Petrology and geochemistry of gabbroic and ultrabasic rocks from eastern Rhum

This work is concerned with the lower part of the Eastern Layered Series (LELS) of Rhum, and with the marginal relationships of the ultrabasic complex in eastern Rhum. The Lower Eastern Layered Series comprises approximately Units 1-5 of previous workers. Remapping has revealed considerable along-strike lithological variation in the units of the L.E.L.S. It is suggested, on the basis of field and geochemical evidence, that two layers formerly regarded as 'conformable intrusive sheets of fine grained olivine gabbro'. may be evolved allivalite layers rather than later intrusions. Xenolith suites in these layers and elsewhere, indicate a component derived from the roof or walls of the magma chamber. Cryptic variation is more extensive in the L.E.L.S. than in other parts of Rhum: olivine forsterite content varies from 85.6 to 70, and clinopyroxene MgX100/(Mg+Fe) varies from 88 to 74. Post-cumulus effects and sub-solidus re-equilibration have altered the initial compositions of the mineral phases. The migration of interstitial liquids has had a major effect on mineral chemistry. Replacement of plagioclase-rich rocks by peridotite is a significant process in parts of the sequence. This is ascribed to disequilibrium between migrating pore liquids and plagioclase. The data are consistent with a model of repeated replenishment by picritic magma, although the replenishing liquids may have been slightly less magnesian than those subsequently available during the formation of the upper ELS .Re-examination of the eastern margin of the ultrabasic complex suggests that the ultrabasic rocks formed more or less in situ, and that fragments of the roof to the intrusion occur in places. Locally under these roof fragments variolitic olivine-rich gabbros are developed, which may represent the chilled margin to the ultrabasic complex

Identifying and managing asbestiform minerals in geological collections

Asbestos is widely recognised as a serious hazard, and its industrial use is now banned within the UK, and EU, and strict regulations govern the use of older manufactured materials which may contain asbestos. However, asbestos is also a natural geological material, and may occur in museum collections as minerals or constituents of rock specimens. In the UK the Control of Asbestos Regulations 2012 (CAR 2012) provides the legal framework for the safe identification, use and disposal of asbestos. However, these regulations, and other EU regulations, provide no specific guidance on dealing with potentially asbestos-containing natural materials. CAR 2012 specifies just six asbestos minerals although a number of other minerals in museum collections are known to have asbestiform structures and be hazard-ous, including other amphiboles, and the zeolite erionite. Despite the lack of specific guid-ance, museums must comply with CAR 2012, and this paper outlines the professional ad-vice, training and procedures which may be needed for this. It provides guidance on identifi-cation of potential asbestos-bearing specimens and on procedures to document them and store them for future use, or to prepare them for professional disposal. It also makes sug-gestions how visitors, employees and others in a museum can be protected from asbestos as incoming donations and enquiries, managed in the event of an emergency, and safely included in displays

David Ferguson’s mineral prospecting expedition to South Georgia in 1912

The mineral exploration work in the Falkland Islands by the Scottish geologist and mineral prospector David Ferguson, during the 1913-1914 austral summer, was described in the 2013 issue of Falkland Island Journal (Volume 10, Part 2). But that was Ferguson’s second expedition to the South Atlantic region on behalf of the Christian Salvesen Whaling Company. During 1912 he had visited South Georgia to assess the rocks there for the possible presence of economic minerals. When the Salvesen Company established their onshore whaling station in Stromness Bay in 1909, naming it Leith Harbour after the company’s home port in Scotland, negotiations for mineral rights were promptly begun with the Falkland Islands Government (at that time South Georgia was a Dependency of the Falkland Islands). These were successfully concluded and a formal license allowing prospecting was signed on 31 May 1911 by the Governor of the Falklands, William Allardyce. A copy of the license is preserved in the Salvesen Archive, now held by the University of Edinburgh Library’s Centre for Research Collections, along with other material relevant to Ferguson’s survey including his geological report and some of his photographic prints and glass-plate negatives

Quantifying Holocene Relative Sea-level Changes and Paleoclimate Using the Scottish Speleothem Record

Speleothems, secondary cave carbonates, are valuable archives for reconstructing paleoclimate and relative sea-level changes where the caves are in coastal locations. Unlike the typical speleothems found in carbonate caves, speleothems were recently discovered in a meta-silicate sea cave in Iona, on the west coast of Scotland. Although speleothems have previously been reported from caves in volcanic rocks, speleothems in metamorphic caves have rarely been reported. The Iona speleothems are potentially crucial because paleoclimate reconstructions spanning the Holocene are scarce in Scotland due to a lack of material, particularly speleothems, which can be dated precisely using geochemical dating methods. In this research, the U-Th and 14C dating techniques will be used to constrain the precise age and growth history of the Iona speleothem. Results from pilot U-Th dating of the first speleothem sampled show it is about 1760 ~ 4780 years old (the data, however, have uncertainties up to 69.9%, due to the presence of non-authigenic Th). As for paleoclimate, oxygen isotopes indicate that the amount of precipitation was at a relatively low level between 3000 and 2000 years ago, then increased dramatically from ~2000 to 1760 years ago. These preliminary data indicate that the Iona speleothem has the potential to provide important insights into the Late Holocene relative sea-level changes and climate

