Artículos de revistas: "Low accommodation succession"

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Lang, S. C., P. Grech, R. Root, A. Hill y D. Harrison. "THE APPLICATION OF SEQUENCE STRATIGRAPHY TO EXPLORATION AND RESERVOIR DEVELOPMENT IN THE COOPER-EROMANGA-BOWEN-SURAT BASIN SYSTEM". APPEA Journal 41, n.º 1 (2001): 223. http://dx.doi.org/10.1071/aj00011.

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The application of sequence stratigraphy to non-marine strata in intracratonic basins is still in its infancy, however, the predominantly non-marine Cooper- Eromanga-Surat-Bowen basin system of Eastern Australia provides an excellent opportunity to demonstrate how sequence stratigraphic concepts can be applied to non-marine successions to assist with exploration and reservoir development. The key to applying sequence stratigraphic concepts in non-marine basins lies in understanding the role of alluvial sediment accommodation relative to sediment supply. Accommodation is created by a combination of tectonic subsidence, compaction and changing water tables in floodplain lakes, marshlands and peat mires. If the alluvial basin is directly connected to the marine system then eustacy may influence accommodation in the lower reaches of the alluvial network, but its effect will significantly diminish upstream depending on the slope. Climate change will, however, have an impact on fluvial discharge, rising water tables, floodplain lake levels, and sediment flux. For sediments to accumulate, accommodation must be positive, whereas negative accommodation leads to erosion. Fluvial accommodation is, therefore, comparable with the concept of base-level. During an episode of basin-wide tectonic uplift or tilting, falling base-level (negative accommodation) leads to widespread erosion on the basin margins or over intra-basinal highs, and an unconformity equivalent to a sequence boundary develops. If followed by a period of low accommodation, rivers rework much of their floodplain, resulting in a sheetlike, amalgamated succession of predominantly sandy bedload deposits of high nett to gross, equivalent to an alluvial lowstand. Further downstream, lowstand deltas may form in the lakes.

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Ellwanger, Dietrich, Gerald Gabriel, Theo Simon, Ulrike Wielandt-Schuster, Reinhard O. Greiling, Eva-Marie Hagedorn, Jürgen Hahne y Jürgen Heinz. "Long sequence of Quaternary Rocks in the Heidelberg Basin Depocentre". E&G Quaternary Science Journal 57, n.º 3/4 (1 de abril de 2009): 316–37. http://dx.doi.org/10.3285/eg.57.3-4.3.

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Abstract. A description and classification of the successions of the new scientific core drillings at Heidelberg is presented. Since 2002 drilling and research activities were ongoing in the Heidelberg Basin (HDB), as a mid-continental sedimentary archive within the Upper Rhine Graben (URG), Germany. The HDB is supposed to host one of the longest continuous successions of Quaternary sediments in Europe, due to continuous subsidence of the basin and sediment input from various sources. The HDB is about half-way between the Alpine source area of the Rhine and the North Sea. Here the Quaternary input is least affected by discontinuities due to climate events as alpine glacier meltdown events or periods of low sea level. Reversely, the low influence of climate leads to a larger tectonic control. The sedimentary succession of more than 500 m is considered as primarily controlled by tectonics, but with incorporated climate signals. For classification purposes, sediment provenance, lithofacies-associations, and the ratio of accommodation space and sediment input are used. Some biostratigraphic markers are also available. We suggest a sedimentary scenario where the overall fluvial environment is twice interrupted by lacustrine intervals. The accommodation space varies too: in one period it expands even beyond the eastern boundary fault of the HDB.

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Antia, Jonathan y Christopher R. Fielding. "Sequence stratigraphy of a condensed low-accommodation succession: Lower Upper Cretaceous Dakota Sandstone, Henry Mountains, southeastern Utah". AAPG Bulletin 95, n.º 3 (marzo de 2011): 413–47. http://dx.doi.org/10.1306/06301009182.

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Simplicio, Fábio y Giorgio Basilici. "Unusual thick eolian sand sheet sedimentary succession: Paleoproterozoic Bandeirinha Formation, Minas Gerais". Brazilian Journal of Geology 45, suppl 1 (agosto de 2015): 3–11. http://dx.doi.org/10.1590/2317-4889201530133.

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ABSTRACTSome present-day eolian sand sheets have small and width dunes, called zibars, as common type of depositional morphology. Their formation is related to different stabilizing factors, which reduce the availability of clastic materials for eolian processes. In fact, zibars are dunes which do not have time to develop a larger dune with slipface (proto-dune). Dunes in sands sheet areas generally are constructed by wind ripple laminations and commonly generate sedimentary succession less than 20 m thick, which are the consequence of low sand supply. This study deals with an uncommon eolian sand sheet sedimentary succession more than 50 m thick, Proterozoic in age, known as Bandeirinha Formation. This paper tries to explain the anomalous thick of this sand sheet sedimentary succession. High thickness was probably the result of a high input of sand material, combine with low availability of sand, thus allowing the only construction of proto-dunes (zibars). Early cementation, due to near-surface evaporation of saline water, has been proposed as main factor that reduced the sand availability into this eolian system. Finally, the subsidence processes related to the first stage of rift Espinhaço Basin must have generated the accommodation space to preserve the sand sheet succession.

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Kifumbi, Carrel, Claiton Marlon dos Santos Scherer, Fábio Herbert Jones y Juliano Kuchle. "High resolution stratigraphy of initial stages of rifting, Sergipe-Alagoas Basin, Brazil". Brazilian Journal of Geology 47, n.º 4 (diciembre de 2017): 657–71. http://dx.doi.org/10.1590/2317-4889201720170003.

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ABSTRACT: The present work aims to characterize the Neo-Jurassic to Neocomian succession of the Sergipe-Alagoas Basin, located in northeast region of Brazil, in order to discover the influence of tectonics on sedimentation in detailed scale and thus separating this sedimentary succession in tectono-stratigraphic units. Fieldwork observations and stratigraphic sections analysis allowed subdividing this rift succession into three depositional units that indicate different paleogeographic contexts. Unit I, equivalent to the top of Serraria Formation, is characterized by braided fluvial channel deposits, with paleocurrent direction to SE; unit II, corresponding to the base of Feliz Deserto Formation, is composed of anastomosed fluvial channel and floodplain facies associations; and unit III, equivalent to the major part of Feliz Deserto Formation, is characterized by delta deposits with polymodal paleocurrent pattern. The changes of depositional system, as well as paleocurrent direction, suggest that the previously described units were deposited in different evolutionary stages of rifting. Units I and II represent the record of a wide and shallow basin associated with the first stage of rifting. Unit I is characterized by incipient extensional stress generating a wide synclinal depression, associated to the low rate of accommodation and low tectonic activity. These two parameters progressively increase in unit II. The paleocurrent direction of unit I indicates that the depocenter of this wide basin was located at SE of the studied area. No conclusion could be done on paleocurrent from unit II because of the low amount of measurements. Unit III suggests a second stage marked by a deeper basin context, with a high rate of accommodation space associated with the lateral connection of faults and individualization of the half-graben. The scattering in the paleocurrent direction in this unit indicates sedimentary influx coming from several sectors of the half-graben. The boundary between these two stages is marked by a flooding surface that indicates an extremely fast transition and suggests a radical change in geometric characteristics of the basin due to the increase of tectonic activity.

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McKie, T. "Relative sea-level changes and the development of a Cambrian transgression". Geological Magazine 130, n.º 2 (marzo de 1993): 245–56. http://dx.doi.org/10.1017/s0016756800009894.

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AbstractThe Lower Cambrian in northwest Scotland is one example of a Lower Palaeozoic ‘orthoquartzite-carbonate’ succession deposited on a slowly subsiding, peneplained Precambrian basement during a period of relative sea-level rise. This particular setting led to the development of a very wide, low gradient shelf which was extremely sensitive to minor sea-level changes. The basal quartz arenite section (Lower Member-Pipe Rock) is a transgressive, tide-dominated systems tract, but lacks a systematic parasequence architecture because of three factors: a fluvial sediment flux was insufficient to induce shoreline progradation, accommodation space was limited during sea-level falls (which are commonly expressed by widespread erosional surfaces), and sediment yield to the shelf by transgressive reworking was a major contributor towards the preserved stratigraphy. The storm-dominated Fucoid Beds represent a condensed section and also show the effects of rapid and widespread facies belt oscillations because of the low shelf gradient. An overlying highstand systems tract is also lacking, partly due to the absence of a large fluvial sediment yield and also due to lowstand and transgressive reworking. An erosively based tidal sandsheet at the top of the Fucoid Beds, interpreted to be a lowstand systems tract, therefore rests directly on the condensed section of the underlying sequence. This was in turn reworked into linear tidal sandbanks (Salterella Grit) during slow sea-level rise, prior to the next major transgression. The limited accommodation space therefore introduced a preservational bias towards deepening-upward trends on a parasequence and sequence scale. The oscillations in facies belts, episodic subareal exposure and the potential to remove substantial portions of systems tracts suggests that Lower Palaeozoic ‘orthoquartzite’ successions may exhibit regular and abrupt vertical shifts in depositional environment which, given their subtle lithological character, may require detailed analysis to identify. Such successions may also display incomplete development of several components of transgressive-regressive sequence architecture.

