Structural controls on the interaction between basin fluids and a rift flank fault: constraints from the Bwamba Fault, East African Rift

We present petrographic and structural analyses of a basement-hosted border fault in the East African Rift. Understanding the mechanical evolution and fluid-rock interaction of rift-flank faults is integral to developing models of fluid flow in the crust, where hydraulic connections may occur between basement faults and basin sediments. The Bwamba Fault forms the flank of the Rwenzori Mountains Horst in western Uganda, and has locally reactivated older mylonitic fabrics in the basement gneisses. The fault core features discrete mineralised and veined units. Shear fabrics and fault scarp striations indicate predominately normal kinematics, with minor strike-slip faulting and fabrics. Transient brittle failure was accompanied by two phases of fluid ingress, associated with veining and mineralisation. The first was localised and strongly influenced by host lithology. The second involved widespread Fe-oxide and jarosite mineralisation. The latter signals the onset of a hydraulic connection between Fe- and S-rich sedimentary rocks in the adjacent Semliki Rift Basin and the Bwamba Fault, involving co-seismic and or post-seismic fluid injection into the fault at ca. 150–200 °C, and 2.5–3 km depth. Such evolving permeability connections between basin sediments and basement faults are important for local hydrocarbon and geothermal systems, and may be typical of active rifts

Deformation-induced and reaction-enhanced permeability in metabasic gneisses, Iona, Scotland: controls and scales of retrograde fluid movement

The spatial distribution of greenschist-facies retrograde reaction products in metabasic gneisses from Iona, western Scotland, has been investigated. The retrograde products may be broadly accounted for by a single reaction, but their different spatial and temporal development indicates that a series of reactions occur with significantly different scales of metasomatic transfer. After initial fluid influx linked to deformation-induced high permeability, reaction-enhanced permeability, coupled to cycling of fluid pressure during faulting, strongly controls the pervasive retrogression. Ca-plagioclase and pyroxene in the gneisses are replaced by albite and chlorite in pseudomorphic textures, and this is followed by localized epidotization of the albite. Two main generations of epidote are formed in the gneisses. Epidosite formation is associated with prominent zones of cataclasite indicating a strong link between faulting and fluid influx. In contrast, complete alteration of albite to epidote in the host metabasic gneisses is spatially complex, and areas of pervasive alteration may be constrained by both epidote-rich veins and cataclasites. In other instances, reaction fronts are unrelated to structural features. Volume changes associated with individual stages of the reaction history strongly control the localized distribution of epidote and the earlier more widespread development of chlorite and albite. Such behaviour contrasts with adjacent granitic gneisses where epidotization is restricted to local structural conduits. Many small-scale mineralized fractures with evidence of having previously contained fluids do not enhance the pervasive retrogression of the metabasic gneisses and represent conduits of fluid removal. Retrogression of these basement gneisses is dominated by a complex combination of reaction-enhanced and reaction-restricted permeability, kinetic controls on the nucleation of reaction products, changes in fluid composition buffered by the reactions, and periodic local migration of fluids associated with fault movements. This combination generates spatially complex patterns of epidotization that are limited by cation supply rather than fluid availability and alternations between focused and pervasive types of retrogression

How should health service organizations respond to diversity? A content analysis of six approaches

Background Health care organizations need to be responsive to the needs of increasingly diverse patient populations. We compared the contents of six publicly available approaches to organizational responsiveness to diversity. The central questions addressed in this paper are: what are the most consistently recommended issues for health care organizations to address in order to be responsive to the needs of diverse groups that differ from the majority population? How much consensus is there between various approaches? Methods We purposively sampled six approaches from the US, Australia and Europe and used qualitative textual analysis to categorize the content of each approach into domains (conceptually distinct topic areas) and, within each domain, into dimensions (operationalizations). The resulting classification framework was used for comparative analysis of the content of the six approaches. Results We identified seven domains that were represented in most or all approaches: organizational commitment, empirical evidence on inequalities and needs, a competent and diverse workforce, ensuring access for all users, ensuring responsiveness in care provision, fostering patient and community participation, and actively promoting responsiveness. Variations in the operationalization of these domains related to different scopes, contexts and types of diversity. For example, approaches that focus on ethnic diversity mostly provide recommendations to handle cultural and language differences; approaches that take an intersectional approach and broaden their target population to vulnerable groups in a more general sense also pay attention to factors such as socio-economic status and gender. Conclusions Despite differences in labeling, there is a broad consensus about what health care organizations need to do in order to be responsive to patient diversity. This opens the way to full scale implementation of organizational responsiveness in healthcare and structured evaluation of its effectiveness in improving patient outcomes

