The composition of the Earth's mantle is influenced by plate tectonic processes, and one of the ways to study the geochemical evolution of the mantle and test plate tectonic and geodynamic models is to investigate the composition of ancient mantle-derived rocks. In this work, we study the Neoproterozoic oceanic basalts that occur as fragments in an olistostromal m & eacute;lange in the Ll & ycirc;n Peninsula of North Wales. Based on field, petrographic, and geochemical evidence, we argue that these rocks represent pieces of seamounts. Petrogenetic modelling shows that the basalts can be linked to the same source, with geochemical variations being explained by intraplate plume-related melting under variably thickened lithosphere and differing degrees of fractional crystallisation. The Nd-Hf isotopic data indicate a depleted mantle source, with mean epsilon Nd(t) and epsilon Hf(t) of 7.0 and 9.4, respectively. The depleted Nd and Hf signatures associated with elevated Pb isotopic ratios suggests that the mantle source tapped by this plume was dominated by a component similar to modern-day PREMA. Monte Carlo simulations utilising constraints on the age of accretion to an active margin and lithospheric thickness at the time of plume impingement yield results that show plume activity between 655-590 Ma. The Late Neoproterozoic timing of accretion of these rocks to the active margin might also help explain the exhumation of blueschists in North Wales. Paleogeographic and geochronological constraints show that, rather than being derived from the Iapetus Ocean, the seamounts preserved in North Wales likely originated in the shrinking circum-Rodinia Mirovoi super-ocean. Records of preserved seamounts elsewhere in the world show that Neoproterozoic plume activity must have been common in the Mirovoi ocean. The isotopic characteristics of the plume-related basalts in this study show that the PREMA component was present in the mantle sources of magmatism in the Mirovoi superocean and support the hypothesis of the longevity of this component. This study shows how a multidisciplinary approach integrating geochemistry and plate reconstruction can help tracking mantle evolution in response to plate tectonics.

The opening and closure of the Iapetus Ocean were key geodynamic events during the transition from Rodinia to Pangaea. Mantle-derived rocks formed during this period provide critical insights into the processes that shaped the mantle composition and structure during this tectonic transition. The Ballantrae Complex in Scotland is a well-preserved remnant of the Iapetus Ocean seafloor obducted during the Grampian Orogeny (ca. 475-465 Ma) and provides a window into the composition of the mantle at this period. The complex structure, and the overlying sedimentary rocks that cover the ophiolite, however, have made it difficult to parse the competing processes involved in the generation of the ophiolite. geochemical, Nd-Hf-Pb isotopic, and geochronological analyses on zircon, calcite, and titanite, guided by fieldwork observations, which help unravel the protracted evolution of the Ballantrae Complex. The oldest rock (571 +/- 27 Ma) found in the region is a portains zircon xenocrysts with a characteristic possibly an intrusion that occurred proxidevelopment of the main body of the ophio lite. Rocks dated at ca. 500-480 Ma are light rare earth element (LREE)-depleted and have low Zr/Y ratios, reminiscent of depleted island-arc tholeiites and boninites, whereas rocks from ca. 475 Ma to 462 Ma are generally more LREE enriched and follow higher Zr/Y trends, akin to more evolved arc basalts and ocean-island basalt (OIB) compositions, including the Downan Point Lava Formation. We suggest that the late OIB-like basalts of the Ballantrae Complex are correlated with similar basalts in the Tyrone Volcanic Group of Northern Ireland and might be related to an intra-arc rifting event or the subduction of a slab window. The Ballantrae Complex, therefore, records a protracted history from the opening until the early-stage closure of the Iapetus Ocean.

