global patterns in sandy beach macrofauna species richness abundance biomass and body size abstract global patterns in species richness in sandy beach ecosystems have been poorly understood until comparatively recently because of the difficulty of compiling high resolution databases at continental scales we analyze information from more than 200 sandy beaches around the world which harbor hundreds of macrofauna species and explore latitudinal trends in species richness abundance and biomass species richness increases from temperate to tropical sites abundance follows contrasting trends depending on the slope of the beach in gentle slope beaches it is higher at temperate sites whereas in steep slope beaches it is higher at the tropics biomass follows identical negative trends for both climatic regions at the whole range of beach slopes suggesting decreasing rates in carrying capacity of the environment towards reflective beaches various morphodynamic variables determine global trends in beach macrofauna species richness abundance and biomass are higher at dissipative than at reflective beaches whereas a body size follows the reverse pattern a generalized linear model showed that large tidal range which determines the vertical dimension of the intertidal habitat small size of sand particles and flat beach slope a product of the interaction among wave energy tidal range and grain size are correlated with high species richness suggesting that these parameters represent the most parsimonious variables for modelling patterns in sandy beach macrofauna large scale patterns indicate a scaling of abundance to a body size suggesting that dissipative beaches harbor communities with highest abundance and species with the smallest body sizes additional information for tropical and northern hemisphere sandy beaches underrepresented in our compilation is required to decipher more conclusive trends particularly in abundance biomass and body size further research should integrate meaningful oceanographic variables such as temperature and primary production in deciphering latitudinal trends

multi scale morphodynamics of an estuarine beach adjacent to a flood tide delta assessing decadal scale erosion abstract estuarine beaches are ubiquitous yet understudied coastal systems the mixed hydrodynamic processes such as combined tidal and wave forcing and the influence of adjacent sedimentary features such as flood tide deltas ftds leads to complex morphodynamic processes as such the dynamics and evolution of these important coastal systems are poorly understood this study synthesises a set of analyses conducted on an estuarine beach in southeast australia over multiple temporal scales nearshore waves and currents were measured and used to determine the processes driving seasonal to yearly beach change between 2007 and 2010 these results were compared to decadal scale beach change determined from aerial photos between 1963 and 2006 we found the westward transport of sediment towards the inner estuary was the dominant nearshore process leading to erosion in the eastern regions of the beach near the estuary entrance and accretion in the west over yearly time scales cross shore sediment transport occurred during winter storm swell conditions leading to erosion in more exposed sites and some limited accretion in sheltered zones most likely due to sediment input from the flood tide delta however severe storm swell events that propagated into the estuary led to a loss of sediment and erosion across the entire beach which was not recovered during the study period it is likely that the erosion processes observed in the short to medium term days to years analyses are the conditions that led to the long term shoreline retreat observed in the aerial photograph record the long term shoreline retreat since 1963 is likely a result of a negative sediment balance due to movement of the ftd and a lack of sediment input in the eastern regions of shoal bay shoreline retreat will likely continue unless increased sediment input occurs from marine sources or shoreline interventions are maintained

tropical cyclone genesis factors in simulations of the last glacial maximum abstractlarge scale environmental factors that favor tropical cyclogenesis are calculated and examined in simulations of the last glacial maximum lgm from the paleoclimate modelling intercomparison project phase 2 pmip2 despite universally colder conditions at the lgm values of tropical cyclone potential intensity which both serves as an upper bound on thermodynamically achievable intensity and indicates regions supportive of the deep convection required are broadly similar in magnitude to those in preindustrial era control simulation some regions including large areas of the central and western north pacific feature higher potential intensities at the lgm than they do in the control runs while other regions including much of the atlantic and indian oceans are lower changes in potential intensity are strongly correlated with the degree of surface cooling during the lgm additionally two thermodynamic parameters one that measures midtropospheric entropy deficits relevant for tropical cyclogen

palaeoecology of macroneuropteris scheuchzeri and its implications for resolving the paradox of xeromorphic plants in pennsylvanian wetlands abstract the medullosan pteridosperm macroneuropteris scheuchzeri hoffmann cleal shute zodrow was widespread and abundant in the middle to late pennsylvanian forests of tropical pangaea on the basis of its thick cuticles few adaxial stomata sunken stomata and dense trichomes it has been inferred to be a xeromorphic plant here we test that hypothesis by analyzing its facies distribution especially in relation to coals at 273 site collections from 45 stratigraphic horizons accessioned in the smithsonian national museum of natural history washington d c u s a the collections represent mostly par autochthonous assemblages and cover the taxon s complete known temporal range west of the appalachians in west central pangaea chi square analysis of facies occurrence data indicates that m scheuchzeri had a strong preference for mineral enriched wetlands that immediately preceded and followed the development of peat swamps and mires coals particularly during the late middle pennsylvanian late moscovian times coincident with a period of reduced polar ice volume in the late pennsylvanian following an interval of global warming and tropical wetland reorganization palaeoequatorial climate shifted to an overall drier mode this was accompanied by the disappearance of m scheuchzeri from europe and its limitation west of the appalachians to the wettest available habitats on the landscape thus our data falsify the hypothesis that m scheuchzeri was a conventional xerophyte but highlight the paradox of a plant with apparent xeromorphic features confined to a wetland habitat we consider several possible explanations for this association 1 response to nutrient deficiency 2 response to substrate salinity due to growth in coastal mangrove habitats 3 response to the composition of the palaeozoic atmosphere 4 return on investment long leaf lifespan and 5 phylogenetic constraint reflecting ancestral conditions our findings have broader implications for interpreting a wide variety of other pennsylvanian wetland plants which similarly show xermorphic features

distribution of surface pebbles with changes in wave energy on a sandy estuarine beach abstract a 29 day field experiment in delaware bay nj identified the dispersion of surface pebbles due to cross shore transport on a mesotidal estuarine beach composed mainly of sand wave heights were 0 04 0 56 m dissipation of wave energy on the low tide terrace increases as water levels become lower creating a spatial gradient in wave energy delivered to the foreshore analysis of surface sediment samples taken daily at 4 m intervals across the foreshore and two experiments using dyed pebbles as tracers document increasing quantities of pebbles with distance downslope on the beach corresponding to the decreasing energy gradient there is a second locus of high pebble concentration near the upper limit of swash at high water numbers of surface pebbles are at a minimum following high energy events wind speed 8 0 m s wave height 0 3 m the most conspicuous pebble accumulations result from low energy conditions wind speed 3 0 m s wave height 0 2 m pebbles move up and down the foreshore within the beach step they accumulate just above the low tide terrace on the falling tide when wave energy diminishes at low water under both storm and nonstorm conditions finer particles are moved onshore from this location by low energy post storm accretional waves and offshore by outflow from the beach water table leaving pebbles as a surface lag a fraction of these pebbles is moved up the beach by the swash of low energy waves or within the beach step in subsequent tidal cycles there is insu ficient sand in the backwash of low energy waves to bury pebbles they project into the flow of the swash and have low pivoting angles increasing the probability of entrainment and movement over the sand particles to the upper limit of swash

short and medium term grain size changes in deltaic beaches ebro delta nw mediterranean abstract the beach sediment of the ebro delta shows significant temporal grain size changes unrelated with seasonal processes the evolution of the grain size during the 1988 1991 period shows coarsening and fining variations with a general coarsening trend which ranges from 2 10 to 1 96 phi about 8 10 3 mm year this low magnitude grain size change is considered significant because it is indicated by both mean values from the data set textural zones and individualized sampling points the coarsening trend of the beach sediment in the ebro delta is mainly caused by the sedimentary deficit affecting the ebro coast the finer sand fractions of the sediment are progressively winnowed from the initial beach deposit without being replaced by new river sediment supplies superimposed on the general coarsening trend there exist grain size variations that may be related with processes of a shorter period such as changes in the sediment supplied from the river into the nearshore zone variations in the wave energy affecting the beach and man induced actions such as beach nourishment the mean grain size of beach sediment sampled 20 years ago indicates that the coarsening gradient measured during the study period cannot be extrapolated to longer periods of time decades this work shows that processes of a different temporal scale but a similar magnitude must be integrated in order to explain the evolution of sediment grain size in deltaic beaches

coastal barriers nomenclature processes and classification issues abstract the designation coastal barrier related terms and their varied interpretations and critical concepts in coastal plain and nearshore geology underwent numerous reincarnations over the years this designation was first applied to shore parallel sand and gravel built ocean front islands and spits that separate open marine environments from paralic inshore environments that they shelter a more recently recognized third category includes mainland strandplain chenier and dunefield barriers either as original components of mainland coasts or subsequently welded to the coastal plain a parallel but closely related terminology developed mostly in australia and brazil identifies several specific process categories recognizable in the three basic barrier groups in the absence of lagoons and tidal wetlands shore ridges that front and are contiguous with the mainland coastal plain have been mistakenly assigned to the barrier island category greatly diminished wave energy and consequently minor littoral drift volumes account for the relative rarity and much smaller dimensions of prograded landforms in estuarine islands and bay shore beaches in paralic inshore basins due to wave and related littoral drift processes however diminished in comparison with open marine shores morphological similarities between aggraded landforms of open marine through estuarine settings are to be expected however the multitude of proposed fetch limited diminished wave energy estuarine islands characterized by diminutive narrow beaches sand spits even occasional small dunes and miniature strandplains lack the essential functional attributes intrinsic to true barrier islands while barrier islands may form even on relatively low wave energy and or sediment deficient marine shores the term is inappropriate for islands located in low energy paralic basins including estuaries or in coastal plains where frontal shore ridges are not backed by lagoons landforms erroneously ascribed in a variety of facies settings as barrier islands or islands frequently are mainland attached beach ridge plains or beach fringed marshlands instead narrow marshland beaches and mainland strandplain barriers are segmented into short islands by intervening narrow tidal creeks fluvial distributary channels or storm cuts that separate them improved fundamental and functional definitions of barrier islands their comparison with the many genetic categories of islands and mainland shore beaches found in estuarine basins and wetlands should lead to a better understanding of paralic island evolution processes on the global scale

longshore variability of beach states and bar types in a microtidal storm influenced low energy environment beach classification models are widely used in the literature to describe beach states in response to environmental conditions these models were essentially developed for sandy barred to barless beaches in micro to mesotidal environments subject to moderate to high wave energy conditions and have been based on field studies over limited stretches of coast here we further interrogate the performance of the australian beach classification scheme by analysing beach states and corresponding bar types on a regional scale in a storm influenced low wave energy microtidal environment using a large and unique spatial and temporal dataset of supra and subtidal beach morphology and sedimentology the 200 km long coast of the gulf of lions in themediterranean consists of quasi continuous sandy beaches with a well developed double sandbar system all the reported classical beach stateswere observed on this coast from reflective to dissipative alongwith two more unusual states the rock platform constrained beach state which is associated with bedrock outcrops and the non barred dissipative beach statewhich ismore commonly found in large tidal range settings lidar bathymetry shows that the transitions between beach state zones are marked mainly headlands but transitions also occur progressively along stretches of continuous sandy beach the longshore distribution of beach states and associated bar types on a regional scale can be related to the variability of hydrodynamic conditions wave incidence and energy and sediment characteristics particle size however the influence of these parameters on beach state seems to be largely controlled by the geological context such as the presence of a river mouth headland or rock platform finally we assessed the ability of the parameter commonly used to characterise beach states which combines wave characteristics and sediment fall velocity to predict the observed beach states and bar types using a very large set of hydrodynamic and sedimentary data our results based on high frequency spatial sampling show that the fall velocity of the subtidal sediment coupled with wave statistics one month prior the observed beach state strongly improved the predictive power of the parameter