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Ratcliffe, K. T., A. M. Wright, C. Hallsworth, A. Morton, B. A. Zaitlin, D. Potocki y D. S. Wray. "An example of alternative correlation techniques in a low-accommodation setting, nonmarine hydrocarbon system: The (Lower Cretaceous) Mannville Basal Quartz succession of southern Alberta". AAPG Bulletin 88, n.º 10 (octubre de 2004): 1419–32. http://dx.doi.org/10.1306/05100402035.

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Field, Brad, Jan Baur, Kyle Bland, Greg Browne, Angela Griffin, Brad Ilg, Zoe Juniper et al. "Tectonostratigraphic development and hydrocarbon reservoir quality on a convergent margin: East Coast, North Island, New Zealand". APPEA Journal 49, n.º 2 (2009): 600. http://dx.doi.org/10.1071/aj08073.

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Hydrocarbon exploration on the East Coast of the North Island has not yet yielded significant commercial reserves, even though the elements of a working petroleum system are all present (Field et al, 1997). Exploration has focussed on the shallow, Neogene part of the succession, built up during plate margin convergence over the last ∼24 million years. Convergent margins are generally characterised by low-total organic carbon (TOC) source rocks and poor clastic reservoir quality due to poor sorting and labile grains. However, the obliquely-convergent Hikurangi subduction margin of the East Coast has high TOC source rocks that pre-date the subduction phase, and its reservoir potential, though variable, has several aspects in its favour, namely: deep-water rocks of high porosity and permeability; preservation of pore space by overpressure; the presence of fractured reservoirs and hybrid reservoirs, where low clastic permeability is enhanced by fractures. The East Coast North Island is a Neogene oblique subduction margin, with Neogene shelf and slope basins that developed on Late Cretaceous-Paleogene passive margin marine successions. The main hydrocarbon source rocks are Late Cretaceous and Paleocene and the main reservoir potential is in the Neogene (Field et al, 2005). Miocene mudstones with good seal potential are common, as is significant over-pressuring. Neogene deformation controlled basin development and accommodation space and strongly-influenced lateral facies development and fractured reservoirs. Early to Middle Miocene thrusting was followed by later Neogene extension (e.g. Barnes et al 2002), with a return to thrusting in the Pliocene. Local wells have flow-tested gas shows.

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Winkler, Antoniony S., Jaqueline T. da Silva, José M. B. Parfitt, Claudia F. A. Teixeira-Gandra, Germani Conceço y Luis C. Timm. "Surface drainage in leveled land: Implication of slope". Revista Brasileira de Engenharia Agrícola e Ambiental 22, n.º 2 (febrero de 2018): 77–82. http://dx.doi.org/10.1590/1807-1929/agriambi.v22n2p77-82.

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ABSTRACT In the lowlands of Rio Grande do Sul, land leveling is mostly carried out with no slope for the purpose of rice production. In this environment, soils with a low hydraulic conductivity are predominant owing to the presence of a practically impermeable B-horizon near the surface. Land leveling leads to soil accommodation resulting in the formation of depressions where water accumulates after heavy rainfalls, subsequently leading to problems with crops implanted in succession to rice, such as soybeans. The objective of this research was to quantify the areas and volumes of water accumulation in soil as a function of the slope of land leveling. Five typical leveled lowland areas were studied as a part of this research. The original areas presented slopes of 0, 0.20, 0.25, 0.28 and 0.40%, which were used to generate new digital elevation models with slopes between 0 and 0.5%. These newly generated digital models were used to map the depressions with surface water storage. In conclusion, land leveling with slopes higher than 0.1% is recommended to minimize problems with superficial water storage in rice fields.

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Dillinger, Antoine, Annette D. George y Romain Vaucher. "Evolution of a complex early Permian coarse-grained shoreline along a rift basin margin". Journal of Sedimentary Research 91, n.º 3 (31 de marzo de 2021): 317–47. http://dx.doi.org/10.2110/jsr.2020.063.

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ABSTRACT Tectonic activity in extensional basins has a profound control on accommodation and sediment supply through the interplay between footwall uplift and hanging-wall subsidence, and thus largely influences the three-dimensional architecture of syn-rift sequences. This is emphasized in areas close to major rift-border faults, where steep coastal reliefs and fluvial gradients produce compound facies zonation and stratigraphic styles with strong lateral variability. The lower Permian High Cliff Sandstone was deposited in an array of shallow marine environments along the margin of the northern Perth Basin during a protracted late Paleozoic rifting episode in Western Australian basins. The formation is composed of fluvio-deltaic and nearshore strata sharply overlying a thick succession of offshore mudstone that was deposited during a phase of tectonic quiescence. This basal contact likely reflects submarine erosion and is, therefore, interpreted as a regressive surface of marine erosion generated in response to forced regression. The facies arrangement consisting of interbedded sandstone, conglomerate, and heterolithic facies chiefly records the evolution of a low- to high-gradient paleoshoreline punctuated by coastal streams, steep sea cliffs, and back-barrier lagoons. Extraformational outsized clasts were probably emplaced by the erosion of exhumed basement and older sedimentary rocks through fluvial incision, wave sapping, or landsliding. The along-strike variability between low- and high-gradient shoreline deposits indicates a dynamic depositional setting with a complex tectonic influence. The basal regressive surface of marine erosion is attributed to footwall uplift during the early reactivation stage of basin-bounding normal faults and, therefore, records the initiation of a new syn-rift phase in the northern Perth Basin.

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Fielding, Christopher R., W. John Nelson y Scott D. Elrick. "Sequence stratigraphy of the late Desmoinesian to early Missourian (Pennsylvanian) succession of southern Illinois: Insights into controls on stratal architecture in an icehouse period of Earth history". Journal of Sedimentary Research 90, n.º 2 (26 de febrero de 2020): 200–227. http://dx.doi.org/10.2110/jsr.2020.10.

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ABSTRACT Uncertainty persists over whether repetitive stratal rhythms in the Pennsylvanian of Euramerica (so-called “cyclothems”) were externally forced, in all likelihood by waxing and waning of glacial ice centers on Gondwana, or were controlled by autogenic processes. A key to resolving this dispute is the lateral extent of the individual cyclothems, with broad regional extent (beyond the plausible breadth and length of individual depositional systems such as deltas) arguing in favor of an external forcing control. This study provides a sedimentological and sequence stratigraphic analysis of the middle Pennsylvanian (Desmoinesian to early Missourian in North American stratigraphic terminology, Moscovian to early Kasimovian in the terms of the global stratigraphic nomenclature) succession of the southern Illinois Basin in Illinois, Indiana, and Kentucky, eastern USA. An array of eleven lithofacies is recognized, recording deposition of clastic, humic organic, and bioclastic carbonate sediments on a broad, low-gradient, low-paleolatitude shelf and coastal plain that were undersupplied by sediment. These facies are arranged into thirteen repetitive vertical cycles (sequences), each of which can be traced across the entire basin west to east (perpendicular to the paleoslope direction) across a distance of 250 km. Sequences are bounded by erosion surfaces that define 1–4 km-wide, deeply incised valley-fills (IVFs) that are mostly elongate towards the south-southwest, the dominant direction of paleoflow. In the west–east direction, valley erosion surfaces pass laterally into well-developed paleosols, incised locally by smaller channels. Each of these surfaces is laterally persistent across the basin. IVFs comprise multi-story bodies of conglomerate–breccia and sandstone, passing upward into heterolithic sandstone–mudrock associations, recording fluvial and later estuarine environments. Coal bodies typically occur at the tops of IVFs and are interbedded with heterolithic facies recording tidal influence, indicative of initial flooding by the sea. They are in turn overlain by estuarine and marine mudrocks and bioclastic carbonates, recording the maximum extent of marine flooding in a cycle. Each sequence is completed by heterolithic to sandstone-dominated facies of deltaic aspect that are typically truncated by the next erosion surface (sequence boundary). Plausible modern analogs suggest that sea-level excursions were of the order of 20–40 m. The great lateral persistence of not only the thirteen sequences, but also many of their component beds, argues strongly for an external control on sediment accumulation. Eccentricity-paced glacial cycles in Gondwana are invoked as the most likely cause of the cyclicity. The low-accommodation context of the Illinois Basin (average accumulation rate 6 cm/ky) contributed to the incomplete, condensed, and strongly top-truncated nature of preserved sequences.