The geochemical community increasingly generates and requires large volumes of analytical data from a wide array of acquisition methods, analytical scales, and sample types in order to address broad research applications. Resulting datasets are commonly collected and reported through non-standardised protocols and reporting formats, if indeed standards are applied at all, which inhibits easy sharing of data during collaborative research projects or repurposing of legacy data. Existing repository services do not presently satisfy requirements for Findable, Accessible, Interoperable and Reusable (FAIR) data, and especially contain significant flaws as to the reuse and interoperability of geochemical data. Generalist repositories such as Zenodo or Figshare do not provide consistent data structures or curation, hence data held within these services is highly variable with regard to format, parameters reported and potentially quality. While domain repositories commonly do implement internally consistent data formats and a level of curation, data within repositories is gathered from published sources which may be incomplete or unstructured, and hence often lack the complete information (metadata) required to appropriately describe the data and allow it to be confidently reused. To truly unlock the potential of the ever expanding wealth of geochemical data and meet FAIR requirements, improvements to the data infrastructure landscape are clearly required. The AuScope Geochemistry Network (AGN) is an Australian-based collaboration of geoscientists producing bespoke data resources and infrastructure for the international community to capture, normalise, and share geochemical data resources. These resources include best practice data reporting schema and vocabularies for a variety of data types, produced through collaborations with expert advisory groups and, where available, following or expanding on existing international community recommendations. These data resources have been implemented to the EarthBank platform (formerly AusGeochem), an open web service designed by the AGN to capture, share, store and evaluate geochemical data and metadata. Unlike many other services, researchers are able to upload data prior to publication which can assist both in allowing researchers to compare their data with other existing resources prior to submission, but importantly also improves the likelihood of capturing the full data and metadata associated with analyses required for reuse. Once data is uploaded to this service it may be associated with a dataset DOI to support data access requirements for publication, in order to streamline the publication process and provide a domain specific repository for supplemental data. Data models for U/Pb, fission track, (U-Th-Sm)/He, 40Ar/39Ar and inorganic major and trace geochemistry data types are presently implemented within EarthBank, allowing users to freely upload generated research data for these systems, or explore and integrate existing datasets. Best practice templates for upload are openly available through the EarthBank platform, and vocabularies are openly discoverable through the Research Vocabularies Australia (RVA) service. These resources may be used not only to upload data, but also to develop cross-walks for machine-to-machine interoperability with other repository services to build a global FAIR compliant infrastructure required to maximise data access and improve research outcomes.

The distribution of mineral systems is heterogeneous over space and time, reflecting transient element enrichment within Earth’s evolving crust. Australian Proterozoic rocks host some of the world’s largest ore deposits, including the Broken Hill Pb-Zn-Ag deposit within the Curnamona Province, and the Olympic Dam Cu-U-Au-Ag super-deposit, within the Gawler Craton, offering key insights into crustal preconditioning for mineralization. New feldspar and whole-rock Pb isotopic data, and complementary apatite geochronology, support a common source for Mesoproterozoic magmatism in the Curnamona Province and Gawler Craton and hence a genetic link between their world-class ore deposits. Exceptionally radiogenic Pb isotope ratios in the Curnamona Province indicate extreme crustal fractionation, likely driven by a positive feedback scenario where crustal anatexis produced melts strongly enriched in heat-producing, incompatible elements, which in turn prolonged anatectic conditions through radiogenic heat production. The resulting granitic rocks may have acted as important metal sources for certain ore deposits, while more generally fostering metal enrichment by providing a persistent heat source for hydrothermal systems. This chemical hotspot may have been triggered by the combination of insulating thickened crust and gravitational destabilization following the assembly of the Nuna supercontinent.

Major, minor and trace geochemistry is perhaps the most commonly collected form of analytical data within the Earth sciences, either as the sole approach to a research question or to supplement other methods such as geochronology, thermochronology or isotopic studies. With increasing access to instrumentation and diversification of research applications, inorganic geochemistry data is being produced in volumes which exceed the capacity of existing data management systems, reducing the ability of data to be found, accessed and reused as part of the data lifecycle, thus consigning much data as ‘single use’. Lack of visibility additionally removes the ability to critically assess data quality and validity of interpretations, which is vital for maintaining a healthy research ecosystem. Here we propose a new, flexible inorganic geochemistry reporting schema available within the open access EarthBank platform, as a service to store, interpret, disseminate and explore geochemistry data. The application of this data structure, augmented by purpose-built data interrogation tools, is demonstrated using real-world case studies, including volcanic evolution and magma genesis, mineralisation prospectivity, and catchment provenance and contamination through stream sediment geochemistry. The combination of data schema and integrated data analytics through EarthBank offers a service beyond a basic repository, and allows for active exploration and interpretation of in-house and community geochemistry data, providing a resource beneficial across the entire data lifespan, from generation to publication and reuse.

