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Recent developments in tandem laser ablation mass spectrometer technology have demonstrated the capacity for separating parent and daughter isotopes of the same mass online. As a result, beta-decay chronometers can now be applied to the geological archive in situ as opposed to through traditional whole-rock digestions. One novel application of this technique is the in situ Rb–Sr dating of Proterozoic shales that are dominated by authigenic clays such as illite. This method can provide a depositional window for shales by differentiating signatures of early diagenetic processes versus late-stage secondary alteration. However, the hydrothermal sensitivity of the Rb–Sr isotopic system across geological timescales in shale-hosted clay minerals is not well understood. As such, we dated the Mesoproterozoic Velkerri Formation from the Altree 2 well in the Beetaloo Sub-basin (greater McArthur Basin), northern Australia, using this approach. We then constrained the thermal history of these units using common hydrocarbon maturity indicators and modelled effects of contact heating due to the intrusion of the Derim Derim Dolerite. In situ Rb–Sr dating of mature, oil-prone shales in the diagenetic zone from the Velkerri Formation yielded ages of 1448 ± 81, 1434 ± 19, and 1421 ± 139 Ma. These results agree with previous Re–Os dating of the unit and are interpreted as recording the timing of an early diagenetic event soon after deposition. Conversely, overmature, gas-prone shales in the anchizone sourced from deeper within the borehole were dated at 1322 ± 93 and 1336 ± 40 Ma. These ages are younger than the expected depositional window for the Velkerri Formation. Instead, they are consistent with the age of the Derim Derim Dolerite mafic intrusion intersected 800 m below the Velkerri Formation. Thermal modelling suggests that a single intrusion of 75 m thickness would have been capable of producing a significant hydrothermal perturbation radiating from the sill top. The intrusion width proposed by this model is consistent with similar Derim Derim Dolerite sill thicknesses found elsewhere in the McArthur Basin. The extent of the hydrothermal aureole induced by this intrusion coincides with the window in which kerogen from the Velkerri Formation becomes overmature. As a result, the mafic intrusion intersected here is interpreted to have caused kerogen in these shales to enter the gas window, induced fluids that mobilize trace elements, and reset the Rb–Sr chronometer. Consequently, we propose that the Rb–Sr chronometer in shales may be sensitive to temperatures of ca. 120 ∘C in hydrothermal reactions but can withstand temperatures of more than 190 ∘C in thermal systems not dominated by fluids. Importantly, this study demonstrates a framework for the combined use of in situ Rb–Sr dating and kerogen maturation indicators to help reveal the thermochronological history of Proterozoic sedimentary basins. As such, this approach can be a powerful tool for identifying the hydrocarbon potential of source rocks in similar geological settings.

Abstract Glauconite is an authigenic clay mineral that is common in marine sedimentary successions. Dating of glauconite to determine the depositional age of sedimentary sequences has a long history but has fallen into disfavor due to the difficulty of obtaining “pure” glauconite separates. Recent advances in sedimentary petrography and reaction cell mass spectrometry permit rapid in situ Rb‐Sr dating of carefully screened glauconite grains. However, glauconite remains susceptible to burial alteration so that successful application of in situ Rb‐Sr glauconite geochronology requires improved, microscale constraints on the impact of postdepositional alteration on glauconite Rb‐Sr systematics and articulation of robust criteria for identifying grains suitable for geochronology. Here, we address these questions by combining SEM‐EDS mineral mapping, geochemical characterization, and in situ Rb‐Sr dating of glauconite grains in partially altered lower Cambrian sedimentary sequences from the Arrowie and Amadeus basins in Australia. Our approach provides information at high spatial resolution, representing new insights into the interplay between source material, burial fluids, and diagenetic processes. Among the different glauconite classes, which we classify based on alteration and inclusion type, only the primary apatite‐bearing “pristine” glauconite returns an age within the error of the expected stratigraphic age. We attribute the preservation of a depositional Rb‐Sr age to the influence of Sr‐rich, alteration‐resistant apatite and the limited permeability of the clay‐rich strata hosting these grains. We conclude that our combined petrographic–geochemical screening approach holds considerable potential for identifying the best preserved glauconite grains for in situ Rb‐Sr geochronology.

Introduction Exploring the positive psychological and behavioural dimensions of people living with mental disorders can establish a firm ground in a therapeutic alliance for setting up positive life goals. Objectives The present study aimed to explored whether the strength of the mental health capacities and the severity of mental disorder symptoms and the interaction of the two differ in the strength of their associations with several dimensions of well-being on Hungarian adult psychiatric and non-clinical community samples. Methods The psychiatric sample (129 patients (44 male, 85 female)) was collected in four Hungarian healthcare facilities using a cross-sectional design. The non-clinical community sample (253 adults (43 male, 210 female)) was collected online using a cross-sectional design. All the respondents completed the Mental Health Test, six well-being and mental health measures, and the Symptom Checklist-90-Revised. Results Including both the mental health competencies and mental disorder symptoms variables in one regression model in both samples can predict patients’ well-being even more accurately. Mental health competencies related positively; mental disorder symptoms connected negatively to subjective well-being. In all models and both samples, mental health competencies were found to be a stronger determinant of well-being than the mental disorder symptoms. The interaction of mental health functioning and mental disorders is no more predictive of well-being in either psychiatric or non-clinical samples than when the effects of each are considered separately. Conclusions The assessment of mental health competencies has an important predictive value for well-being in the presence of psychopathological symptoms and/or mental disorders. Disclosure of Interest None Declared