multiple intertidal bars on beaches a review abstract ridge and runnel features were originally described by king and wiiliams 1949 from observations at blackpool beach u k and laboratory experiments they were characterised as intertidal shore parallel sandbars ridges commonly 2 6 bars in total and disconnected from each other by troughs runnels the nomenclature ridge and runnel was however also used by hayes 1967 to describe multiple barred beaches but referring to subtidal bars the more specific term multiple inter tidal bars mitb was subsequently adopted for intertidal beaches exhibiting successive shore parallel sandbars to date a detailed understanding of the formation of mitb has remained elusive and their precise definition is still unclear it has been suggested that mitb features are the result of both swash and surf zone processes acting on the intertidal beach profile these processes are involved in the formation the long term persistence and behaviour of mitb despite the long term persistence of mitb systems they are dynamic at short timescales ridge crest positions are regularly modified over each tidal cycle by successive surf and swash processes at seasonal scales ridges may undergo erosion and cross shore migration under high energy conditions winter while ridges are well developed during summers via a meta analysis of 93 separate published works at 67 sites globally we define mitb characterise their morphodynamics and assess their global distribution our study shows that the distribution of mitb is a function of thresholds in beach slope 3 m and on low gradient wide intertidal beach slopes

observations on delta forming processes in a fjord head delta british columbia canada abstract the bella coola delta is a laterally confined steep fronted fjord head delta in north bentinck arm in the pacific coast mountains of british columbia the principal controls on sedimentation are 1 the high sediment yield and bedload dominance of the bella coola river which reflect climatic conditions and high drainage basin relief 2 river mouth processes which are controlled by tidal stage and delta morphology and 3 delta front deformational processes which are related primarily to oversteepening in the upper delta front wave processes are of limited significance the large tidal range 3 9 m mean range 5 9 m large range changes the location of distributary outlets at high tide and high discharge frictional forces dominate and the effluent disperses as a plane jet over the delta plain at low tide and high discharge inertial frictional and buoyant forces are important and the effluent disperses over saline basin water subaqueous landslides and debris flows have produced a series of erosional chutes on the delta front

the importance of cyclogenesis on the short term evolution of gulf coast barriers abstract over the past several years research has been conducted to determine the importance of cyclones on the morphodynamics and morphological maintenance of barrier islands along the northern gulf of mexico data are presented indicating the complexity and highly variable response of a 12 km stretch of barrier along the florida panhandle to cold front passage across the northern gulf in addition to the impacts of tropical storms hurricanes and winter storms in the gulf of mexico two temporal scales are used to evaluate short term response and adjustment to these events i e months and a near five year record of sediment volume change the combination of which have resulted in a time series of change for the subaerial and nearshore environments these data incorporate the morphological signature of six tropical storms hurricanes and approximately 100 frontal passages three important conclusions have been reached based on these data 1 low lying barrier islands which are vulnerable to overwash can conserve mass during catastrophic hurricanes e g hurricane opal a strong category 4 hurricane near landfall 2 less severe hurricanes can promote rapid dune and berm aggradation and contribute sediment to the entire barrier system and 3 cold fronts play a critical role in the post storm adjustment of the barrier by deflating the subaerial portion of the overwash terrace and eroding its marginal lobe the data presented also indicate that barrier systems along the northern gulf do not necessarily enter an immediate post storm recovery phase after catastrophic hurricanes even though they are nested in sediment rich nearshore environments it is anticipated that these findings will have important implications for better understanding the longer term evolution of barrier systems in mid latitude micro tidal settings elsewhere around the globe

low energy sandy beaches in marine and estuarine environments a review this review was undertaken to identify locations where low energy beaches may occur and their diagnostic forms and process controls including waves tides and water levels examples are drawn from the sheltered coastline of western australia near perth and fetch limited estuarine environments on the northeast coast of the united states we suggest that the term low energy be used in locations where 1 non storm significant wave heights are minimal e g 0 25 m 2 significant wave heights during strong onshore winds are low e g 0 50 m 3 beachface widths are narrow e g 20 m in microtidal environments and 4 morphologic features include those inherited from higher energy events micro topographic features can persist in the swash zone of low energy beaches under non storm wave conditions there is little evidence of cyclic cross shore sediment exchange bars excepting transverse forms located seaward of low still water level do not appear to be part of the sediment exchange system with the foreshore developing a better definition of the term low energy requires understanding the occurrence and duration of morphological characteristics and the type magnitude and frequency of hydrodynamic controls that are responsible for these characteristics efforts also should be directed toward 1 discriminating between processes generated within basins in true fetch limited environments and processes generated outside basins that affect sheltered environments 2 identifying the relative contributions of tide and surge related water level fluctuations on low energy beach shape and 3 estimating thresholds for beach change

interannual evolution of multiple longshore sand bars in a mesotidal environment truro massachusetts usa abstract multiple longshore bars 0 30 1 5 m in amplitude are present in the nearshore zone off truro ma in cape cod bay these bars exist in a mesotidal environment with a tidal range of 3 0 m a detailed interannual investigation of these bars over a 16 year time period using orthorectified vertical aerial photography has been carried out to characterize the behavior of multiple bars forming in a mesotidal environment over a temporal scale of observation not generally achieved by direct field study this investigation reveals that the bars are dynamic over the time interval studied with offshore extents of up to 660 m and wavelengths of 45 150 m generally increasing in the seaward direction at any one location 4 to 10 bars are present with an apparent addition of bars at the southern end of the study area in addition the bars are consistently parallel to offshore bathymetric contours and comparison of more recent photographs with a 1960 image reveals a 0 5 km alongshore zone without bars that has persisted and grown since 1960 the characteristics of the truro multiple bar field are consistent with several existing theories of multiple bar formation including formation by breaking waves standing infragravity waves and edge waves the demonstrated dynamic nature of the truro multiple bar field over a long temporal scale suggests that field experiments designed to distinguish between possible formation theories may provide an explanation for the continuing modern creation and modification of this and similar multiple bar fields occurring in mesotidal environments

morphosedimentary multiyear changes on a barred coast gulf of lions mediterranean sea france abstract an overall estimate of the relationship between the changes in the nearshore morphology the evolution of the sedimentary budget the beach morphodynamics and the variation of grain size characteristics along the beach barrier of thau lagoon languedoc france was attempted by synthesizing the data from different surveys a basic survey of two separate grids of 11 closely spaced 50 m transverse profiles during 1989 1991 a long baseline 11 km survey of 11 beach profiles during 1988 1991 and an earlier long run 1984 1990 survey of 6 widely spaced bathymetric profiles covering discretely the whole stretch of the nearshore zone time intervals between profile monitorings within each type of survey differed but many measurements during the recent 1989 1991 period were coincident the stable two bar system that was generally developed all over this nearshore zone has been gradually changing at the northeastern end south of the town of sete since 1989 under the effect of a series of new defense structures upstream in the dominant ne sw wave induced longshore current with a tendency toward a single bar profile the average nearshore slope was steeper 0 91 in the sete close survey area than in the southwestern area 0 83 during the same period acceleration in beach erosion has been observed at the northeast in contrast with a stable dynamic equilibrium over the southwestern beach and nearshore profiles over a longer period 1984 1990 scouring of the nearshore sand prism down to the 10 m isobath at the northeastern end between the extreme bathymetric profiles could be estimated at about 37 000 m 3 while the overall sedimentary budget was positive bar migration and morphologic changes in the study areas were not related to any seasonal cycle in the wave climate but were more significant when this was more energetic as during 1989 an overall attenuation in nearshore morphodynamics was observed during the following two years although some rapid local changes between consecutive measurements could be detected temporal variation of grain size characteristics were therefore small and or not significant conversely on the subaerial beach alongshore differentiation in mean diameter and in sorting and skewness parameters is consistent with the evolution of the erosion accumulation processes following a long period wave like sand transfer from northeast to southwest

restoring sediment to compensate for human induced erosion of an estuarine shore abstract shoreline erosion is often exacerbated by reduction of sediment inputs because of interference with sediment transport by human structures we evaluate use of sediment dredged from a navigation channel to establish a feeder beach adjacent to a bulkhead as a solution for addressing erosion of landforms and habitats on sandy estuarine shores the objectives are to determine how beach volume position and shape within and downdrift of the fill area change and whether the volumes supplied by dredging match sediment losses caused by human actions the fill was placed along a 75 m length of shoreline adjacent to a marina in great south bay at fire island new york usa changes in beach shape and volume were determined from topographic surveys conducted before and after fill and at half year intervals for 18 months the quantity of fill was 1747 m3 maximum shoreline advance due to fill emplacement was 20 7 m the maximum volume placed at any transect was 28 6 m3 m 1 of shoreline length erosion of the fill occurred rapidly with landward migration of a conspicuous scarp the edge of the upland 18 months after the fill was placed was up to 4 6 m farther landward than prior to the fill movement of sediment alongshore downdrift of the fill occurred as wave like pulses extending the active foreshore bayward causing accretion of the inner low tide terrace burying saltmarsh peat outcrops on the foreshore and creating a higher and wider overwash platform over portions of the saltmarshes landforms downdrift of the fill area underwent successive stages including erosion pre nourishment accretion stability with throughput of sediment and then erosion beach nourishment compensates for human induced sediment losses the volume of sediment added from maintenance dredging can slow the rate of erosion but may not prevent long term shoreline retreat restoration and maintenance of coastal landforms and habitats to specific target states at a given location is difficult but augmenting longshore sediment inputs can allow those locations to undergo cycles of erosion and accretion creating a variety of landforms and habitats where only erosional forms existed previously alternatively nourishment could occur more frequently and in smaller volumes to reduce fluctuations in accretion erosion cycles

shoreline variability at a low energy beach contributions of storms megacusps and sea breeze cycles abstract the temporal and spatial variations in shoreline position were analysed at a low energy beach in southwestern australia fronted by an offshore reef to examine the relative contributions of storm events megacusps and diurnal sea breeze cycles to the beach morphologic response the shoreline position did not exhibit a seasonal sinusoidal erosion accretion pattern as often observed at open coast sandy beaches but instead a dynamic morphology dominated by storm and recovery cycles that generated fluctuations of 10 m in the shoreline position during low swell recovery periods the beach rapidly developed megacusps wavelength 100 m amplitude 5 m which despite generating local erosive changes within the megacusps embayments the beach still tended to accrete during these low swell conditions in most cases the embayments coincided with locations of rip currents suggesting that rip currents might contribute to the formation of the megacusps additionally high frequency measurements collected over a series of diurnal sea breeze cycles typical of the site during summer months demonstrated that the erosive impact due to sea breezes was much smaller than that observed during storms despite wave heights often being similar during these events while the beach eroded during intensification of the diurnal sea breeze the beach mostly exhibited net daily accretion due to the low energy swell that dominated the wave spectrum during the overnight and morning hours the formation and alongshore migration of megacusps during sea breeze cycles also contributed to beach accretion overwhelming the erosion due to the consecutive sea breezes events after a few days

characteristics distribution and morphogenesis of subtidal microbial systems in shark bay australia abstract the distribution nature and extent of microbial deposits in hamelin pool shark bay have been investigated and mapped with emphasis on the occurrence external morphologies internal fabrics constructional mechanisms microbial communities growth rates and sediment associations in the intertidal and previously little researched subtidal zone detailed georeferenced substrate mapping revealed extensive subtidal microbial deposits occupying approximately 300 km 2 of the total holocene 1400 km 2 area of hamelin pool the microbial pavement covers 227 km 2 of the subtidal substrate that together with columnar structures reveals a subtidal microbial habitat which occupies an area 10 times larger than the area of the intertidal deposits microbial carbonate is composed of aragonite 80 98 that reveals high positive values of 13 c 4 46 to 5 88 and 18 o 3 06 to 3 88 as a characteristic of the highly evaporative environment with extensive microbial activity oldest dated heads are 1915 and 1680 14 c years bp and the overall system was deposited in two stages the first between 2000 and 1200 and the last from 900 years bp to the present slow growth rates vary from less than 0 1 mm year to 0 5 mm year different internal fabrics were constructed according to their position in relation to the littoral zone by distinct microbial communities and lateral fabric relations have been established evidence of shallowing upward fabric sequences of microbial origin reflects relative falling sea levels during the late holocene and is likely useful in ancient environmental interpretation a sequence of events and mechanisms are described emphasizing differences between the stromatolitic thrombolitic and cryptomicrobial deposits in shark bay the new substrate map and depositional history for this distinctive and peculiar microbial habitat establish the significance of subtidal structures and emphasize the geoscientific importance of hamelin pool especially with respect to early life studies and ancient analogues for understanding microbial activity deposit characteristics fenestral fabrics and distribution