High-precision 41K/39K measurements by MC-ICP-MS indicate terrestrial variability of δ41K

Potassium is a major component in continental crust, the fourth-most abundant cation in seawater, and a key element in biological processes. Until recently, difficulties with existing analytical techniques hindered our ability to identify natural isotopic variability of potassium isotopes in terrestrial materials. However, measurement precision has greatly improved, and a range of K isotopic compositions has now been demonstrated in natural samples. In this study, we present a new technique for high-precision measurement of K isotopic ratios using high-resolution, cold plasma multi-collector mass spectrometry. We apply this technique to demonstrate natural variability in the ratio of 41K to 39K in a diverse group of geological and biological samples, including silicate and evaporite minerals, seawater, and plant and animal tissues. The total range in 41K/39K ratios is ca. 2.6‰, with a long-term external reproducibility of 0.17‰ (2σ, N=108). Seawater and seawater-derived evaporite minerals are systematically enriched in 41K compared to silicate minerals by ca. 0.6‰, a result consistent with recent findings (1, 2). Although our average bulk- silicate Earth value (-0.54‰) is indistinguishable from previously published values, we find systematic δ41K variability in some high-temperature sample suites, particularly those with evidence for the presence of fluids. The δ41K values of biological samples span a range of ca. 1.2‰ between terrestrial mammals, plants, and marine organisms. Implications of terrestrial K isotope variability for the atomic weight of K and K-based geochronology are discussed. Our results indicate that high-precision measurements of stable K isotopes, made using commercially available mass spectrometers, can provide unique insights into the chemistry of potassium in geological and biological systems

Prehabilitation for adults diagnosed with cancer: A systematic review of long‐term physical function, nutrition and patient‐reported outcomes

Objective: Prehabilitation is increasingly being used to mitigate treatment-related complications and enhance recovery. An individual's state of health at diagnosis, including obesity, physical fitness and comorbidities, are influencing factors for the occurrence of adverse effects. This review explores whether prehabilitation works in improving health outcomes at or beyond the initial 30 days post-treatment and considers the utility of prehabilitation before cancer treatment. Methods: A database search was conducted for articles published with prehabilitation as a pre-cancer treatment intervention between 2009 and 2017. Studies with no 30 days post-treatment data were excluded. Outcomes post-prehabilitation were extracted for physical function, nutrition and patient-reported outcomes. Results: Sixteen randomised controlled trials with a combined 2017 participants and six observational studies with 289 participants were included. Prehabilitation interventions provided multi-modality components including exercise, nutrition and psychoeducational aspects. Prehabilitation improved gait, cardiopulmonary function, urinary continence, lung function and mood 30 days post-treatment but was not consistent across studies. Conclusion: When combined with rehabilitation, greater benefits were seen in 30-day gait and physical functioning compared to prehabilitation alone. Large-scale randomised studies are required to translate what is already known from feasibility studies to improve overall health and increase long-term cancer patient outcomes

The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton

The geodynamic regime(s) that predominated during the Archaean remains controversial, with the plethora of competing models largely informed by felsic lithologies. Ultramafic-mafic rocks displaying distinctive geochemical signatures are formed in a range of Phanerozoic geotectonic environments. These rocks have high melting points, making them potentially useful tools for investigating Archaean geodynamic processes in highly metamorphosed regions. We present field mapping, petrography, traditional bulk-rock geochemistry, and platinum-group element geochemistry for 12 ultramafic-mafic bodies in the Lewisian Gneiss Complex (LGC), which is a highly metamorphosed fragment of the North Atlantic Craton in northwest Scotland. Our data indicate that most of these occurrences are layered intrusions emplaced into the tonalite-trondhjemite-granodiorite (TTG)-dominated crust prior to polyphase metamorphism, representing a significant re-evaluation of the LGC's magmatic evolution. Of the others, two remain ambiguous, but one (Loch an Daimh Mor) has some geochemical affinity with abyssal/orogenic peridotites and may represent a fragment of Archaean mantle, although further investigation is required. The ultramafic-mafic bodies in the LGC thus represent more than one type of event/process. Compared with the TTG host rocks, these lithologies may preserve evidence of protolith origin(s), with potential to illuminate tectonic setting(s) and geodynamic regimes of the early Earth