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La Fontaine, Nathan y Michael Hofmann. "Quantifying the stratigraphic and spatial facies distribution in an ancient mixed-influence delta". Mountain Geologist 56, n.º 1 (febrero de 2019): 19–44. http://dx.doi.org/10.31582/rmag.mg.56.1.19.

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Analysis of the sedimentology and stratigraphic architecture of tightly spaced three dimensional outcrops reveals that the Turonian (Upper Cretaceous) Wall Creek Member of the Frontier Formation in the western Powder River Basin, Wyoming, USA, is not composed of one continuous coarsening upward succession but of a complex stacked delta system containing three distinct sequences (S1-S3), each with a unique facies distribution and architectural heterogeneity. The basal sequence S1 consists of a fluvial dominated delta with two distinct lobes. These lobes are spatially constrained to the northeastern study area and show a rapid facies transition from trough crossbedded mouthbar deposits to lower delta front turbidites. Low angle clinoforms suggest a low accommodation setting with main sediment transport to the south. The middle S2 sequence is common throughout the study area and contains an abundance of storm-derived deposits, including hummocky cross stratification, suggesting the transition to a wave and storm-dominated delta setting. Sediment transport is largely to the south controlled by wind induced shear stresses. Lastly, heterolithic trough crossbedded sandstones with flaser bedding and abundant thin mudstones and rip-up clasts are characteristic for sequence S3. These deposits are interpreted as tidal bars in a tidal influenced delta. Quantitative evaluation of facies in the Wall Creek Member sequences shows that the dimensions and connectivity (baffle or barrier competence) of fine-grained thin beds varies systematically within the three delta types. The S1 fluvial delta is largely composed of laterally continuous delta front turbidites with continuous fine-grained thin beds (mean length 21.1 m or 69.2 ft, max length 83.9 m or 275.2 ft) separating individual sandstone beds. Conversely, abundant bioturbation and intense scouring by storms results in high amalgamation of sandy beds in sequence S2 and a limited length of fine-grained thin beds (mean 8.5 m or 27.9 ft) in the wave-dominated delta sequence. Tidally influenced deposits of sequence S3 are largely composed of heterolithic trough crossbedded sandstones and mudstones with low bioturbation, resulting in an intermediate fine-grained thin bed deposit (mean 12.1 m or 39.7 ft).

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Astini, Ricardo A., Federico Martina y Federico M. Davila. "The Los Llantenes Formation in the Precordillera of Jagüe (La Rioja Province) and the recognition of a rifting stage in the early evolution of the late Paleozoic basins in western Argentina." Andean Geology 38, n.º 2 (9 de agosto de 2011): 245. http://dx.doi.org/10.5027/andgeov38n2-a01.

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In the northern part of the Argentine Precordillera, northwestern La Rioja, the Upper Paleozoic is over 4,000 m thick. Very coarse conglomerates from the basal section have not been described nor adequately interpreted. This work analyses this unit in the context of a stratigraphic revision of the upper Paleozoic of the region, and interprets the conglomerate as a rift deposit. The thick (>1,000 m) and coarse purple conglomeratic succession, herein named ‘Los Llantenes Formation’, non-conformably rests on the basement rocks of the region and underlies deposits of the first glacial record associated with the Gondwanan glaciation. While its great thickness and restricted areal extent indicate localized subsidence, the crude stratification, poor sorting and abundance of >1-m boulders indicate an origin related to high-gradient, low-efficiency alluvial fans. Their composition and coarse-grained size indicate local provenance, abrupt relief and incipiently developed drainage systems and a highly compartmentalized and abrupt paleogeography. A complex glacial history generated deep ‘U’-shaped paleovalleys in the Los Llantenes Formation, developing paleovalleys that accommodated basal lodgment tills and glacial diamictites with sedimentologic features comparable to the Cerro Tres Condores Formation (Visean in age) exposed to the south. The age of the conglomerates of Los Llantenes Formation, clearly preglacial, can be stratigraphically bracketed between the Middle Devonian substrate cropping out to the south in the sierra de Las Minitas and the Middle Mississippian, age of the Cerro Tres Condores Formation. Consequently, Los Llantenes Formation may partly correlate with the Agua de Lucho Formation (Tournaisian-Vissean) that in the area of Rio del Penon, immediately to the south, underlies the glacigenic Cerro Tres Condores Formation. Mapping relationships with limited areal extent, together with the great thickness of Los Llantenes Formation and the local provenance, allow interpreting accommodation in extensional or pull-apart depocenters, conclusions that are relevant in order to reconstruct the history of the basin.

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Amosu, Adewale, Mohamed Imsalem, Anne Raymond y Yuefeng Sun. "FischerLab: An Application for Generating Fischer Plots and Dynamic Fischer Plots from Wireline Well-Logs and Stratigraphic Data". Earth 1, n.º 1 (17 de septiembre de 2020): 36–48. http://dx.doi.org/10.3390/earth1010004.

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Fischer plots are a technique that is used to graph changes in accommodation in cyclic carbonate successions. They typically depict the cumulative departure from the average cycle thickness as a function of the cycle number or stratigraphic depth. Many applications of Fischer plots focus on their construction from exposed cyclic carbonate successions. No published programs allow the direct construction of Fischer plots from digital wireline well-logs or dynamic presentations of Fischer plots. Here, we introduce a program known as FischerLab, which facilitates the generation and analysis of Fischer plots. In addition to accepting interpreted stratigraphic data input, FischerLab facilitates the interpretation of digital wireline logs for the generation of Fischer plots in cycle and depth domains, as well as in a dynamic evolving cycle and relative depth domain from an easy-to-use interface. The dynamic construction facilitates the correlation of specific stratigraphic packages to parts of the accommodation cycle while simultaneously tracking the locus of the mean subsidence vector. We demonstrate the use of FischerLab on data derived from the carbonate succession outcrops of the Al-Athrun Formation, Libya, and the Glen Rose Formation, Central Texas, USA, as well as on wireline well-log data from the Western Great Bahama Bank, the Bahamas.

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Raspini, A. "Shallow water carbonate platforms (Late Aptian–Early Albian, Southern Apennines) in the context of supraregional to global changes: re-appraisal of palaeoecological events as reflectors of carbonate factory response". Solid Earth 3, n.º 2 (20 de agosto de 2012): 225–49. http://dx.doi.org/10.5194/se-3-225-2012.

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Abstract. This paper discusses the palaeoenvironmental significance of the "Orbitolina Level", the microbial carbonates and the Salpingoporella dinarica-rich deposits encased in the Aptian/Albian shallow water carbonate platform strata of Monte Tobenna and Monte Faito (Southern Italy). These facies show a peculiar field appearance due to their color and/or fossil content. In the shallow water carbonate strata, the Late Aptian "Orbitolina Level" was formed during a period of decreasing accommodation space. Microbial carbonates occur in different levels in the composite section. They reach their maximum thickness around the sequence boundaries just above the "Orbitolina Level" and close to the Aptian–Albian transition, and were not deposited during maximum flooding. S. dinarica-rich deposits occur in the lower part of the Monte Tobenna-Monte Faito composite section, in both restricted and more open lagoonal sediments. S. dinarica has its maximum abundance below the "Orbitolina Level" and disappears 11 m above this layer. On the basis of δ13C and δ18O values recorded at Tobenna-Faito, the succession has been correlated to global sea-level changes and to the main volcanic and climatic events during the Aptian. Deterioration of the inner lagoon environmental conditions was related to high trophic levels triggered by volcano-tectonic activity. Microbial carbonates were deposited especially in periods of third-order sea level lowering. In such a scenario, periods of increased precipitation during the Gargasian induced the mobilization of clay during flooding of the exposed platform due to high-frequency sea-level changes, with consequent terrigenous input to the lagoon. This and the high nutrient levels made the conditions unsuitable for the principle carbonate producers, and an opportunistic biota rich in orbitolinids (Mesorbitolina texana and M. parva) populated the platform. In the more open marine domain, the increased nutrient input enhanced the production of organic matter and locally led to the formation of black shales (e.g. the Niveau Fallot in the Vocontian Basin). It is argued that the concomitant low Mg/Ca molar ratio and high concentration of calcium in seawater could have favoured the development of the low-Mg calcite skeleton of the S. dinarica green algae. During third-order sea-level rise, no or minor microbial carbonates formed in the shallowlagoonal settings and S. dinarica disappeared. Carbonate neritic ecosystems were not influenced by the environmental changes inferred to have been induced by the mid-Cretaceous volcanism. The "Orbitolina Level", the microbial carbonates and the Salpingoporella dinarica-rich deposits in the studied Aptian/Albian shallow water carbonate strata are interpreted to be the response to environmental and oceanographic changes in shallow-water and deeper-marine ecosystems.