history of applied coal petrology in the united states iv reflections on the centennial of the introduction of coal petrology to north america abstract reinhardt thiessen introduced a thin section based botanically oriented method of coal petrology to north america in 1920 the nomenclature derived from this system although eventually reconciled with and largely superseded by the european reflected light techniques and nomenclature persisted for decades after thiessen s death in 1938 the research by thiessen and his colleagues at the u s bureau of mines was the foundation of applied coal petrology in the united states with research on the preparation coking and hydrogenation properties of coals thiessen s botanical training enabled him to recognize distinct spores in coals although he did not macerate the samples and he did not provide genus and species names the demonstration that he could use spores to correlate coals through the northern appalachian coal basin provided a foundation for regional stratigraphic palynology homer turner an american geologist and fuel scientist was a pioneer in the petrographic study of anthracite using a method of etching polished blocks of anthracite he developed a parallel approach to reinhardt thiessen s studies of thin sections of bituminous and lower rank coals describing well preserved botanical structures this in turn supported the view that anthracite just had a higher degree of metamorphism than bituminous coals opposed to the older view that anthracite had a different botanical origin in a joint study with the u s bureau of mines turner produced a map of equal volatile matter contours isovol across the pennsylvania anthracite fields he was also a collaborator in a study on the x ray diffraction structure of anthracite presaging better known studies by rosalind franklin and others

coastal geomorphology and restoration abstract increases in human development of the coastal zone sea level rise and intensity of coastal storms will test the resilience of coastal systems an integrated approach is needed to describe geomorphic biologic dependencies feedbacks between processes and responses and determine how coastal systems can be maintained or restored the 2013 binghamton geomorphology symposium focused on three themes in these research areas 1 the geomorphic response of coastal landforms to changes in sea level and episodic storms 2 the way these stressors alter geomorphic biotic interactions and reduce the resilience of coastal environments and 3 the way natural and human processes are being integrated to restore or maintain dynamic geomorphic and biologic linkages this issue contains eighteen papers presented at the symposium six papers are devoted to each of these themes the papers point to the importance of ecological systems in modulating the responses to natural physical processes and in turn responding to geomorphic change and the role of humans in assisting natural processes

rhythmic topography in a mesotidal low wave energy environment abstract the intertidal zone in craig bay extends 1200 m offshore making it the broadest non estuarine tidal flat on the east coast of vancouver island british columbia canada superimposed on the low gradient foreshore 1 360 are up to fourteen low amplitude 0 6 m ridges with an average wavelength of 86 3 m these are permanent fixtures of the intertidal zone exhibiting considerable stability in both form and position they are generally symmetrical in cross section and in no instance is a landward slip face evident the ridges have developed in medium to fine sand atop a coarse deltaic platform the thickness of this surficial sand unit is often equal only to the height of the ridges and the gravel sustrate is frequently exposed in the depressions the morphology sediments and hydraulic environment of this rhythmic foreshore were examined to provide insight into the factors controlling ridge development and maintenance although the maximum tidal range exceeds 5 0 m tidal currents are of limited importance only in the major runnels are velocities sufficient to initiate sediment transport waves within the strait of georgia are locally generated h1 3 3 0 m t1 3 7 0 s and appear to the the prime agent responsible for the formation and maintenance of this variant of ridge and runnel morphology the dominant bedform across the intertidal zone is the wave formed ripple although current ripples may locally predominate small scale cross stratification which is associated with these bedforms is the most common primary physical sedimentary structure in the surficial sand unit however a large proportion of the cores were structureless this is attributed to bioturbation by sand dollars dendraster excentricus and to a lesser extent to air entrapment and water escape

role of wave forcing storms and nao in outer bar dynamics on a high energy macro tidal beach abstract outer sand bar dynamics on a high energy macro tidal beach were investigated using long term multi year field datasets of intertidal morphology and offshore bathymetry utilising a 15 year time series of argus video images five distinct outer bar types were identified mega rip longshore crescentic crescentic attached and welded the most common classification was crescentic attached with the outer bar oscillations being out of phase with the inner bar oscillations as would be expected for the shore normal wave approach at this site the outer bar had a typical amplitude of 0 5 1 m and a longshore wavelength of 600 m changes in outer bar morphology were related to measured and modelled nearshore wave data however the outer bar morphology changed over a much longer timescale monthly to annual than the daily to weekly variations in wave height and period an extended duration of energetic wave action was required to bring about an upstate bar transition to the longshore or mega rip state where the bar then remained arrested for a significant amount of time requiring several months of low wave conditions to induce a down state transition through crescentic to welded this slow morphological response is explained by extended relaxation times attributed to the large tidal range at the study site where the outer bar morphology is only active for part of the tidal cycle several hours around low tide the configuration and position of the outer bar were related the more upstate downstate bar types being associated with a more offshore onshore bar position the detrended outer bar position was significantly related to a forcing term based on wave power and disequilibrium of the dimensionless fall velocity with offshore onshore bar migration occurring when wave conditions were more less energetic that the antecedent conditions the upstate end member longshore or mega rip was attained sometime during the winter months for 14 out of the 16 years of monitoring the outer bar remained attached to the low tide shoreline over the winter 2005 2006 and 2010 2011 these two winters with incomplete upstate cycles were characterised by the lowest winter wave conditions and negative winter north atlantic oscillation nao indices suggesting that the winter nao is correlated with both beach state and nearshore bar configuration

volcanic forcing of climate over the past 1500 years an improved ice core based index for climate models 1 understanding natural causes of climate change is vital to evaluate the relative impacts of human pollution and land surface modification on climate we have investigated one of the most important natural causes of climate change volcanic eruptions by using 54 ice core records from both the arctic and antarctica our recently collected suite of ice core data more than double the number of cores ever used before reduces errors inherent in reconstructions based on a single or small number of cores which enables us to obtain much higher accuracy in both detection of events and quantification of the radiative effects we extracted volcanic deposition signals from each ice core record by applying a high pass loess filter to the time series and examining peaks that exceed twice the 31 year running median absolute deviation we then studied the spatial pattern of volcanic sulfate deposition on greenland and antarctica and combined this knowledge with a new understanding of stratospheric transport of volcanic aerosols to produce a forcing data set as a function of month latitude and altitude for the past 1500 years we estimated the uncertainties associated with the choice of volcanic signal extraction criteria ice core sulfate deposition to stratospheric loading calibration factor and the season for the eruptions without a recorded month we forced an energy balance climate model with this new volcanic forcing data set together with solar and anthropogenic forcing to simulate the large scale temperature response the results agree well with instrumental observations for the past 150 years and with proxy records for the entire period through better characterization of the natural causes of climate change this new data set will lead to improved prediction of anthropogenic impacts on climate the new data set of stratospheric sulfate injections from volcanic eruptions for the past 1500 years as a function of latitude altitude and month is available for download in a format suitable for forcing general circulation models of the climate system

seabed wave resonance and sand bar growth the interaction of surface water waves with undulating sea bed topography is of fundamental importance to coastal engineersand sedimentologists for example wave reflection from submerged bars on beaches may provide a mechanism for protecting the beach from further wave attack additionally the interaction of surface water waves with other tidally or wave generated bedforms such as sandwaves on offshore banks may modify wave climates on adjacent coastlines while there have been numerous studies of the interaction of sea waves with engineering structures such as breakwaters piers and jetties there have been comparatively few investigations of wave interactions with naturally occurring bedforms predictions have recently been made of the amount of wave energy reflected as a result of resonant interactions between surface water waves and undulating sea bed topography but with no supporting experimental proof i describe here preliminary results from what are believed to be the first published laboratory measurements of resonant interactions between surface water waves and submerged bars which show that significant and large amounts of wave energy may be reflected and that these reflections are brought about by resonant interactions between surface water waves and the bedforms in particular at resonance incident surface water wavelengths are approximately twice the bedform wavelengths these results have implications not only in terms of wave reflection from naturally occurring bedforms say bars on beaches but also for sediment transport processes in general

amplitude frequency and drivers of caspian sea lake level variations during the early pleistocene and their impact on a protected wave dominated coastline the caspian sea the largest isolated lake in the world witnessed drastic lake level variations during the quaternary this restricted basin appears very sensitive to lake level variations due to important variations in regional evaporation precipitation and runoff the amplitude frequency and drivers of these lake level changes are still poorly documented and understood studying geological records of the caspian sea might be the key to better comprehend the complexity of these oscillations the hajigabul section documents sediment deposited on the northern margin of the kura basin a former embayment of the caspian sea the 2035 m thick well exposed section was previously dated by magneto biostratigraphic techniques and provides an excellent record of early pleistocene environmental lake level and climate changes within this succession the 1050 m thick apsheronian regional stage between ca 2 1 ma and 0 85 ma represents a particular time interval with 20 regressive sequences documented by sedimentary and palaeontological changes sequences are regressing from offshore to coastal lagoonal or terrestrial settings and are bounded by abrupt flooding events sediment reveals a low energy wave dominated reflective beach system wave baselines delimiting each facies association appear to be located at shallower bathymetries compared to the open ocean water depth estimations of the wave baselines allow reconstruction of a lake level curve recording oscillations of ca 40 m amplitude cyclostratigraphic analyses display lake level frequency close to 41 kyr pointing to allogenic forcing dominated by obliquity cycles and suggesting a direct or indirect link with high latitude climates and environments this study provides a detailed lake level curve for the early pleistocene caspian sea and constitutes a first step towards a better comprehension of the magnitude occurrence and forcing mechanisms of caspian sea lake level changes facies models developed in this study regarding sedimentary architectures of palaeocoastlines affected by repeated lake level fluctuations may form good analogues for other semi isolated basins worldwide

facies architecture and sequence stratigraphic features of the tumbiana formation in the pilbara craton northwestern australia implications for depositional environments of oxygenic stromatolites during the late archean abstract the tumbiana formation ca 2 7 ga is a succession developed in response to late archean crustal extension in the pilbara craton northwestern australia the formation is characterized by intercalations of stromatolitic carbonates and provides a perspective of the evolution of photosynthetic organisms which are interpreted to have been responsible for the oxygenation of earth surface environments in early earth here we investigated the depositional setting of the stromatolitic carbonates for the better understand of the environments which may have controlled the massive development of oxygenic photosynthesis we studied lithofacies and sequence stratigraphic features of the tumbiana formation in the redmont area a southern margin of the northern pilbara craton on the basis of three dimensional analyses of onshore outcrops the tumbiana formation as much as 170 m thick unconformably overlies the early to middle archean basement rocks and is unconformably overlain by the maddina formation that consists of mafic tuffaceous sediments and basalt lavas the lower part of the tumbiana formation is characterized by planar and trough cross stratified conglomerates which are interpreted to be an alluvial fan deposit shed from the northern hinterlands and developed mainly in local depressions of the basement rocks during late lowstand and early transgressive stages the base of the middle part is defined by a transgressive surface of erosion overlain by conglomerates and or breccias that pass upward to mafic tuffaceous mudstones and sandstones intercalated with accretionary lapillis breccias and basalt pillow lavas mudstones are commonly laminated and sandstones contain current and wave ripple lamination parallel lamination hummocky cross stratification and trough cross stratification in general the middle part exhibits an overall fining and coarsening upward pattern and is interpreted to indicate transgressive and regressive shelf to coastal lithofacies successions in particular the uppermost horizon of the middle part is characterized by sandstone beds with herringbone structures and desiccation cracks and is interpreted to indicate an intertidal deposit developed during late highstand and or following falling stages the middle part of the formation in general thickens to the northern proximal area and eventually flattened out the topographic irregularity of the basement rocks the upper part is characterized by stromatolitic carbonates associated with minor mudstones and wave and current rippled sandstones and does not exhibit distinct lateral variation in thickness and vertical lithofacies organization the base of the upper part is characterized by a transgressive lag deposit the ensuing transgression over the intertidal deposits of the uppermost middle part is interpreted to have developed a new accommodation space for the vertical stacking of stromatolites with different external shapes from elongated small domal and columnar types associated with desiccation cracks to stratiform and large domal types these changes may have responded to the increase in paleowater depth possibly from intertidal to subtidal environments in conclusion stromatolites in the upper tumbiana formation in the redmont area are interpreted to have developed in coastal and shallow marine environments in response to the rise in relative sea level rather than in ephemeral saline lakes as proposed by previous studies however the outcome of the present research does not necessarily deny the previously proposed interpretation but suggests spatial variations in depositional environments of the tumbiana formation from the north to south