Lead isotopes provide valuable insight into the geological processes involved in the formation of continental crust, revealing information that may be difficult to access through other isotopic systems. While Lu-Hf (or SmNd) and oxygen isotopes conceptually track mantle extraction or interaction with the hydrosphere, respectively, Pb isotopes are more sensitive to intracrustal processes. Here, we present new in situ LA-MC-ICP-MS K-feldspar and TIMS whole-rock Pb isotope data from I-, S-, and A-type granites covering an east-west transect across major lithotectonic boundaries in the Delamerian and the Lachlan Fold Belts, southeastern Australia. Initial Pb isotopic ratios determined from U- and Th-poor minerals (e.g., K-feldspar) and granite whole-rock samples (corrected for radiogenic Pb ingrowth) show no correlation with granite type nor have a statistically significant relationship with most whole-rock geochemistry and show little correlation with Nd isotopes. However, Pb isotope ratios reveal similar spatial patterns to various proxies of crustal thickness, such as regional gravity free-air anomalies, topographic elevation, and Moho depth, as well as changes in Sr/Y and Eu anomalies, which may be linked to melt extraction depths. These results support an interpretation in which Pb isotope signatures are set in the magma source region within the crustal column, essentially unaffected by later-stage fractionation. Lead isotopes thus effectively distinguish lower crustal, U- and Th-depleted sources from upper crustal, enriched sources. An enigmatic lower crustal Selwyn Block has previously been inferred in central Lachlan Fold Belt. Lead isotope data may provide insight into this block, resolving a U and Th depleted zone aligning with its areal extent, suggesting a previous high-grade melt depletion event. We conclude that granite Pb isotope signatures ultimately track the degree of intracrustal fractionation prior to the final melt extraction, which contributes to building a thickened crust.

Re‐Os isotope‐dilution geochronology has been widely used to date the timing of molybdenite, pyrite and chalcopyrite formation across a variety of geological settings. However, in situ methods have been impeded by the isobaric interference of 187Re on 187Os. In situ Re‐Os geochronology using LA‐ICP‐MS/MS has been shown to be a useful technique to chemically separate Os from Re, as Os reacts with CH4 to create higher‐mass reaction products, which can then be measured with minimised interference of 187Re. However, application of the method requires matrix‐matched primary reference materials, e.g., age‐homogenous molybdenite amenable to laser ablation. Here, we characterise and present two new molybdenite mineral reference materials for in situ Re‐Os geochronology by LA‐ICP‐MS/MS, verified by ID‐TIMS Re‐Os measurements. We also present case studies from molybdenite samples with varying Re mass fractions and Re‐Os age mapping. The method provides accurate and precise age data, with excellent precision for high Re samples. The benefits of the LA‐ICP‐MS/MS approach include: (1) simple sample preparation, (2) rapid data acquisition, (3) targeting of specific textural domains including growth zones and (4) the ability to simultaneously collect trace elements used to link the timing and conditions of ore‐formation.

The majority of geochemical and cosmochemical research is based upon observations and, in particular, upon the acquisition, processing and interpretation of analytical data from physical samples. The exponential increase in volumes and rates of data acquisition over the last century, combined with advances in instruments, analytical methods and an increasing variety of data types analysed, has necessitated the development of new ways of data curation, access and sharing. Together with novel data processing methods, these changes have enabled new scientific insights and are driving innovation in Earth and Planetary Science research. Yet, as approaches to data-intensive research develop and evolve, new challenges emerge. As large and often global data compilations increasingly form the basis for new research studies, institutional and methodological differences in data reporting are proving to be significant hurdles in synthesising data from multiple sources. Consistent data formats and data acquisition descriptions are becoming crucial to enable quality assessment, reusability and integration of results fostering confidence in available data for reuse. Here, we explore the key challenges faced by the geo-and cosmochemistry community and, by drawing comparisons from other communities, recommend possible approaches to overcome them. The first challenge is bringing together the numerous sub-disciplines within our community under a common international initiative. One key factor for this convergence is gaining endorsement from the international geochemical, cosmochemical and analytical societies and associations, journals and institutions. Increased education and outreach, spearheaded by ambassadors recruited from leading scientists across disciplines, will further contribute to raising awareness, and to uniting and mobilising the community. Appropriate incentives, recognition and credit for good data management as well as an improved, user-oriented technical infrastructure will be essential for achieving a cultural change towards an environment in which the effective use and real-time interchange of large datasets is common-place. Finally, the development of best practices for standardised data reporting and exchange, driven by expert committees, will be a crucial step towards making geo-and cosmochemical data more Findable, Accessible, Interoperable and Reusable by both humans and machines (FAIR).