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Van Yperen, Anna E., John M. Holbrook, Miquel Poyatos-Moré y Ivar Midtkandal. "Coalesced Delta-front Sheet-like Sandstone Bodies from Highly Avulsive Distributary Channels: The Low-accommodation Mesa Rica Sandstone (Dakota Group, New Mexico, U.S.A.)". Journal of Sedimentary Research 89, n.º 7 (25 de julio de 2019): 654–78. http://dx.doi.org/10.2110/jsr.2019.27.

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Abstract Low-accommodation deltaic systems are often challenging to interpret due to their condensed, low-gradient nature, which often results in extensive, sheet-like sandstone bodies. As a result, detailed studies of such systems are scarce, and their internal depositional architecture is still poorly understood. We analyze one such system, the Cenomanian deltaic Mesa Rica Sandstone (Dakota Group), which was deposited in the Western Interior Seaway, in east-central New Mexico, USA. A > 20-km-long escarpment, subparallel to the main delta progradation direction, allows a detailed analysis of facies distribution, depositional architecture, and the spatial extent of stratigraphic surfaces. Results reveal an arrangement of laterally variable shallowing-upward facies successions with three depositional cycles preserved. The first cycle is characterized by deltaic sheet-like sandstone bodies that are consistently overlain by sand-filled amalgamated distributary-channel deposits. The two successive cycles record a progressive reduction of sediment supply into the basin. Vertical and lateral relationships between facies associations and architectural geometries allow the recognition of regional key stratal surfaces, incised-valley fills, and the presence of lagoonal deposits at a sub-regional scale. The Mesa Rica deltaic system represents a river-dominated delta with multiple distributary channels. The sheet-like delta-front sandstone bodies are interpreted as the result of the combined effect of high sandy-sediment supply and low accommodation. The latter acted as an accelerator for autogenic depositional mechanisms such as mouth-bar deposition and abandonment, and for the highly avulsive character of distributary channels. After deposition, minor wave reworking facilitated lateral sand redistribution and favored bioturbation. This study demonstrates that sheet-like delta-front sandstone geometries from low-accommodation systems can be formed without the dominance of wave redistribution processes. This cautions against interpretations of amalgamated shoreline systems based solely on apparent sandstone geometries, without taking into account the preservation potential and postdepositional modification of primary deltaic characteristics.

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Fanti, Federico y Octavian Catuneanu. "Stratigraphy of the Upper Cretaceous Wapiti Formation, west-central Alberta, Canada". Canadian Journal of Earth Sciences 46, n.º 4 (abril de 2009): 263–86. http://dx.doi.org/10.1139/e09-020.

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The lithostratigraphic interval between the marine Puskwaskau Formation (Smoky Group, Santonian–Campanian) and the fluvial Scollard Formation (early Maastrichtian) in west-central Alberta and easternmost British Columbia (Canada) is represented by the nonmarine deposits of the Wapiti Formation. Its subdivision into regionally mappable stratigraphic units and the correlation of such units with the better known successions of central and southern Alberta are the main goals of this study. We present a detailed stratigraphic revision of the Wapiti Formation in the Grande Prairie region, where the entire succession crops out extensively and intensive oil and gas exploration activity provides excellent subsurface control. This study indicates that the Wapiti Formation consists in five stratigraphic units: their description has been based in particular on facies analysis and well-log signatures. In ascending order, units 1 to 5 record major differences in depositional architecture related to variation in accommodation and climatic conditions. Upper and lower contacts of these units are represented by regionally mappable subaerial unconformities or conformable facies contacts. Three major coal zones are identified within the Wapiti Formation, the Basal, Red Willow, and Cutbank: coals referred to these intervals have been documented in both outcrop and subsurface in the entire study area, thus representing a reliable tool for regional correlations. Furthermore, results presented here indicate that the maximum flooding surfaces of the Bearpaw seaway and the Drumheller Marine Tongue, both marine reference units in central and southern Alberta, lie, respectively, within coals of unit 3 and the Red Willow coal zone.

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Long, Joshua H., Till J. J. Hanebuth y Thomas Lüdmann. "The Quaternary stratigraphic architecture of a low-accommodation, passive-margin continental shelf (Santee Delta region, South Carolina, U.S.A.)". Journal of Sedimentary Research 90, n.º 11 (30 de noviembre de 2020): 1549–71. http://dx.doi.org/10.2110/jsr.2020.006.

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ABSTRACT The Quaternary stratigraphy of the continental shelf offshore of South Carolina consists of stratigraphic units deposited in coastal-plain, shallow marine, and shelfal environments bounded by composite erosional surfaces that developed in response to numerous glacioeustatic cycles and were overprinted by regional uplift. These units are commonly distributed laterally, rather than stacked vertically, a function of the long-term low shelf gradient and the resulting lack of accommodation. Additionally, marine processes such as waves and geostrophic currents can rework both relict and modern sediments across the continental shelf. This study integrates high-resolution geological and geophysical datasets acquired offshore and onshore with existing data onshore into a comprehensive conceptual model describing the Quaternary geologic evolution of the coastal plain and continental shelf within a study area of approximately 8,000 km2. We use seismic facies and core analysis to define stratigraphic units associated with transgressive, regressive, and lowstand systems offshore. Regressive systems include progradational wave- and river-dominated deltaic and shoreface deposits. Lowstand systems consist of a complex network of paleo-incisions produced by regional, Piedmont-draining fluvial systems and smaller coastal plain rivers. Transgressive systems include paleochannel-fill successions dominated by mud-rich, tidally influenced backbarrier deposits, cuspate and linear shelf sand ridges, and transgressive sand sheets and shoals. The low-accommodation setting of the continental shelf influences the stratigraphic record in several ways: 1) the geometry of progradational coastal lithosomes, 2) the development of composite allogenic erosional surfaces, 3) the deposition of widespread, thin transgressive sand sheets, and 4) the restriction of thicker transgressive deposits to paleo-incisions. In this setting, the use of a bounding surface scheme that is hierarchical is preferable to the more common sequence stratigraphic or allostratigraphic convention for several reasons: 1) major erosional bounding surfaces are commonly amalgamated; 2) lower-order surfaces capture internal variability, which is key to the genetic interpretation of stratigraphic units, and 3) stratal stacking patterns typically used to define a sequence stratigraphic framework are rare.

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19

Lantzsch, Hendrik, Till J. J. Hanebuth y Vera B. Bender. "Holocene evolution of mud depocentres on a high-energy, low-accumulation shelf (NW Iberia)". Quaternary Research 72, n.º 3 (noviembre de 2009): 325–36. http://dx.doi.org/10.1016/j.yqres.2009.07.009.

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AbstractThe high-energy, low-accumulation NW Iberian shelf features three confined Holocene mud depocentres. Here, we show that the evolution of such depocentres follows successive steps. The flooding of inner shelf zones and river catchment areas by the late deglacial sea-level rise provided the precondition for shelf mud deposition. Following this, the Holocene deceleration of the sea-level rise caused a rapid refill of the accommodation space within river valleys. Subsequently, the export of major amounts of fines was initiated. The initial onset and loci of shelf mud deposition were related to deposition-favouring conditions in mid-shelf position or to the presence of morphological highs, which act as sediment traps by providing protection against stronger hydrodynamic energy. The detailed reconstruction of the Holocene depocentre evolution shows for the first time that the expansion of such shelf mud deposits cannot only occur by linear growth off the associated sediment source. Rather, they might develop around centres that are fully disconnected from the source of original sediment supply, and expand later into specific directions. Based on these differences and on the connection of the individual mud depocentres to the material source we propose a conceptual subdivision of the group “mid-shelf mud depocentres”.

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20

Nakanishi, T. y S. C. Lang. "THE SEARCH FOR STRATIGRAPHIC TRAPS GOES ON—VISUALISATION OF FLUVIAL-LACUSTRINE SUCCESSIONS IN THE MOORARI 3D SURVEY, COOPER-EROMANGA BASIN". APPEA Journal 41, n.º 1 (2001): 115. http://dx.doi.org/10.1071/aj00006.

