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Rocks of coastal to shallow‐marine origin are challenging to interpret owing to the complex interplay of various depositional processes. This study reevaluates the relative roles of fluvial, tidal and wave processes in the Upper Cretaceous Sego Sandstone (and subordinately in the underlying Buck Tongue) of the Book Cliffs, USA, a well‐studied ancient coastal to shallow‐marine succession. Detailed sedimentological and ichnological analyses were used to interpret a previously underemphasised riverine signature, consisting of centimetre‐ to decimetre‐thick alternations of sandstone and heterolithic beds inferred to represent flood–interflood periods of variable river discharge. Recognition of a widespread fluvial‐dominated signature across the studied units better agrees with other sedimentological and regional observations in the study area, such as high sandstone–mudstone ratios, largely unidirectional and seaward‐oriented palaeocurrents, and modelled weak tidal conditions in the basin. When considering all of the sedimentological, ichnological and stratigraphic observations together with its regional depositional context, the Sego Sandstone/Buck Tongue system is better explained using a mixed‐energy but fluvial‐dominated deltaic model. This highlights an historical over‐interpretation of tidal processes and subordinate wave processes in the Sego Sandstone and likely in similar units. The widely used approach that emphasises only certain sedimentary features in discerning the process regime from analysis of rocks of inferred coastal to shallow‐marine origin is unrefined and may therefore underrepresent the actual complexity of these systems. [ABSTRACT FROM AUTHOR]

& Olariu, C. (2018) Mixed-energy process interactions read from a compound-clinoform delta (paleo-orinoco Delta, Trinidad): preservation of river and tide signals by mud-induced wave damping. Keywords: hydrodynamics; sedimentology; shallow-marine EN hydrodynamics sedimentology shallow-marine 206 212 7 05/30/23 20230401 NES 230401 Sketch diagram illustrating the various hydrodynamic processes occurring in coastal to shelf environments, with numbers referring to articles from this issue. Furthermore, certain systems are or were dominated by a single depositional process, yet their deposits lack any characteristics commonly assigned to such systems: for example, the Venice lagoon is tide-dominated, yet no tidal rhythmites are preserved in the sediments (Ghinassi et al., [19]). [Extracted from the article]

Simulating hydrodynamic conditions in palaeo‐ocean basins is needed to better understand the effects of tidal forcing on the sedimentary record. When combined with sedimentary analyses, hydrodynamic modelling can help inform complex temporal and spatial variability in the sediment distribution of tide‐dominated palaeo‐ocean basins. Herein, palaeotidal modelling of the epicontinental Upper Jurassic (160 Ma, lower Oxfordian) Sundance and Curtis seas of North America reveals possible regional‐scale variations in tidal dynamics in response to changes in ocean tidal forcing, physiographic configuration and bottom drag coefficient. A numerical model forced with an M2 tidal constituent at the open boundary shows that the magnitude and location of tidal amplification, and the variability in current velocity and bed shear stress in the basin, were controlled by palaeophysiography. Numerical results obtained using a depth of 600 m at the ocean boundary of the system enable the prediction of major facies trends observed in the lower Curtis Formation. The simulation results also highlight that certain palaeophysiographic configurations can either permit or prevent tidal resonance, leading to an overall amplification or dampening of tides across the basin. Furthermore, some palaeophysiographic configurations generated additional tidal harmonics in specific parts of the basins. Consequently, similar sedimentary successions can emerge from a variety of relative sea‐level scenarios, and a variety of sedimentary successions may be deposited in different parts of the basin in any given relative sea‐level scenario. These results suggest that the interpretation of sedimentary successions deposited in strongly tide‐influenced basins should consider changes in tidal dynamics in response to changing sea level and basin physiography. [ABSTRACT FROM AUTHOR]

