Search

Research in outdoor education and more specifically on wilderness expeditions has almost exclusively focused on short-term benefits (<5yrs) despite their findings suggesting these are "life-changing" experiences. This study examined long-term outcomes (40 years later) of three (month-long) adventurous school expeditions to mainland Europe, by staff and pupils from a high school (11-to 16-year-olds) in Scotland in the 1970s. The investigation was initiated by a call for life stories from 45 participants, followed by 10 interviews at a school reunion. The interviews revealed a transference of learning qualities attributed to the expedition, indicating a long-term impact on participants' personal and/or professional lives, with individuals still drawing upon their expedition experiences some 40 years later. Significant themes emerging were planning and preparation, confidence, and feelings of gratefulness, which led to participants wanting to undertake service that contributes back into society for young peoples' benefit. This study adds to the knowledge of long-range educational outcomes from school expeditions. [ABSTRACT FROM AUTHOR]

Notions of 'personal and social development' within experiential learning literature remain philosophically underdeveloped, often identified as something like practical wisdom or practical reasoning. Experiential learning practitioners and theorists make frequent claims regarding the 'life-changing' significance for participants; particularly in terms of character development. Surprisingly rare, however, is a long-range study investigating these claims. This article shares findings from a retrospective study examining perceptions of program alumni from a tall ship sailing study school with a view for personal and social development during the experience and since, understood through an Aristotelian virtue lens. Four themes emerged from data: Significance, practice, values clarification and friendships and community. Themes are examined in relation to virtue theory and implications for practice and future research explored. [ABSTRACT FROM AUTHOR]

In aiming to support school-based outdoor learning opportunities, this paper critiques the extent to which Deweyan and neo-Aristotelian theorising is helpful in highlighting how personal growth and practical wisdom gains can be realised. Such critique is necessary, as there are signs of an implementation gap between practice and policy, which is made worse by a lack of conceptual clarity about how educational aspirations can be dependably achieved. Dewey's habit-forming social constructivist emphasis on learning and problem-solving is reviewed and the prospects of a neo-Aristotelian conception of human flourishing, which recognises that virtues are nurtured as moral sensitivities, are then considered. Concerns that Dewey's writings are often vague on how ideas can be operationalised and criticisms that Aristotle's educational thoughts rather over-privilege cognition relative to emotions are also addressed. The article concludes by teasing out suggestions on how Deweyan and neo-Aristotelian ideas on learning might coherently inform curriculum planning and pedagogical practices. [ABSTRACT FROM AUTHOR]

The Blue Lias Formation at Lyme Regis (Dorset, UK) includes an exceptional pavement of abundant large ammonites that accumulated during a period of profound sedimentary condensation. Ammonites were originally composed of aragonite, an unstable polymorph of calcium carbonate, and such fossils are typically prone to dissolution; the occurrence of a rich association of aragonitic shells in a condensed bed is highly unusual. Aragonite dissolution occurs when pore-water p H is reduced by the oxidization of hydrogen sulphide close to the sediment-water interface. Evidence suggests that, in this case, the oxygen concentrations in the overlying water column were low during deposition. This inhibited the oxidation of sulphides and the associated lowering of p H, allowing aragonite to survive long enough for the shell to be neomorphosed to calcite. The loss of aragonite impacts upon estimates of past biodiversity and carbonate accumulation rates. The preservational model presented here implies that diagenetic loss of aragonite will be greatest in those areas where dysoxic-anoxic sediment lies beneath an oxic waterbody but least where the sediment and overlying water are oxygen depleted. Unfortunately, this implies that preservational bias through aragonite loss will be greatest in those biotopes which are typically most diverse and least where biodiversity is lowest due to oxygen restriction. [ABSTRACT FROM AUTHOR]

The new ‘Curriculum for Excellence’ in Scotland outlines a policy vision of a more integrated and holistic form of education; a commitment which offers considerable prospects for increased levels of outdoor learning in schools. With reference to Fullan’s theorizing on achieving educational change, this study investigated four main implementation areas, namely: policy aims, partnerships arrangements, and associated professionalism and sustainability issues. Evidence was collected through a series of 16 semi-structured interviews with key stakeholders at national, local authority, and school level. Despite increased agreement on aims, it was found that improving the frequency and quality of outdoor learning in schools was adversely influenced by the patchwork nature of partnership support at national and local authority levels. This has curtailed the prioritizing of outdoor learning in schools and of teachers being supported when trying to make use of their increased curriculum decision-making responsibilities. Thus, only limited evidence was found of policy-related innovation and considerable evidence of policy stasis. As such, building national capacity is proving difficult. It is concluded that further research on how some atypical schools have managed to develop their programmes offers the best prospects for understanding the complexities of achieving greater levels of outdoor learning. [ABSTRACT FROM PUBLISHER]