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Exploration and development in the Cooper-Eromanga Basin have been predominantly focussed on structural traps. However, the future for exploration and field development lies in exploration for stratigraphic traps. Using advanced visualisation techniques on open file 3D seismic survey data from the Moorari and Woolkina fields in the Patchawarra Trough, Cooper Basin, we have sought to characterise the variety of possible stratigraphic traps in the Permian Patchawarra, Epsilon and Toolachee Formations and also the basal Jurassic Poolowanna Formation. The key to the analysis lies in a genetic-stratigraphic framework using sequence stratigraphy concepts as applied to non-marine basins.Five different types of possible stratigraphic traps are illustrated from the Moorari 3D survey: Isolated fluvial channels in a transgressive systems tract of the lower Patchawarra Formation.Fluvial sand bodies in low accommodation intervals in a lowstand systems tract of the upper Patchawarra Formation.Highstand lacustrine delta of the Epsilon Formation below the regional sequence boundary at the base of the Toolachee Formation.Isolated fluvial channels in the transgressive systems tract of the Toolachee Formation.Crevasse splay channels and crevasse splay delta complex of the transgressive systems tract of the Poolowanna Formation.For each trap type, three dimensional distributions of the possible reservoir and seal rocks are presented and the ranking of stratigraphic trap opportunities is discussed.

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21

Kolenko, Petr, Jakub Svoboda, Jiří Černý, Tatsiana Charnavets y Bohdan Schneider. "Structural variability of CG-rich DNA 18-mers accommodating double T–T mismatches". Acta Crystallographica Section D Structural Biology 76, n.º 12 (24 de noviembre de 2020): 1233–43. http://dx.doi.org/10.1107/s2059798320014151.

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Solution and crystal data are reported for DNA 18-mers with sequences related to those of bacterial noncoding single-stranded DNA segments called repetitive extragenic palindromes (REPs). Solution CD and melting data showed that the CG-rich, near-palindromic REPs from various bacterial species exhibit dynamic temperature-dependent and concentration-dependent equilibria, including architectures compatible with not only hairpins, which are expected to be biologically relevant, but also antiparallel duplexes and bimolecular tetraplexes. Three 18-mer oligonucleotides named Hpar-18 (PDB entry 6rou), Chom-18 (PDB entry 6ros) and its brominated variant Chom-18Br (PDB entry 6ror) crystallized as isomorphic right-handed A-like duplexes. The low-resolution crystal structures were solved with the help of experimental phases for Chom-18Br. The center of the duplexes is formed by two successive T–T noncanonical base pairs (mismatches). They do not deform the double-helical geometry. The presence of T–T mismatches prompted an analysis of the geometries of these and other noncanonical pairs in other DNA crystals in terms of their fit to the experimental electron densities (RSCC) and their geometric fit to the NtC (dinucleotide conformational) classes (https://dnatco.datmos.org/). Throughout this work, knowledge of the NtC classes was used to refine and validate the crystal structures, and to analyze the mismatches.

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22

Zirkel, Perry A. "Court Decisions Specific to Public School Responses to Student Concussions". Physical Disabilities: Education and Related Services 35, n.º 1 (6 de mayo de 2016): 1–16. http://dx.doi.org/10.14434/pders.v35i1.20696.

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This article provides an up-to-date and comprehensive canvassing of the judicial case law concerning the responses to students with concussions in the public school context. The two categories of court decisions are (a) those concerning continued participation in interscholastic athletics, referred to under the rubric of "return to play” and (b) those concerning the legal obligations in facilitating the continued educational progress of the student, referred to under the rubric of "return to school." The case law in the first category primarily addresses state common law claims of negligence and federal constitutional claims under the Fourteenth Amendment due process clause. The court decisions in the second category primarily address the successive issues of child find, eligibility, and "free appropriate public education" (including but not necessarily limited to accommodations) under Section 504 of the Rehabilitation Act and the Individuals with Disabilities Education Act. The outcomes of the court decisions thus far have been largely in favor of the district defendants, but the case law is far from crystallized and complete.

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23

Arimoro, Augustine Edobor. "Are they not Nigerians? The obligation of the state to end discriminatory practices against persons with disabilities". International Journal of Discrimination and the Law 19, n.º 2 (30 de mayo de 2019): 89–109. http://dx.doi.org/10.1177/1358229119846764.

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Nigeria has ratified several international instruments that protect the rights of, and guarantee freedom from discrimination of persons with disabilities (PWD). Despite the above, the country is yet to fully implement the appropriate measures required to achieve the objective of protecting PWD. Successive administrations since the return to civil administration in the country in 1999 have not fulfilled the mandate in the 1999 Constitution of the Federal Republic of Nigeria (as amended) dealing with disability rights. While the passing into law in January 2019 of the Discrimination Against Persons with Disabilities (Prohibition) Act 2018 is commendable, it only reflects the pressure on the Federal Government of Nigeria by disability rights advocates and PWD. This article aims to, among others, highlight the plight of PWD in Nigeria, the need to protect their rights and guarantee their freedom from discriminatory practices. To achieve this aim, a review of international and domestic instruments, as well as literature on the subject, is undertaken. The article proposes that the Nigerian government should aim towards inclusivity and accommodation of PWD. For example, instead of merely establishing special schools for PWD, there should be a design to allow for the training of teachers to meet the needs of special children in regular schools.

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24

Plamanescu, Radu, Ana-Maria Dumitrescu, Mihaela Albu y Siddharth Suryanarayanan. "A Hybrid Hilbert-Huang Method for Monitoring Distorted Time-Varying Waveforms". Energies 14, n.º 7 (27 de marzo de 2021): 1864. http://dx.doi.org/10.3390/en14071864.

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The electric power systems together with the entire energy sector are rapidly evolving towards a low-carbon, secure, and competitive economy facing revolutionary transformations from technical structure to economic value chain. Pathways to achieve sustainability led to the development of new technologies, accommodation of larger shares of unpredictable and stochastic electricity transfer from sources to end-users without loss of reliability, new business models and services, data management, and so on. The new technologies and incentives for local energy communities along with large development of microgrids are main forces driving the evolution of the low voltage energy sector changing the context and paradigm of rigid contractual binding between utilities and end-user customers (now progressing to flexible prosumers with generation and storage capabilities). The flexibility and operation of a prosumer can be enhanced by a non-intrusive time-frequency analysis of distorted power quality waveforms for both generation and demand at the point of common connection. Therefore, it becomes of importance to discriminate among successive quasi-steady-state operation of a given local system using only the aggregated waveforms information available in the PCC. This paper focuses on the Hilbert–Huang method with modifications such as empirical mode decomposition improved with masking signals based on the Fast Fourier Transform, Hilbert spectral analysis, and a post-processing method for separating components and their amplitudes and frequencies within distorted power signals for a low-voltage prosumer operation. The method is used for a time-frequency-magnitude representation with promising localization capabilities enabling efficient operation for prosumers.

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25

Cusack, Alan. "Addressing vulnerability in Ireland’s criminal justice system: A survey of recent statutory developments". International Journal of Evidence & Proof 24, n.º 3 (6 de mayo de 2020): 280–306. http://dx.doi.org/10.1177/1365712720922753.

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For over a quarter of century Ireland’s statutory special measures framework, as originally enacted by the Criminal Evidence Act 1992, remained largely unchanged, falling beyond the reformative gaze of successive Irish governments. This period of political inertia, however, came to an abrupt end in 2017 when Irish policymakers, motivated by developments at a European Union level, introduced two landmark legislative instruments which promised to reimagine the availability and diversity of Ireland’s store of statutory testimonial accommodations, namely the Criminal Law (Sexual Offences) Act 2017 and the Criminal Justice (Victims of Crime) Act 2017. By interrogating these newly-commenced instruments in light of the experience of crime victims with intellectual disabilities, this paper surveys the current procedural landscape governing the treatment of vulnerable crime victims in Ireland and is intended to go some way towards exposing the embedded evidential barriers which continue to prejudice efforts aimed at securing their best evidence in court.

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26

Buske, Christian, Shalal Sadullah, Efsthatios Kastritis, Giulia Benevolo, Ramon Garcia-Sanz, Lukasz Bolkun, Xavier Leleu et al. "Generation of a Large Observational Pan-European Data Platform for Treatment and Outcome Patterns in Patients with Waldenstrom's Macroglobulinemia". Blood 126, n.º 23 (3 de diciembre de 2015): 2096. http://dx.doi.org/10.1182/blood.v126.23.2096.2096.