The interaction of river and marine processes in the fluvial to marine transition zone fundamentally impacts delta plain morphology and sedimentary dynamics. This study aims to improve existing models of the facies distribution, stratigraphic architecture and preservation in the fluvial to marine transition zone of mixed‐process deltas, using a comprehensive sedimentological and stratigraphic dataset from the Middle Miocene Lambir Formation, Baram Delta Province, north‐west Borneo. Eleven facies associations are identified and interpreted to preserve the interaction of fluvial and marine processes in a mixed‐energy delta, where fluvial, wave and tidal processes display spatially and temporally variable interactions. Stratigraphic successions in axial areas associated with active distributary channels are sandstone‐rich, comprising fluvial‐dominated and wave‐dominated units. Successions in lateral areas, which lack active distributary channels, are mudstone‐rich, comprising fluvial‐dominated, tide‐dominated and wave‐dominated units, including mangrove swamps. Widespread mudstone preservation in axial and lateral areas suggests well‐developed turbidity maximum zones, a consequence of high suspended‐sediment concentrations resulting from tropical weathering of a mudstone‐rich hinterland. Within the fluvial to marine transition zone of distributary channels, interpreted proximal–distal sedimentological and stratigraphic trends suggest: (i) a proximal fluvial‐dominated, tide‐influenced subzone; (ii) a distal fluvial‐dominated to wave‐dominated subzone; and (iii) a conspicuously absent tide‐dominated subzone. Lateral areas preserve a more diverse spectrum of facies and stratigraphic elements reflecting combined storm, tidal and subordinate river processes. During coupled storm and river floods, fluvial processes dominated the fluvial to marine transition zone along major and minor distributary channels and channel mouths, causing significant overprinting of preceding interflood deposits. Despite interpreted fluvial–tidal channel units and mangrove influence implying tidal processes, there is a paucity of unequivocal tidal indicators (for example, cyclical heterolithic layering). This suggests that process preservation in the fluvial to marine transition zone preserved in the Lambir Formation primarily records episodic (flashy) river discharge, river flood and storm overprinting of tidal processes, and possible backwater dynamics. [ABSTRACT FROM AUTHOR]

The 2 to 5 km thick, sandstone‐dominated (>90%) Jura Quartzite is an extreme example of a mature Neoproterozoic sandstone, previously interpreted as a tide‐influenced shelf deposit and herein re‐interpreted within a fluvio‐tidal deltaic depositional model. Three issues are addressed: (i) evidence for the re‐interpretation from tidal shelf to tidal delta; (ii) reasons for vertical facies uniformity; and (iii) sand supply mechanisms to form thick tidal‐shelf sandstones. The predominant facies (compound cross‐bedded, coarse‐grained sandstones) represents the lower parts of metres to tens of metres high, transverse fluvio‐tidal bedforms with superimposed smaller bedforms. Ubiquitous erosional surfaces, some with granule–pebble lags, record erosion of the upper parts of those bedforms. There was selective preservation of the higher energy, topographically‐lower, parts of channel‐bar systems. Strongly asymmetrical, bimodal, palaeocurrents are interpreted as due to associated selective preservation of fluvially‐enhanced ebb tidal currents. Finer‐grained facies are scarce, due largely to suspended sediment bypass. They record deposition in lower‐energy environments, including channel mouth bars, between and down depositional‐dip of higher energy fluvio‐ebb tidal bars. The lack of wave‐formed sedimentary structures and low continuity of mudstone and sandstone interbeds, support deposition in a non‐shelf setting. Hence, a sand‐rich, fluvial–tidal, current‐dominated, largely sub‐tidal, delta setting is proposed. This new interpretation avoids the problem of transporting large amounts of coarse sand to a shelf. Facies uniformity and vertical stacking are likely due to sediment oversupply and bypass rather than balanced sediment supply and subsidence rates. However, facies evidence of relative sea level changes is difficult to recognise, which is attributed to: (i) the areally extensive and polygenetic nature of the preserved facies, and (ii) a large stored sediment buffer that dampened response to relative sea‐level and/or sediment supply changes. Consideration of preservation bias towards high‐energy deposits may be more generally relevant, especially to thick Neoproterozoic and Lower Palaeozoic marine sandstones. [ABSTRACT FROM AUTHOR]

Despite extensive outcrop and previous sedimentologic study, the role of tidal processes along sandy, wave- and river-dominated shorelines of the North American Cretaceous Western Interior Seaway remains uncertain, particularly for the extensive mid-Campanian (ca. 75-77.5 Ma) tidal deposits of Utah and Colorado, USA. Herein, paleotidal modeling, paleogeographic reconstructions, and interpretations of depositional process regimes are combined to evaluate the regional-scale (hundreds to thousands of kilometers) basin physiographic controls on tidal range and currents along these regressive shorelines in the "Utah Bight", southwestern Western Interior Seaway. Paleotidal modeling using a global and astronomically forced tidal model, combined with paleobathymetric sensitivity tests, indicates the location of stratigraphic units preserving pronounced tidal influence only when the seaway had a deep center (~400 m) and southern entrance (>100 m). Maximum tidal velocity vectors under these conditions suggest a dominant southeasterly ebb tide within the Utah Bight, consistent with the location and orientation of paleocurrent measurements in regressive, tideinfluenced deltaic units. The modeled deep paleobathymetry increased tidal inflow into the basin and enhanced local-scale (tens to hundreds of kilometers) resonance effects in the Utah Bight, where an amphidromic cell was located. However, the preservation of bidirectional, mudstone-draped cross-stratification in fine- to medium-grained sandstones requires tides in combination with fluvial currents and/or local tidal amplification below the maximum resolution of model meshes (~10 km). These findings suggest that while regional-scale controls govern tidal potential within basins, localized physiography exerts an important control on the preservation of tidal signatures in the geologic record. [ABSTRACT FROM AUTHOR]