"Unwell while Aboriginal": iatrogenesis in Australian medical education and clinical case management

INTRODUCTION: Attention to Aboriginal health has become mandatory in Australian medical education. In parallel, clinical management has increasingly used Aboriginality as an identifier in both decision making and reporting of morbidity and mortality. This focus is applauded in light of the gross inequalities in health outcomes between indigenous people and other Australians. METHODS: A purposive survey of relevant Australian and international literature was conducted to map the current state of play and identify concerns with efforts to teach cultural competence with Aboriginal people in medical schools and to provide "culturally appropriate" clinical care. The authors critically analyzed this literature in light of their experiences in teaching Aboriginal studies over six decades in many universities to generate examples of iatrogenic effects and possible responses. RESULTS AND DISCUSSION: Understanding how to most effectively embed Aboriginal content and perspectives in curriculum and how to best teach and assess these remains contested. This review canvasses these debates, arguing that well-intentioned efforts in medical education and clinical management can have iatrogenic impacts. Given the long history of racialization of Aboriginal people in Australian medicine and the relatively low levels of routine contact with Aboriginal people among students and clinicians, the review urges caution in compounding these iatrogenic effects and proposes strategies to combat or reduce them. CONCLUSION: Long overdue efforts to recognize gaps and inadequacies in medical education about Aboriginal people and their health and to provide equitable health services and improved health outcomes are needed and welcome. Such efforts need to be critically examined and rigorously evaluated to avoid the reproduction of pathologizing stereotypes and reductionist explanations for persistent poor outcomes for Aboriginal people

Impact of reservoir quality on the carbon storage potential of the Bunter Sandstone Formation, southern North Sea

The Lower Triassic Bunter Sandstone Formation is a major prospective reservoir for carbon capture, utilization and storage in the UK Southern North Sea, and is likely to play a pivotal role in the UK reaching mid-century Net Zero targets. A knowledge gap in reservoir quality exists between previous detailed, but highly focused front-end engineering and development projects, and large-scale regional analysis. This study integrates a regional approach with locally derived reservoir characterization, offering a holistic analysis of the prospectivity of the Bunter Sandstone Formation for subsurface CO2 storage. Petrophysical analysis of ninety-six wells across the UK Southern North Sea is coupled with seismic interpretation to understand spatial variations of reservoir thickness, facies and quality that underpin theoretical CO2 storage capacity models. Electrofacies classification is employed to identify and correlate baffles and barriers to permeability over areas currently licensed for geological carbon storage. Our findings point to variable, but broadly favourable reservoir conditions, though identification and correlation of laterally extensive intraformational mudstones and halite-cemented horizons will likely present challenges to CO2 injection. Within carbon storage license blocks CS001, CS006 and CS007, the Bunter Sandstone Formation has the potential to store 5700 MCO2t, the equivalent of seventy-nine years of the UK's 2022 business and industrial CO2 emissions. A further 434 MCO2t is offered by Triassic closures within license CS005, with many neighbouring moderate (100–1000 MCO2t) and small (<100 MCO2t) closures forming part of newly awarded carbon storage licenses that will likely form part of the UK SNS CCUS portfolio in the future. Supplementary material: well-correlation panels and tabulated velocity and storage capacity modelling parameters are available at https://doi.org/10.6084/m9.figshare.c.702745

Use of exploration methods to repurpose and extend the life of a super basin as a carbon storage hub for the energy transition

Funding Information: The authors acknowledge funding from the Net Zero Technology Centre and Shell that enabled the research to be undertaken. We thank Rachel Jamieson for her help and support for the project and SLB for permission to use their Petrel software under academic license. Data access was obtained via the North Sea Transition Authority’s National Data Repository portal, and where gaps existed, additional, proprietary, seismic data was provided by WesternGeco, access to which we acknowledge and appreciate. Publisher Copyright: © 2023 Copyright The American Association of Petroleum Geologists. All rights reserved.Peer reviewedPublisher PD