Despite the long history of youth expeditions and a growing number of participants and claims of being concerned with ‘youth development’, expeditions have received little attention by leisure and/or educational researchers in the UK. Recent literature specifically examining expeditions in the UK demonstrates an increasing interest in this phenomenon that sits on the juncture of education and leisure. There has been some critique regarding lack of clarity of recreational or educational aims and ethical issues. Literature from travel and tourism, management learning and international education all indicate that culture shock and reverse culture shock (RCS) are experienced in a range of contexts. These two literatures are summarised and inform the present research. This research focused on gaining an initial understanding of young people’s experiences of returning home after an expedition. Data were gathered six months after a six-week expedition (n = 19) to south-west Greenland to undertake science and journeys on the ice cap. Using a qualitative approach to analyse these data the following themes were identified as affecting the participants’ expedition reverse culture shock (ERCS): Sense of Isolation, Extending the Lessons of the Group and Using the Group as a Compass for the Future. Connections are made to literature on RCS and some suggestions made for facilitating ERCS. Other implications are considered. [ABSTRACT FROM AUTHOR]

Travel and overseas experiences, particularly those involving some form of outdoor education, are regarded by many young people, parents, university admissions and employers as somehow beneficial to a young person's development. Often, expedition experiences are happening at crucial times in life (the teen years) when metaphysical (rather than empirical) questions dominate. This paper explores the explicit connections that can be made between the current curriculum in the United Kingdom and expeditions on the basis of contributions to personal and social development through values, choices and decisions. In order for such experiences to be of educational value we argue that creating space for students to make mistakes and to explore (in literal and metaphorical terms) is of crucial importance. The paper concludes that expeditions may provide a useful context for personal and social development and, in particular, exploration of values. [ABSTRACT FROM AUTHOR]

Abstract: Tsunamis are frequent events in modern marine environments but evidence of their passing in subtidal ancient epicontinental sea deposits is elusive. It has been suggested that this is due to mis-identification or poor preservation potential. Herein a numerical modelling approach is used to show that tsunami propagation in one large ancient epicontinental sea was hindered by the damping effect of shallow bathymetries and reflection, refraction and diffraction from emergent landmasses. The Imperial College Ocean Model (ICOM) is used for this study and is first validated against data from the Sumatra–Andaman Tsunami of December 2004. A palaeobathymetric dataset is then presented for the Hettangian (Lower Jurassic) Laurasian Seaway with idealised tsunami sources situated on the continental shelf and within the adjacent oceanic basin. Results show that tsunamis forced from within ocean basins adjacent to the epicontinental sea are rapidly attenuated over the continental slope and fail to propagate great distances onto the shelf. Similarly, the sedimentological effect of tsunamis forced from within the epicontinental sea is also restricted. It is concluded that tsunami deposits in ancient epicontinental seas are most likely to occur in relative proximity to the source region and this must contribute to their scarcity in the geological record. [Copyright &y& Elsevier]

New devolutionary powers for education have been enthusiastically seized on by politicians and policy-makers alike to promote a more integrated and holistic form of education in Scotland. This period of curriculum renewal offers the prospect of increased levels of outdoor education; however, to date there is a lack of a clearly agreed rationale for learning and clarity about how curriculum will be experienced by students. Consequently, we analyse pertinent conceptual questions about these matters through reviewing articles and policy announcements prior to advancing, in a preliminary fashion, a rationale for outdoor education which conceives of outdoor learning primarily as a moral endeavour. In developing the proposed rationale as the organising framework for learning, the article critically considers the multifarious challenges of connecting policy intentions with the authentic learning experiences of students. In so doing it discusses many of the most apparent curriculum and pedagogical barriers to learning, which have led in recent years to fragmented provision and the under-realisation of increased levels of deeply embedded and connected outdoor learning experiences. [ABSTRACT FROM AUTHOR]

The article focuses on a study that describes and uses a technique using Passive Induced Transponder (PIT) tags to monitor individual use of supplementary feed in wild mountains hare Lepus timidus populations and tests the assumption that supplementary feed reaches the target population. It cites the role of food availability in vertebrate population dynamics despite the proliferation of supplementary feeding studies. The Generalised Linear Models (GLM) were used to assess the time individuals spent feeding.