Numerical tidal modelling, when integrated with other geological datasets, can significantly inform the analysis of physical sedimentation processes and the depositional and preservational record of ancient tide‐influenced shoreline–shelf systems. This is illustrated in the Oligo–Miocene of the South China Sea, which experienced significant changes in basin physiography and where tide‐influenced, shoreline–shelf deposition is preserved in ca 10 sub‐basins. Palaeogeographic reconstructions, palaeotidal modelling and regional sedimentary facies analysis have been integrated in order to evaluate the spatial–temporal evolution and physiographic controls on tidal sedimentation and preservation during the ca 25 Myr Oligo–Miocene record in the South China Sea. Palaeotidal modelling, using an astronomically‐forced and global tidal model (Fluidity) at a maximum 10 km resolution, indicates that spring tides along Late Oligocene to Middle Miocene coastlines were predominantly mesotidal–macrotidal and capable of transporting sand, which reflects two main conditions: (i) increased tidal inflow through wider ocean connections to the Pacific Ocean; and (ii) tidal amplification resulting from constriction of the tidal wave in a 'blind gulf' type of basin morphology. Since the Middle to Late Miocene, a reduction in the amplitude and strength of tides in the South China Sea was mainly due to diminishing tidal inflow from the Pacific Ocean caused by the northward movement of the Philippines and Izu–Bonin–Mariana arc. Sensitivity tests to palaeogeographic and palaeobathymetric uncertainty indicate that regional‐scale (hundreds to thousands of kilometres) palaeogeographic changes influencing tidal inflow versus outflow can override local‐scale (one to hundreds of kilometres) changes to tidal resonance and convergence effects (funnelling and shoaling), such as shelf width and shoreline geometry. Palaeotidal model results compare favourably to the distribution and sedimentary fabric of Oligo–Miocene, tide‐influenced, shoreline–shelf successions in peripheral South China Sea basins. However, the preservation potential of tidal deposits is lower in open coastline environments, probably due to enhanced reworking during storms and river floods. [ABSTRACT FROM AUTHOR]

The Miocene to Modern Baram Delta Province is a highly efficient source to sink system that has accumulated 9 to 12 km of coastal-deltaic to shelf sediments over the past 15 Myr. Facies analysis based on ca 1 km of total vertical outcrop stratigraphy, combined with subsurface geology and sedimentary processes in the present-day Baram Delta Province, suggests a 'storm-flood' depositional model comprising two distinct periods: (i) fair-weather periods are dominated by alongshore sediment reworking and coastal sand accumulation; and (ii) monsoon-driven storm periods are characterized by increased wave-energy and offshore-directed downwelling storm flow that occur simultaneously with peak fluvial discharge caused by storm precipitation ('storm-floods'). The modern equivalent environment has the following characteristics: (i) humid-tropical monsoonal climate; (ii) narrow ( ca <100 km) and steep ( ca 1°), densely vegetated, coastal plain; (iii) deep tropical weathering of a mudstone-dominated hinterland; (iv) multiple independent, small to moderate-sized (102 to 105 km2) drainage basins; (v) predominance of river-mouth bypassing; and (vi) supply-dominated shelf. The ancient, proximal part of this system (the onshore Belait Formation) is dominated by strongly cyclical sandier-upward successions (metre to decametre-scale) comprising (from bottom to top): (i) finely laminated mudstone with millimetre-scale silty laminae; (ii) heterolithic sandstone-mudstone alternations (centimetre to metre-scale); and (iii) sharp-based, swaley cross-stratified sandstone beds and bedsets (metre to decimetre-scale). Gutter casts (decimetre to metre-scale) are widespread, they are filled with swaley cross-stratified sandstone and their long axes are oriented perpendicular to the palaeo-shoreline. The gutter casts and other associated waning-flow event beds suggest that erosion and deposition was controlled by high-energy, offshore-directed, oscillatory-dominated, sediment-laden combined flows within a shoreface to delta front setting. The presence of multiple river mouths and exceptionally high rates of accommodation creation (characteristic of the Neogene to Recent Baram Delta Province; up to 3000 m Ma−1), in a 'storm-flood'-dominated environment, resulted in a highly efficient and effective offshore-directed sediment transport system. [ABSTRACT FROM AUTHOR]

This paper studies the expressive and computational power of discrete Ordinary Differential Equations (ODEs), a.k.a. (Ordinary) Difference Equations. It presents a new framework using these equations as a central tool for computation and algorithm design. We present the general theory of discrete ODEs for computation theory, we illustrate this with various examples of algorithms, and we provide several implicit characterizations of complexity and computability classes. The proposed framework presents an original point of view on complexity and computation classes. It unifies several constructions that have been proposed for characterizing these classes including classical approaches in implicit complexity using restricted recursion schemes, as well as recent characterizations of computability and complexity by classes of continuous ordinary differential equations. It also helps understanding the relationships between analog computations and classical discrete models of computation theory. At a more technical point of view, this paper points out the fundamental role of linear (discrete) ODEs and classical ODE tools such as changes of variables to capture computability and complexity measures, or as a tool for programming many algorithms. [ABSTRACT FROM AUTHOR]

