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Extensive research into the evolution of wave‐dominated estuaries has been documented since the 1960s. However, there has only been limited research on the prograding bay‐head deltas that are the primary drivers for the rate and stage of estuary evolution. This paper presents the findings of a high‐resolution spatial study into the evolution of the Macquarie Rivulet bayhead delta in the Lake Illawarra barrier estuary. The delta's evolution has been established based on sedimentological analysis of 74 cores, two 14C ages and 45 amino acid racemization ages. This study intersected two Pleistocene and 10 Holocene sedimentary facies associations representing both the retrogradational and progradational phases of delta development. The distribution of bayhead delta facies associations in shallow barrier estuaries is initially controlled by the antecedent morphology, but, in contrast to deeper estuaries, this influence decreases as sedimentation proceeds. Changing relative sea level also has a major control on facies distribution with transgressive facies deposited as relative sea‐level rises being replaced by prograding deltaic facies during the highstand and subsequent minor relative sea‐level fall. Fluvial sediment supply and river flood events affect the rate of delta progradation, and produce low and high flow sediment deposits within the overall deltaic sequence. The low tidal flux in barrier estuaries, the muddy cohesive nature of the sediments and the prevalence of bioturbation means that primary sedimentary structures are rarely preserved in these bayhead delta facies. The depositional model of bayhead delta evolution shown by the Macquarie Rivulet delta would be widely applicable to other similar barrier estuary settings. [ABSTRACT FROM AUTHOR]

Subaqueous mass‐transport processes are one of the mechanisms for transport of sediment into the deep sea. Internal structures and depositional processes of carbonate mass‐transport deposits are relatively poorly understood relative to siliciclastic facies due to their comparative paucity in the rock record. A variety of carbonate mass‐transport deposits, including slumps, debrites and deep‐channel‐confined density flow deposits, occur in Middle–Upper Ordovician slope deposits in western Inner Mongolia (Wuhai), China. These provide a rare opportunity to illustrate the emplacement history of carbonate mass‐transport deposits at the outcrop scale. The slumps and debrites host remarkable folds, chaotic beds and imbricated beds that reflect differences in both rheology and position on the slope. Individual slump sheets show gradations between undulating laminae, inclined and recumbent folds, highly deformed folds, and chaotic textures upslope from the toe region. Debrites are commonly interbedded with slump deposits, whereas imbricated beds are present in the middle and lower parts of the toes of slump sheets near the terminal wall. In the study area, thin‐bedded limestone with slump deposits of the Kelimoli Formation are overlain by fine‐grained, siliciclastic‐dominated, slope deposits of the Wulalike Formation. A thick breccia of the Wulalike Formation was deposited in a main feeder channel in south‐east Wuhai, but to the west‐north‐west the breccia was deposited in distributary channels possibly represented as a unique lower‐slope pattern of gullies. At the latter locality, the breccia was deposited solely within the channels on a steep west‐north‐west dipping slope under density‐driven flows. The mass‐transport deposits documented herein records passive to foreland basin tectonic transitions, and associated platform foundering and steepening of the slope. A slope facies model was constructed to demonstrate the spatial and temporal variations of mass‐transport deposits during basin evolution, and as such it provides a template for the interpretation of the deposits of ancient slopes that underwent passive to active tectonic transitions. [ABSTRACT FROM AUTHOR]

Current knowledge of submarine fan deposits has historically relied heavily on qualitative field and subsurface observations and interpretations, but recent studies using statistical analyses have enhanced the understanding of submarine fan sub‐environments, including the degree of confinement, stratigraphic patterns and potential control factors. The purpose of this study is to improve the quantitative understanding of synorogenic submarine fan deposition at foreland basin settings with a statistical approach. A suite of statistical methods is integrated and developed (Hurst Statistics/rescaled range analysis, bed thickness frequency distribution analysis, Markov Chains and time‐series analysis), and applied to the well‐understood Pennsylvanian lower Atoka submarine fan system in the Ouachita Mountains, United States, for this purpose. The results of the Hurst Statistics and bed thickness analyses corroborate qualitative interpretations that: (i) the lower Atoka is lobe‐dominated; and (ii) the south‐eastern (wedge top) portion of the system is more strongly confined than the northern (foredeep) portion. The Markov Chains and time‐series analyses reveal the prevalence (56% of the measured sections) of stratigraphic orderliness and cyclicity; these results are used to discuss potential control signals, which are otherwise difficult to distinguish, on the turbidite sandstone recurrence cycles. The results of this study demonstrate that these integrated statistical methods can be utilized to quantify depositional interpretations and extract hidden information using outcrops with limited exposures. [ABSTRACT FROM AUTHOR]