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Abstract Introduction Waldenström's Macroglobulinemia (WM) is a rare indolent lymphoma with a low incidence of ~3 cases per million per year. There are few randomized trials and no well-established treatment standards in WM. Treatment landscapes for treatment-naïve and relapsed WM are heterogeneous and data on treatment choices and their outcome in patients (pts) outside clinical trials are lacking. The goal of this project was to generate data on epidemiologic/treatment patterns and efficacy outcomes for WM over a prolonged period of time (~10 yr) in a large pan-European effort. Methods In this observational chart review, physicians completed a retrospective electronic record for pts who fit the following inclusion criteria: confirmed WM, symptomatic disease at treatment initiation, front line treatment initiated between Jan 2000-Jan 2014, and availability of complete clinical/biologic evaluation at diagnosis/initial therapy. Study endpoints included initial/subsequent lines of treatment, progression-free survival (PFS), and overall survival (OS). The number of pt records per country was prespecified to balance the distribution between European countries. Results Of 454 pt records reviewed, cases were from France (n=92), United Kingdom (UK; n=72), Germany (n=66), Spain (n=60), Italy (n=56), Greece (n=25), Netherlands (n=25), Poland (n=21), Austria (n=19), and Czech Republic (n=16). Data were summarized across 5 lines of treatment for 454, 397, 160, 61, and 26 pts, respectively. Median age at initiation of front-line treatment was 65 yr (range, 29-89); 61% were male. The most common reasons for initiating treatment at diagnosis were constitutional symptoms (58%), cytopenias (72%; anemia [69%]), and IgM-related symptoms (57%). Choice of therapy varied with line of treatment; monotherapy fell from 31% in front-line to 20%/21% in 2nd/3rd-line ( Table 1). Combination therapy with antibody increased from 40% in front-line to 64%/56% in 2nd/3rd-line. Across all lines, rituximab followed by cyclophosphamide, and to a lesser extent, chlorambucil, fludarabine, vincristine, and bendamustine, were the most common agents, excluding steroids, that were used as monotherapy or in any combination with use varying between countries (Table 1). Median PFS decreased with successive lines of treatment (29 vs 23 vs 16 mo), (Figure 1) and varied by country and choice of agents (Table 1). Median OS was 123 mo, but significantly lower in pts ≥75 yr (75 mo) or with high-risk IPSSWM risk score (91 mo) and similar for pts with low/intermediate risk groups. Considerable country-specific OS differences were noted. Other malignancies were reported in 12% after diagnosis of WM. Conclusions The retrospective chart review of WM pts treated in Europe shows that constitutional symptoms and anemia are the most common reasons for initiating therapy. Rituximab was the most commonly used agent across all lines of treatment. Outside clinical trials, monotherapy is widely used even at first relapse with notable differences between countries. This large observational dataset will be an important tool to improve understanding of treatment practice and survival of WM pts in Europe outside of clinical trials, as well as unmet medical needs in the community. Table 1. Use of Monotherapy or Combination Regimens and Median PFS in Front -, 2nd -, and 3rd-Line Settings Overall and by Country Country Number of Cases, n Monotherapy, % Combination Therapy With Antibody†, % Combination Therapy Without Antibody, % Median PFS,Months (95% CI) Front line 2nd line 3rd line Front line 2nd line 3rd line Front line 2nd line 3rd line Front line 2nd line 3rd line Front line 2nd line 3rd line Overall 454 397 160 31 20 21 40 63 56 28 14 21 29.0 (25-31) 23.0 (20-26) 16.0 (10-18) France 92 86 43 62 26 16 24 66 70 14 8 14 28.5 (22-32) 30.0 (20-37) 16.0 (9-32) United Kingdom 72 64 19 18 22 21 19 55 42 63 23 37 31.5 (25-36) 20.0 (11-35) 13.0 (9-33) Germany 66 52 18 9 8 22 61 81 50 30 8 11 36.5 (29-44) 24.0 (16-29) 8.0 (3-16) Spain 60 58 21 43 28 38 38 59 52 18 12 5 18.0 (15-25) 16.0 (12-24) 11.0 (9-24) Italy 56 47 20 20 17 15 57 68 70 23 6 15 30.5 (20-39) 30.0 (18-42) 17.0 (4-21) Eastern European* 37 30 12 8 13 8 32 40 0 60 47 92 33.0 (26-38) 20.0 (16-26) 20.5 (4-38) Smaller European** 71 60 27 35 22 26 56 67 63 7 12 11 23.0 (18-29) 16.0 (13-25) 16.0 (7-26) * Includes Czech Republic and Poland **Includes Austria, Greece, and Netherlands † Antibodies other than rituximab, <1% Figure 1. Figure 1. Kaplan-Meier PFS Estimates by Line of Treatment Disclosures Buske: CELLTRION, Inc.: Consultancy, Honoraria. Sadullah:Roche: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau; NAPP: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; TEVA: Consultancy; Boehringer: Other: Travel, Accommodations, Expenses. Kastritis:Janssen: Consultancy, Other: Travel, Accommodations, Expenses. Garcia-Sanz:Janssen: Honoraria, Other: Travel, Accommodations, Expenses; Takeda: Honoraria, Other: Travel, Accommodations, Expenses; Novartis: Research Funding. Leleu:Pierre Fabre: Honoraria; BMS: Honoraria; Novartis: Honoraria; TEVA: Honoraria; Amgen: Honoraria; Takeda: Honoraria; Celgene: Honoraria; Janssen: Honoraria; LeoPharma: Honoraria; Chugai: Honoraria. Willenbacher:Celgene: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Roche: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; Janssen: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; Amgen: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; Gilead: Consultancy, Other: Travel, Accommodations, Expenses, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; CTI: Consultancy, Other: Travel, Accommodations, Expenses. Hajek:Amgen: Honoraria; Celgene: Consultancy; Janssen: Consultancy. Cheng:Pharmacyclics LLC, an AbbVie Company: Employment. Graef:Pharmacyclics LLC, an AbbVie Company: Employment, Membership on an entity's Board of Directors or advisory committees; AbbVie: Equity Ownership. Dimopoulos:Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Onyx: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Genesis Pharma: Research Funding.

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Nadiri, Khalid Homayun. "Old Habits, New Consequences: Pakistan's Posture toward Afghanistan since 2001". International Security 39, n.º 2 (octubre de 2014): 132–68. http://dx.doi.org/10.1162/isec_a_00178.

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Since September 11, 2001, Pakistan has pursued seemingly incongruous courses of action in Afghanistan. It has participated in the U.S. and international intervention in Afghanistan at the same time as it has permitted much of the Afghan Taliban's political leadership and many of its military commanders to visit or reside in Pakistani urban centers. This incongruence is all the more puzzling in light of the expansion of indiscriminate and costly violence directed against Islamabad by Pakistani groups affiliated with the Afghan Taliban. Pakistan's policy is the result not only of its enduring rivalry with India but also of historically rooted domestic imbalances and antagonistic relations with successive governments in Afghanistan. Three critical features of the Pakistani political system—the militarized nature of foreign policy making, ties between military institutions and Islamist networks, and the more recent rise of grassroots violence—have contributed to Pakistan's accommodation of the Afghan Taliban. Additionally, mutual suspicion surrounding the contentious Afghanistan-Pakistan border and Islamabad's long record of interference in Afghan politics have continued to divide Kabul and Islamabad, diminishing the prospect of cooperation between the two capitals. These determinants of Pakistan's foreign policy behavior reveal the prospects of and obstacles to resolving the numerous issues of contention that characterize the Afghanistan-Pakistan relationship today.

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Rogov, MA, EV Shchepetova y VA Zakharov. "Late Jurassic – earliest Cretaceous prolonged shelf dysoxic–anoxic event and its possible causes". Geological Magazine 157, n.º 10 (19 de agosto de 2020): 1622–42. http://dx.doi.org/10.1017/s001675682000076x.

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AbstractThe Late Jurassic – earliest Cretaceous time interval was characterized by a widespread distribution of dysoxiс–anoxiс environments in temperate- and high-latitude epicontinental seas, which could be defined as a shelf dysoxic–anoxic event (SDAE). In contrast to black shales related to oceanic anoxic events, deposits generated by the SDAE were especially common in shelf sites in the Northern Hemisphere. The onset and termination of the SDAE was strongly diachronous across different regions. The SDAE was not associated with significant disturbances of the carbon cycle. Deposition of organic-carbon-rich sediment and the existence of dysoxic–anoxic conditions during the SDAE lasted up to c. 20 Ma, but this event did not cause any remarkable biotic extinction. Temperate- and high-latitude black shale occurrences across the Jurassic–Cretaceous boundary have been reviewed. Two patterns of black shale deposition during the SDAE are recognized: (1) Subboreal type, with numerous thin black shale beds, bounded by sediments with very low total organic carbon (TOC) values; and (2) Boreal type, distinguished by predominantly thick black shale successions showing high TOC values and prolonged anoxic–dysoxic conditions. These types appear to be unrelated to differences in accommodation space, and can be clearly recognized irrespective of the thickness of shale-bearing units. Black shales in high-latitude areas in the Southern Hemisphere strongly resemble Boreal types of black shale by their mode of occurrence. The causes of this SDAE are linked to long-term warming and changes in oceanic circulation. Additionally, the long-term disturbance of planktonic communities may have triggered overall increased productivity in anoxia-prone environments.

