Sediment-matrix igneous breccias at the top contacts of felsic units in the IPB : implications for VHMS exploration

The Volcanic Sedimentary Complex of the Iberian Pyrite Belt is dominated by mudstone units and comprises felsic lavas/domes and pyroclastic units that define lava-cryptodome-pumice cone volcanoes. Sediment-matrix igneous breccias may outline the contacts of volcanic units, occur within them, or lie laterally to the volcanic centres. These breccias can form by several processes, each with its genetic implications, having nevertheless very similar final aspect. We have distinguished and characterized several sediment-matrix breccia types. The most abundant types are sediment-infill volcanic breccia and peperite; however other types of sediment-matrix breccia were also identified. The correct identification of these breccias is crucial to reconstruct the volcanic centres and to define the stratigraphy, which in mineralized volcanic provinces is a major issue both for metallogenic and mineral exploration models

Sulfur, Chlorine, and Flourine Degassing and Atmospheric Loading by the 1783 - 1784 AD Laki (Skaftar Fires) Eruption in Iceland

The 1783-1784 Laki tholeiitic basalt fissure eruption in Iceland was one of the greatest atmospheric pollution events of the past 250 years, with widespread effects in the northern hemisphere. The degassing history and volatile budget of this event are determined by measurements of pre-eruption and residual contents of sulfur, chlorine, and fluorine in the products of all phases of the eruption. In fissure eruptions such as Laki, degassing occurs in two stages: by explosive activity or lava fountaining at the vents, and from the lava as it flows away from the vents. Using the measured sulfur concentrations in glass inclusions in phenocrysts and in groundmass glasses of quenched eruption products, we calculate that the total accumulative atmospheric mass loading of sulfur dioxide was 122 Mt over a period of 8 months. This volatile release is sufficient to have generated approximately 250 Mt of H2SO4 aerosols, an amount which agrees with an independent estimate of the Laki aerosol yield based on atmospheric turbidity measurements. Most of this volatile mass (approximately 60 wt.%) was released during the first 1.5 months of activity. The measured chlorine and fluorine concentrations in the samples indicate that the atmospheric loading of hydrochloric acid and hydrofluoric acid was approximately 7.0 and 15.0 Mt, respectively. Furthermore, approximately 75% of the volatile mass dissolved by the Laki magma was released at the vents and carried by eruption columns to altitudes between 6 and 13 km. The high degree of degassing at the vents is attributed to development of a separated two-phase flow in the upper magma conduit, and implies that high-discharge basaltic eruptions such as Laki are able to loft huge quantities of gas to altitudes where the resulting aerosols can reside for months, or even 1-2 years. The atmospheric volatile contribution due to subsequent degassing of the Laki lava flow is only 18 wt.% of the total dissolved in the magma, and these emissions were confined to the lowest regions of the troposhere and therefore important only over Iceland. This study indicates that determination of the amount of sulfur degassed from the Laki magma batch by measurements of sulfur in the volcanic products (the petrologic method) yields a result which is sufficient to account for the mass of aerosols estimated by other methods

The fluorine link between a supergiant ore deposit and a silicic large igneous province

Olympic Dam is a supergiant Fe oxide Cu-U-Au-Ag ore deposit (~9 × 109 t) that is also enriched in rare earth elements (REEs) and fluorine (F). The immediate host to the ore is hydrothermal breccia within granite and volcanic rocks of a Mesoproterozoic silicic large igneous province. Analyses of melt inclusions in quartz phenocrysts in rhyolite show that the silicic magmas of this province were unusually rich in F (up to 1.3 wt%). Fluorite and other F-rich minerals that crystallized from these magmas provided a gigantic reservoir of F. As a result, the Olympic Dam ore-forming fluid was F-rich and had exceptional capacity to transport diverse elements. Further, we infer that hydrofluoric acid, the most corrosive acid known, contributed to hydrothermal breccia formation by dissolution that in turn increased permeability and accelerated the rate of fluid-rock interaction. It is no accident that the world's largest hydrothermal ore deposit occurs in an F-rich silicic large igneous province

