Origin and distribution of dolomite in Permian Rotliegend siliciclastic sandstones (Dutch Southern Permian Basin)

2019 ◽  
Vol 89 (10) ◽  
pp. 1055-1073 ◽  
Author(s):  
Nicolaas Molenaar ◽  
Marita Felder
Keyword(s):  
Large Scale ◽  
Permian Basin ◽  
Advective Flow ◽  
Gas Reservoirs ◽  
Carbonate Cement ◽  
Thin Section Petrography ◽  
The Uk ◽  
Pressure Dissolution ◽  
Dolomite Cement ◽  
Detrital Carbonate

ABSTRACT Dolomite is a common and volumetrically important mineral in many siliciclastic sandstones, including Permian Rotliegend sandstones (the Slochteren Formation). These sandstones form extensive gas reservoirs in the Southern Permian Basin in the Netherlands, Germany, Poland, and the UK. The reservoir quality of these sandstones is negatively influenced by the content and distribution of dolomite. The origin and the stratigraphic distribution of the dolomite is not yet fully understood. The aim of this study is to identify the origin of carbonate. The main methods used to achieve those aims are a combination of thin-section petrography, scanning electron microscopy (SEM and EDX), and XRD analyses. The present study shows that the typical dispersed occurrence of the dolomite is a consequence of dispersed detrital carbonate grains that served both as nuclei and source for authigenic dolomite cement. The dolomite cement formed syntaxial outgrowths and overgrowths around detrital carbonate grains. The study also shows that dolomite cement, often in combination with ankerite and siderite, precipitated during burial after mechanical compaction. Most of the carbonate grains consisted of dolomite before deposition. The carbonate grains were affected by compaction and pressure dissolution, and commonly have no well-defined outlines anymore. The distribution of dolomite cement in the Rotliegend sandstones was controlled by the presence of stable carbonate grains. Due to the restricted and variable content of carbonate grains and their dispersed occurrence, the cement is also dispersed and the degree of cementation heterogeneous. Our findings have important implications on diagenesis modeling. The presence of detrital carbonate excludes the need for external supply by any large-scale advective flow of diagenetic fluids. By knowing that the carbonate source is local and related to detrital grains instead of being externally derived from an unknown source, the presence of carbonate cement can be linked to a paleogeographic and sedimentological model.

scholarly journals Permeability of rock discontinuities and faults in the Triassic Sherwood Sandstone Group (UK): insights for management of fluvio-aeolian aquifers worldwide

2019 ◽  
Vol 27 (8) ◽  
pp. 2835-2855 ◽  
Author(s):  
Giacomo Medici ◽  
L. Jared West ◽  
Nigel P. Mountney ◽  
Michael Welch
Keyword(s):  
Normal Faults ◽  
Depth Interval ◽  
Well Test ◽  
Deformation Bands ◽  
Gas Reservoirs ◽  
Sandstone Aquifer ◽  
Carbonate Cement ◽  
Aeolian Deposits ◽  
Hydraulic Behaviour ◽  
The Uk

Abstract Fluvio-aeolian sedimentary successions host groundwater aquifers at shallow depths (<~0.15 km), which overlie geothermal and shale-gas reservoirs, and nuclear waste repositories at intermediate depths (~0.15–2.0 km). Additionally, such deposits represent petroleum reservoirs at greater depths (~2.0–4.0 km). The need to improve conceptual understanding of the hydraulic behaviour of fluvial-aeolian sandstone successions over a large depth interval (~0–4 km) is important for socio-economic reasons. Thus, the hydraulic properties of the Triassic Sherwood Sandstone aquifer in the UK have been reviewed and compared to similar fluvio-aeolian successions. The ratio between well-scale and core-plug-scale permeability (Kwell-test/Kcore-plug) acts as a proxy for the relative importance of fracture versus intergranular flow. This ratio (which typically varies from ~2 to 100) indicates significant contribution of fractures to flow at relatively shallow depths (<~0.15 km). Here, permeability development is controlled by dissolution of calcite-dolomite in correspondence of fractures. The observed ratio (Kwell-test/Kcore-plug) decreases with depth, approaching unity, indicating that intergranular flow dominates at ~1 km depth. At depths ≥ ~1 km, dissolution of carbonate cement by rock alteration due to groundwater flow is absent and fractures are closed. Aeolian and fluvial deposits behave differently in proximity to normal faults in the Sherwood Sandstone aquifer. Deformation bands in aeolian dune deposits strongly compartmentalize this aquifer. The hydro-structural properties of fluvio-aeolian deposits are also controlled by mineralogy in fault zones. A relative abundance of quartz vs. feldspar and clays in aeolian sandstones favours development of low-permeability deformation bands.