Abstract: Recurrent taphofacies, including conservation lagerstätten, are identified within a spectrum of facies in fourth-order sequences in the Middle Cambrian Wheeler, and Marjum formations of the Drum Mountains and House Range, west-central Utah. These sequences are 3–20 m thick and commence with sharply-based compact, oncolitic, oolitic, or pelletal pack- and grainstones with sharply-defined, corroded and mineralized upper contacts that record drowning discontinuities and early transgressive systems tracts (TSTs). Overlying intervals of calcareous shale and thin-bedded wacke- to packstones with abundant, disarticulated polymerid and agnostoid trilobites represent late TSTs. These are commonly followed by lavender-gray mudstones rich in sponge spicules and comminuted fossil debris that reflect condensed maximum flooding zones. The overlying early highstand (HST) intervals of black, fissile shales are typically barren except for indistinct, circular carbonized algae, but in rare instances, include soft-bodied animal remains. A combination of lower dysoxic–anoxic conditions, with a fluctuating oxycline, and relatively rapid episodic influx of fine-grained detrital sediment favored repeated burial and preservation of abundant organic detritus and rarely soft-bodied animals. Interbedded dark gray, shales include abundant articulated agnostoid trilobites and diminutive polymerids (e.g., Jenkinsonia). Overlying platy, calcareous bedding planes covered with articulated bodies and molts of the polymerid Elrathia indicate rapid blanketing of undisturbed seafloors by calcareous mud layers. These beds grade upward successively into interbedded, sparsely fossiliferous platy to flaggy shale and thin, pale gray weathering calcisiltites, and burrow-mottled to nodular limestones, recording late HST to falling stage (FSST) carbonate shedding. Thin calcisiltites include fossil debris and articulated larger polymerid trilobites and the eocrinoid Gogia, preserved by obrutionary deposits. The repeated recurrence of these patterns provides the rudiments of a predictive model that not only explains the differing modes of preservation but may also aid in prospecting for new lagerstätten. [Copyright &y& Elsevier]

Abstract: More than two thirds of beds in the lowest Jurassic, Blue Lias Formation lack ammonites, which are commonly preserved in irregular or planar-bedded, bioturbated limestones, very rarely in laminated limestones and almost never in laminated black shales. Ammonites are preserved in 3D in nodular and planar-bedded limestones and at any orientation to bedding. Co-occurrence with macrobenthos and absence from beds without benthos suggest that Blue Lias ammonites were nektobenthonic. Scour structures and imbrication of ammonites in the Best Bed imply presence of traction currents. Lack of epifauna on large cephalopod shells (and other fossils) implies rapid deposition in event beds. Blue Lias deposition was episodic, not slow and continuous as the fine grain size implies. Undistorted trace fossils, uncrushed ammonites and stable isotope values all suggest early cementation of limestone beds from pore waters of a similar composition to contemporary Jurassic sea water. A clear diagenetic trend exists, with limestones having least, and laminated black shales most, modified stable isotope values. Contrast between trace fossil fills and host sediment demonstrates that Blue Lias rhythms are primary, but limestone beds have been diagenetically cemented. [Copyright &y& Elsevier]

Abstract: The rhythmically bedded limestone–marl–shale succession of the Blue Lias Formation (Lias Group, Early Jurassic age) of Kilve in Somerset (SW England) preserves a suite of large conical concretions that formed around methane seeps. These are 1–2 m high, and elliptical in plan (axes 2–4 m), with an outer limestone shell forming the flanks of the cone. The cone flank is composed of micritic carbonate (20–30 cm thick), which locally includes sheets and pods of intraclasts and bioclasts. The cycle-forming limestone beds of the host strata are composed of dark grey micrite with carbon-isotope values (δ 13C=0.6 to 0.8‰) consistent with carbon sourced from a mixture of seawater and by sulphate reduction, and oxygen-isotope values (δ 18O=−6‰) suggesting some degree of later diagenesis. The pale grey micrite that forms the sides of the mounds includes three-dimensional ammonites and intraclasts, and thus cemented close to the sediment–water interface prior to compaction. The mound-forming carbonate is markedly isotopically light with respect to carbon, but not with respect to oxygen (δ 13C=−24.3 to −26.4; δ 18O=−2 to −3.5‰). The isotope signature indicates that cements were probably derived from a mixture of sources that included biogenic methane. The intraclasts within the limestone suggest that syn-depositional physical brecciation and mixing of cements had occurred, and thus mixing of methane rich-fluids with the overlying surface waters is likely also to have occurred. The relatively heavy oxygen-isotope values may be indicative of anaerobic oxidation of methane. The mound-bearing interval of the Blue Lias Formation is benthos-poor and comprises predominantly laminated black shales, characteristic of poor bottom water oxygenation. The largest of the mounds is however, capped with fossiliferous breccias. Thus the mounds either formed benthic islands that elevated the biota into an oxic zone or, alternatively, they may have supported a chemotrophic community. Although cold seep deposits have been documented previously they are still comparatively rare. This example is one of the oldest in Europe, and is unusual amongst described ancient seeps in preserving relief that extended above the ancient seafloor. [Copyright &y& Elsevier]