Psychosocial predictors of exclusive breastfeeding duration to six moths postpartum

The World Health Organization recommend that for optimal growth and development all infants worldwide should be exclusively breastfed for the first six months of life. Previous studies have identified that psychosocial factors are important for the maintenance of exclusive breastfeeding. This study aimed to examine the psychosocial factors associated with exclusive breastfeeding duration to six months postpartum. Method: 125 women completed questionnaires at three time points; 32 weeks gestation, two and six months postpartum. Self-efficacy, body attitude, psychological adjustment, attitude, intention, confidence, motivation and importance of exclusive breastfeeding and breastfeeding status were measured. Findings: At 32 weeks gestation a woman’s confidence to achieve exclusive breastfeeding was a predictor of exclusive breastfeeding to six months postpartum. At two months postpartum, psychological adjustment and self-efficacy were predictive of exclusive breastfeeding duration. At six months postpartum, psychological adjustment, self-efficacy, confidence to maintain and feeling fat were predictive of exclusive breastfeeding duration. Conclusion: Self-efficacy, psychological adjustment, body image, motivation and confidence are important for the maintenance of exclusive breastfeeding to six months. This has clinical application for health psychology as antenatal breastfeeding education and postpartum support may be strengthened by strategies that build a woman’s confidence to exclusively breastfeed

Psychosocial predictors of exclusive breastfeeding duration to six moths postpartum

The World Health Organization recommend that for optimal growth and development all infants worldwide should be exclusively breastfed for the first six months of life. Previous studies have identified that psychosocial factors are important for the maintenance of exclusive breastfeeding. This study aimed to examine the psychosocial factors associated with exclusive breastfeeding duration to six months postpartum. Method: 125 women completed questionnaires at three time points; 32 weeks gestation, two and six months postpartum. Self-efficacy, body attitude, psychological adjustment, attitude, intention, confidence, motivation and importance of exclusive breastfeeding and breastfeeding status were measured. Findings: At 32 weeks gestation a woman’s confidence to achieve exclusive breastfeeding was a predictor of exclusive breastfeeding to six months postpartum. At two months postpartum, psychological adjustment and self-efficacy were predictive of exclusive breastfeeding duration. At six months postpartum, psychological adjustment, self-efficacy, confidence to maintain and feeling fat were predictive of exclusive breastfeeding duration. Conclusion: Self-efficacy, psychological adjustment, body image, motivation and confidence are important for the maintenance of exclusive breastfeeding to six months. This has clinical application for health psychology as antenatal breastfeeding education and postpartum support may be strengthened by strategies that build a woman’s confidence to exclusively breastfeed

Preventing mental health problems in offspring by targeting dietary intake of pregnant women

The concept of \u27early life programming\u27 considers the importance of very early environmental exposures throughout the gestational period on the subsequent health outcomes of offspring. The role of maternal dietary intake, specifically, has been highlighted after recent studies have shown maternal diet quality to predict mental health problems in offspring. Even in the pre-conception period, maternal nutrition can have permanent and sustained phenotypic consequences for offspring

Data collection in support of the Endocrine Disruption (ED) assessment for non-target vertebrates