scholarly journals Differential hydrocarbon enrichment in deep Paleogene tight sandstones of the Dongpu Depression in Eastern China

2021 ◽  
pp. 014459872098811
Author(s):  
Yuanyuan Zhang ◽  
Zhanli Ren ◽  
Youlu Jiang ◽  
Jingdong Liu
Keyword(s):  
Natural Gas ◽  
Crude Oil ◽  
Large Scale ◽  
Eastern China ◽  
Continuous Distribution ◽  
Gas Reservoirs ◽  
Pyrolysis Gas ◽  
Hydrocarbon Charging ◽  
Dongpu Depression ◽  
Kerogen Pyrolysis

To clarify the characteristics and enrichment rules of Paleogene tight sandstone reservoirs inside the rifted-basin of Eastern China, the third member of Shahejie Formation (abbreviated as Es3) in Wendong area of Dongpu Depression is selected as the research object. It not only clarified the geochemical characteristics of oil and natural gas in the Es3 of Wendong area through testing and analysis of crude oil biomarkers, natural gas components and carbon isotopes, etc.; but also compared and explained the types and geneses of oil and gas reservoirs in slope zone and sub-sag zone by matching relationship between the porosity evolution of tight reservoirs and the charging process of hydrocarbons. Significant differences have been found between the properties and the enrichment rules of hydrocarbon reservoirs in different structural areas in Wendong area. The study shows that the Paleogene hydrocarbon resources are quasi-continuous distribution in Wendong area. The late kerogen pyrolysis gas, light crude oil, medium crude oil, oil-cracked gas and the early kerogen pyrolysis gas are distributed in a semicircle successively, from the center of sub-sag zone to the uplift belt, that is the result of two discontinuous hydrocarbon charging. Among them, the slope zone is dominated by early conventional filling of oil-gas mixture (at the late deposition period of Dongying Formation, about 31–27 Ma ago), while the reservoirs are gradually densified in the late stage without large-scale hydrocarbon charging (since the deposition stage of Minghuazhen Formation, about 6–0 Ma). In contrast, the sub-sag zone is lack of oil reservoirs, but a lot of late kerogen pyrolysis gas reservoirs are enriched, and the reservoir densification and hydrocarbon filling occur in both early and late stages.

scholarly journals Establishment and lineage dynamics of the SARS-CoV-2 epidemic in the UK

Science ◽  
2021 ◽  
pp. eabf2946
Author(s):  
Louis du Plessis ◽  
John T. McCrone ◽  
Alexander E. Zarebski ◽  
Verity Hill ◽  
Christopher Ruis ◽  
...  
Keyword(s):  
Large Scale ◽  
Phylogenetic Analyses ◽  
Transmission Dynamics ◽  
Genetic Lineage ◽  
Size Dependent ◽  
Spatio Temporal ◽  
The Uk ◽  
Lineage Structure ◽  
And Control ◽  
Lineage Diversity

The UK’s COVID-19 epidemic during early 2020 was one of world’s largest and unusually well represented by virus genomic sampling. Here we reveal the fine-scale genetic lineage structure of this epidemic through analysis of 50,887 SARS-CoV-2 genomes, including 26,181 from the UK sampled throughout the country’s first wave of infection. Using large-scale phylogenetic analyses, combined with epidemiological and travel data, we quantify the size, spatio-temporal origins and persistence of genetically-distinct UK transmission lineages. Rapid fluctuations in virus importation rates resulted in >1000 lineages; those introduced prior to national lockdown tended to be larger and more dispersed. Lineage importation and regional lineage diversity declined after lockdown, while lineage elimination was size-dependent. We discuss the implications of our genetic perspective on transmission dynamics for COVID-19 epidemiology and control.

scholarly journals Collateral impact of COVID-19: why should children continue to suffer?

