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Systematic variations in the crystal cargo and whole-rock isotopic compositions of mantle-derived basalts in the intraplate Dunedin Volcano (New Zealand) indicate the influence of a complex mantle-to-crust polybaric plumbing system. Basaltic rocks define a compositional spectrum from low-alkali basalts through mid-alkali basalts to high-alkali basalts. High-alkali basalts display clinopyroxene crystals with sector (hourglass) and oscillatory zoning (Mg#61-82) as well as Fe-rich green cores (Mg#43-69), whereas low-alkali basalts are characterized by clinopyroxenes with unzoned overgrowths (Mg#69-83) on resorbed mafic cores (Mg#78-88), coexisting with reversely zoned plagioclase crystals (An43-68 to An60-84 from core to rim). Complex magma dynamics are indicated by distinctive compositional variations in clinopyroxene phenocrysts, with Cr-rich zones (Mg#74-87) indicating continuous recharge by more mafic magmas. Crystallization of olivine, clinopyroxene and titanomagnetite occurred within a polybaric plumbing system extending from upper mantle to mid-crustal depths (485-1059 MPa and 1147-1286°C), whereas crystallization of plagioclase with subordinate clinopyroxene and titanomagnetite proceeded towards shallower crustal levels. The compositions of high-alkali basalts and mid-alkali basalts resemble those of ocean island basalts and are characterized by FOZO-HIMU isotopic signatures (87Sr/86Sri = 0.70277-0.70315, 143Nd/144Ndi = 0.51286-0.51294 and 206Pb/204Pb = 19.348-20.265), whereas low-alkali basalts have lower incompatible element abundances and isotopic compositions trending towards EMII (87Sr/86Sri = 0.70327-70397, 143Nd/144Ndi = 0.51282-0.51286 and 206Pb/204Pb = 19.278-19.793). High- and mid-alkali basalt magma

Diversity and inclusion in the workplace optimise performance through the input of a range of perspectives and approaches that drive innovation and invention. However, gender inequity is prevalent throughout society and females remain underrepresented in geoscience careers. This study provides the current status of gender equity in geosciences throughout Australasia within the context of broader gender equity policy, frameworks and initiatives and suggests additional solutions and opportunities to improve gender equity and the retention of women in the geoscience workforce. At an individual institutional level in academia, females make up between 23 %-52 % of the total geoscience departmental or school staff in Australia, 26 %-39 % of the total staff in New Zealand, 29 % of total staff at the University of Papua New Guinea and 18 % at the University of the South Pacific. Significant gender imbalance exists at more senior levels, with disproportionately more males than females, a pattern typical of many Science Technology Engineering and Maths (STEM) disciplines. Gender inequity is prevalent within the general membership, committee roles and in award recipients of Australasian geoscience professional associations. Within the Geological Society of Australia and Geoscience Society of New Zealand, only 4 % (n D 47) and 18 % (n D 161), respectively of past award recipients for national and general awards were female. All past awards considered in this study that are named in honour of a person were named in honour of a man (n D 9). In recent years, women-focused networks have begun to play an invaluable role to support the retention and promotion of women in geosciences and provide a supportive mentoring environment to discuss challenges and share advice. The improved visibility of women in the geoscientific community is an ongoing issue that can in part be addressed through the development of public databases of women geoscientists. These provide a list of women geoscie

The Pyrenean-Cantabrian Orogen arose through the collision of the Iberian and Eurasian plates, mostly in Cenozoic times. This orogen comprises two main mountain ranges, the Pyrenees to the east, and the Cantabrian Mountains to the west. To date, the early Alpine tectono-sedimentary phases preserved in the Cantabrian Mountains, of Permian and Triassic age, have been considered independently from the same phases in neighbouring basins of SW Europe, and even from the eastern part of the same orogeny (the Pyrenean orogeny). In consequence, the beginning of the Alpine cycle in the Cantabrian Mountains has been interpreted within a specific geodynamic context, far from the general evolutionary phases of the western Peri-Tethys basins. Through detailed field work, including geological mapping, sedimentology, lithostratigraphy and petrology of volcanic rocks, and new palaeontological data, here we define several new lithostratigraphical formations and five new tectono-sedimentary cycles (TS I-V) for the initial phases of evolution of the Mesozoic Basque-Cantabrian Basin, interrupted by periods of tectonic stability. To complete this information, we include data from an onshore borehole (Villabona Mine) and two offshore boreholes constrained by 2D reflection seismic profiles acquired in the North Iberian continental platform. The main tectono-sedimentary cycles, related to the deposition of five major identified lithostratigraphic units, can be described as follows: TS I (late Gzelian-early Asselian), relating to the late Variscan deformation and preserved in a single outcrop in all the Cantabrian Mountains (San Tirso Formation). This formation is constituted by medium-distal alluvial fan deposits in which humid intervals predominate, forming some thin coal beds. TS II (Asselian-Sakmarian), a post-Variscan extensional phase with associated calc-alkaline magmatism, represented by profuse volcanic and volcanosedimentary intercalations in the early Permian sedimentary basins (A