Disclaimer: The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the Authority is subject. It may not be considered as an output adopted by the Authority. The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.To harmonise vertebrate OECD Test Guidelines for endocrine disruption testing between mammalian and non‐mammalian test species, additional Estrogen, Androgen, Thyroid and Steroidogenesis (EATS) modality endpoints in non‐mammalian models need to be assessed. These would mean for example the addition of hormonal measurements in fish, birds and amphibians. Furthermore, a better reporting of gross pathology findings for birds would also be considered advantageous for the assessment of endocrine disrupting properties.To facilitate adoption of additional measures, guidance on how to perform, report and evaluate these new endpoints is required. In this report, a variety of methods including a systematic evidence map, an extensive literature review and a survey of ecotoxicology laboratories were adopted to collect data on the topic. The systematic evidence map uncovered a range of methods for measuring sex and thyroid hormones in fish, birds and amphibians, although methods for measuring sex‐hormones in fish, were by far, the most frequently encountered in the literature and laboratory survey. However, there are still considerable gaps in knowledge for: optimum sample timing for hormonal measurement (diurnal, developmental stage, etc.), issues with inherent variability, low sample volume (plasma/serum), test species selection, possible impacts of housing/diet/stress. The extensive literature review revealed that although gross pathology and histopathology have been used to investigate the effects of endocrine disrupting chemicals in birds, there are no standardised methods for assessment or interpretation, although relative weight of endocrine organs is frequently used as a gross pathology metric. Reports of how histopathology was assessed varied considerably. From the survey, few contract laboratories are experienced in conducting the avian test guideline and these types of pathology techniques.Recommendations for future work with non‐mammalian taxa include: investigating the optimal time (or timings) for measuring hormones, developing non‐invasive hormone measuring techniques, gaining knowledge of baseline/control hormonal data, and further developing guidance on conducting and assessing gross pathology and histopathology in birds

Volcanic facies architecture, hydrothermal alteration and subsea-floor replacement at the Neves Corvo deposit, Iberian Pyrite Belt

Contribution to research project ARCHYMEDESII-POCTI/CTA/45873/2002.Three felsic volcanic sequences constitute the host succession to the Neves Corvo VHMS deposit. The lower volcanic sequence (late Famennian) consists of a rhyolitic fiamme-rich facies association that comprises polymictic and overall graded quartzphyric fiamme breccia units (up to 60 m thick). These units have pyroclastic origin and constitute the substrate to the rhyolite facies association (intermediate volcanic sequence). The rhyolite facies association (late Strunian) comprises intervals of coherent quartz-feldspar-phyric rhyolite (up to 10 m thick) that are enclosed by much thicker intervals (up to 250 m) of jigsaw-fit and clast-rotated monomictic rhyolite breccia. Laterally these breccias grade to beds of monomictic rhyolite breccia that alternate with crystal-rich sandstone. The units defined by the rhyolite facies association are rhyolitic lavas. The massive sulfide orebodies (late Strunian) directly overly the lavas or are interleaved with relatively thin (up to 50 m) intervals of mudstone. The upper volcanic sequence (early Visean) consists of a thin interval of monomictic dacite breccia. The host succession to the Neves Corvo orebodies thus comprises proximal to source vent deposits from submarine explosive and effusive eruptions. However, the ore-forming process relates both in time and space with the rhyolitic lavas, which are coeval with the mineralization. Neves Corvo is well known for its high-grade Cu ores and unique cassiterite mineralization. Ore-related hydrothermal activity overprints an early metasomatic stage and relates with a multi-sourced hydrothermal system, responsible for early stringer and massive cassiterite deposition and subsequent massive sulfide oregeneration. In the Corvo orebody, the early deposition of massive cassiterite ores was fed by an independent stockwork in a tectonically-bounded alignment. Textural and petrographic analyses, geochemistry and oxygen-isotope data indicate brusque flushing of the tin-bearing fluid into seawater after minimal fluid-rock interaction during up flow. Massive sulfide-related hydrothermal alteration is essentially stratabound and controlled by permeability contrasts. Alteration zonation is classical, consisting of an inner chlorite/donbassite-quartz-sulfides-(sericite) core that grades into sericitequartz- sulfides-(chlorite) and paragonite-quartz-sulfides-(chlorite) peripheral envelopes. The aluminous hydrothermal alteration mineralogy coupled with elemental and stable isotope geochemistry indicates very low pH, unusually high maximum interaction temperature and predominant low-sulfidation alteration/mineralization conditions. Textural and mass-balance analyses show extensive silicate-sulfide replacement in the coherent volcanic rocks of the footwall sequence, and disseminated replacement mineralization in the volcaniclatic/sedimentary units