2021 ◽  
Author(s):  
Prasad Nagakumar ◽  
Ceri-Louise Chadwick ◽  
Andrew Bush ◽  
Atul Gupta
Keyword(s):  
Young People ◽  
Large Scale ◽  
Hospital Admissions ◽  
Severe Disease ◽  
Children And Young People ◽  
Collateral Effects ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Set Up ◽  
The Uk

AbstractThe COVID-19 pandemic caused by SARS-COV-2 virus fortunately resulted in few children suffering from severe disease. However, the collateral effects on the COVID-19 pandemic appear to have had significant detrimental effects on children affected and young people. There are also some positive impacts in the form of reduced prevalence of viral bronchiolitis. The new strain of SARS-COV-2 identified recently in the UK appears to have increased transmissibility to children. However, there are no large vaccine trials set up in children to evaluate safety and efficacy. In this short communication, we review the collateral effects of COVID-19 pandemic in children and young people. We highlight the need for urgent strategies to mitigate the risks to children due to the COVID-19 pandemic. What is Known:• Children and young people account for <2% of all COVID-19 hospital admissions• The collateral impact of COVID-19 pandemic on children and young people is devastating• Significant reduction in influenza and respiratory syncytial virus (RSV) infection in the southern hemisphere What is New:• The public health measures to reduce COVID-19 infection may have also resulted in near elimination of influenza and RSV infections across the globe• A COVID-19 vaccine has been licensed for adults. However, large scale vaccine studies are yet to be initiated although there is emerging evidence of the new SARS-COV-2 strain spreading more rapidly though young people.• Children and young people continue to bear the collateral effects of COVID-19 pandemic

scholarly journals Creating restoration landscapes: partnerships in large-scale conservation in the UK

2016 ◽  
Vol 21 (3) ◽  
Author(s):  
William M. Adams ◽  
Ian D. Hodge ◽  
Nicholas A. Macgregor ◽  
Lindsey C. Sandbrook
Keyword(s):  
Large Scale ◽  
The Uk

scholarly journals Adherence and competence assessment in studies of CBT for psychosis: current status and future directions

2011 ◽  
Vol 20 (2) ◽  
pp. 121-126 ◽  
Author(s):  
D. Fowler ◽  
R. Rollinson ◽  
P. French
Keyword(s):  
Cognitive Therapy ◽  
Large Scale ◽  
Rating Scale ◽  
Current Status ◽  
Behaviour Therapy ◽  
Future Directions ◽  
Making Sense ◽  
Cognitive Behaviour ◽  
The Uk ◽  
Careful Assessment

All good quality trials of psychological interventions need to check formally that therapists have used the techniques prescribed in the published therapy manuals, and that the therapy has been carried out competently. This paper reviews methods of assessing adherence and competence used in recent large-scale trials of Cognitive Behaviour Therapy (CBT) for psychosis in the UK carried out by our research groups. A combination of the Cognitive Therapy Rating Scale and specific versions of the Cognitive Therapy for Psychosis Adherence Scales provides an optimal assessment of adherence and competence. Careful assessment of the competence and adherence can help identify the procedures actually carried out with individuals within trials. The basic use of such assessments is to provide an external check on treatment fidelity on a sample of sessions. Such assessment can also provide the first step towards moving research towards making sense of CBT for psychosis as a complex intervention and identifying which techniques work for which problems of people with psychosis, at which stages of disorder?

scholarly journals Exploring economic and legal barriers to commercial aquaponics in the EU through the lens of the UK and policy proposals to address them

2021 ◽  
Author(s):  
Christopher Cammies ◽  
David Mytton ◽  
Rosemary Crichton
Keyword(s):  
Food Production ◽  
Large Scale ◽  
Nutrient Loss ◽  
Soil Conditions ◽  
Application Process ◽  
Organic Certification ◽  
Recirculating Aquaculture ◽  
Economic Barriers ◽  
The Uk ◽  
The Eu