Introduction The Mental Health Test serves as the operationalized, comprehensive measurement of Maintainable Positive Mental Theory which defines mental health (for either the non-clinical or psychiatric population) as a high level of global well-being, psychological, social and spiritual functioning, resilience, effective creative and executive functioning, savoring capacities, coping and enjoyment, regardless of the presence or absence of symptoms of psychopathology. Objectives To assist psychiatrists and clinical psychologists to assess their patients’ psychological immune competence–based capacities and resources, depending on the mental health disorder diagnosis and the severity of the symptoms, the present study examined the psychometric properties of the Mental Health Test in a psychiatric sample. Methods The research was carried out in four Hungarian healthcare facilities using a cross-sectional design. A total of 331 patients (140 male, 188 female, and 3 who preferred not to disclose their gender) completed the Mental Health Test, six well-being and mental health measures, and the Symptom Checklist-90. Clinical psychologists reported the mental disorder status of each participant. Results Confirmatory factor analysis showed a good fit of the five-factor model to the data for the clinical version of the Mental Health Test (CFI = 0.972, RMSEA = 0.034). High internal consistency coefficients (α: 0.70–0.84; ω: 0.71–0.85) and excellent external and content validity were reported. The Mental Health Test was not sensitive to sociodemographic indicators but was sensitive to correlates of well-being and symptoms of mental disorders in a psychiatric sample. Regression analyses demonstrated that unipolar depression and number of mental disorders were related to a lower overall Mental Health Test score. Personality disorders, unipolar depression, and the greater severity and higher number of mental disorders were associated with a lower global well-being score. Unipolar depression was related to lower savouring capacity. Self-regulation showed a correlation with the self-reported number of mental disorders only. Anxiety and somatization disorders, unipolar depression, and a higher number of self-reported mental disorders were related to a lower psychological resilience score. The regression model for the creative and executive efficiency subscale did not fit our data. The interaction of all combinations of psychotherapy and pharmacotherapy was significantly related to the overall Mental Health Test score and to the subscales. These results can later serve as a basis for designing intervention studies. Conclusions Our preliminary findings suggest that the Mental Health Test is a suitable measure for assessing mental health capacities and resources in psychiatric samples. Disclosure of Interest None Declared

Lithium (Li) isotopes in marine carbonates have considerable potential as a proxy to constrain past changes in silicate weathering fluxes and improve our understanding of Earth's climate. To date the majority of Li isotope studies on marine carbonates have focussed on calcium carbonates. The determination of the Li isotope fractionation between dolomite and a dolomitizing fluid would allow us to extend investigations to deep times (i.e. Precambrian) when dolostones were the most abundant marine carbonate archives. Dolostones often contain a significant proportion of detrital silicate material, which dominates the Li budget; thus, pretreatment needs to be designed so that only the isotope composition of the carbonate-associated Li is measured. This study aims to serve two main goals: (1) to determine the Li isotope fractionation between Ca–Mg carbonates and solution, and (2) to develop a method for leaching the carbonate-associated Li out of dolostone while not affecting the Li contained within the detrital portion of the rock. We synthesized Ca–Mg carbonates at high temperatures (150 to 220 ∘C) and measured the Li isotope composition (δ7Li) of the precipitated solids and their respective reactive solutions. The relationship of the Li isotope fractionation factor with temperature was obtained: 103ln⁡αprec-sol=-(2.56±0.27)106(1)/T2+(5.8±1.3) Competitive nucleation and growth between dolomite and magnesite were observed during the experiments; however, there was no notable effect of their relative proportion on the apparent Li isotope fractionation. We found that Li isotope fractionation between the precipitated solid and solution is higher for Ca–Mg carbonates than for Ca carbonates. If the temperature of a precipitating solution is known or can be estimated independently, the above equation could be used in conjunction with the Li isotope composition of dolostones to derive the composition of the solution and hence make inferences about the past Li cycle. In addition, we also conducted leaching experiments on a Neoproterozoic dolostone and a Holocene coral. Results show that leaching with 0.05 M hydrochloric acid (HCl) or 0.5 % acetic acid (HAc) at room temperature for 60 min releases Li from the carbonate fraction without a significant contribution of Li from the siliciclastic detrital component. These experimental and analytical developments provide a basis for the use of Li isotopes in dolostones as a palaeo-environmental proxy, which will contribute to further advance our understanding of the evolution of Earth's surface environments.