el nino like hydroclimate responses to last millennium volcanic eruptions abstractthe hydroclimate response to volcanic eruptions depends both on volcanically induced changes to the hydrologic cycle and on teleconnections with the el nino southern oscillation enso complicating the interpretation of offsets between proxy reconstructions and model output here these effects are separated using the community earth system model last millennium ensemble cesm lme by examination of ensemble realizations with distinct posteruption enso responses hydroclimate anomalies in monsoon asia and the western united states resemble the el nino teleconnection pattern after tropical and northern eruptions even when enso neutral conditions are present this pattern results from northern hemisphere nh surface cooling which shifts the intertropical convergence zone equatorward intensifies the nh subtropical jet and suppresses the southeast asian monsoon el nino events following an eruption can then intensify the enso neutral hydroclimate signature and el nino probability is enhan

an evolutionary categorisation model for backbarrier environments abstract shorelines occurring along restricted fetch environments such as the backsides of barrier islands are extremely diverse with respect to their morphologic characteristics and evolution in order to better understand the morphodynamic evolution of backbarriers and the associated implications for entire barrier systems this study proposes a backbarrier evolutionary categorisation model based on the development of two types of index backbarrier evolution tendency and backbarrier maturation condition the proposed characterisation system is applied to the ria formosa backbarrier located in southern portugal for the period 1947 to 2001 cross shore and longshore backbarrier trends in ria formosa suggest a shrinking of the lagoon system as a consequence of a decrease in the coastal length of the backbarrier coastline and a landward displacement of it even though some of the backbarriers examined were found to be in an immature state the results obtained illustrate a maturing trend for the system overall barriers in ria formosa fall into two main evolutionary categories backbarrier reduction and backbarrier growth this means that neither smoothing nor branching has been significant and therefore that backbarrier recent evolution is closely related to barrier coast length application of the proposed characterisation to the ria formosa case study has helped reveal backbarrier evolutionary trends and therefore should be of use in the management of backbarrier systems

persistence of storm induced morphology on a modal low energy beach a case study from nw iberian peninsula abstract the morphology of low energy beaches is inherited from high energy events showing a non equilibrium state with the prevailing conditions an example of a sheltered low energy beach rodas beach nw iberian peninsula is examined in this paper the evolution of six beach profiles was analysed during three years in order to investigate the response of this beach under fair weather and storm conditions the beach presented significant morphological differences alongshore due to its geographical location with respect to the wave approach these differences determined the sediment transfer pattern longshore or cross shore sediment transport from the emerged beach towards the adjacent inner shoreface zone significant morphological changes at each profile seem to be related to the incidence of sea waves along the beach superimposed on persistent swell during winter morphological changes were recorded under high energy storms during winter whereas the recovery to prestorm conditions occurred under prevailing fair weather conditions during summer the traditional beach classification parameter relative tidal range rtr which takes into account the effect of the tide range was found unsuitable to properly classify such a mesotidal low energy beach therefore a new parameter the relative tidal range maximum rtrmax was introduced which is a modification of the commonly used rtr rtrmax uses the highest wave breaking height observed during high energy storm conditions instead of the modal wave breaking height by using this parameter the studied beach could be properly classified into the traditional beach classification models taking into account the tide range since low energy beaches generally show a morphology that is inherited from higher energy conditions than the prevailing conditions it is expected that the rtrmax will be applicable for the classification of other low energy sheltered beaches

trends in research on beaches and dunes on sandy shores 1969 2019 abstract trends in research on morphologic changes on beaches and foredunes on sandy shores are identified from the 1960s to the present research during this period evolved from early descriptive explanation and classification of profile change to instrumented field investigations to modelling of landform change at larger scales research efforts have become increasingly more collaborative with increasing use of field instrumentation data acquisition systems and remote sensing rich datasets are resulting in more comprehensive computational models human altered systems are of increasing interest but knowledge of these systems lags far behind knowledge of natural systems research is becoming more relevant to societal needs as the vulnerability of coastal populations increases the need for investigation of understudied or unexplored environments including human altered ones is ongoing many basic research issues remain but future studies would profit from the development of new models rather than validating or reconfiguring old models collaboration between geomorphologists and engineers may open up research opportunities particularly in modifying beaches and dunes built for shore protection to provide natural values in restricted space application of models to enhance knowledge of effects of sea level rise and coastal storms would be useful to managers developing resiliency plans

paleoecological interpretation of a middle pennsylvanian coal bed in the central appalachian basin u s a abstract at least 180 small spore species assignable to 62 miospore genera have been identified from the middle pennsylvanian hernshaw coal bed in southern west virginia and its stratigraphic equivalent the fire clay coal bed in eastern kentucky the established natural affinities of a majority of these miospore taxa indicate that the hernshaw fire clay peat swamp supported a diverse flora consisting of arborescent and herbaceous lycopods ferns tree like and small varities calamities and cordaites four floral groupings are recognized in the hernshaw fire clay coal bed the inferred paleoecology and vertical stratification of each of these four floral groupings is similar in structure to the phasic floral communities found in modern domed peat systems suggesting that the ancient hernshaw fire clay peat swamp was a domed deposit compositional characteristics petrographic make up ash yield and sulfur content associated with the four groupings are consistent with and support this interpretation where uninterrupted by inorganic partings the hernshaw fire clay coal bed commonly contains basal coal layers dominated by lycospora bearing arborescent lycopods with successive increments showing a progression to a more fern and herbaceous lycopod dominant flora in younger layers these observations are corroborated by petrographic analyses which show the bed to be compositionally stratified increments dominated by lycospora have high vitrinite contents in contrast to increments containing increased percentages of fern and herbaceous lycopod affiliated taxa that are enriched in inertinite macerals the volcanic ash fall preserved as the flint clay parting in the hernshaw fire clay coal bed had a considerable effect on the development of the ancient hernshaw fire clay peat swamp besides interrupting peat formation the presence of an inorganic substrate represent a major change in edaphic conditions within the swamp this disruption is demonstrated by a change in palynflora and by the establishment and proliferation of some plant groups notably cordaites and calamites that may have been better adapted to growth on mineral soils these palynologic and petrographic relationships thought to be indicative of a domed peat swamp origin are not confined to the hernshaw fire clay coal bed but appear to be characteristic of many coal beds in the appalachian basin and also of coal beds in other basins

hydroclimate responses over global monsoon regions following volcanic eruptions at different latitudes abstractunderstanding the influence of volcanic eruptions on the hydroclimate over global monsoon regions is of great scientific and social importance however the link between the latitude of vol

feedbacks between flow sediment motion and microbial growth on sand bars initiate and shape elongated stromatolite mounds abstract elongated stromatolites are often used as indicators of current direction and shoreline orientation especially in paleoenvironmental reconstructions however mechanisms that create shore parallel m scale elongated stromatolite mounds in carbonate sand are not well understood we propose that this geometry is initiated by microbial growth on the parts of sand bars that experience low wave induced bed shear stresses we test this idea by growing microbial mats on carbonate sand bars in a laboratory wave tank cyanobacterial mats grow on the bar runnels where sediment motion is negligible but are absent from the bar ridges where the waves generate migrating ripples when microbially promoted lithification reinforces and preserves this initial pattern elongated stromatolites should initiate in the runnels of sand bars with long wavelengths 5 100 m and small width to wavelength ratios 0 3 these dimensions are consistent with modern shore parallel stromatolites in hamelin pool western australia and with patterns of microbial colonization in other sandy sediments this model of elongated stromatolite mounds can inform paleoenvironmental reconstructions by clarifying and quantifying feedbacks among waves sediment transport and microbial growth

factors controlling the vegetation distribution and coal forming environments in a strike slip basin the pennsylvanian penarroya belmez espiel basin southern spain

atlantic hurricane activity following two major volcanic eruptions 1 in 1982 and 1991 two major volcanic eruptions loaded the stratosphere with long lived sulfate aerosols altering the global climate by redistributing longwave and shortwave radiation at the surface and throughout the atmosphere cooling the surface and subsurface waters of the tropical oceans theory and observations demonstrate through direct and indirect mechanisms a causal relationship between tropical north atlantic sea surface temperatures and seasonal atlantic hurricane frequency duration and intensity therefore it is plausible that hurricane activity in the seasons immediately following these eruptions is diminished however to date such a theory remains untested here i use observations reanalysis data and output from a numerical model to suggest that the number duration and intensity of hurricanes in the years following the eruptions of el chichon 1982 and mount pinatubo 1991 decreased via the aerosol direct effect determining the effects of each eruption on seasonal cyclone activity is complicated by simultaneous positive enso events thus further study of the relationship between atlantic tropical cyclones and major volcanic eruptions is warranted

morphodynamics of intertidal bars in wave dominated coastal settings a review abstract intertidal bar systems are ubiquitous features on wave dominated beaches in coastal settings with a significant 1 m tidal range depending primarily on the wave conditions and the tidal range and to a lesser extent on the nearshore gradient they can assume a variety of forms slip face bars represent the most pronounced and dynamic intertidal bar morphology and are generally found on their own around the mean high tide level they usually form low on the intertidal beach after storm induced beach erosion and develop into a berm under prolonged calm wave conditions low amplitude ridges and sand waves represent multiple bar morphologies the bars occur across the entire intertidal profile and they remain present throughout the year multiple intertidal bars tend to be rather subdued and relatively static especially sand waves and their origin remains unclear the morphological response of intertidal bars to changing wave conditions is largely forced bars build up and migrate onshore under calm waves and are flattened and may migrate offshore during storms the morphological response is however significantly affected by relaxation time effects and morphological feedback particularly on beaches with multiple intertidal bars despite their morphological differences the intertidal bar types exhibit pronounced similarities in their morphodynamics sediment transport processes and morphological response are principally controlled by the tidal water levels on the beach because these together with the offshore wave energy level and the beach morphology determine the type intensity and duration of the wave processes operating on the cross shore profile it is the dominant importance of tidal water level variations and wave processes in shallow water depths swash and surf zone bores rather than wave height variability and deeper water wave processes breaking and shoaling waves that constitutes the main difference between intertidal and subtidal bar morphodynamics