Scientific determinations are often at the heart of environmental disputes. When those disputes take the form of litigation, the courts may be called on to determine whether an administrative agency's treatment of the science warrants deference. For several reasons, judges are inclined to apply deferential review to agency factual and science-based policy determinations. Most judges are not trained in the language and methods of science. They may be reluctant to intervene on matters on which their lack of expertise risks producing uninformed judgments. If a statute delegates to an agency the responsibility of making those determinations, courts may be loath to usurp that authority by substituting their judgment for the agency's. If the statutory delegations authorize agencies to premise their decisions on the best available information, courts may regard that authorization as a signal not to take agencies to task for failing to do the impossible. Those mandates reflect a congressional judgment that agency determinations should pass judicial muster even if they fall short of conclusiveness, which may be impossible to achieve. Finally, when technical issues arise in the context of uncertainty at "the frontiers of scientific knowledge," the Supreme Court has warned judges that highly deferential review is required. This Article describes a study analyzing cases decided by the federal courts over a period of thirty years that presented issues involving scientific uncertainty tied to climate change that arose under two key environmental statutes, the National Environmental Policy Act and the Endangered Species Act. The Article provides both quantitative and qualitative analyses of those cases, focusing on ascertaining the factors that drove courts to apply either deferential or non-deferential review. We found, as might be expected, that the courts applied deferential review in the majority of climate change cases arising under these two laws that presented disputes in which litigants challenged agency resolution of factual or policy matters characterized by scientific uncertainty. In the remaining cases, however, the courts, applying the arbitrary and capricious standard of judicial review, refused to defer, engaging instead in relatively rigorous review of agency science. They did so for any one of several reasons, including irrationality in agency reasoning, incomplete analysis of record science, evidentiary shortcomings, and end result-oriented reasoning. These practices induced courts to reject rote acceptance of agency pleas for deference to their scientific expertise. The Article concludes by suggesting further studies that may be useful in understanding how courts can be expected to strike the balance between deferential review and insistence that agencies provide adequate reasons for their actions in contexts of scientific uncertainty. [ABSTRACT FROM AUTHOR]

The rise of food security up international political, societal and academic agendas has led to increasing interest in novel means of improving primary food production and reducing waste. There are however, also many 'post-farm gate' activities that are critical to food security, including processing, packaging, distributing, retailing, cooking and consuming. These activities all affect a range of important food security elements, notably availability, affordability and other aspects of access, nutrition and safety. Addressing the challenge of universal food security, in the context of a number of other policy goals (e.g. social, economic and environmental sustainability), is of keen interest to a range of UK stakeholders but requires an up-to-date evidence base and continuous innovation. An exercise was therefore conducted, under the auspices of the UK Global Food Security Programme, to identify priority research questions with a focus on the UK food system (though the outcomes may be broadly applicable to other developed nations). Emphasis was placed on incorporating a wide range of perspectives ('world views') from different stakeholder groups: policy, private sector, non-governmental organisations, advocacy groups and academia. A total of 456 individuals submitted 820 questions from which 100 were selected by a process of online voting and a three-stage workshop voting exercise. These 100 final questions were sorted into 10 themes and the 'top' question for each theme identified by a further voting exercise. This step also allowed four different stakeholder groups to select the top 7-8 questions from their perspectives. Results of these voting exercises are presented. It is clear from the wide range of questions prioritised in this exercise that the different stakeholder groups identified specific research needs on a range of post-farm gate activities and food security outcomes. Evidence needs related to food affordability, nutrition and food safety (all key elements of food security) featured highly in the exercise. While there were some questions relating to climate impacts on production, other important topics for food security (e.g. trade, transport, preference and cultural needs) were not viewed as strongly by the participants. [ABSTRACT FROM AUTHOR]

This paper compares the comovement of individual stock returns across emerging markets. Campbell et al. and Morck et al. have shown that the United States saw rising firm-specific stock return variations, and thus declining comovement, over the second half of the twentieth century. We detect a similar, albeit weaker, pattern in most, but not all, emerging markets. We further find that higher firm-specific variation is associated with greater capital market openness, but not goods market openness. Moreover, this relationship is magnified by institutional integrity (good government). Goods market openness is associated with higher marketwide variation. [ABSTRACT FROM AUTHOR]

The article presents a list of the reviewers of the periodical including the C. Brown, Jay Carlisle and the David Irons.