13 research outputs found

    Foundation stone of empire: the role of Portland stone in ‘heritage’, commemoration, and identity.

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    In 2013, Portland Stone, a creamy white limestone from the Isle of Portland in Dorset, was named the world’s first ‘Global Heritage Stone Resource’ (GSHR) by the Heritage Stone Task Group, a sub-commission of the International Union of Geological Sciences. The criteria for GSHR designation are ambiguous, with the Task Group championing Portland Stone’s ‘cultural value’ and ‘heritage’, neither of which are critically interrogated. In this paper we undertake a detailed critical discourse analysis of Hansard entries mentioning Portland Stone between 1803 and 2020. We reveal that the use of Portland Stone is intertwined with colonial oppression, class subjugation, empire politics, structural racism, and a mythologised, England-centric vision of British national identity. In celebrating the use of Portland Stone as part of Britain’s ‘heritage’, we are condoning a narrative of Britishness that is exclusionary and whitewashed, and that supports an elite rewriting of national and international history. Drawing on critical heritage literature, we argue that the Heritage Stone Task Group must urgently reconsider their uncritical appraisal of ‘heritage’ and ‘culture’ and consult with social science colleagues to ensure that all voices are heard. Our study shows that through the history and nature of their usage, the rocks beneath our feet, our natural foundation, can become imbued with notions of regional and national identity, belonging and exclusion, memory and loss – they can become a powerful manifestation of symbolic and unequal power structures. While British society’s attention is turned to the imprint of colonialism, empire, and race on our geographies, we urge further consideration of the built environment: the very stones that construct our towns and cities, the plinths on which statues are erected, tell stories of oppression and domination that are an important part of British history, culture, and heritage

    Dva predavanja o partizanskoj umjetnosti

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    MRW was supported by a NERC-studentship through the University of Manchester. MRW also acknowledges financial support from IAS via a postgraduate grant. SS was supported through a Strategy Grant of the Faculty of Engineering and Physical Sciences at the University of Manchester.The Paleoproterozoic Great Oxidation Event (GOE) marks the first significant oxidation of atmosphere and surface environments, and is causally associated with the global disappearance of mass-independent sulfur isotope fractionation (MIF-S). However, fundamental sedimentary aspects of sedimentary successions recording this event (e.g. depositional environment, tectonic setting and stratigraphic correlation) are poorly constrained and often debated, restricting full understanding of causes and effects related to the GOE. In South Africa, MIF-S disappears across the ‘mid-Duitschland unconformity’ (MDU) in the Duitschland Formation (Transvaal Supergroup). New sedimentological observations of the lower Duitschland Formation have identified up to 5 times thicker and more diverse chert-pebble conglomerates than previously documented. New facies observed include lenticular conglomerates which incise cross-bedded dolomites, and imbricated conglomerates. The overlying MDU is angular in nature, recording an ∼15° N dip of the lower Duitschland strata; elsewhere it possesses a disconformable geometry. A new depositional model is proposed where shallow-marine carbonate (ramp) deposition interfaced with wave-influenced Gilbert-type fan deltas in an isolated depocentre produced during synsedimentary faulting. There is no evidence that the MDU formed due to direct glaciation as proposed previously, however glacio-eustatic changes may have had an influence. This study supports lithostratigraphic correlations between the Duitschland and Rooihoogte formations which both register the MIF-S disappearance, but are considered separate lithostratigraphic units, which implies oscillations in MIF-S. The correlation proposed in this study implies a unique MIF-S signal and has important consequences for differentiating true spatiotemporal oscillations in MIF-S chemistry from artificial variations caused by unresolved stratigraphic relations.PostprintPeer reviewe

    Sedimentology and isotope geochemistry of transitional evaporitic environments within arid continental settings : from erg to saline lakes

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    This research was supported by grants to RPP from the AAPG (Gustavus E. Archie Memorial Grant) and by the European Union’s Horizon 2020 research and innovation programme (Grant 678812 to M.W.C.).Arid continental basins typically contain a spectrum of coeval environments that coexist and interact from proximal to distal. Within the distal portion, aeolian ergs often border playa, or perennial, desert lakes, fed by fluvial incursions or elevated groundwaters. Evaporites are common features in these dryland, siliciclastic dominant settings. However, sedimentary controls upon evaporite deposition are not widely understood, especially within transitional zones between coeval clastic environments that are dominantly controlled by larger scale allocyclic processes, such as climate. The sulphur (δ34S) and oxygen (δ18O, Δ17O) isotope systematics of evaporites can reveal cryptic aspects of sedimentary cycling and sulphate sources in dryland settings. However, due to the lack of sedimentological understanding of evaporitic systems, isotopic data can be easily misinterpreted. This work presents detailed sedimentological and petrographic observations, coupled with δ34S, δ18O and Δ17O data, for the early Permian Cedar Mesa Sandstone Formation (western USA). Depositional models for mixed evaporitic / clastic sedimentation, which occurs either in erg-marginal or lacustrine-marginal settings, are presented to detail the sedimentary interactions present in terms of climate variations that control them. Sedimentological and petrographical analysis of the evaporites within the Cedar Mesa Sandstone Formation reveal a continental depositional environment and two end member depositional models have been developed: erg-margin and lake-margin. The δ34S values of gypsum deposits within the Cedar Mesa Sandstone Formation are consistent with late Carboniferous to early Permian marine settings. However, a marine interpretation is inconsistent with sedimentological and petrographic evidence. Consequently, δ34S, δ18O and Δ17O values are probably recycled and do not reflect ocean-atmosphere values at the time of evaporite precipitation. They are most likely derived from the weathering of older marine evaporites in the hinterland. Thus, the results demonstrate the need for a combination of both sedimentological and geochemical analysis of evaporitic systems to better understand their depositional setting and conditions.PostprintPeer reviewe