Due to a lack of modern analogues, debate surrounds the importance of tides in ancient epi-continental seas. However, numerical modelling can provide a quantitative means of investigating palaeo-tidality without recourse to analogues. Finite element modelling of the European Upper Carboniferous epi-continental seaway predicts an exceedingly low Lunar tidal range ( ca 5 cm in the open water regions of the UK and Southern North Sea). The Imperial College Ocean Model (ICOM) uses finite element methods and an unstructured tetrahedral mesh that is computationally very efficient. The accuracy and sensitivity of ICOM tidal range predictions were tested using bathymetric data from the present-day Mediterranean Sea. The Mediterranean Sea is micro-tidal and varies in depth up to 5·4 km with an average depth of 1–2 km. ICOM accurately predicts the tidal range given both a realistic, but smoothed, bathymetry and a straight sided basin with a uniform depth of 1 km. Variation in uniform depth from 100 to 3000 m with and without islands consistently predicts micro-tidality, demonstrating that the model is robust and the effect of bathymetric uncertainty on model output is relatively small. The extremely low tidal range predicted for the European Upper Carboniferous is thus deemed robust. Putative Upper Carboniferous tidal deposits have been described in the UK and southern North Sea, but are represented by cyclic rhythmites and are limited to palaeo-estuaries. Calculations based on an embayed coast model show that the tidal range could have been amplified to ca 1 m in estuaries and that this is sufficient to form cyclic rhythmites. Without tidal mixing, the tropical equatorial heat and salinity enhancement would promote stratification in the open water body. The introduction of organic matter probably caused anoxia, biotic mortality and carbon accumulation, as evidenced by numerous black ‘marine-band’ shales. [ABSTRACT FROM AUTHOR]

Examines the value of biotechnology. Revenue from the final product; Rational basis for investment; Expression of biotechnology in terms of risk-adjusted net present value.

Shows that the present-day pattern can be tracked back only to the Jurassic, and that Paleozoic bryozoan-rich deposits were more common in the tropics than elsewhere. Methodology used in the study; Results of the study.

Presents findings of a study regarding the preservation of the soft-bodied fossil biotas in the Middle Cambrian Burgess Shale of British Columbia, Canada. Outcrop lithology and sedimentology; Depositional environment.

Depositional stratigraphy represents the only physical archive of palaeo‐sediment routing and this limits analysis of ancient source‐to‐sink systems in both space and time. Here, we use palaeo‐digital elevation models (palaeoDEMs; based on high‐resolution palaeogeographic reconstructions), HadCM3L general circulation model climate data and the BQART suspended sediment discharge model to demonstrate a predictive, forward approach to palaeo‐sediment routing system analysis. To exemplify our approach, we use palaeoDEMs and HadCM3L data to predict the configurations, geometries and climates of large continental catchments in the Cenomanian and Turonian North American continent. Then, we use BQART to estimate suspended sediment discharges and catchment‐averaged erosion rates and we map their spatial distributions. We validate our estimates with published geologic constraints from the Cenomanian Dunvegan Formation, Alberta, Canada, and the Turonian Ferron Sandstone, Utah, USA, and find that estimates are consistent or within a factor of two to three. We then evaluate the univariate and multivariate sensitivity of our estimates to a range of uncertainty margins on palaeogeographic and palaeoclimatic boundary conditions; large uncertainty margins (≤50%/±5°C) still recover estimates of suspended sediment discharge within an order of magnitude of published constraints. PalaeoDEMs are therefore suitable as a first‐order investigative tool in palaeo‐sediment routing system analysis and are particularly useful where stratigraphic records are incomplete. We highlight the potential of this approach to predict the global spatio‐temporal response of suspended sediment discharges and catchment‐averaged erosion rates to long‐period tectonic and climatic forcing in the geologic past. [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]