Monitoring of modern deep‐water channels has revealed how migrating channel‐floor features generate and remove stratigraphy, improving understanding of how channel morphologies relate to their deposits. Here, seafloor and subsurface data are reconciled through an integrated study of high‐resolution bathymetry and three‐dimensional seismic data imaging a ca 150 km stretch of the trench‐axial Hikurangi Channel, offshore New Zealand. On the seafloor, terraced channel‐walls bound a flat, wide, channel‐floor, ornamented with three scales of features that increase then decrease in longitudinal gradient downstream, and widen downstream: cyclic‐steps, knickpoints and knickpoint‐zones (in increasing size). Mass‐transport deposits derived from channel‐wall collapse, are bordered by wide and flat reaches of channel‐floor upstream and by knickpoint‐zones (reaches containing multiple knickpoints) downstream. In the subsurface, recognition of ten seismofacies and five types of surface enables identification of four depositional elements: channel‐fill, sheet or terrace, levée, and mass‐transport deposits. Integration of subsurface and seafloor interpretations reveals that knickpoint‐zones initiate on the downstream margins of channel‐damming mass‐transport deposits; they migrate and incise through the mass‐transport deposits and weakly‐confined deposits formed upstream, as the channel tends towards equilibrium. Downstream of a knickpoint‐zone, a flat channel‐floor is bounded by newly‐formed terraces. Knickpoints migrate by eroding upstream and depositing downstream, generating filled concave‐up (cross‐sectional) surfaces in their wake. Within knickpoint‐zones, knickpoint‐generated surfaces are re‐incised by subsequently‐passing knickpoints to produce a composite bounding surface; this surface does not delineate the morphology of any palaeo‐conduit. The Hikurangi Channel's subsurface architecture records the localized erosional response to mass‐transport deposit emplacement via knickpoint‐zone migration, showcasing how transient seafloor features can build channelized stratigraphy. This model provides an additional mechanism to conventional models of channel deposit formation through 'cut‐and‐fill' over long stretches of channel. These findings may aid subsurface interpretation in systems lacking a contemporary self‐analogue or with poor data coverage. [ABSTRACT FROM AUTHOR]

This paper examines particle settling dynamics in a tidally‐influenced delta, including observations of convective settling, strongly modulated by seasonal discharge and tidal cycles. Long time series of Acoustic Doppler Current Profiler backscatter, a proxy for suspended sediment concentration in the water column, current and sediment accumulation measurements from the slope of the Fraser River delta show variability of sedimentary processes over timescales from semi‐diurnal to annual. Acoustic Doppler Current Profiler backscatter shows a lagged response to river discharge and strong diurnal/semi‐diurnal variability. Most of the tidal cycle is characterized by a buoyant effluent plume. During the ebbing phase of diurnal major tides, discrete settling events are observed extending through the entire water column. The pulse‐like nature of these events is the result of downward plunging fingers characteristic of convective settling, similar to those observed in laboratory flume experiments, and appear to be initiated at the interface between the surface buoyant plume and the underlying ambient water. Currents show strong variability in a three‐layer water column. The surface plume shows offshore and southward directed transport of sediments. The remaining water column is influenced by tidal flows, but near surface and intermediate water‐depth currents are out of phase by several hours, indicating a stratification of the basin water and decoupled propagation of surface and internal tides. This phase lag is unlikely to cause discernible facies changes, but may have implications for basin‐fill patterns in restricted basins with strong tidal range. The results of this work will help to better understand river mouth sedimentation processes and dispersal patterns in other modern deltas and in the geological record. [ABSTRACT FROM AUTHOR]