lateral variation in geochemistry petrology and palynology in the elswick coal bed pike county kentucky abstract the middle pennsylvanian langsettian westphalian a elswick coal bed correlative to the upper banner of virginia is a rare example of a mined high sulfur 2 coal in eastern kentucky a region known for low sulfur coals to characterize lateral variation in the geochemistry petrography and palynology of the elswick coal bed three sites were sampled along a southeast northwest transect within a single mine at the southeastern site the lower 101 cm of the 116 cm thick coal is dull generally dominated by durain and dull clarain while all benches at this site fit within the previously defined mixed palynoflora moderate low vitrinite group suggesting a stressed environment of deposition the palynology of the benches of the dull interval show greater diversity than might be expected just from the petrology lithology is generally similar between the sites but each site has some differences in the petrology overall the coal bed shows significant lateral variation in properties at the mine scale some of which can be attributed to the gain or loss of upper and lower lithologies either through an actual physical merging or through the change in character of lithotypes sulfur content varies between the three sites examined for this study site 3 located in the northwestern portion of the study area is characterized by a strikingly high sulfur zone 7 45 in the middle of the coal bed a feature missing at the other sites pyrite and marcasite in a mid seam lithotype at the northwestern site site 3 show signs of overgrowths indicating multiple generations of sulfide emplacement the high sulfur site 3 lithologies all have massive overgrowths of euhedral and framboidal pyrite fracture and cleat fill pyrite and sulfide emplacement in fusinite lumens sulfur is high throughout the mine area but variations are evident in the extent of secondary growth of sulfides

palynology of late middle pennsylvanian coal beds in the appalachian basin abstract fossil spores and pollen have long been recognized as valuable tools for identifying and correlating coal beds this paper describes the palynology of late middle pennsylvanian coal beds in the appalachian basin with emphasis on forms that assist both intra and interbasinal coal bed correlation stratigraphically important palynomorphs that originate in late middle pennsylvanian strata include torispora securis murospora kosankei triquitrites minutus cadiospora magna mooreisporites inusitatus and schopfites dimorphus taxa that terminate in the late middle pennsylvanian include radiizonates difformis densosporites annulatus dictyotriletes bireticulatus vestispora magna and savitrisporites nux species of lycospora cirratriradites vestispora and thymospora as well as granasporites medius triquitrites sculptilis and t securis end their respective ranges slightly higher in earliest late pennsylvanian age strata late middle pennsylvanian and earliest late pennsylvanian strata in the appalachian basin correlate with the radiizonates difformis rd mooreisporites inusitatus mi schopfites colchesterensis s dimorphus cp and lycospora granulata granasporites medius gm spore assemblage zones of the eastern interior or illinois basin in the western interior basin these strata correlate with the middle upper portion of the torispora securis laevigatosporites globosus sg and lower half of the thymospora pseudothiessenii schopfites dimorphus pd assemblage zones in western europe late middle pennsylvanian and earliest late pennsylvanian strata correlate with the middle upper portion of the torispora securis t laevigata sl and the middle part of the thymospora obscura t thiessenii ot spore assemblage zones allegheny formation coal beds also correlate with the torispora securis x and thymospora obscura xi spore assemblages which were developed for coal beds in great britain

depositional environments and sequence stratigraphy of the late carboniferous early permian coal bearing successions shandong province china sequence development in an epicontinental basin abstract this study focuses on the late carboniferous early permian coal bearing successions in shandong province north china in order to understand the depositional processes and sequence stratigraphic framework in an epicontinental basin based on detailed analysis of eleven facies five facies assemblages fas were recognized in the studied succession fa1 3 are present mainly in the benxi and taiyuan formations and consist of mixed siliciclastic and carbonate lithofacies representing eluvial lagoon barrier lagoon and tidal flat environments fa4 occurs in the shanxi formation and consists mainly of interbedded medium to fine sandstone siltstone mudstone and coal lithofacies representing river dominated deltaic environments fa5 is characterized by interbeds of trough cross stratified coarse sandstone and silty mudstone mainly in the lower shihezi formation which was deposited in meandering river channel and floodplain three third order sequences were established based on the vertical arrangement of facies assemblages and identification of physical surfaces i e subaerial unconformity transgressive surface and regressive surface each sequence comprises a transgressive systems tract tst and a highstand systems tract hst tst of sequence 1 is composed of eluvial lagoonal deposits fa1 whereas hst formed in lagoon barrier and tidal flat settings fa2 and fa3 tst of sequence 2 formed in a barrier lagoon system fa2 whereas hst is characterized by repetitive accumulation of interbedded limestone sandstone mudstone and coal deposited under lagoonal and tidal flat settings fa2 and fa3 tst of sequence 3 comprises fa2 and hst mainly fa4 deposited in a river dominated shallow water delta system sequence 3 is overlain by a fluvial sequence fa5 the three third order sequences in the shandong region are generally correlated with those in the taebaeksan basin south korea the eastern part of the north china block the relative sea level curves established in the two regions show a generally similar long term rising trend

petrology and palynology of the no 5 block coal bed northeastern kentucky abstract the upper middle pennsylvanian middle westphalian d equivalent no 5 block coal bed eastern kentucky coal field of the central appalachian basin is a low sulfur compliance coal resource dominantly comprised of dull inertinite rich lithotypes ash yields tend to be highly variable in the no 5 block as does bed thickness and frequency of bed splitting this study describes the petrographic palynologic and geochemical characteristics of the no 5 block coal bed and reports on some temporal and spatial trends among these parameters in eastern northeastern kentucky petrographically the no 5 block coal is predominated by dull often high ash lithotypes with inertinite contents commonly exceeding 30 mmf the coal thins to the north northwest where it tends to be higher in vitrinite and sulfur content representatives of large and small lycopsids and ferns both tree like and small varieties dominate the no 5 block coal bed palynoflora calamite spores and cordaite pollen also occur but are less abundant small lycopsid densosporites spp and related crassicingulate genera and tree fern e g punctatisporites minutus laevigatosporites globosus spore taxa are most abundant in dull lithotypes bright lithotypes contain higher percentages of arboreous lycopsid spores lycospora spp regionally the no 5 block coal contains abundant torispora securis a tree fern spore specially adapted for desiccation prevention this along with overall high percentages of inertinite macerals suggest that peat accumulation may have taken place in a seasonally dry paleoclimate the no 5 block coal bed thickens rather dramatically in a nw se direction as does the frequency of coal bed splitting this phenomenon appears to be related to increased accomodation space in the southeastern portion of the study area perhaps via penecontemporaneous growth faulting maceral and palynomorph variations within the bed correspond with these changes thin coal along the northwestern margin tends to be vetrinite rich and contains abundant lycospora perhaps reflecting relatively stable peat forming conditions thicker coal to the southeast contains more inertinite high ash coal layers and inorganic partings spore floras contain more small lycopsid and tree fern components and are temporally variable perhaps indicating a more unstable peat forming environment

a comparison of the post storm recovery of two sandy beaches on hong kong island southern china abstract typhoon hagupit was one of six tropical cyclones that affected hong kong in 2008 when the typhoon made landfall the combined effect of the waves storm surge and seasonal high tides resulted in a maximum sea level of 3 53 m at the nearest tide gauge to the study site the highest since 1962 the event caused considerable damage to coastal infrastructure and large scale erosion on many sandy beaches in hong kong to study the degree of erosion and recovery of hong kong beaches we surveyed two sandy beaches tai long wan tlw a relatively high energy exposed beach system and to tei wan ttw a relatively low energy sheltered beach system we examined the two beaches for changes in their beach profiles and sediment properties tlw recovered quickly with significant post storm accretion of fine to medium grained sand within four months after the typhoon tlw regained 700 m 3 sand forming a new 1 0 m high berm with the beach face prograding approximately 5 0 m seaward in contrast within the same four months after the typhoon ttw showed little evidence of sand accretion or recovery with only minor changes in the beach profile in fact instead of post storm sand accretion the landward migration of the high tide mark shown in the pre and post storm satellite images suggested that the post storm beach elevation at ttw decreased the results which reflect the different background energy regimes of each beach indicate that different coastal management strategies should be applied in the case of relatively high energy beaches of hong kong we suggest not interfering with their natural state in contrast in the case of relatively low energy beaches of hong kong which appear unlikely to recover rapidly from erosion during storms we suggest further investigation before applying any long to medium term management strategies

divergent responses of tropical cyclone genesis factors to strong volcanic eruptions at different latitudes to understand the behaviors of tropical cyclones tcs it is very important to explore how tcs respond to anthropogenic greenhouse gases and natural forcings volcanic eruptions are a major natural forcing mechanism because they inject sulphate aerosols into the stratosphere which modulate the global climate by absorbing and scattering solar radiation the number of atlantic hurricanes is thought to be reduced following strong tropical eruptions but whether the response of tcs varies with the locations of the volcanoes and the different ocean basins remains unknown here we use the community earth system model last millennium ensemble to investigate the response of the large scale environmental factors that spawn tcs to strong volcanic eruptions at different latitudes a composite analysis indicates that tropical and northern hemisphere volcanic eruptions lead to significantly unfavorable conditions for tc genesis over the whole pacific basin and the north atlantic during the 3 years post eruption relative to the preceding 3 years southern hemisphere volcanic eruptions result in obviously unfavorable conditions for tc formation over the southwestern pacific but more favorable conditions over the north atlantic the mean response over the indian ocean is generally muted and insignificant it should be noted that volcanic eruptions impact on environmental conditions through both the direct effect i e on radiative forcing and the indirect effect i e on el nino southern oscillation which is not differentiated in this study in addition the spread of the tc genesis response is considerably large for each category of eruptions over each ocean basin which is also seen in the observational proxy based records this large spread is attributed to the differences in stratospheric aerosol distributions initial states and eruption intensities and makes the short term forecast of tc activity following the next large eruption challenging

a 3000 yr paleostorm record from st catherines island georgia abstract tropical cyclones hurricanes in the northern hemisphere are amongst the most devastating of the world s natural disasters and cause billions of dollars in damage every year data on the likelihood of a coastal site being struck by a major hurricane strike can potentially aid in planning and mitigation efforts that could save money and lives however forecasting requires data that are currently insufficient for the georgia bight this study provides information to enhance the paleohurricane record by analysis of a 467 cm thick vibracore raised from st catherines island ga sediment geochemistry and foraminiferal assemblages indicate deposits attributable to seven paleohurricane events five of which were likely major hurricanes when they made landfall on st catherines magnitudes were estimated by comparison to the overwash deposit left by the sea islands hurricane of 1893 a major hurricane recorded by the recent sediment of st catherines island the st catherines record also shows a change in the activity levels on the georgia coast with two distinct activity regimes over the past 3000 years

morphodynamic characteristics and classification of beaches in england and wales abstract the use of beach classification models has become widespread in literature in recent years beach classification models that recognise distinct modal beach states in response to environmental conditions are most widely used these models were developed largely in high energy micro to meso tidal sandy environments and subsequent attention has focussed on extending their use into other beach environments here the applicability of these traditional beach classification models to the highly diverse coastline of england and wales was assessed through collection of detailed morphodynamic characteristics of 92 beaches yielding a comprehensive multi variate data set containing morphological sedimentological and hydrodynamic information the complex and diverse study region incorporates beach morphology covering the full spectrum from reflective to dissipative and non barred to multi barred cluster analysis supplemented by mds ordination resulted in the identification of 9 distinct beach types traditional morphodynamic indices and rtr were found to be effective in discriminating between beach groups providing some support for the beach state models derived using information from australian beaches it was found that absolute wave energy wave power is important as well in controlling beach type for intermediate beaches a wave energy flux p h 2 t value of 3 kw m 1 was found to differentiate between beaches with p 3 kw m 1 and without p 1 three dimensional bar rip morphology a key component controlling recreational beach hazard levels observations presented here inform a beach classification model to be used as the basis for a national beach risk assessment programme beach classification models based on environmental parameters are by necessity simplifications and should be used as tools for understanding morphodynamic systems rather than beach type prediction