    A copper isotope investigation of methane cycling in Late Archaean sediments

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    This research was supported by NERC award NE/L002590/1 to the IAPETUS DTP, and by NERC Standard Grant NE/J023485/2 to A.L.Z. The initiation of Cu isotope analysis at the University of St Andrews was aided significantly by a Carnegie Trust Research Incentive Grant awarded to P.S.S.The rise of oxygenic photosynthesis arguably represents the most important evolutionary step in Earth history. Recent studies, however, suggest that Earth’s pre-oxidative atmosphere was also heavily influenced by biological feedbacks. Most notably, recent geochemical records propose the existence of a hydrocarbon haze which periodically formed in response to enhanced biospheric methane fluxes. Copper isotopes provide a potential proxy for biological methane cycling; Cu is a bioessential trace metal and a key element in the aerobic oxidation of methane to carbon dioxide (methanotrophy). In addition, Cu isotopes are fractionated during biological uptake. Here, we present a high-resolution Cu isotope record measured in a suite of shales and carbonates from core GKF01, through the ~2.6–2.5 Ga Campbellrand-Malmani carbonate platform. Our data show a 0.85‰ range in Cu isotope composition and a negative excursion that predates the onset of a haze event. We interpret this excursion as representing a period of enhanced aerobic methane oxidation before the onset of the Great Oxidation Event. This places valuable time constraints on the evolution of this metabolism and firmly establishing Cu isotopes as a biomarker in Late Archaean rocks.PostprintPeer reviewe

    Certain differences between old people\u27s households and agricultural households which include members capable of work

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    Using data obtained from an investigation, the article points to the difficult position of old people’s agricultural households in comparison to agricultural households with members fit for active work. In general, old people\u27s households possess small farms. Due to inadequate mechanical- equipment and lack of labour old people’s households also achieve lower yields per hectare, as can be seen from »natural effect of the cultivation of one hectare of arable land«. For the same reason, old people’s households, although possessing small farms, often lease their land or use hired labour and equipment. The article also deals with the pattern of spending both of old people’s and of agricultural households: generally, old people’s households appear to spend twice less and to have a less favourable structure of expenses, because they spend a comparatively larger proportion of their money on maintaining production while investing 7.5 times less money in development and modernization than do agricultural households which have enough man-power available. In recent years a large number of old people’s households have sold their land and thus ensured a livelihood for themselves

    Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

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    BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

    Synsedimentary fault control on the deposition of the Duitschland Formation (South Africa):implications for depositional settings, Paleoproterozoic stratigraphic correlations, and the GOE

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    The Paleoproterozoic Great Oxidation Event (GOE) marks the first significant oxidation of atmosphere and surface environments, and is causally associated with the global disappearance of mass-independent sulfur isotope fractionation (MIF-S). However, fundamental sedimentary aspects of sedimentary successions recording this event (e.g. depositional environment, tectonic setting and stratigraphic correlation) are poorly constrained and often debated, restricting full understanding of causes and effects related to the GOE. In South Africa, MIF-S disappears across the ‘mid-Duitschland unconformity’ (MDU) in the Duitschland Formation (Transvaal Supergroup). New sedimentological observations of the lower Duitschland Formation have identified up to 5 times thicker and more diverse chert-pebble conglomerates than previously documented. New facies observed include lenticular conglomerates which incise cross-bedded dolomites, and imbricated conglomerates. The overlying MDU is angular in nature, recording an ∼15° N dip of the lower Duitschland strata; elsewhere it possesses a disconformable geometry. A new depositional model is proposed where shallow-marine carbonate (ramp) deposition interfaced with wave-influenced Gilbert-type fan deltas in an isolated depocentre produced during synsedimentary faulting. There is no evidence that the MDU formed due to direct glaciation as proposed previously, however glacio-eustatic changes may have had an influence. This study supports lithostratigraphic correlations between the Duitschland and Rooihoogte formations which both register the MIF-S disappearance, but are considered separate lithostratigraphic units, which implies oscillations in MIF-S. The correlation proposed in this study implies a unique MIF-S signal and has important consequences for differentiating true spatiotemporal oscillations in MIF-S chemistry from artificial variations caused by unresolved stratigraphic relations