Abstract: This work presents the first detailed facies analysis of the upper Nyalau Formation exposed around Bintulu, Sarawak, Malaysia. The Lower Miocene Nyalau Formation exposures in NW Sarawak represent one of the closest sedimentological outcrop analogues to the age equivalent, hydrocarbon-bearing, offshore deposits of the Balingian Province. Nine types of facies associations are recognised in the Nyalau Formation, which form elements of larger-scale facies successions. Wave-dominated shoreface facies successions display coarsening upward trends from Offshore, into Lower Shoreface and Upper Shoreface Facies Associations. Fluvio-tidal channel facies successions consist of multi-storey stacks of Fluvial-Dominated, Tide-Influenced and Tide-Dominated Channel Facies Associations interbedded with minor Bay and Mangrove Facies Associations. Estuarine bay facies successions are composed of Tidal Bar and Bay Facies Associations with minor Mangrove Facies Associations. Tide-dominated delta facies successions coarsen upward from an Offshore into the Tidal Bar Facies Association. The Nyalau Formation is interpreted as a mixed wave- and tide-influenced coastal depositional system, with an offshore wave-dominated barrier shoreface being incised by laterally migrating tidal channels and offshore migrating tidal bars. Stratigraphic successions in the Nyalau Formation form repetitive high frequency, regressive–transgressive cycles bounded by flooding surfaces, consisting of a basal coarsening upward, wave-dominated shoreface facies succession (representing a prograding barrier shoreface and/or beach-strandplain) which is sharply overlain by fluvio-tidal channel, estuarine bay or tide-dominated delta facies successions (representing more inshore, tide-influenced coastal depositional environments). An erosion surface separates the underlying wave-dominated facies succession from overlying tidal facies successions in each regressive–transgressive cycle. These erosion surfaces are interpreted as unconformities formed when base level fall resulted in deep incision of barrier shorefaces. Inshore, fluvio-tidal successions above the unconformity display upward increase in marine influence and are interpreted as transgressive incised valley fills. [Copyright &y& Elsevier]

Quantitative reconstruction of palaeohydrology from fluvial stratigraphy provides sophisticated insights into the response, and relative impact, of tectonic and climatic drivers on ancient fluvial landscapes. Here, field measurements and a suite of quantitative approaches are used to develop a four‐dimensional (space and time) reconstruction of palaeohydrology in Late Cretaceous palaeorivers of central Utah, USA – these rivers drained the Sevier mountains to the Western Interior Seaway. Field data include grain‐size and cross‐set measurements and span five parallel fluvial systems, two of which include up‐dip to down‐dip transects, across seven stratigraphic intervals through the Blackhawk Formation, Castlegate Sandstone and Price River Formation. Reconstructed palaeohydrological parameters include fluvial morphologies (flow depths, palaeoslopes, palaeorelief and planform morphologies) and various hydrodynamic properties (flow velocities, water discharges and sediment transport modes). Results suggest that fluvial morphologies were similar in space and time; median flow depths spanned 2 to 4 m with marginally greater flow depths in southerly systems. Meanwhile palaeoslopes spanned 10−3 to 10−4, decreasing downstream by an order of magnitude. The most prominent spatio‐temporal change is an up to four‐fold increase in palaeoslope at the Blackhawk–Castlegate transition; associated alluvial palaeorelief is tens of metres during Blackhawk deposition and >100 m during Castlegate Sandstone deposition. This study observed no change in unit water discharges at the Blackhawk–Castlegate transition, which argues against a climatically driven increase in palaeoslope and channel steepness. These findings instead point to a tectonically driven palaeoslope increase, although one limitation in this study is uncertainty in palaeochannel widths, which directly influences total water discharges. These reconstructions complement and expand on extensive previous work in this region, which enables the efficacy of quantitative reconstruction tools to be tested. Comparison of results with facies‐based interpretations indicates that quantitative tools work well, but inconsistencies in more complex reconstructions (for example, planform morphologies) highlight the need for further work. [ABSTRACT FROM AUTHOR]

The latitudinal biodiversity gradient (LBG), in which species richness decreases from tropical to polar regions, is a pervasive pattern of the modern biosphere. Although the distribution of fossil occurrences suggests this pattern has varied through deep time, the recognition of palaeobiogeographic patterns is hampered by geological and anthropogenic biases. In particular, spatial sampling heterogeneity has the capacity to impact upon the reconstruction of deep time LBGs. Here we use a simulation framework to test the detectability of three different types of LBG (flat, unimodal and bimodal) over the last 300 Myr. We show that heterogeneity in spatial sampling significantly impacts upon the detectability of genuine LBGs, with known biodiversity patterns regularly obscured after applying the spatial sampling window of fossil collections. Sampling-standardization aids the reconstruction of relative biodiversity gradients, but cannot account for artefactual absences introduced by geological and anthropogenic biases. Therefore, we argue that some previous studies might have failed to recover the 'true' LBG type owing to incomplete and heterogeneous sampling, particularly between 200 and 20 Ma. Furthermore, these issues also have the potential to bias global estimates of past biodiversity, as well as inhibit the recognition of extinction and radiation events. [ABSTRACT FROM AUTHOR]