effects of beach slope breaks on nearshore groundwater dynamics interactions between fresh groundwater and seawater affect significantly the nearshore pore water flow which in turn influences the fate of nutrients and contaminants in coastal aquifers prior to discharge to the marine environment field investigations and numerical simulations were carried out to examine the groundwater dynamics in the intertidal zone of a carbonate sandy aquifer on the tropical island of rarotonga cook islands the study site was featured by distinct cross shore slope breaks on the beach surface measured pore water salinities revealed different distributions under the influences of different beach profiles inland heads and tidal oscillations fresh groundwater was found to discharge around a beach slope break located in the middle area of the intertidal zone the results indicate a strong interplay between the slope break beach morphology and tidal force in controlling the nearshore groundwater flow and solute transport the fresh groundwater discharge location was largely determined by the beach morphology in combination with the tidal force the nearshore groundwater flow can be very sensitive to beach slope breaks which induce local circulation and flow instabilities as slope breaks are a common feature of beaches around the world these results have important general implications for future studies of nutrients transport and transformations in nearshore aquifers and associated fluxes via submarine groundwater discharge

beach morphodynamics in a strong wind bay a low energy environment abstract the morphodynamic behaviour of a multibarred beach in a fetch limited strong wind bay seaford beach se australia was examined during both high and low energy conditions and considered in the context of a definition of low energy provided in the literature measurements of nearshore waves currents and morphology revealed a bimodal behaviour under initial low energy conditions the beach exhibited a low tide terrace state and waves and currents were of very low magnitude during subsequent high energy conditions the beach demonstrated dynamic behaviour through the formation of a transitional transverse bar and rip rhythmic bar and beach and migration of the middle bar with the morphology remaining in an arrested high energy state during intervening low energy periods although broadly conforming to the morphodynamic model the beach did exhibit some distinct characteristics attributable to its fetch limited location limited progression through the morphodynamic model and the importance of wind direction and magnitude in governing morphodynamic behaviour furthermore rip currents were not significant in driving beach change through intermediate states the presence of infragravity energy in the storm wave spectra a dissipative multibarred surf zone dynamic inner and middle bars and the attainment of a transitional transverse bar and rip rhythmic bar and beach state during rising wave conditions underline seaford beach as bimodal exhibiting process and morphologic features of both higher and lower energy beaches as an example of a beach in a strong wind bay seaford illustrates that not all fetch limited beaches are low energy furthermore the presence of infragravity energy in a highly fetch limited environment indicates that infragravity energy may occur commonly in fetch limited environments that are subject to periodic strong winds a process that has remained largely unrecognised

morphology and composition of beach cast posidonia oceanica litter on beaches with different exposures abstract posidonia oceanica seagrass litter is commonly found along sandy shores in the mediterranean region forming structures called banquettes which are often removed in order to allow the beach to be used for tourism this paper evaluates the relationship between the morphology and composition of banquettes and beach exposure to dominant waves a real time kinematic differential global positioning system was used to evaluate the variability of banquettes and beach morphology over a period of 1 year banquette samples collected at two different levels of the beach profile i e foreshore and backshore were used to evaluate the contribution of leaves rhizomes and sediments to the total weight banquettes showed a higher volume thickness and cross shore length on exposed beaches whereas narrower litter deposits were found on the sheltered beach on exposed beaches banquettes were deposited in beach zones characterized by changes in elevation these changes in elevation were mainly due to the deposition and erosion of sediments and secondly to the deposition and or erosion of leaf litter on sheltered beaches the variability in beach morphology was low and was restricted to areas where the banquettes were located the leaf sediment ratio changed along the cross shore profile on the backshore banquette s were a mixture of sediments and leaves whereas leaves were the main component on the foreshore independently of the beach exposure the processes which control the morphodynamics in the swash zone could explain the variability of banquette composition along the cross shore profile finally this study highlighted that posidonia oceanica seagrass litter plays an important role in the geomorphology of the beachface and its removal can have a harmful impact on the beaches

the spatial and temporal variability of sand bar morphology the spatial and temporal variability of nearshore sand bar morphology is quantified using a unique data set spanning 2 years the data consist of daily time exposure images of incident wave breaking on an open coast sandy beach which may be used to infer bar morphology lippmann and holman 1989 the morphology in each image is classified into an eight state morphologic scheme in which bars are uniquely defined by four independent criteria the most frequently observed morphologies are the longshore periodic rhythmic bars observed in 68 of the data linear bars occur under highest wave conditions h s 1 78 m and are unstable mean residence time 2 days shore attached rhythmic bars are the most stable mean residence time 11 days and generally form 5 16 days following peak wave events non rhythmic three dimensional bars are very transient mean residence time 3 days eighty seven percent of transitions to lower bar types defined in text occurred one state at a time supporting our selection of the ordering of states and suggesting the suitability of a sequential morphology model transitions to higher states occurred under rising wave energy and were evenly spread among the possible higher states with more substantial changes in morphology resulting from larger wave increases this suggests that up state erosional transitions based on offshore bar migration are better described by an equilibrium model where response is better correlated with incident wave energy than with preceding morphological state time exposure images were also digitized to yield quantitative estimates of bar crest location as a function of longshore distance principal component analysis was used to decompose bar position into two dimensional linear and three dimensional longshore variable components cross shore linear bar position ranges 50 m about the 2 year mean 27 m standard deviation and dominates bar variability 74 6 three dimensional bar structure accounts for 14 of the variance 12 m standard deviation changes in incident wave height precede cross shore bar migration by less than 1 day changes in longshore variability are inversely correlated to changing wave conditions with bar morphology becoming linear rapidly during storms on time scales of less than 1 day evolution to significantly three dimensional structure typically occurs over 5 7 days following peak wave events

seascape level variation in turbulence and wave generated hydrodynamic signals experienced by plankton abstract plankton exhibit diverse and dramatic responses to fluid motions and these behaviors are likely critical for survival and fitness fluid motions can be generated by organisms or by physical processes including turbulence and surface gravity waves physical processes vary geographically in their intensity and generate hydrodynamic signals experienced by plankton as fluid forces on their sensory receptors in this synthesis we review how turbulence and waves vary in space the scales and statistics of their motions and the forces exerted on plankton we then quantify the hydrodynamic signals produced by turbulence and waves in four seascape types surf zones inlets and estuaries the continental shelf and the open ocean using published dissipation rates wind and wave data from buoys and observations from two coastal sites in massachusetts usa we relate these geographic patterns in signals to the observed behaviors of example species and to the forces sensed by typical plankters with different receptor types turbulence generated shears are largest in the surf zone inlets and estuaries while wave generated accelerations are larger offshore as a result each seascape exhibits some range of combined shears and accelerations that is distinct these signals generate forces on plankton that vary among habitats and with plankton size and swimming speed spatial patterns in fluid forces create a potential mechanism for dispersing larvae to distinguish habitats by their hydrodynamic signatures however turbulence can be strong in all seascapes and may cause widespread interference in signaling among predators and prey plankton with a single receptor type could identify nearshore habitats while those with multiple receptor types potentially could distinguish inshore vs offshore seascapes or decode signals produced by physical processes and by other organisms

mesoscale geomorphic change on low energy barrier islands in chesapeake bay u s a this paper presents an analysis of decadal mesoscale geomorphic change on sandy barrier islands in thefetch limited environment of chesapeake bay low energy barrier islands exist in two settings on the fringe of marshes and in open water and this analysis shows the various types of barrier island to be genetically related barrier islands that face the dominant wind and wave direction e or w retreat via barrier translation preserving the barrier island volume those that exist in re entrants are dominated by longshore transport processes are strongly affected by sediment supply and are subject to disintegration marsh fringe barrier islands are perched on or draped over the surface of the underlying marsh they migrate landwards via barrier translation during periodic high water events accompanied by large waves hurricanes and northeasters the underlying marsh surface erodes under all water levels and the rate of retreat of the barrier island and underlying marsh may take place at different rates leading to various configurations from perched barrier islands several metres landward of themarsh edge to barrier islands that have a sandy shoreface extending into the subtidal zone the coastal configuration during landward retreat of marsh fringe barrier islands is subject to strong local control exerted by the underyling marsh topography as erosion ofmarsh promontories occurs and marsh creeks are intersected and bypassed the configuration is subject to rapid change periodic sediment influxes cause spits to develop at re entrants in themarsh the spits are initiated as extensions of adjacentmarsh fringe barrier islands but as the sediment volumeis finite the initial drift aligned spits become sediment starved and begin to develop a series of swash aligned cells as they strive formorphodynamic equilibrium the individual cells are stretched until breaches form in the barrier islands creating inlets with tidal deltas at this stage the low energy barrier islands closely resemble open ocean barrier islands continued reworking leads towidening of the inletswith consequent loss of constriction of tidal flow the tidal deltas are thus no longermaintained and ultimately the island systemdisintegrates through inlet widening and is transformed to subtidal shoals barrier islands at various stages in this evolutionary cycle can be observed around the bay mid bay barrier islands are affected by wave processes from both sides this helps maintain the barrier island form and enables barrier islands to persist as sediment is exchanged between both sides of the island rates of barrier island translation are extremely high up to 30 m year over a 12 year period this is attributed to the lowvolume of sand which facilitates complete rollover in short periods accelerated sea level rise is likely to hasten the translation rates ofmarsh fringe barrier islands the rapid disintegration ofmost spits compared to the persistence of marsh fringe barrier islands points to a reliance on the marsh as a stabilising point if the marshes are overstepped by rising sea level as appears to be happening the complete disintegration of the barrier islands is highly likely

are coal balls rare a cyclostratigraphic analysis of coal ball occurrence in north america abstract from the perspective of phanerozoic time coal balls are rare apparently limited to a 24 m y interval 323 299 ma in the pennsylvanian and earliest permian yet within this interval coal balls occur in many coals approximately 82 transgressive regressive sedimentary cycles have been described for the midcontinent illinois and appalachian basins of north america during the mid to late pennsylvanian one third 27 82 have coal balls including 57 of major cycles 36 of intermediate cycles and 16 of minor cycles coal ball occurrence in the donets basin is similar over an interval of about 4 m y 315 311 ma latest bashkirian to mid moscovian 39 11 28 of transgressive regressive cycles have coal balls as north american paleoclimate became drier tree ferns replaced lycopsids as the dominant plant in peat swamps at the desmoinesian missourian boundary and coal ball occurrence declined overall 47 of cycles 19 40 with lycopsid or cordaitean dominance have coal balls whereas 19 8 42 of cycles with tree fern dominance have coal balls p this pattern may reflect the relative abundance of coal in the late pennsylvanian with drier paleotropical climates in the missourian virgilian leading to less paleotropical coal fewer mines and a lower probability of discovering missourian and virgilian coal balls however average cycle duration decreased from 150 kyr in the desmoinesian to 100 kyr in the missourian and virgilian and faster rates of relative sea level rise could have affected coal ball abundance particularly if coal balls formed in marine swamps with more rapid transgression leading to thinner coals or to freshwater coals directly overlain by marine sediments rygel et al 2008 suggested that missourian virgilian cycles recorded more erosional relief than desmoinesian cycles consistent with increased amplitude and rates of sea level rise during each glacial eustatic cycle changes in missourian virgilian cycles may have been augmented by stratigraphic attenuation as sediment filled the antecedent topography

coal facies studies in the eastern united states coals in the eastern united states east of the mississippi river have been the subject of a number of coal facies studies going back to the 19th century such studies would not necessarily fall within a strict modern classification of coal facies studies but if a study encompassed some aspects of paleobotany palynology petrology geochemistry or sedimentology we assumed that some data and interpretations may be of use in evaluations of the facies references are presented as a guide for further research with annotation in the tables