    Positive cerium anomalies imply pre-GOE redox stratification and manganese oxidation in Paleoproterozoic shallow marine environments

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    MRW was supported by a NERC-studentship through the University of Manchester (NEL501591/1) and by the REI Fund of the Geological Society of South Africa. SS was supported through a Strategy Grant of the Faculty of Engineering and Physical Sciences at the University of Manchester.The Paleoproterozoic Koegas Subgroup (Transvaal Supergroup, South Africa) was deposited in the immediate prelude to the Great Oxidation Event (GOE), and can therefore shed light on the oceanic paleoredox conditions just before atmospheric oxidation. Manganese enrichments of ∼16 wt% in diagenetic kutnahorite horizons suggest that Mn2+ oxidation occurred, either by free O2 or by an ancient photosystem. Iron and molybdenum isotope trends also support the existence of a Mn4+-oxide sediment flux, suggesting that the Koegas basin may have been redox stratified. Evidence from detrital and authigenic pyrite with mass-independently fractionated sulfur isotopes, however, suggests that the atmosphere was devoid of oxygen. To resolve this contradiction, this paper presents new constraints on pathways of Mn2+ oxidation from field, petrographic, stable isotope, and rare earth element and yttrium (REYSN) analysis of stromatolitic carbonates from the upper Koegas Subgroup. Ferroan dolostones and limestones preserve marine REYSN arrays with positive CeSN anomalies. These differences are explained by a redox stratified basin, whereby Mn2+ and Ce3+ are oxidized at a redoxcline and Ce is adsorped onto sinking Mn-oxide particles. Mn-oxide particles and a negative Ce anomaly from the oxidized upper water column are transferred into carbonates accumulating above the redoxcline. Diagenetic fluids later reduce the Mn-oxides to kutnahorite. Below the redoxcline, reduction of Mn-oxides particles enriches carbonates in Mn and a positive Ce anomaly. This contribution adds evidence for development of oxygen oases and redox-stratified basins before the GOE. Redox stratification was best developed during transgressions. During regressions, a deltaic system prograded into the Koegas Basin. High sedimentation rates likely allowed for preservation of detrital pyrite only in the deltaic sandstones, thus explaining the contradictory geochemical evidence. No previously unknown ancient photosystem of Mn oxidation is required to explain Mn oxidation.PostprintPeer reviewe

    Positive cerium anomalies imply pre-GOE redox stratification and manganese oxidation in Paleoproterozoic shallow marine environments

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    The Paleoproterozoic Koegas Subgroup (Transvaal Supergroup, South Africa) was deposited in the immediate prelude to the Great Oxidation Event (GOE), and can therefore shed light on the oceanic paleoredox conditions just before atmospheric oxidation. Manganese enrichments of ∼16 wt% in diagenetic kutnahorite horizons suggest that Mn2+ oxidation occurred, either by free O2 or by an ancient photosystem. Iron and molybdenum isotope trends also support the existence of a Mn4+-oxide sediment flux, suggesting that the Koegas basin may have been redox stratified. Evidence from detrital and authigenic pyrite with mass-independently fractionated sulfur isotopes, however, suggests that the atmosphere was devoid of oxygen. To resolve this contradiction, this paper presents new constraints on pathways of Mn2+ oxidation from field, petrographic, stable isotope, and rare earth element and yttrium (REYSN) analysis of stromatolitic carbonates from the upper Koegas Subgroup. Ferroan dolostones and limestones preserve marine REYSN arrays with positive CeSN anomalies. These differences are explained by a redox stratified basin, whereby Mn2+ and Ce3+ are oxidized at a redoxcline and Ce is adsorped onto sinking Mn-oxide particles. Mn-oxide particles and a negative Ce anomaly from the oxidized upper water column are transferred into carbonates accumulating above the redoxcline. Diagenetic fluids later reduce the Mn-oxides to kutnahorite. Below the redoxcline, reduction of Mn-oxides particles enriches carbonates in Mn and a positive Ce anomaly. This contribution adds evidence for development of oxygen oases and redox-stratified basins before the GOE. Redox stratification was best developed during transgressions. During regressions, a deltaic system prograded into the Koegas Basin. High sedimentation rates likely allowed for preservation of detrital pyrite only in the deltaic sandstones, thus explaining the contradictory geochemical evidence. No previously unknown ancient photosystem of Mn oxidation is required to explain Mn oxidation
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