AbstractAquaponics is a food production system which connects recirculating aquaculture (fish) to hydroponics (plants) systems. Although aquaponics has the potential to improve soil conditions by reducing erosion and nutrient loss and has been shown to reduce food production related carbon emissions by up to 73%, few commercial aquaponics projects in the EU and UK have been successful. Key barriers to commercial success are insufficient initial investment, an uncertain and complex regulatory environment, and the lack of projects operating on a large scale able to demonstrate profitability. In this paper, we use the UK as a case study to discuss the legal and economic barriers to the success of commercial aquaponics in the EU. We also propose three policies: (1) making aquaponics eligible for the new system of Environmental Land Management grants; (2) making aquaponics eligible for organic certification; and (3) clarifying and streamlining the aquaponics licence application process. The UK’s departure from the EU presents a unique opportunity to review agricultural regulations and subsidies, which in turn could provide evidence that similar reforms are needed in the EU.

COVID-19 personal protective behaviors during mass events: Lessons from observational measures in Wales, UK.

2021 ◽  
Author(s):  
Ashley Gould ◽  
Lesley Lewis ◽  
Lowri Evans ◽  
Leanne Greening ◽  
Holly Howe-Davies ◽  
...  
Keyword(s):  
Large Scale ◽  
Protective Behaviors ◽  
Mass Gatherings ◽  
Observational Measures ◽  
Behavioral Observations ◽  
The Government ◽  
Additional Support ◽  
The Uk ◽  
Trained Observers ◽  
Personal Protective Behaviors

Within the context of reopening society in the summer of 2021, as the UK moved away from ’lockdown,’ the Government of Wales piloted the return on organised ‘mass gatherings’ of people at a number of test events. Behavioral observations were made at two of the test events to support this process. The research was particularly interested in four key factors: How (1) context within a venue, (2) environmental design, (3) staffing and social norms, and (4) time across an event, affected personal protective behaviors of social distancing, face covering use, and hand hygiene. Data collection was undertaken by trained observers across the above factors. Findings suggest that adherence of attendees was generally high, but with clear indications that levels were shaped in a systematic way by the environment, situational cues, and the passage of time during the events. Some instances of large-scale non-adherence to personal protective behaviors were documented. Overall, there were three main situations where behavioral adherence broke down, under conditions where: (1) staff were not present; (2) there was a lack of environmental signalling (including physical interventions or communications); and (3) later into the events when circumstances were less constrained and individuals appeared less cognitively vigilant. Behavioral observations at events can add precision and identify critical risk situations where/when extra effort is required. The findings suggest a liberal paternal approach whereby state authorities, health authorities and other key organisations can help nudge individuals towards COVID-safe behaviors. Finally, an individual’s intentions are not always matched by their actions, and so behavioral insights can help identify situations and contexts where people are most likely to require additional support to ensure COVID-19 personal protective behaviors are followed and hence protecting themselves and others.

Madri single che lavorano: uno studio longitudinale

2009 ◽  
pp. 123-137
Author(s):  
Tess Ridge ◽  
Jane Millar
Keyword(s):  
Large Scale ◽  
Tax Credits ◽  
Poor People ◽  
Limited Mobility ◽  
Lone Parents ◽  
Poverty Risk ◽  
Lone Mothers ◽  
Rich People ◽  
Large Scale Survey ◽  
The Uk

- Analysis of poverty dynamics based on large-scale survey data shows that there is limited mobility across the income distribution for most individuals and families. Some people may get better-off over the lifecourse, as their careers develop and wages rise, but overall most poor people do not become very rich and most rich people do not become very poor. Lone parents are at high risk of poverty in the UK, but this poverty risk is reduced for those who are in employment and who receive state financial support through Tax Credits to supplement their wages. This article reports on longitudinal qualitative research which has involved repeat interviews with lone mothers and their children over a period of three to four years. The analysis here explores the experiences of sustaining employment while living on a low, but complex, income and highlights the challenges faced in seeking financial security in this context.

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