variability are also within the analytical uncertainty, and provide no evidence for additional uncertainty associated with processing quartz relative to liquid reference materials. The implications for cosmogenic-nuclide research are that: (1) the reproducibility and precision of cosmogenic ¹⁰Be and ²⁶Al analyses are typically 2–3% when sufficient counting statistics are achieved; (2) at lower isotope concentrations, counting statistics and/or background corrections may limit the achievable measurement uncertainty, although the resulting variability remains consistent with the reported analytical precision; and (3) precision of approximately 1% is achievable for high-concentration liquid reference materials, as demonstrated by Be-KN-5-4 and Al-KN-4-3, but has not yet been demonstrated for quartz samples.

To quantify the reproducibility and precision of cosmogenic 10Be and 26Al analyses, we analysed a suite of liquid and quartz reference materials, together with duplicate preparations of unknown research samples. Comparison among these materials allows us to constrain uncertainties associated with AMS measurement, chemical extraction, and quartz purification, and to assess whether additional variability is introduced at successive stages of the analytical process. Samples were prepared in three chemistry laboratories at the Australian Nuclear Science and Technology Organisation (ANSTO), the University of Wollongong (UOW), and Imperial College London, and subsequently analysed by accelerator mass spectrometry (AMS) using the 6 MV SIRIUS accelerator at ANSTO. All three laboratories showed intra-laboratory variability below the routine 2% analytical uncertainty, while measured values were consistent with the nominal values of the reference materials. These results indicate that both methodological reproducibility and inter-laboratory variability are also within the analytical uncertainty, and provide no evidence for additional uncertainty associated with processing quartz relative to liquid reference materials. The implications for cosmogenic-nuclide research are that: (1) the reproducibility and precision of cosmogenic 10Be and 26Al analyses are typically 2–3% when sufficient counting statistics are achieved; (2) at lower isotope concentrations, counting statistics and/or background corrections may limit the achievable measurement uncertainty, although the resulting variability remains consistent with the reported analytical precision; and (3) precision of approximately 1% is achievable for high-concentration liquid reference materials, as demonstrated by Be-KN-5-4 and Al-KN-4-3, but has not yet been demonstrated for quartz samples.

The American Geophysical Union (AGU) announces the new living collection “Impactful Datasets in Earth, Space, and Environmental Sciences” which recognizes the creation and curation of datasets enabling research, analysis, and decision making beyond what is captured by traditional academic impact metrics. The collection highlights datasets through the dimensions of People, Planet, and Prosperity, and includes a curated set of nominated datasets and accompanying special collection of data papers. Developed with the Earth Science Information Partners (ESIP) community, the nomination and review process initially invites contributors from across research, operations, and public service, to nominate datasets important to their work, and then submit a data paper that expands upon the nomination text for inclusion in the special collection. This commentary highlights the rationale for the living collection, and the process of nomination. The collection serves as a living reference that strengthens data culture, supports reproducible geoscience, and provides enduring access to critical information for science and society.