Sand ridges, a common feature of modern open shelves, reflect persistent currents and sediment availability under recent transgressive conditions. They represent the largest bedforms in the oceans and, as such, can yield information on long‐term oceanographic processes. However, there is a limited number of tidal sand ridges documented from the rock record, examples of regressive tidal sand ridges are scarce and studies describing ridges in straits are even more rare. This study analyses a Gelasian succession within a structurally controlled, tide‐dominated strait in the Siderno Basin, southern Italy. The strait connected two wider basins, and accumulated sediments reworked by amplified tidal (bi‐directional) currents. A series of tidal sand ridges with superimposed dunes developed close to the south‐eastern end of the strait, where bathymetry was deeper and flow expansion occurred. One of the best‐exposed tidal sand ridges, 65 m thick, crops out along a ca 2 km long cliff. Large‐scale, ESE‐prograding, seaward‐offlapping shingles contain sets of bioclastic–siliciclastic, coarse‐grained, cross‐stratified sandstones, erosionally overlying upper Pliocene shelf marls and fine‐grained sandstones. Cross‐strata show angular, tangential and sigmoidal foresets with compound architectures and a SSE migration, i.e. oblique to the main growth direction. Fossil content indicates open‐marine conditions. The succession changes abruptly across an erosion surface to non‐tidal, highly burrowed mixed siliciclastic–bioclastic fine‐grained sandstones, less than 15 m thick. Documented features reflect stages of nucleation, active accretion and abandonment of an individual sand ridge, during a complete cycle of relative sea‐level change. The ridge formed during a phase of normal regression, with accretion occurring during an initial highstand and the ensuing falling stage. During the lowstand the ridge was split into several minor bodies by enhanced tidal currents. The ensuing transgression draped the moribund ridge with tabular strata, whereas final highstand shelf sedimentation reworked the top of the underlying sand body with weak currents. [ABSTRACT FROM AUTHOR]

Improved understanding of mouth bar morphodynamics, and the resulting stratigraphic architectures, is important for predicting the loci of deposition of different sediment fractions, coastal geomorphic change and heterogeneity in mouth bar reservoirs. Facies and architectural analysis of exceptionally well‐exposed shallow water (ca 5 m depth) mouth bars and associated distributaries, from the Xert Formation (Lower Cretaceous), of the Maestrat Basin (east‐central Spain), reveal that they grew via a succession of repeated autogenic cycles. An initial mouth bar accretion element forms after avulsion of a distributary into shallow standing water. Turbulent expansion of the fluvial jet and high bed friction results in rapid flow deceleration, and deposition of sediment in an aggradational to expansional bar‐form. Vertical bar growth causes flattening and acceleration of the jet. The accelerated flow scours channels on the bar top, which focuses further expansion of the mouth bar at individual loci where the channels break through the front of the mouth bar. Here, new mouth bar accretion elements form, downlapping and onlapping against a readily recognizable surface of mouth bar reorganization. Vertical growth of the new mouth bar accretion elements causes flattening and re‐acceleration of the jet, leading to channelization, and initiation of the next generation of mouth bar accretion elements. Thus the mouth bar grows, until bed‐friction effects cause backwater deceleration and super‐elevation of flow in the feeding distributary. Within‐channel sedimentation, choking and upstream avulsion of the feeding channel, results in mouth bar abandonment. In this study, mouth bars are formed of at least two to three accretion elements, before abandonment happened. The results of this study contrast with the notion that mouth bars form by simple vertical aggradation and radial expansion. However the architecture and facies distributions of shallow water mouth bars are a predictable product of intrinsic processes that operate to deposit them. [ABSTRACT FROM AUTHOR]

