Metamorphic and basin fluids in quartz–carbonate–sulphide veins in the SW Scottish Highlands: a stable isotope and fluid inclusion study

Metalliferous (Fe–Cu–Pb–Zn) quartz–carbonate–sulphide veins cut greenschist to epidote–amphibolite facies metamorphic rocks of the Dalradian, SW Scottish Highlands, with NE–SW to NW–SE trends, approximately parallel or perpendicular to regional structures. Early quartz was followed by pyrite, chalcopyrite, sphalerite, galena, barite, late dolomite–ankerite and clays. Both quartz–sulphide and carbonate vein mineralisation is associated with brecciation, indicating rapid release of fluid overpressure and hydraulic fracturing. Two distinct mineralising fluids were identified from fluid inclusion and stable isotope studies. High temperature (>350°C) quartz‐precipitating fluids were moderately saline (4.0–12.7 wt.% NaCl equivalent) with low (approximately 0.05). Quartz δ¹⁸O (+11.7 to +16.5‰) and sulphide δ³⁴S (?13.6 to ?1.1‰) indicate isotopic equilibrium with host metasediments (rock buffering) and a local metasedimentary source of sulphur. Later, low‐temperature (T_H = 120–200°C) fluids, probably associated with secondary carbonate, barite and clay formation, were also moderately saline (3.8–9.1 wt.% NaCl equivalent), but were strongly enriched in ¹⁸O relative to host Dalradian lithologies, as indicated by secondary dolomite–ankerite (δ¹⁸O = +17.0 to +29.0‰, δ¹³C = ?1.0 to ?3.0‰). Compositions of carbonate–forming fluids were externally buffered. The veins record the fluid–rock interaction history of metamorphic host rocks during cooling, uplift and later extension. Early vein quartz precipitated under retrograde greenschist facies conditions from fluids probably derived by syn‐metamorphic dehydration of deeper, higher‐grade rocks during uplift and cooling of the Caledonian metamorphic complex. Veins are similar to those of mesothermal veins in younger Phanerozoic metamorphic belts, but are rare in the Scottish Dalradian. Early quartz veins were reactivated by deep penetration of low‐temperature basin fluids that precipitated carbonate and clays in veins and adjacent Dalradian metasediments throughout the SW Highlands, probably in the Permo‐Carboniferous. This event is consistent with paragenetically ambiguous barite with δ³⁴S characteristic of late Palaeozoic basinal brines.     

Paracondylar process: Manifestation of an occipital vertebra

In the examination of over 1300 burials from medieval Canterbury, one individual displayed a well-defined paracondylar process. Four other adults and two children presented with small tubercles at the same site. The aetiology of the trait is discussed with reference to cranial base variants and the so-called manifestation of an occipital vertebra.     

Faith-based Queer Space in Washington,DC: The Metropolitan Community Church-DC and Mount Vernon Square

Religion and spirituality are important in queer place-making processes. More than a private part of life relegated beneath sexual identity, religious affiliation and spirituality motivate queers to interpret, experience, and shape space in distinct ways. Just as studies of queer residential spaces have neglected religion and spirituality, so have studies of queer religiosity and spirituality ignored less morally charged arenas of life such as residential choices and gentrification. Considering the material impact of spirituality and religion and understanding competing visions for the future of space in queer residential communities contributes to a clearer view of queer residential strategies. In Washington, DC, Christian queers are working with others to shape a distinct residential space called Mount Vernon Square. This ethnographic study offers a broader framework for understanding how some queers integrate sexuality and spirituality in their residential choices.     

Population and Affective Perception: Biopolitics and Anticipatory Action in US Counterinsurgency Doctrine

Abstract: This paper analyses the biopolitical logics of current US counterinsurgency doctrine in the context of the multiple forms of biopower that make up the “war on terror”. It argues that counterinsurgency doctrine aims to prevent spectral networked insurgencies by intervening on the “environment” of insurgent formation—the relations between three different enactments of “population” (species being, logistical life and ways of life) and a fourth—affectively imbued perception. Counterinsurgency is best characterised, then, as an “environmentality” (Foucault M 2008 The Birth of Biopolitics: Lectures at the Collége De France, 1978–1979. Translated by G Burchell. London: Palgrave Macmillan) that redeploys elements from other forms of biopolitics alongside an emphasis on network topologies, future‐orientated action and affective perception.     

Class Monopoly Rent and the Redevelopment of Portland's Pearl District

This study examines the role of class monopoly rent in shaping the spatial form and pattern of urban redevelopment processes in the contemporary neoliberal city. Since an initial flourishing literature during the 1970s and 1980s, urban land rent theory has fallen from the analytic radar of critical urban studies since the early 1990s, with the influence of class monopoly rent often considered an aberration of how capitalist real estate markets normally operate, if not rejected. Consequently, class monopoly rent has never been systematically elaborated. Based on an empirical analysis of Portland's Pearl District, this study suggests that the influence of class monopoly rent in contemporary processes of urban redevelopment is far more pervasive than often recognised, representing a “standard institutional practice” that is endemic (rather than aberrational) to the working of neoliberal urban governing regimes, and embeds in the social and physical landscape in a multiplicity of ways.     

Umkomasia (megasporophyll): part 1 of a reassessment of Gondwana Triassic plant genera and a reclassification of some previously attributed

The genus Umkomasia, a megasporophyll, belonging to the pteridosperms (seed ferns) in the family Umkomasiaceae (Corystospermaceae), is reassessed comprehensively worldwide. All previous records are analysed. Certain fertile structures previously attributed are reclassified. Umkomasia is shown to be restricted to the Triassic of Gondwana where it is associated with the genus Pteruchus, a microsporophyll, and the genus Dicroidium, a vegetative leaf. It is well represented from Argentina, Australia and southern Africa where the Molteno Formation is by far the most comprehensively sampled with eight species described. Two specimens from the upper Permian of India attributed to Umkomasia are reclassified as cf. Arberiopsis sp. A whorled fertile structure from Antarctica, previously assigned to Umkomasia, is reclassified in a new genus as Axsmithia uniramia. Another compression fossil and the permineralized Umkomasia resinosa remain as valid records from Antarctica. The material described as Umkomasia from the Triassic of China is reclassified as Stenorachis asiatica. The Lower Jurassic record from Germany is placed in a new genus as Kirchmuellia franconica. The records of Umkomasia sp. from the Rhaetic of Germany are reclassified as cf. Kirchmuellia sp. and the single specimen from the Jurassic of Libya as genus et sp. indet. The Lower Cretaceous record from Mongolia has been reclassified by other researchers as Doylea mongolica. A pictorial key to Umkomasia species is provided, geographic and stratigraphic distributions are tabulated.