facies relations depositional environments and diagenesis in a major early proterozoic stromatolitic carbonate platform to basinal sequence campbellrand subgroup transvaal supergroup southern africa the campbellrand subgroup and its correlative the malmani subgroup of the transvaal supergroup represent a major 2300 2600 ma old carbonate buildup it is on average between 1500 and 1700 m thick and covers an area of approximately 190 000 km2 on the kaapvaal craton the original depository probably extended across the entire 600 000 km2 surface area of the craton and beyond the buildup consists essentially of two major lithofacies assemblages namely a basinal non stromatolitic laminated carbonate and shale sequence with minor chert iron formation and mafic tuff interbeds off the craton to the west and a shallow water stromatolitic carbonate sequence on the craton proper growth faults along the edge of the craton controlled the platform margin defined by columnar stromatolite oolite and carbonate arenite shoal deposits these are flanked basinward by reef like giant subtidal stromatolitic mounds elongated perpendicular to the platform margin and grading into slope deposits consisting of laminated carbonates with interbeds of chaotic dolomite breccia and conophyton stromatolites platform lagoonal deposits consist of dark grey laminoid fenestrate stratified stromatolites interfingering to the interior of the craton with intertidal to supratidal light grey cherty dolomite units with a variety of structures such as domal and stratified stromatolites laminoid fenestrae tepee structures and flat pebble conglomerates the buildup consisted primarily of limestone which was replaced by early diagenetic dolomite the chemical composition of the dolomite is related to depofacies platform margin and lagoonal dolomites are manganese rich basinal dolomites are iron rich and intertidal to supratidal deposits are virtually free of iron and manganeses indications are that the carbonate buildup developed from an early carbonate ramp stage into a mature rimmed carbonate shelf eventually the carbonate shelf was drowned by a major transgression followed by the deposition of the kuruman iron formation

oceanographic processes and sediment mixing on a sand flat in an enclosed sea manukau harbour new zealand abstract studies of oceanographic and sedimentary processes on intertidal sand flats in an enclosed sea were undertaken to gain a better understanding of the factors controlling the mixing and dispersal of sediment bound contaminants field investigations included a 90 day process experiment during which wind waves tidal currents tides depth of disturbance and sand flat morphology were measured and 27 months of sand flat profile monitoring sediment entrainment by strong spring tidal currents is restricted to the middle and lower regions of the sand flat which are inundated during the peak tidal flows the upper 2 3 cm of sediment is re worked across the middle and upper sand flat by mild storm wave events h s 70 cm which occurred four times during the 90 day experiment numerous ridges and runnels in the upper sand flats are wave formed features and are maintained by the lack of currents of sufficient magnitude to re work the features the ridge and runnel morphology is testimony to large infrequent storm events which re work the sediment to depths of 20 cm such storms are an important mechanism for the release of contaminants and were recorded on 3 occasions in the 27 month profile record

palynological correlation of major pennsylvanian middle and upper carboniferous chronostratigraphic boundaries in the illinois and other coal basins

wave built shelves on some low energy coasts abstract a nearshore terrace has formed in unconsolidated deposits of the low energy coast of the strait of georgia scale modelling concepts have been used to draw similarities between this small scale terrace and the continental shelf the beach grades seaward onto an upward concave shelf the outer edge of the shelf is marked by an abrupt increase in gradient on the steep offshore slope the morphology of the shelf varies systematically with the degree of exposure to wave energy the width of the shelf and depth of water over the shelf break increase with effective fetch length sediments grade seaward across the shelf with a transition from sand to mud at the shelf break calculated near bed velocities under waves recorded at six sites of differing fetch length within the strait show the shelf break has formed in a transitional zone between high and low wave effectiveness the profile form shelf sediments and nearshore dissipation of wave energy suggest that the shelf evolves as an equilibrium form in response to contemporary wave processes similar terraces have developed on sheltered lake shores and on the fiordland coast of new zealand suggesting a general model of terrace formation at effective fetch lengths up to 50 km data from the great lakes indicate that the model may be extended up to 100 km but break down at larger fetch lengths where effective fetch is probably an unreliable indicator of wave conditions similarities between the restricted fetch model and the continental terrace suggest there may be a continuum of shelf forms from small lakes through to proto continental shelves

depth of activation on a mixed sediment beach abstract the relationship between wave height and depth of sediment activation is evaluated on an estuarine beach to determine whether activation depth is less in pebbles than sand rods with washers were used to monitor three excavated beach plots filled with 1 pebbles with mean grain size of 11 5 mm 2 sand and granules and 3 sand granules and pebbles plots were monitored for 26 events over 27 days significant wave heights ranged from 0 18 to 0 40 m and activation depths from 0 02 to 0 12 m activation depths in the pebble plot were less than the other two plots when waves reworked sediment not activated during previous tidal cycles proportionality coefficients for activation depth to wave height when net change was

vegetational zonation in a swamp forest middle pennsylvanian illinois basin u s a indicates niche differentiation in a wetland plant community abstract a rich fossil flora occurs in the roof shale of the middle pennsylvanian moscovian age springfield coal flanking the galatia channel a river deposit approximately 1 km in width and 150 km long partially contemporaneous with the springfield peat swamp siltstone and sandstone 30 m thick were deposited in the channel during the final estuarine phase the river formed under seasonal subhumid climate during early deglaciation as marine waters retreated from the land surface it existed continuously through glacial maximum under increasingly humid climate as a low sediment or black water river with peat along its flanks during early deglaciation under subhumid climate and sea level rise the river became a sediment laden estuary drowning the peat swamp and burying vegetation in place under extensive mudflats this buried flora was studied in three underground mines in southern illinois permitting vegetation to be characterized spatially three transects comprising 100 sites a total linear distance of 12 km reveal distinct zonation perpendicular to the channel margin an innermost belt 0 5 to 2 5 km wide consists almost exclusively of the pteridosperm neuropteris flexuosa north of a river bend three belts succeed the n flexuosa zone mixed pteridosperms and marattialean tree ferns mixed arborescent lycopsids and marattialians lycopsids with rare marattialians south and inside the same bend n flexuosa is succeeded by mixed lycopsids particularly sigillaria and marattialean ferns within the transects marattialian ferns have wider distribution than other groups suggesting broader environmental tolerances neuropteris flexuosa channel margin mono dominance may reflect high sedimentation rates elevated nutrient conditions or floating seed dispersal lycopsid dominance in interior areas conforms with tolerance of deep standing water the spatial scale examined affects our perception of community assembly overall distinct vegetational zonation suggests niche assembly however within vegetational bands there is considerable small scale spatial variation suggesting stochastic properties

cyclic changes in pennsylvanian paleoclimate and effects on floristic dynamics in tropical pangaea abstract wetland floras narrowly define perceptions of pennsylvanian tropical ecosystems the so called coal age such wetlands reflect humid to perhumid climate leading to characterizations of pennsylvanian tropics as everwet swampy these views are biased by the high preservation potential of wetlands sedimentation patterns paleosols and fossil floras indicate the presence of vegetation tolerant of subhumid to dry subhumid perhaps semi arid climate in basins between peat formation times understanding the significance of this seasonally dry vegetation has suffered from conceptual and terminological confusion a clearer view has emerged as models for framing the data have improved basinal floras typical of seasonally dry conditions relatively low soil moisture regimes are well documented but mainly from isolated deposits some of the earliest dominated by primitive pteridosperms flozfern floras occur in clastic rocks between european early pennsylvanian coal beds later early pennsylvanian fern cordaitalean vegetation different from coal floras is preserved in marine goniatite bullions conifers are first suggested by late mississippian potoniesporites pollen about the same time in north america broadleaf foliage lesleya and megalopteris occur in basin margin settings on drought prone limestone substrates the best known xeromorphic floras found between coal beds appear in the middle through late pennsylvanian containing conifers cordaitaleans and pteridosperms the middle pennsylvanian appearances of this flora are mainly allochthonous though parautochthonous occurrences have been reported parautochthonous assemblages are mostly late pennsylvanian the conifer flora became dominant in western and central pangaean equatorial lowlands in earliest permian location of the humid perhumid wetland flora during periods of relative dryness though rarely discussed is as or more perplexing than the spatial location of seasonally dry floras through time wetland plants had few migratory options and possibly survived in small refugia within and outside of basins coupled oscillations in climate sea level and vegetation were driven most likely by glacial interglacial fluctuations perhaps controlled by orbital cyclicity

multiple longshore sand bars in the upper chesapeake bay abstract in the upper chesapeake bay maryland u s a field surveys were conducted at 18 multiple longshore sand bar sites the multiple bar systems were found in water depths less than approximately 2 m mean sea level and exhibited mild bottom slopes of 0 0052 or less the number of bars composing each system ranged from four to 17 and the spacing between the crests typically increased in the offshore direction ranging from 12 to 70 m bar height also typically increased with distance offshore and ranged from 0 03 to 0 61 m a grain size analysis of crest and trough sediment did not reveal any significant differences and the sediment was categorized as fine sand a review of the literature data indicated that the chesapeake bay multiple bars possessed similar characteristics to those found in gelding bay baltic sea similarities in fetch wave height and tidal range between the two bays may account for this finding the surf scaling parameter indicated that the multiple bar systems were extremely dissipative with regard to wave energy and wave height appeared to be an important factor in controlling bar spacing and bar height a multiple wave break point hypothesis was discussed as a possible mechanism for the formation of chesapeake bay multiple longshore bars and limited observational evidence appeared to support such a mechanism

langmuir turbulence in shallow water part 1 observations during extended deployment at an ocean observatory off the coast of new jersey a bottom mounted five beam acoustic doppler current profiler measured large scale velocity structures that we interpret as langmuir circulations filling the entire water column these circulations are the large eddy structures of wind wave driven turbulent flows that occur episodically when a shallow water column experiences prolonged strong wind forcing many observational characteristics agree with former descriptions of langmuir circulations in deep water the three dimensional velocity field reveals quasi organized structures consisting of pairs of surface intensified counter rotating vortices aligned approximately downwind maximum downward velocities are stronger than upward velocities and the downwelling region of each cell defined as a pair of vortices is narrower than the upwelling region maximum downward vertical velocity occurs at or above mid depth and scales approximately with wind speed the estimated crosswind scale of cells is roughly 3 6 times their vertical scale set under these conditions by water depth the long axis of the cells appears to lie at an angle 10 20 to the right of the wind a major difference from deep water observations is strong near bottom intensification of the downwind jets found typically centred over downwelling regions accessible observational features such as cell morphology and profiles of mean velocities turbulent velocity variances and shear stress components are compared with the results of associated large eddy simulations reported in part 2 of shallow water flows driven by surface stress and the craik leibovich vortex forcing generally used to represent generation of langmuir cells a particularly sensitive diagnostic for identification of langmuir circulations as the energy containing eddies of the turbulent flow is the depth trajectory of invariants of the turbulent stress tensor plotted in the lumley triangle corresponding to realizable turbulent flows when langmuir structures are present in the observations the lumley map is distinctly different from that of surface stress driven couette flow again in agreement with the large eddy simulations les unlike the les observed velocity fields contain two distinct and significant scales of variability documented by wavelet analysis of observational records of vertical velocity variability with periods of many minutes is that expected from langmuir cells drifting past the instrument at the slowly time varying crosswind velocity shorter period variability of the order of 1 2 min has roughly the observed periodicity of surface wave groups suggesting a connection with the wave groups themselves and or the wave breaking associated with them in high wind conditions

the geomorphology and evolution of intermittently open and closed estuaries in large embayments in victoria australia abstract intermittently open and closed estuaries ioce are common landforms on open ocean microtidal coasts they are often viewed as evolutionary end members of open estuaries where all the accommodation space has been infilled by sediment while ioce are typically recognised to form in wave dominated microtidal environments they can also form within embayments where the relative balance between waves and tides is highly spatially and temporally variable this study examines the geomorphology and infill of two such embayed ioce in victoria southern australia in order to assess how these systems compare to their open ocean counterparts in order to gain an understanding of the boundary conditions of such landforms it is found that ioce s can occur in embayments where there is sufficient energy to form a beach berm the infill of these systems broadly follows the transgressive stillstand pathways of open coast systems but the facies are modulated by the size of the catchment and open ocean wave exposure these boundary conditions also affect the evolution of the coastal plain in which the embayed ioce may form and in turn the estuary planform the entrance dynamics of these estuaries are highly variable and it appears that they may switch between permanently open or closed states in relation to modification of boundary conditions such as roughness it is inferred that the relative tidal range rtr of the marine environment at the estuary mouth is an important determination of entrance condition with the observed systems being close to the maximum rtr value on the open coast at which these landforms can exist

