Terrane evolution of the paratectonic Caledonides of northern Britain

A stratigraphically constrained re-evaluation of terrane amalgamation in the Caledonides of northern Britain allows the development of a new orogenic scenario which accounts for many of the outstanding problems in the paratectonic Caledonides and includes a new terrane template which correlates well with that proposed for Newfoundland. The Arenig Grampian Orogeny resulted from the accretion of two arc terranes to Laurentia: the Midland Valley (=Notre Dame Arc in Newfoundland) and a terrane of probable Avalonian/Gondwanan origin, here termed 'Novantia' (= Annieopsquotch Accretionary Tract (partim)), now hidden beneath the Southern Uplands allochthon. The Tyrone and Ballantrae ophiolites mark the northern boundary of Novantia within the composite Midland Valley Terrane. The Popelogan-Victoria Arc-Grangegeeth Terrane accreted to the amalgamated Midland Valley Terrane during the late Ordovician and initiated the Southern Uplands thrust duplex. A brief period of northward subduction during the Silurian followed, is ascribed to the northerly drift of the amalgamated Avalon-Baltica plate, and a final Wenlock (Scandian) collision and caused underplating of the Midland Valley Terrane. Caledonian deformation had ceased by the Emsian, the age of the undeformed Cheviot lavas that overlie the uplifted and peneplaned Southern Uplands

Structural adjustment and the contemporary sub-Saharan African city

Although it has been suggested that structural adjustment policies have slowed Third World urban growth and have stimulated a spatial deconcentration of economic activity, this paper argues that African cities continue to grow and mainly through peri-urban development. This investment comes mainly from domestic sources and migrants' remittances, and tends to he in consumption rather than production. Reasons include cultural factors lack of confidence in the national economy and in the state's long-term economic objectives, an increasing demand for housing, improvements in intraurban transport, and a desire to spread investment risk among a range of alternatives including housing

Rare earth geochemistry of Arenig cherts from the Ballantrae Ophiolite and Leadhills Imbricate Zone, southern Scotland: implications for origin and significance to the Caledonian Orongeny

Rare earth element (REE) data from low to mid-Arenig cherts are used to test competing models for the early Ordovician evolution of the Laurentian margin in the northern British Isles. Cherts from the Ballantrae Ophiolite Complex have chondrite-normalized REE patterns typical of continental margin settings with LREE enrichment, a slight negative Eu(anom) and shale and chondrite-normalized La/Yb values of 0.97-1.41 and 7.78-11.4 respectively. This pattern, together with a large positive chondrite-normalized Ce(anom) (1.44-1.70), is virtually identical to that found in radiolarian chert of the Gascoyne Abyssal Plain, in the Timor Sea. Cherts from the Raven Gill Formation within the Leadhills Imbricate Zone, Northern Belt, Southern Uplands have typical continental margin REE patterns, chondrite-normalized Ce(anom) (0.9-1.21) and Eu(anom) (0.61-0.79) values indicating that they formed closer to the continental margin than those from Ballantrae. Shale and chondrite-normalized and La/Yb values of 0.95-1.27 and 4.92-13.88 respectively confirm this interpretation. It is concluded that the Ballantrae ophiolite formed in a rifted-arc basin above a northwards dipping, intra-oceanic subduction zone. The modest depth of burial of the Raven Gill Formation precludes it being part of a marginal basin which was subsequently trapped as the Ballantrae Ophiolite was obducted in the late Arenig. The Arenig rocks of the Leadhills Imbricate Zone represent an allochthonous terrane accreted to the western extension of the Midland Valley in Ireland in pre-Caradoc times. Here it formed the basement to the Southern Uplands basin. Palaeontological evidence places this basin adjacent to Pomeroy, Co. Tyrone in the early Caradoc. Sinistral strike-slip faulting, from the late Ashgill transported the Southern Uplands Terrance to its present location, a distance of less than 250 km

Process Safety Competence Assurance

PresentationCompetence is a critical component of an organization’s success—one that is also very relevant for process safety. In fact, process safety competence can help ensure compliance with regulatory requirements and can be an important business improvement driver, particularly when it comes to process safety risk. Competence is often confused with knowledge; therefore, it can be difficult to assess competence levels. However, having a well-defined framework to assess process safety competence across the organization can offer many benefits, including helping the organization to: Identify gaps in organizational understanding and competence, and uncover opportunities to close those gaps; Ensure that personnel have the appropriate process safety competence levels (i.e., knowledge, experience, education and training); Ensure correct decisions and actions are taken to prevent incidents; Facilitate training to help effectively manage process safety in the workplace; and Create a sustainable model to support ongoing staffing and succession planning. This paper introduces a structured and scalable approach to process safety competence assurance, which is modeled using recognized industry guidelines, publications, and experience. This approach is fit-for-purpose and provides a framework designed to encourage intentional learning and development to close identified process safety competence gaps. The ultimate outcome of this approach is a competent staff who help recognize and drive process safety improvement