The Cretaceous/Paleogene mass extinction, 66 Ma, included the demise of non-avian dinosaurs. Intense debate has focused on the relative roles of Deccan volcanism and the Chicxulub asteroid impact as kill mechanisms for this event. Here, we combine fossiloccurrence data with paleoclimate and habitat suitability models to evaluate dinosaur habitability in the wake of various asteroid impact and Deccan volcanism scenarios. Asteroid impact models generate a prolonged cold winter that suppresses potential global dinosaur habitats. Conversely, long-term forcing from Deccan volcanism (carbon dioxide [CO2]-induced warming) leads to increased habitat suitability. Short-term (aerosol cooling) volcanism still allows equatorial habitability. These results support the asteroid impact as the main driver of the non-avian dinosaur extinction. By contrast, induced warming from volcanism mitigated the most extreme effects of asteroid impact, potentially reducing the extinction severity. [ABSTRACT FROM AUTHOR]

Fluvial sediment discharges are governed by tectonic and climatic boundary conditions, which influence spatio-temporal patterns in sediment routing, as well as denudation rates in upland source regions. Depositional stratigraphy represents the only physical archive of ancient source-to-sink systems, which limits palaeo-sediment routing system analyses both spatially and temporally. Therefore, understanding how, when and where sediment was delivered from the continents to the oceans in the geologic past remains a prominent research challenge in Earth science. In this study we use new high-resolution palaeogeographies, which have been digitised as palaeo-digital elevation models (palaeoDEMs), and HadCM3L climate data to predict the configurations, geometries and climates of large continental catchments in the Cenomanian and Turonian North American continent. Moreover, we use the BQART sediment discharge model to make first-order estimates of fluvially-derived suspended sediment discharges in catchments, and we assess their spatial distribution across the North American continent.We analysed palaeoDEMs in ArcGIS and reconstructed over 1500 North American catchments with areas greater than 500 km2 for both Cenomanian and Turonian time slices. Using BQART, we predicted fluvial sediment discharges in each catchment and mapped their spatial distribution across the continent. Total continental suspended sediment discharges are projected to be 3.5 GT/yr and 3.1 GT/yr in the Cenomanian and Turonian stages, respectively. This implies that continental sediment discharges in the late Cretaceous may have been a factor of 2 bigger than estimated Holocene pre-anthropogenic continental discharges of 1.7 GT/yr. To validate our results, we compared BQART estimates with published constraints from the Cenomanian Dunvegan Formation in Alberta, Canada, and the Turonian Ferron Sandstone in Utah, USA. In each case study, BQART estimates are the same order of magnitude as published constraints, which were derived from previous field-based approaches, and most lie within a factor of 2. Finally, we evaluated and quantified the univariate and multivariate sensitivity of our sediment discharge estimates to a range of uncertainty margins on BQART input parameters, which includes palaeogeographic and palaeoclimatic boundary conditions. Our results demonstrate that high-resolution palaeogeographies can be used to make first order estimates of fluvial sediment discharges in the geologic past on a variety of spatial and temporal scales. We consider our approach particularly useful where stratigraphic records are incomplete. Moreover, we highlight the potential to use this approach to address big picture research questions, such as the global spatio-temporal response of sediment supply to major tectonic and climatic events in the geologic past. [ABSTRACT FROM AUTHOR]

Turbidity currents are one of the main drivers of sediment transport from the continental shelf to the deep ocean. The resulting sediment deposits can reach hundreds of kilometres into the ocean. Computer models that simulate turbidity currents and the resulting sediment deposit can help us to understand their general behaviour. However, in order to recreate real-world scenarios, the challenge is to find the turbidity current parameters that reproduce the observations of sediment deposits. This paper demonstrates a solution to the inverse sediment transportation problem: for a known sedimentary deposit, the developed model reconstructs details about the turbidity current that produced the deposit. The reconstruction is constrained here by a shallow water sediment-laden density current model, which is discretised by the finite-element method and an adaptive time-stepping scheme. The model is differentiated using the adjoint approach, and an efficient gradientbased optimisation method is applied to identify the turbidity parameters which minimise the misfit between the modelled and the observed field sediment deposits. The capabilities of this approach are demonstrated using measurements taken in the Miocene Marnoso-arenacea Formation (Italy). We find that whilst the model cannot match the deposit exactly due to limitations in the physical processes simulated, it provides valuable insights into the depositional processes and represents a significant advance in our toolset for interpreting turbidity current deposits. [ABSTRACT FROM AUTHOR]