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Robertson, Danielle, Andrew Jones y Daniel Mantle. "New insights into the stratigraphy and basin evolution of the Houtman Sub-basin, offshore North Perth Basin, from a detailed sequence stratigraphic study". APPEA Journal 51, n.º 2 (2011): 745. http://dx.doi.org/10.1071/aj10125.

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A detailed sequence stratigraphic study has been undertaken on the three wells in the Houtman Sub-basin: Gun Island–1, Houtman–1 and Charon–1. The study focused on the early–late Jurassic Cattamarra Coal Measures, Cadda Formation and Yarragadee Formation succession. Wireline log character, cuttings, sidewall core and conventional core lithologies and palynological data were used to identify facies and paleoenvironments. Palynology for all wells has been reviewed, including new data collected by Geoscience Australia for Gun Island–1. Facies stacking patterns were used to define systems tracts and subsequently ten third-order depositional sequences. At the second-order (supersequence) level, the Cattamarra Coal Measures recorded a transgression culminating in maximum flooding in the Cadda Formation, followed by highstand aggradation and regression in the Yarragadee Formation. The third-order sequences characterised in this study overprint this supersequence and control the local distribution of facies. The relative dominance of a facies may be either enhanced or diminished depending upon its position in the larger second-order supersequence—for example: a number of transgressive systems tracts in the dominantly non-marine Yarragadee Formation and Cattamarra Coal Measures record multiple, dinocyst-bearing, minor marine incursions into the Houtman Sub-basin. These marine incursions are not evident in the Yarragadee Formation in Charon—1, indicating a lack of accommodation space or proximal sediment input in the north during the mid-late Jurassic. The combined influence of these third-order and second-order sequences on facies distribution has significant implications for the distribution of potential reservoirs and seals in the Houtman Sub-basin and for regional palaeogeographic reconstructions of the Perth Basin.

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30

Rautenbach, Christa. "Editorial". Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad 17, n.º 3 (24 de abril de 2017): 1. http://dx.doi.org/10.17159/1727-3781/2014/v17i3a2297.

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The third issue of PER contains ten articles and one case note on a variety of themes. Shaun de Freitas shares his views on improper irreligious proselytism in religious rights and freedoms jurisprudence within a public school context and introduces an equitable and accommodative understanding of proselytism, which places the potentially harmful effects of both religious and irreligious beliefs on an equal footing with each other. Yvette Joubert and Juanitta Calitz analyse the role of the so-called private examinations in South African insolvency law and deal with the question of whether or not section 417 of the Insolvency Act 24 of 1936 is adequately and effectively framed in order to fulfil its intended purpose in South African law. Howard Chitimira gives a historical overview of the regulation of market abuse in South Africa. He concludes his contribution with a discussion by isolating certain flaws in the previous market abuse laws that were re-incorporated into the current South African market abuse legislation and makes recommendations in that regard. Juanita Jamneck discusses the contemporary meaning of the word "spouse" and the recognition of the family as an important social institution in the light of the provisions of the Intestate Succession Act 81 of 1987. Shannon Bosch reviews the scope and nature of "direct participation in hostilities" in international humanitarian law in the light of the Interpretive Guide on the Notion of Direct Participation in Hostilities issued by the International Committee for the Red Cross. The primary objective of the article by Vinesh Basdeo is to determine if the asset forfeiture measures employed in the South African criminal justice system are in need of any reform and/or augmentation in accordance with the "spirit, purport and object" of the South African Constitution. Eddie Hurter and Tana Pistorius examine the new .Africa Top Level Domain - an Africa initiative to ensure that Africa gets its rightful place in the global network. Geo Quinot tracks the development of the role of functionality in public tender adjudication as prescribed by public procurement regulation since the enactment of the Preferential Procurement Policy Framework Act 5 of 2000, which spearheaded the development of contemporary public procurement regulation in South Africa. Thino Bekker discusses the scope and application of the integration rule in the South African law of contract and deals with the question if rectification can be utilised to avoid the strict application of the integration rule and consequently serve as an instrument for the (indirect) abolition or modification of the rule in the South-African law of contract. Yeukai Mupangavanhu discusses the case of Naidoo v Birchwood Hotel 2012 6 SA 170 (GSJ) in the light of the exemption clauses in the Consumer Protection Act 68 of 2008 (CPA). The case note, which is also the final contribution, by Martha Radebe evaluates the unconstitutional practices of the Judicial Service Commission under the guise of judicial transformation as they came to the fore in the case of the Cape Bar Council v Judicial Service Commission [2012] 2 ALL 143 (WCC).

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31

Borer, James. "High-Resolution Stratigraphy of the lower portion of the Green River Formation at Raven Ridge and Red Wash Field, NE Uinta Basin, Utah, Colorado, USA: Facies and Stratigraphic Patterns in a High-Gradient, High-Energy Lacustrine System". Mountain Geologist 53, n.º 3 (julio de 2016): 119–223. http://dx.doi.org/10.31582/rmag.mg.53.3.119.

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Lacustrine strata of a portion of the Green River Formation studied in outcrops along Raven Ridge and in the subsurface around Red Wash Field in the northeastern Uinta Basin represent cyclic storm-dominated shoreface to deep lake deposition within a syntectonic embayment on the margin of Eocene Lake Uinta. The study interval consists of the lower Green River Formation, including the Douglas Creek, Garden Gulch, and lower Parachute Creek members, from the top of the underlying Wasatch to the Mahogany Zone of the Parachute Creek Member. Data consists of 11,900 ft (3627 m) of section measured at 23 locations across Raven Ridge, including 7,800 ft (2377 m) of hand-held gamma-ray scintillometer measurements, and over 500 wells in the greater Red Wash Field area, including pay zone analysis correlated to stratigraphy in the field. Facies analysis, as the basis for an integrated stratigraphic approach, reveals a seven-fold hierarchy of stratigraphic cycles ranging from two orders of large-scale cycles to five orders of progressively higher-frequency (smaller scale) shoreface-lake cycles across an 18-mile (29 km) long and 1900-ft (579 m) thick dip-oriented stratigraphic transect. This study recognized twenty-two facies grouped into eight facies tracts using Walther’s Law for two composite shoreface successions: one for a siliciclastic storm-graded shoreface profile that was dominant during times of regression and one for a carbonate profile that dominated in times of transgression. Two important regional facies trends across Raven Ridge include: 1) greater proportions of mudstone facies present in the southern, upper portion of the Green River Formation; and 2) significantly higher proportion of bioturbated sandstone in the northern, lower portion of the formation. The long-term 2nd-order transgression of Lake Uinta from base to top of the study interval results in an evolution from a low-gradient shoreline with marshes, ponds, and sand/mud flats to a high-gradient high-energy profile composed of spits and shorefaces that grew southward away from the emergent highlands. A composite storm-graded shelf profile shows how trough, hummocky, and swaley cross stratification type and amalgamation style change offshore proportionally to contain mud-dominated tempestites, erosional storm furrows, and oil shale. In the most offshore positions, diastasis cracks caused by differential loading are common. The lacustrine shoreface profile is compressed in the Green River Fm. in the study area with narrow facies tracts and large local gradient changes as a result of different responses to sediment supply. As a lake grows and shorelines migrate, the increase in accommodation is balanced, or in-phase, by a corresponding increase in sediment supply resulting in shoreface progradation keeping up with lake-level rise. As the shoreface stacks vertically during the rise, over steepening and failure of the profile generates gravity-flow sandstone facies. Little reworking of hummocky cross stratification high on the profile was observed, probably because wave power was limited by a shallow fair-weather wave-base. These differences also result in more symmetrical lacustrine shoreface cycles, with a large proportion of sediment partitioned into rise hemicycles, as opposed to the classical fall-asymmetric marine para-sequence which tends to have little to no strata preserved in the rise hemicycle along most of the shoreface profile. Landward-stepping lacustrine shoreface cycles are more common during the early rise portions of larger-scale 3rd-order megacycles for similar reasons. Strata at Raven Ridge support the concept that Eocene Lake Uinta was chemically stratified, or meromictic, at least during certain periods. The equable subtropical Eocene paleoclimate is interpreted to be the most important control on meromixis. Chemical stratification played a critical role in the development and preservation of organic matter, as evidenced by oil shale facies. The equable climate, however, might also have made the lake prone to thermal stratification. A paradox exists in the storm dominance of the lacustrine shorefaces and the coeval lake stratification: wave energy apparently was insufficient to break through the strong chemocline. Red Wash Field, directly downdip from the Raven Ridge outcrop belt, is an example of an oil field in a setting where the lake margin is not coincident with a structural feature: a “non-coincident” margin. Reservoirs mostly are present in the 6th-order aggradational shoreface cycles that are interpreted to have accumulated in the rise portions of 3rd-order megacycles. The best reservoir facies are trough, hummocky, and swaley cross-stratified sandstone deposited by storm processes and structureless sandstone probably derived from over steepening and failure of the shoreface during transgression. A petroleum accumulation model encompassing the Red Wash-Raven Ridge area proposes that lacustrine-sourced petroleum originated from an over-pressured mature cell in the Altamont-Bluebell field region. Oil migrated updip through leaky seals and became trapped in reservoirs within the non-coincident lake margin strata. An irregular shoreline configuration and compaction folds at Red Wash Field trapped petroleum. After reaching spill point at Red Wash Field, oil migrated farther updip to Raven Ridge and Asphalt Ridge, forming tar sand accumulations.