Hypervelocity impacts throughout Earth's history have profoundly affected the evolution of the continental crust. Accessory minerals like zircon are typically used to date impact events and rock-forming minerals like quartz are routinely used as shock barometers. However, feldspar group minerals – a major constituent of most crustal rocks – are generally underutilized in the documentation of impact-induced deformation and alteration. Alkali feldspar contains appreciable amounts of Pb and analysis of Pb isotopes in feldspar may offer the opportunity to identify impact-related isotopic modifications of shocked crustal target rocks and estimate their timing. Here, we apply a combination of laser ablation inductively coupled plasma (LA-ICP) and thermal ionization mass spectrometry (TIMS) Pb isotope analysis with imaging techniques, including electron backscatter diffraction (EBSD), cathodoluminescence (CL), and time of flight secondary ion mass spectrometry (ToF-SIMS), to shocked alkali feldspar from monzogranite in the oldest confirmed terrestrial impact structure (2229 ± 5 Ma) at Yarrabubba, Western Australia. Alkali feldspar preserves microstructures such as sub-planar and irregular fractures, sets of planar deformation bands that accommodate misorientations of up to ∼20°, sets of damage lamellae, and broad domains of lattice damage that can be linked to impact-related deformation. The Pb isotope compositions in alkali feldspar correlate with variations in electron diffraction band contrast – a proxy for crystallinity – and also the degree of misorientation and CL response. Less damaged alkali feldspar yields Pb model ages similar to the igneous zircon U–Pb crystallization age of the host monzogranite (∼2650 Ma), whereas younger Pb model ages correspond to zones of damage (high relative misorientation, low crystallinity, weak CL response). The observed Pb isotope behaviour implies radiogenic ingrowth of Pb, from decay of U and Th within damaged alkali feldspar, and therefore mixing with a grain-scale Pb reservoir that formed at the time of impact. The U and Th zonation in some shock-deformed alkali feldspar is broadly similar and follows the orientation of sub-planar fractures and damage lamellae. Detailed imaging reveals the zones of U and Th enrichment are associated with trains of monazite micro-inclusions, in conjunction with magnetite and/or hematite in places, which are inferred to have precipitated during impact-induced hydrothermal circulation. Hence, the Pb isotopic data record grain-scale hydrothermal alteration in superficially weakly altered monzogranite target rocks.

One of the most impassioned topics in large igneous province (LIP) research is how prolonged the duration of these large-scale magmatic events are, as LIP magmatism has considerable impact on models of associated reconstructions, of climate variability or tectonic events. High-precision geochronology is pivotal to LIP basalt emplacement rate, and thus to unravel the role these enormous magmatic events have throughout Earths geological and environmental history. Four high-precision 40Ar/39Ar plagioclase plateau ages for the Tasmanian dolerites (Ferrar) indicate ∼1.6 ± 0.4 Ma of resolvable, continuous magmatic activity; 184.27 ± 0.24 to 182.69 ± 0.54 Ma (2σ). The 40Ar/39Ar results provide evidence of distinctly older intrusions and a more prolonged duration than the observed 182.4-182.9 Ma age range and duration indicated by the main zircon record. Moreover, the precision of our 40Ar/39Ar results coupled with secondary electron microscopy analyses provide evidence of plagioclase crystal inheritance from slightly older magmatism entrained into younger magmatic pulses by exploiting pre-existing conduits. Numerical diffusion models, calculated for a theoretical age spectrum resulting from two slightly different plagioclase ages, provide an excellent match for measured data. Coupling geochemical data to the new age data indicates a silica and incompatible element evolution of the Ferrar magmatic system through time. The older generation of intrusions (ca. Zr: 92 ppm, SiO2: 53.67 wt.%) are seemingly less enriched in incompatible elements and silica than the youngest generation (ca. Zr: 147 ppm, SiO2: 56.5 wt.%). Here, we suggest that the magma chambers differentiated to more incompatible/silica-rich compositions saturating zircon only at evolved magmatic stages. This implies that plagioclase dates the full duration of magmatic Ferrar LIP activity of ca. 1.6 Myrs whilst zircon ages might be naturally biased and restricted to post-Zr saturation stage. The extended duration of Ferrar magmatism indicates that it is coeval with the Pliensbachian-Toarcian boundary. Therefore, we speculate that Ferrar (±Karoo) magmatism triggered the Pliensbachian-Toarcian extinction event and contributed to the Toarcian oceanic anoxic event, from which the environment did not begin to recover until only after the waning and cessation of Ferrar magmatic activity at ∼182 Ma, with zircon crystals recording the final flux of magma.