Assessing the validity of negative high field strength-element anomalies as a proxy for Archaean subduction: evidence from the Ben Strome Complex, NW Scotland

The relative depletion of high field strength elements (HFSE), such as Nb, Ta and Ti, on normalised trace-element plots is a geochemical proxy routinely used to fingerprint magmatic processes linked to Phanerozoic subduction. This proxy has increasingly been applied to ultramafic-mafic units in Archaean cratons, but as these assemblages have commonly been affected by high-grade metamorphism and hydrothermal alteration/metasomatism, the likelihood of element mobility is high relative to Phanerozoic examples. To assess the validity of HFSE anomalies as a reliable proxy for Archaean subduction, we here investigate their origin in ultramafic rocks from the Ben Strome Complex, which is a 7 km2 ultramafic-mafic complex in the Lewisian Gneiss Complex of NW Scotland. Recently interpreted as a deformed layered intrusion, the Ben Strome Complex has been subject to multiple phases of high-grade metamorphism, including separate granulite- and amphibolite-facies deformation events. Additional to bulk-rock geochemistry, we present detailed petrography, and major- and trace-element mineral chemistry for 35 ultramafic samples, of which 15 display negative HFSE anomalies. Our data indicate that the magnitude of HFSE anomalies in the Ben Strome Complex are correlated with light rare earth-element (LREE) enrichment likely generated during interaction with H2O and CO2-rich hydrothermal fluids associated with amphibolitisation, rather than primary magmatic (subduction-related) processes. Consequently, we consider bulk-rock HFSE anomalies alone to be an unreliable proxy for Archaean subduction in Archaean terranes that have experienced multiple phases of high-grade metamorphism, with a comprehensive assessment of element mobility and petrography a minimum requirement prior to assigning geodynamic interpretations to bulk-rock geochemical dat

Obesity and low levels of physical activity impact on cardiopulmonary fitness in older men after treatment for prostate cancer

The purpose of this study was to compare fitness parameters and cardiovascular disease risk of older and younger men with prostate cancer (PCa) and explore how men's fitness scores compared to normative age values. 83 men were recruited post‐treatment and undertook a cardiopulmonary exercise test (CPET), sit‐to‐stand, step‐and‐grip strength tests and provided blood samples for serum lipids and HbA1c. We calculated waist‐to‐hip ratio, cardiovascular risk (QRISK2), Charlson comorbidity index (CCI) and Godin leisure‐time exercise questionnaire [GLTEQ]. Age‐group comparisons were made using normative data. Men > 75 years, had lower cardiopulmonary fitness, as measured by VO2 Peak (ml/kg/min) 15.8 + 3.8 p 75 years had more cardiovascular risk factors compared to normative standards for men of their age. Although ADT was more frequent in older men, this was not found to be associated with cardiopulmonary fitness, but obesity and low levels of physical activity were. Secondary prevention should be addressed in men with PCa to improve men's overall health

Trace-element abundances in the shallow lithospheric mantle of the North Atlantic Craton margin: implications for melting and metasomatism beneath Northern Scotland

Bulk rock geochemistry and major- and trace-element compositions of clinopyroxene have been determined for three suites of peridotitic mantle xenoliths from the North Atlantic Craton (NAC) in northern Scotland, to establish the magmatic and metasomatic history of subcontinental lithospheric mantle (SCLM) below this region. Spinel lherzolites from the southernmost locality (Streap Com'laidh) have non-NAC mantle compositions, while the two northern xenolith suites (Loch Roag and Rinibar) are derived from the thinned NAC marginal keel. Clinopyroxene compositions have characteristic trace-element signatures which show both 'primary' and 'metasomatic' origins. We use Zr and Hf abundances to identify ancient cryptic refertilization in 'primary' clinopyroxenes. We suggest that Loch Roag and Rinibar peridotite xenoliths represent an ancient Archaean-Palaeoproterozoic SCLM with original depleted cratonic signatures which were overprinted by metasomatism around the time of intrusion of the Scourie Dyke Swarm (∼2.4 Ga). This SCLM keel was preserved during Caledonian orogenesis, although some addition of material and/or metasomatism probably also occurred, as recorded by Rinibar xenoliths. Rinibar and Streap xenoliths were entrained in Permo-Carboniferous magmas and thus were isolated from the SCLM ∼200 Ma before Loch Roag xenoliths (in an Eocene dyke). Crucially, despite their geographical location, lithospheric mantle peridotite samples from Loch Roag show no evidence of recent melting or refertilization during the Palaeogene opening of the Atlantic