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Minor, Keith P., Ronald J. Steel y Cornel Olariu. "Tectonic and eustatic control of Mesaverde Group (Campanian−Maastrichtian) architecture, Wyoming-Utah-Colorado region, USA". GSA Bulletin, 18 de mayo de 2021. http://dx.doi.org/10.1130/b36032.1.

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We describe and analyze the depositional history and stratigraphic architecture of the Campanian and Maastrichtian succession of the southern greater Green River basin of Wyoming, USA, and surrounding areas to better understand the interplay between tectonic and eustatic drivers that built the stratigraphy. By integrating new measured sections with published outcrop, well-log, and paleogeographic data, two new stratigraphic correlation diagrams, 35 new paleogeographic reconstructions, and six new tectonic diagrams were created for this part of the Western Interior Seaway. From this work, two time-scales of organization are evident: (1) 100−300 k.y.-scale, mainly eustatically driven regressive-transgressive shoreline oscillations that generated repeated sequences of alluvial-coastal plain-shoreline deposits, passing basinward to subaqueous deltas, then capped by transgressive estuarine/barrier lagoon deposits, and (2) 3.0−4.0 m.y.-scale, tectonically driven groups of 10 to 15 of these eustatically driven units stacked in an offset arrangement to form larger clastic units, which are herein referred to as clastic wedges. Four regional clastic wedges are recognized, based on the architectures of these clastic packages. These are the: (1) Adaville, (2) Rock Springs, (3) Iles, and (4) Williams Fork clastic wedges. Pre-Mesaverde deposition in the Wyoming-Utah-Colorado (USA) region during the Middle Cretaceous was characterized by thickening of the clastic wedge close to the thrust-front, driven primarily by retroarc foreland basin (flexural) tectonics. However, a basinward shift in deposition during the Santonian into the early Campanian (Adaville clastic wedge) signaled a change in the dominant stratigraphic drivers in the region. Shoreline advance accelerated in the early to middle Campanian (Rock Springs clastic wedge), as the end of activity in the thrust belt, growing importance of flat-slab subduction, and steady eastward migration of the zone of dynamic subsidence led to loss of the foredeep and forebulge, with the attendant formation of a low-accommodation shelf environment. This “flat-shelf” environment promoted large shoreline advances and retreats during sea-level rise and fall. During the middle to late Campanian (Iles clastic wedge), deep erosion on the crest of the Moxa Arch, thinning on the crests of the Rock Springs and Rawlins uplifts, and subsequent Laramide-driven basin formation occurred as the Laramide blocks began to partition the region. The next clastic package (Williams Fork clastic wedge) pushed the shoreline over 400 km away from the thrust belt during the late Campanian. This was followed by a very large and persistent marine transgression across the region, with the formation of a Laramide-driven deepwater turbidite basin with toe-of-slope fans into the early Maastrichtian. The Mesaverde Group in the Wyoming-Utah-Colorado region is thus characterized by: (1) a succession of four tectonically driven classic wedges, each comprised of a dozen or so eustatically driven packages that preserve large basinward and landward shoreline shifts, (2) broad regional sand and silt dispersal on a low-accommodation marine shelf setting, (3) a progressive, tectonically driven, basinward shift of deposition with offset, basinward stacking of successive clastic wedges, and (4) the gradual formation of various uplifts and sub-basins, the timing and sizes of which were controlled by the movement of deep-seated Laramide blocks. The Mesaverde Group in the Wyoming-Utah-Colorado region provides an outstanding opportunity to study the dynamic interaction among the tectonic control elements of a subducting plate (crustal loading-flexure, dynamic subsidence/uplift, and regional flat-slab basin partitioning), as well as the dynamic interaction of tectonic and eustatic controls.

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33

Olariu, Cornel, Chuanmin Zhou, Ronald Steel, Zhijie Zhang, Xuanjun Yuan, Jinyu Zhang, Si Chen, Dawei Cheng y Wonsuck Kim. "Controls on the stratal architecture of lacustrine delta successions in low‐accommodation conditions". Sedimentology, 17 de diciembre de 2020. http://dx.doi.org/10.1111/sed.12838.

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34

Partibane, B., R. Kalidoss y R. Karthipan. "Security Improvement in Next Generation Wireless System by Interleaver in Transceiver Structures". Journal of Cyber Security and Mobility, 7 de noviembre de 2017. http://dx.doi.org/10.13052/2245-1439.641.

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This paper presents the multiple-input multiple-output Interleave division multiple access (MIMO-IDMA) system with dual polarized division multiplexing (DPDM). Dual polarized antenna system replaces the uni-polarized antenna system availing cost and space features. We have considered dual- Polarized antennas at both the transmitter and the receiver ends to establish DPDM. For the purpose of accommodation, the users are separated with userspecific interleaver in combination with a low rate spreading sequence. In the receiver, we consider the minimum mean square error (MMSE) algorithm based successive interference cancellation (SIC) Multi-user detection (MUD) technique to diminish the effects of multi-stream interference (MSI). Furthermore, we implement Log-maximum a posteriori probability (MAPP) decoding algorithm at the mobile stations (MSs) to alleviate the effects of multi-user interference (MUI).We evaluate the effects of codedMIMO-IDMA system in the context of downlink (DL) communication pertaining to the Stanford University Interim (SUI) and Long-term Evolution (LTE) channel model specifications.We observe that our simulation results considered turbo coded Dual-PolarizedMIMO-IDMAsystem with iterative decoding algorithm provides a better bit error rate (BER) performance with less signal to noise ratio (SNR) when compared to uncoded system. Furthermore our simulation results show that MIMO-IDMA system with Dual-Polarized antenna requires higher SNR than uni-polarized antennas in order to achieve same BER. However, it provides the advantage of replacing two uni-polarized antennas by a single Dual-Polarized antenna which can therefore help achievement of a higher data rate with a reduced size of MS in the context of DL transmission.

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35

JOLLEY, David W., John M. MILLETT, Nick SCHOFIELD, Lena BROADLEY y Malcolm J. HOLE. "Stratigraphy of volcanic rock successions of the North Atlantic rifted margin: the offshore record of the Faroe–Shetland and Rockall basins". Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 26 de mayo de 2021, 1–28. http://dx.doi.org/10.1017/s1755691021000037.

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ABSTRACT The integration of biostratigraphical, wireline log, geophysical and available geochronological ages has identified two principal periods of volcanism in the Faroe–Shetland and Rockall basins. The first is pre-breakup, upper Danian to lower Thanetian: in the Rockall and Faroe–Shetland basins, isolated volcanic activity from 62 Ma to 58.7 Ma is identified in areas closely linked to the SSW–NNE structural fabric of the continental margin. Volcanic activity was concentrated at basin flank fissures and localised point sources. This rift-flank volcanism led to widespread volcanic ash deposition, localised lava flow fields and the formation of igneous centres. Some of the Hebridean and onshore central complexes (e.g., Rum) were uplifted and rapidly eroded during the later pre-breakup period, while additional accommodation space was developed in the adjacent offshore basins. Onset and termination of pre-breakup volcanism is correlated to intra-plate stress regimes in Europe, following the cessation of convergence of Africa and Europe in the Danian. The second is syn-breakup, upper Thanetian to Ypresian, initiated at ca.57 Ma in the Rockall and Faroe–Shetland basins. Initial high-volume extrusive igneous successions were focussed to the W in the Faroe–Shetland Basin. In the centre and E of the Faroe–Shetland and Rockall basins, separate eruption loci developed along pre-existing lineaments either as fissure or point-sourced lava fields. Short-term cessation of eruption at ~55.8 Ma was followed by resumption of flood basalt eruptions and a shift in focus to the NW. Fluctuations in the syn-breakup eruption tempo are reflected in the formation and subsequent rejuvenation of prominent unconformities, only previously recognised as a single erosive event. The W and northward shift of eruption focus, and the eruption of mid ocean ridge basalt-type lavas in the syn-breakup period reflect the onset of lithospheric thinning in the nascent North Atlantic Rift prior to flooding of the rift and eruption of the widespread lower Ypresian Balder Formation tephras.

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