Ordovician limestone clasts in the Lower Old Red Sandstone, Pentland Hills, southern Midland Valley Terrane

In the southern part of the Scottish Midland Valley Lower Old Red Sandstone sedimentary and volcanic strata of the Lanark Group unconformably overlie inliers of largely marine Silurian rocks. The oldest of the four formations of the Lanark Group is the Greywacke Conglomerate Formation which contains clasts predominantly of greywacke, with subordinate volcanic rocks, cherts and limestones. The greywackes are known to have been derived from a cryptic source which lay to the south and east of the Midland Valley. Contrary to earlier, Silurian, age assessments of limestone clasts from the Greywacke Conglomerate Formation of the Pentland Hills, a conodont faunule described herein belongs in the uppermost Llanvirn to lower Caradoc P. anserinus Biozone. There are no Ordovician rocks exposed within the Pentland Hills inlier, and thus our new age data suggest that along with the other clasts, the limestones in the Greywacke Conglomerate are exotic to the Pentlands Sub-basin. The source area had a cover succession that included mid-Ordovician shallow marine carbonate and flysch

Determination of the absorption length of CO2, Nd:YAG and high power diode laser radiation for a selected grouting material

The laser beam absorption lengths of CO2, Nd:YAG and a high power diode laser (HPDL) radiation for a newly developed SiO2/Al2O3-based tile grout have been determined through the application of Beer-Lambert’s law. The findings revealed marked differences in the absorption lengths despite the material having similar beam absorption coefficients for the lasers. The absorption lengths for the SiO2/Al2O3-based tile grout for CO2, Nd:YAG and HPDL radiation were calculated as being 23211 m, 1934 m and 1838 m respectively. Moreover, this method of laser beam absorption length determination, which has hitherto been used predominantly with lasers operated in the pulsed mode, is shown to be valid for use with lasers operated in the continuous wave (CW) mode, depending upon the material being treated

Techno-economic assessment guidelines for CO2 utilization

Carbon Capture and Utilization (CCU) is an emerging technology field that can replace fossil carbon value chains, and that has a significant potential to achieve emissions mitigation or even “negative emissions”—however in many cases with challenging technology feasibility and economic viability. Further challenges arise in the decision making for CCU technology research, development, and deployment, in particular when allocating funding or time resources. No generally accepted techno-economic assessment (TEA) standard has evolved, and assessment studies often result in “apples vs. oranges” comparisons, a lack of transparency and a lack of comparability to other studies. A detailed guideline for systematic techno-economic (TEA) and life cycle assessment (LCA) for CCU technologies was developed; this paper shows a summarized version of the TEA guideline, which includes distinct and prioritized (shall and should) rules and which allows conducting TEA in parallel to LCA. The TEA guideline was developed in a co-operative and creative approach with roughly 50 international experts and is based on a systematic literature review as well as on existing best practices from TEA and LCA from the areas of industry, academia, and policy. To the best of our knowledge, this guideline is the first TEA framework with a focus on CCU technologies and the first that is designed to be conducted in parallel to LCA due to aligned vocabulary and assessment steps, systematically including technology maturity. Therefore, this work extends current literature, improving the design, implementation, and reporting approaches of TEA studies for CCU technologies. Overall, the application of this TEA guideline aims at improved comparability of TEA studies, leading to improved decision making and more efficient allocation of funds and time resources for the research, development, and deployment of CCU technologies

Properties of the Interstellar Medium and the Propagation of Cosmic Rays in the Galaxy

The problem of the origin of cosmic rays in the shocks produced by supernova explosions at energies below the so called 'knee' (at ~3*10$^6$ GeV) in the energy spectrum is addressed, with special attention to the propagation of the particles through the inhomogenious interstellar medium and the need to explain recent anisotropy results, [1]. It is shown that the fractal character of the matter density and magnetic field distribution leads to the likelihood of a substantial increase of spatial fluctuations in the cosmic ray energy spectra. While the spatial distribution of cosmic rays in the vicinity of their sources (eg. inside the Galactic disk) does not depend much on the character of propagation and is largely determined by the distribution of their sources, the distribution at large distances from the Galactic disk depends strongly on the character of the propagation. In particular, the fractal character of the ISM leads to what is known as 'anomalous diffusion' and such diffusion helps us to understand the formation of Cosmic Ray Halo. Anomalous diffusion allows an explanation of the recent important result from the Chacaltaya extensive air shower experiment [1], viz. a Galactic Plane Enhancement of cosmic ray intensity in the Outer Galaxy, which is otherwise absent for the case of the so-called 'normal' diffusion. All these effects are for just one reason: anomalous diffusion emphasizes the role of local phenomena in the formation of cosmic ray characteristics in our Galaxy and elsewhere.Comment: 18 pages, 5 figures, accepted by Astropartoicle Physic