We perform a multidisciplinary study of biotite porphyroblasts and veinlet infills hosted in Cambrian strata of the hanging walls from the NW-SE-trending Datos, Jarque and Daroca thrusts (Iberian Chains). Stratigraphic and microstructural crosscutting features indicate that a biotite isograd runs parallel to the southeastern transects of the three thrusts. The metamorphic grade reached in the southeastern edge of the Iberian Chains is clearly distinct from both the Cadomian epizonal metamorphism, exclusively recorded in the Ediacaran–basal Cambrian Paracuellos Group, and the Variscan anchizone metamorphism recorded throughout Cambrian–Devonian strata. During post–Variscan negative inversion tectonics, renewed K-metasomatism along the same thrusts led to crystallisation of geochemically similar biotites in parallel fissures and veins. 40Ar/39Ar ages are (i) latest Westphalian–to–Guadalupian (285.82 ± 23.75 Ma) for metamorphic biotite porphyroblasts affected by diffusion loss of Ar, including the Carboniferous–Permian transition within error; and (ii) Early Triassic (246.87 ± 5.36 Ma) for biotite occlusion in post–Variscan veinlets. The Iberian Chains represent the southeastern prolongation of the Cantabrian and West Asturian-Leonese zones. The latter displays a uniform eastward decrease in metamorphic grade, whereas the Iberian Chains exhibits a heterogeneous distribution of low-grade metamorphic conditions (chlorite zone). The local presence of the biotite isograd is linked to the higher tectonic gradients associated with the Daroca, Jarque and Datos thrusts, quite similar to the metamorphic isogrades recognized both in the northeastern edge of the Demanda Massif and the Novellana-Pola de Allande-Degaña Belt of the West Asturian-Leonese Zone. This distribution allows the identification of a broad NW-SE belt of biotite-in isograd-related synkinematic metamorphism, following the western contact of the Narcea Antiform, the Anguiano Thrust and the southeastern edges of

New age data have been obtained to time constrain the recent Quaternary volcanism of El Hierro (Canary Islands) and to estimate its recurrence rate. We have carried out 40Ar/39Ar geochronology on samples spanning the entire volcanostratigraphic sequence of the island and 14C geochronology on the most recent eruption on the northeast rift of the island: 2280 ± 30 yr BP. We combine the new absolute data with a revision of published ages onshore, some of which were identified through geomorphological criteria (relative data). We present a revised and updated chronology of volcanism for the last 33 ka that we use to estimate the maximum eruptive recurrence of the island. The number of events per year determined is 9.7 × 10-4 for the emerged part of the island, which means that, as a minimum, one eruption has occurred approximately every 1000 years. This highlights the need of more geochronological data to better constrain the eruptive recurrence of El Hierro.

[EN] The Panticosa dyke swarm was emplaced into the late Carboniferous (301 ± 7 Ma) Panticosa pluton. It consists of diabase and lamprophyre dykes. According to their composition, two lithotypes are differentiated: (i) an early system of calc-alkaline affinity and N-S average trend and (ii) a late system of alkaline affinity and E-W average trend. The fracture pattern distribution with respect to both dyke systems suggests that all dykes occupied pre-existing fractures. The magnetic fabric analysis and petrological data indicate that the emplacement model differed for each dyke system. For the calc-alkaline dykes, magma flow and tectonic stress conditions influenced emplacement. The emplacement of alkaline dykes, on the other hand, was mainly controlled by tectonic stress. The combined interpretation of structural and magnetic fabric data suggests an emplacement history for all late-Variscan dykes during a constant regional N-S trending extension. This study emphasizes the role of pure extension in the late-Variscan evolution of the Pyrenean Axial Zone. © 2012 Elsevier Ltd.