Storms are increasingly identified as a key depositional process. Their deposits show unique sedimentary characteristics, distinct from deposits of fair‐weather wave processes, but are not currently separated in classic ternary deltaic classification schemes. The term 'storm‐flood‐dominated delta' is proposed for a new type of delta that more fully represents deltas dominated by storm‐flood processes. This study describes several outcrop cliffs of the Gallup Formation, deposited during the Late Turonian to Early Coniacian in north‐west New Mexico, that exemplify storm‐generated facies and provide examples that can be used to generate a facies model for storm‐flood‐dominated deltas. Key identification criteria include extensive sharp‐based planar to hummocky cross‐stratified sandstone beds, commonly presenting as large‐sized gutter casts. They are interbedded with mudstones that show low bioturbation intensity and normally and inversely graded beds, suggesting direct deposition from river plumes. Major types of gutter casts are classified based on geometry and dimension. The gutter casts are interpreted as storm channels of storm‐flood‐dominated deltas and formed by erosion and infill of submerged channels resulting from offshore‐oriented downwelling currents that may include localized rip currents. These amalgamated channels are likely linked to multiple feeding rivers and distributary channels that ensured high sediment supply rates and highly efficient offshore‐directed sediment transport through hyperpycnal flows. A four‐component pyramidal classification scheme of deltaic deposition is employed to emphasize storms as a distinct process in contrast to the traditional classification that lumps storm and fair‐weather processes in a single 'wave' end‐member. The four‐component depositional model can be readily applied to interpret storm‐dominated environments and provide new insights into depositional processes of the marine realm. Recognition of storm processes in deciphering depositional evolution will also help to better understand control mechanisms of sequence stratigraphy, such as relative sea‐level changes, and to analyze sedimentary processes governing sediment transport in 'source to sink' systems. [ABSTRACT FROM AUTHOR]

Contourite drift systems form a significant component of the marine clastic sedimentary record. Although contourites form in all tectonic settings, few studies have described their development along convergent margins; such characterization is needed to underpin oceanographic and palaeoenvironmental studies in active settings. This study is the first to document contourite drift development along the Hikurangi subduction margin of New Zealand. Integration of bathymetric, seismic and well data enables five classes of drift to be recognized around the subduction wedge, occurring in three principal associations: (i) an upper slope drift association of giant elongate mounded (ca 150 km long, 50 km wide and up to 1100 m thick) and plastered drifts (ca 300 km long, 8 km wide and <600 m thick), which occurs upon and inboard of a major intrabasinal thrust‐cored high, whose long axis parallels the coast; shallow bottom currents disperse sub‐parallel to this axis; (ii) a spatiotemporally discontinuous association of confined and mounded hybrid drifts (ca 500 m long, <2 km wide and up to 500 m thick) that occurs along the mid‐to‐outer slope domain of the wedge, recording the interaction of along‐slope and downslope currents within trench‐slope basins; and (iii) a trench fill assemblage that implies the passage of abyssal bottom currents across a 40 km reach of the trench‐axial Hikurangi Channel‐levée, with associated modification of the channel form and of overbank sediment waves. The fundamental presence of contourites along this margin appears to depend on the orientation and strength of oceanographic bottom currents. However, drift type and evolution vary depending on the slope gradient and the presence of irregular seafloor topography created by tectonic structures. The documented drifts are generally smaller, less continuous, and develop more intermittently than similar styles of drifts documented on passive margins; this mode of occurrence may be characteristic of contourite development on convergent margins. [ABSTRACT FROM AUTHOR]

The partitioning of different grain‐size classes in gravity flow deposits is one of the key characteristics used to infer depositional processes. Turbidites have relatively clean sandstones with most of their clay deposited as part of a mudstone cap or as a distal mudstone layer, whereas sand‐bearing debrites commonly comprise mixtures of sand grains and interstitial clay; hybrid event beds develop alternations of clean and dirty (clay‐rich) sandstones in varying proportions. Analysis of co‐genetic mudstone caps in terms of thickness and composition is a novel approach that can provide new insight into gravity flow depositional processes. Bed thickness data from the ponded Castagnola system show that turbidites contain more clay overall than do hybrid event beds. The Castagnola system is characterized by deposits of two very different petrographic types. Thanks to this duality, analyses of sandstone and mudstone composition allow inference of which proportion of the clay in each of the deposit types was acquired en route. In combination with standard sedimentological observations the new data allow insight into the likely characteristics of their parent flows. Clean turbidites were deposited by lower concentration, long duration, erosive, muddy turbidity currents which were more efficient at fractionating clay particles away from their basal layer. Hybrid event beds were deposited by shorter duration, higher‐concentration, less‐erosive sandier flows which were less efficient at clay fractionation. The results are consistent with data from other turbidite systems (for example, Marnoso‐arenacea). The approach represents a new method to infer the controls on the degree of clay partitioning in gravity flow deposits. [ABSTRACT FROM AUTHOR]