Turbidity currents are one of the main drivers for sediment transport from the continental shelf to the deep ocean. The resulting sediment deposits can reach hundreds of kilometres into the ocean. Computer models that simulate turbidity currents and the resulting sediment deposit can help to understand their general behaviour. However, in order to recreate real-world scenarios, the challenge is to find the turbidity current parameters that reproduce the observations of sediment deposits. This paper demonstrates a solution to the inverse sediment transportation problem: for a known sedimentary deposit, the developed model reconstructs details about the turbidity current that produced these deposits. The reconstruction is constrained here by a shallow water sediment-laden density current model, which is discretised by the finite element method and an adaptive time-stepping scheme. The model is differentiated using the adjoint approach and an efficient gradient-based optimisation method is applied to identify turbidity parameters which minimise the misfit between modelled and observed field sediment deposits. The capabilities of this approach are demonstrated using measurements taken in the Miocene-age Marnoso Arenacea Formation (Italy). We find that whilst the model cannot match the deposit exactly due to limitations in the physical processes simulated, it provides valuable insights into the depositional processes and represents a significant advance in our toolset for interpreting turbidity current deposits. [ABSTRACT FROM AUTHOR]

Laboratory experiments and numerical simulations have shown that volcanic ash particles immersed in water can either settle slowly and individually, or rapidly and collectively as particle-laden plumes. The ratio of timescales for individual and collective settling, in the form of analytical expressions, provides a dimensionless quantitative measure of the tendency for such plumes to grow and persist which has important implications for determining particle residence times and deposition rates. However, existing measures in the literature assume that collective settling obeys Stokes' law and is therefore controlled by the balance between gravitational forces and viscous drag, despite plume development actually being controlled by the balance between gravitational forces and inertial drag even in the absence of turbulence during early times. This paper presents a new measure for plume onset which takes into account the inertial drag-controlled (rather than viscous drag-controlled) nature of plume growth and descent. A parameter study comprising a set of numerical simulations of small-scale volcanic ash particle settling experiments highlights the effectiveness of the new measure and, by comparison with an existing measure in the literature, also demonstrates that the timescale of collective settling is grossly under-estimated when assuming that plume development is slowed by viscous drag. Furthermore, the formulation of the new measure means that the tendency for plumes to form can be estimated from the thickness and concentration of the final deposit; the magnitude and duration of particle flux across the water's surface do not need to be known. The measure therefore permits the residence times of particles in a large body of water to be more accurately and practically determined, and allows the improved interpretation of layers of volcaniclastic material deposited at the seabed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to carry out a preliminary investigation to explore the use of outdoor and adventurous project work (PW) within an educational setting. Specifically, differences between the PW and normal academic school experiences were examined using a self-determination theory framework integrated with a goal orientation and psychological skills perspective. Additionally, an exploratory investigation was carried out to examine the extent to which key motivation constructs predicted skill development (i.e. problem solving, collaboration and communication) through the PW experience. Six questionnaires were adapted and utilised to collect the relevant data for both school and PW experiences (Basic Psychological Needs questionnaire; the Learning Climate Questionnaire; Intrinsic Motivation Inventory; the Motivated Strategies for Learning Questionnaire; 2 × 2 Achievement Goal Questionnaire and perceived skills learned in PW questionnaire) from the 224 students (Mean age 13.2 ± 0.3 years) who participated in the 12-day PW. Results indicated that there were significant differences between school and PW experience (p < 0.01). Specifically, PW experience rated higher in autonomy supportive climate, autonomous motivation, perceived competence, and a greater emphasis on task approach goal orientation. Furthermore as a cohort, the students reported improvements in problem solving, collaboration and communication as a result of the PW experience. Finally, an exploratory hierarchical regression analysis revealed potential importance of perceived value, utilising meta-cognitive skills, and experiencing relatedness and autonomy in the prediction of skill development through PW experiences. The findings of this study present preliminary support the potential usefulness of outdoor and adventurous PW within a school context and provide implications for future research which are discussed further. [ABSTRACT FROM PUBLISHER]

Ancient shoreline–shelf depositional systems are influenced by an unusually wide array of geological, biological and hydrodynamic processes, with sediment transport and deposition primarily determined by the interaction of river, wave (including storm) and tidal processes, and changes in relative sea level. Understanding the impact of these processes on shoreline–shelf morphodynamics and stratigraphic preservation remains challenging. Numerical modelling integrated with traditional facies analysis provides an increasingly viable approach, with the potential to quantify, and thereby improve understanding of, the impact of these complex coastal sedimentary processes. An integrated approach is presented here that focuses on palaeotidal modelling to investigate the controls on ancient tides and their influence on sedimentary deposition and preservation – one of the three cornerstones of the ternary process classification scheme of shoreline-shelf systems. Numerical tidal modelling methodology is reviewed and illustrated in three palaeotidal model case studies of different scales and focus. The results are synthesised in the context of shoreline–shelf processes, including a critique and modification of the process-based classification scheme. The emphasis on tidal processes reflects their global importance throughout Earth's history. Ancient palaeotidal models are able to highlight and quantify the following four controls on tidal processes: (1) the physiography (shape and depth) of oceans (1000s km scale) determines the degree of tidal resonance; (2) the physiography of ocean connections to partly enclosed water bodies (100–1000s km scale) determines the regional-scale flux of tidal energy (inflow versus outflow); (3) the physiography of continental shelves influences shelf tidal resonance potential; and (4) tides in relatively local-scale embayments (typically 1–10s km scale) are influenced by the balance of tidal amplification due to funnelling, shoaling and resonance effects versus frictional damping. In deep time, palaeogeographic and palaeobathymetric uncertainty can be accounted for in palaeotidal models by performing sensitivity analyses to different scenarios, across this range of spatial scales. These tidal process controls are incorporated into an updated predictive decision tree for determining shoreline–shelf process regime in terms of the relative interaction of wave, fluvial and tidal processes. The predictive decision tree considers the effects of basin physiography, shelf width and shoreline morphology on wave, fluvial and tidal processes separately. Uncertainty and ambiguity in applying the widely used three-tier process classification scheme are reduced by using the decision tree in conjunction with a proposed two-tier classification of process regime that is limited to primary and secondary processes. This two-tier classification scheme is illustrated in the three case studies, showing how integration of numerical modelling with facies analysis of the preserved stratigraphic record improves confidence in prediction of tide-influenced shoreline-shelf process regimes. Wider application of this approach will further improve process-based classifications and predictions of modern and ancient shoreline–shelf systems. [ABSTRACT FROM AUTHOR]

Lower to Middle Turonian deposits within the Bohemian Cretaceous Basin (Central Europe) consist of coarse-grained deltaic sandstones passing distally into fine-grained offshore sediments. Dune-scale cross-beds superimposed on delta-front clinoforms indicate a vigorous basinal palaeocirculation capable of transporting coarse-grained sand across the entire depth range of the clinoforms ( ca 35 m). Bi-directional, alongshore-oriented, trough cross-set axes, silt drapes and reactivation surfaces indicate tidal activity. However, the Bohemian Cretaceous Basin at this time was over a thousand kilometres from the shelf break and separated from the open ocean by a series of small islands. The presence of tidally-influenced deposits in a setting where co-oscillating tides are likely to have been damped down by seabed friction and blocked by emergent land masses is problematic. The Imperial College Ocean Model, a fully hydrodynamic, unstructured mesh finite element model, is used to test the hypothesis that tidal circulation in this isolated region was capable of generating the observed grain-size distributions, bedform types and palaeocurrent orientations. The model is first validated for the prediction of bed shear stress magnitudes and sediment transport pathways against the present-day North European shelf seas that surround the British Isles. The model predicts a microtidal to mesotidal regime for the Bohemian Cretaceous Basin across a range of sensitivity tests with elevated tidal ranges in local embayments. Funnelling associated with straits increases tidal current velocities, generating bed shear stresses that were capable of forming the sedimentary structures observed in the field. The model also predicts instantaneous bi-directional currents with orientations comparable with those measured in the field. Overall, the Imperial College Ocean Model predicts a vigorous tide-driven palaeocirculation within the Bohemian Cretaceous Basin that would indisputably have influenced sediment dispersal and facies distributions. Palaeocurrent vectors and sediment transport pathways however vary markedly in the different sensitivity tests. Accurate modelling of these parameters, in this instance, requires greater palaeogeographic certainty than can be extracted from the available rock record. [ABSTRACT FROM AUTHOR]