Clean basal and capping argillaceous sandstone couplets in deep water settings have been previously interpreted as the result of spatially segregated turbidity currents and debris flows or spatio‐temporal transitioning of a turbulent flow to a transitional/laminar state. However, this paper presents three‐dimensional laboratory experiments demonstrating that a single sediment‐gravity flow can develop sand–mud couplets by autogenic remobilization of sediments that are still in the process of being deposited. This remobilization appears common to flows composed of mixtures of sand and mud with viscosities and strengths measurably greater than water, but not so high as to fully suppress the settling of sand through the depositional current. Dewatering in the early sand deposit acts to lubricate the basal portion of the increasingly muddy upper division of the flow, causing it to accelerate downslope, triggering a secondary flow with a sediment composition distinct from the original mixture. Sediment deposition and remobilization processes in a single sediment‐gravity flow and their resultant deposit were imaged acoustically and cored at representative locations within the deposit. The acoustic data and cores show sand–mud couplets that are qualitatively similar to interpreted turbidite–debrite‐like couplets in natural systems. [ABSTRACT FROM AUTHOR]

Background: A high ability to understand symptoms and conceptualize illness, schizophrenia, may play a central role for long-term outcome. This based on the assumption that better insight will promote increased adherence. In this work insight is defined as patients´ ability to experience symptoms and furthermore understand what causes them. Cognitive performance and symptomatic remission are analyzed to explore in what way they are contributing to the level of insight. Methods: The study population is 294 patients with schizophrenia spectrum disorder. Two items with focus on insight, each 1 to 4 points, are used to decide level of insight. The first item “Experience of symptom” and the second item “Understanding the reason for symptoms”, where 1 point representing high and 4 point low level of insight and with a total of 8 points. Patients are then divided into three groups, Good (2 points), Moderate (3 – 5 points) and Poor (6 –8 points). Cognitive domains identified to be impaired in schizophrenia are analyzed related to the three groups of insight. Symptomatic remission is compared to the total score of insight with a Mann-Whitney test and then the different categories of insight in a cross-tabulation and Chi-square test. Results: Differences were found in insight between patients in symptomatic remission and those who are not. This in contrast to when patients were divided into the three insights groups and compared on cognitive performance. Only working memory and neurocognitive flexibility showed significant differences to insight. However, crystalized intelligence, as an expression of over-all cognitive ability, did not. Discussion: In conclusion, only symptomatic remission seems to be related to insight indicating more of a state than a trait phenomenon. Surprisingly could not different levels of insight be connected to differences in cognitive ability. As this is a cross-sectional study, further research are needed where insight and symptomatic remission are analyzed in longitudinal conditions. Such a study has to focus on if successful treatment promote insight or the other way around. [ABSTRACT FROM AUTHOR]

Background: Patients with schizophrenia have difficulties in judging their own performance. Patients with no or little practical experience of demands from active performance in society tends to overestimate their ability. Research has also found that patients who overestimate their function also runs a risk to be perceived as better functioning than what they actually are when judged by caregivers. The aim with this study is to examine if patients who overestimate their ability will receive less community support compared to patients who have an accurate perception of their ability? Methods: The study population was 184 patients with schizophrenia spectrum disorder. They were tested with the Swedish version of the UCSD Performance-based Skills Assessment–Brief Version (UPSA-B). Before the test they were asked how they thought their functioning were in four different domains covered in the UPSA-B. After the test they were divided into four groups: “Good functioning with realistic perception”, “Good functioning but underestimating their function”, “Impaired function with realistic perception” and “Impaired function but overestimating their performance”. The amount of received community support were investigated and related to patients´ actual performance and self-perception. Results: Analyzes showed that patients who had an impaired function and a realistic view of their ability had more support than those who were impaired but overestimated their ability. Also, patients with good functioning but underestimating their performance had more support than those who had a good ability and a realistic perception. Finally, there were no difference in community support to the patients in the two groups “Good function with realistic perception” and “Impaired function but overestimating their performance”. Discussion: Our results indicate that patients with impaired functioning who overestimate their ability risk an insufficient community support. This in combination with earlier findings, that staff-members in psychiatric outpatient settings are likely to base their judgement on patients´ report consequential leading to false positive conclusions, may have both short- and long-term implications. Not achieving symptomatic remission, as a consequence of inability to follow medical prescriptions, and sub-optimal social functioning with isolation are two possible implications. The findings once again raises the need for the testing of patients´ function instead of only conducting interviews. [ABSTRACT FROM AUTHOR]