facies associations and controls on the evolution from a coastal bay to a lagoon system santa catarina coast brazil abstract the diverse holocene morphological features along the south coast of the state of santa catarina include lagoons and residual lakes a barrier a delta constructed by the tubarao river and pre existing incised valleys that have flooded and filled this scenario contains the sedimentary record of the transition from a bay to a lagoon system which occurred during the rise and subsequent semi stabilisation of the relative sea level during the holocene the geomorphological evolution of this area was investigated using a combination of morphology stratigraphic analysis of rotary push cores vibracores and trenches with radiocarbon dating taxonomic determination and taphonomic characterisation of holocene fossil molluscs palaeogeographic maps were constructed to illustrate how the bay evolved over the last 8000 years the relative sea level rise and local sedimentary processes were the prime forcing factors determining the depositional history and palaeogeographic changes the holocene sedimentary succession began between 8000 and 5700 cal bp with the deposits of transgressive sandsheets these deposits correspond to the initial marine flooding surface that was formed while the relative sea level rose at a higher rate than the input of sediments prior to the formation of the coastal barrier the change from a bay to a lagoon system occurred around 5700 and 2500 cal bp during the mid holocene highstand with the formation of the barrier and with the achievement of a balance between sea level rise and sedimentary supply until 2500 cal bp the presence of this barrier the following gentle decline in sea level and the initial emergence of back barrier features restricted the hydro dynamic circulation inside the bay and favoured an increase in the tubarao river delta progradation rate the final stage during the last 2500 years was marked by the increasing back barrier width with the establishment of salt marshes the arrival of the delta in the back barrier and the advance of aeolian dunes along the outer lagoon margins this study shed light on the mechanisms of coastal bay evolution in a setting existed prior to the beginning of barrier lagoon sedimentation

seagrass berm deposition on a mediterranean embayed beach abstract seagrass leaf litter is commonly found along shores all around the world the mediterranean sea is not an exception and along the sandy shore wide and thick deposits of leaf litter can be found the deposition of these structures has not yet been studied our aim is to clarify the depositional erosive process of seagrass leaf litter on a mediterranean beach a video image system consisting of a camera and a video camera was used to investigate the dynamics of the deposition of seagrass litter on beaches time exposure images proved useful in investigating the seagrass berm deposition over the monitored period by using the eof analysis while videos are used to describe every deposition and erosion cycle the deposition of seagrass berms occurred from late october to early april while during the rest of the year the beach was free of litter the first deposition occurred in october when seagrass litter was available on the submerged bay domain the seagrass berm erosion occurred after several peaks of wind speed while the deposition started when the wind speed increases and the waves start to break near to the shoreline the deposition of the leaf litter on the beach starts as a strandline at the landward edge of the wave action and proceeds seaward up to the shoreline litter residue eroded away by the waves and floating in the inner surf zone can be redeposited in little patches at the end of an erosion cycle in conclusion leaf litter may be relevant to berm formation and litter floating in the inner surf zone and in the lower swash zone is part of the materials exchanged between submerged and emerged beach

pocket beach hydrodynamics the example of four macrotidal beaches brittany france during several field experiments measurements of waves and currents as well as topographic surveys were conducted on four morphologically contrasted macrotidal beaches along the rocky iroise coastline in brittany france these datasets provide new insight on the hydrodynamics of pocket beaches which are rather poorly documented compared to wide and open beaches the results notably highlight a cross shore gradient in the magnitude of tidal currents which are relatively strong offshore of the beaches but are insignificant inshore despite the macrotidal setting the hydrodynamics of these beaches are thus totally wave driven in the intertidal zone the crucial role of wind forcing is emphasized for both moderately and highly protected beaches as this mechanism drives mean currents two to three times stronger than those due to more energetic swells when winds blow nearly parallel to the shoreline moreover the mean alongshore current appears to be essentially wind driven wind waves being superimposed on shore normal oceanic swells during storms and variations in their magnitude being coherent with those of the wind direction we also found evidence for the contribution of infragravity waves to the formation of an intertidal sand bar through prolonged duration of swash processes at the same beach level and to the development of beach cusps but not to their initiation for which the observed standing edge wave pattern may have been enhanced by the enclosed pocket beach setting the paper highlights some of the specificities of pocket beach with regards to their hydrodynamics and morphodynamics more detailed observations would be needed however prior to a more comprehensive review

compartmentalisation of beachface sediments along the southwestern coast of australia abstract identification of littoral cells is a prerequisite for the determination of sediment budgets on sandy coasts in this context the aims of the project were first to investigate the applicability of statistical techniques particularly auto correlation and cluster analysis to the definition of littoral cell boundaries second add detail to sedimentological and environmental observations previously reported for the southwestern australian coast and third provide a basis for future examination of sediment transport in a nearshore environment that is generally subject to low wave energy the alongshore component of sediment compartmentalisation has been determined for the sandy beaches of the study area and relationships between environmental parameters and beachface sediment characteristics have been established using data describing textural and compositional attributes the systematic alongshore variation in sediments was determined from the cluster analysis and auto correlation results from the grouping of sediments were then used in conjunction with geomorphic variables to determine boundaries of six sediment compartments littoral cells are better developed on the southern sector of the coast where shoreline salients and headlands are larger and act as boundaries these barriers limit but do not prevent inter compartment sediment transport the findings of this study provide a context for further investigation of littoral cell dynamics and coastal sediment transport the statistical techniques applied to data describing the alongshore distribution of sediments are readily repeatable in other contexts and have general applicability and offer a rigorous procedure for definition of coastal regions

short and medium term evolution of a coastal sector in cadiz sw spain abstract the present paper is a combined study on the medium and short term evolution of the littoral between chipiona and rota sw spain the analysis of coastal evolution over a period of 24 years i e medium term was carried out using six well temporally spaced photogrammetric flights cliff top and dune toe were used as shoreline indicators to solve problems related to the use of watermark in tidal environments short term littoral variations were monitored monthly by means of an electronic theodolite over a period of 2 years the width variations of the dry beach were surveyed by always using a constant average value for the mean sea level position derived from the numerous surveys carried out the obtained data was representative of both seasonal and annual variations over medium term most of the littoral recorded erosion while accretion has been recorded over recent years in the southern part coastal erosion was related to the impact of several storms and dune accretion was linked to the action of eastern winds over the short term time frame about the same percentage of coastal erosion and accretion was recorded most of the important accretion trends were observed at the central and southern parts of the littoral the largest amount of erosion being recorded in the southern end of the littoral in a nourished beach all the studied beaches except punta candor dunes showed more short term changes than medium term ones because of different factors essentially the great seasonal variability of the studied beaches the partial discrepancy between the medium and the short term trends was related to the applied methodology which demonstrates the problem of comparing different coastal features dunes and cliffs on one hand and beaches on the other and to the implications of 2 3 years of lasting fair weather conditions that favoured beach and dune accretion within an historical retreat tendency related to storm actions

consistent decrease in north atlantic tropical cyclone frequency following major volcanic eruptions in the last three centuries injection of sulphate aerosols into the stratosphere following major volcanic eruptions alters global climate through the absorption and scattering of solar radiation one proposed consequence is a decrease in north atlantic tropical cyclone tc activity as was observed following the el chichon 1982 and mount pinatubo 1991 eruptions we test this relationship using documentary and proxy reconstructions of major volcanic eruptions and tc frequency in the north atlantic basin over the last three centuries we find a consistent reduction in the number of tcs formed during the 3 years following major eruptions compared to the preceding 3 years including after eruptions located at northern high latitudes our findings suggest that low latitude eruptions reduce atlantic tc frequency by decreasing local sea surface temperatures whereas the mechanisms for the decrease in tc frequency following high latitude eruptions are less clear and attribution is hampered by poor identification of these events

morphological characteristics and medium term evolution of the beaches between ceuta and cabo negro morocco this work presents the results of a combined study on the beach morphology and the evolution at short and medium term of the littoral between ceuta and cabo negro morocco it is an interesting sector showing a great increase of human occupation and coastal structures the monitoring program allowed for the reconstruction of the beach morphological behavior and the seasonal changes the studied beaches presented reflective profiles recording little seasonality with the most notable morphological changes being strictly related to storms surf similarity and surf scaling parameters highlighted the existence of intermediate and reflective beach states characterized by plunging breakers aerial photographs and a satellite image have been geo referenced and elaborated with gis tools to reconstruct the short and medium term evolution of the littoral and the sediment transport pathways the littoral showed important erosion at short and medium term related to a negative sedimentary budget because of offshore transport sand accumulation was recorded close to the main ports i e marina smir and marina kabila these port structures constituted impermeable fixed limits which divided the studied area into littoral cells other free transit limits were also observed

a conifer dominated palynological assemblage from pennsylvanian late moscovian alluvial drylands in atlantic canada implications for the vegetation of tropical lowlands during glacial phases abstract new research suggests that pennsylvanian coal forests were commonly replaced by conifer dominated vegetation during seasonally dry glacial phases here we describe palynological assemblages from stacked sequences of the middle pennsylvanian late moscovian sydney mines formation of nova scotia canada which lends some support to this hypothesis one critical sample from a widespread redbed succession below the harbour coal is dominated by conifer pollen 55 together with abundant representatives of cordaitaleans other coniferopsids and rare pteridosperms ferns and lepidodendrids it differs markedly from 13 other samples obtained from coals their roof shale limestone and associated channel bodies which are dominated by lepidodendrids marattialean tree ferns cordaitaleans and or calamiteans the latter beds represent coastal wetlands and are attributed to late transgressive and highstand systems tracts whereas the conifer bearing sample represents a dryland alluvial plain and may be attributed to lowstand or earliest transgressive systems tracts three additional samples from grey shale below a sequence boundary late highstand and between a redbed succession and major coal seam early to mid transgressive deposits contain transitional palynofloras with a high proportion of herbaceous gleicheniaceous and sphenopteroid ferns herbaceous lycopsids and sphenophylls interspersed with cordaitaleans and or lepidodendrids the dominance of conifer pollen within the dryland components of well defined sequences which have been linked to relative sea level change promoted by gondwanan glaciation supports the view that pennsylvanian tropical biomes responded to the beat of glacial interglacial cycles

morphodynamic classification of sandy beaches in low energetic marine environment abstract morphodynamic classification of beaches has achieved widespread acceptance in both geological and geomorphological literature in this sense the present work classifies twelve mediterranean low energetic beaches according to the dimensionless fall parameter parameter in the island of mallorca propagation of 44 yr of wave data as well as a detailed sediment study allows to provide probabilities for morphodynamical beach state on an annual and seasonal basis consequently beaches in mallorca fall between three major categories which are a truly reflective b reflective skewed to intermediate and c intermediate beaches the mallorcan beach position in the morphodynamical scheme is close related to the physiographical and geological framework comparison of observed values with those obtained in the analysis leads that for gross beach classification there is agreement between predicted and real state however on a seasonal classification mainly during summer there is no agreement between the predicted state and the real one as the model does not incorporate the role of summer sea breezes beach reflective states are highlighted real beach configurations correspond to more energetic wave dynamic conditions and to intermediate state scenarios

variation of the summer asian westerly jet over the last millennium based on the pmip3 simulations investigation of the evolution of summer asian westerly jet awj in earth history may deepen our understanding of the behavior of awj in the present and future here the variation of summer weste

a drowned lycopsid forest above the mahoning coal conemaugh group upper pennsylvanian in eastern ohio u s a over 800 mud filled casts of upright lycopsid tree stumps have been documented immediately above the mahoning coal in an active underground mine located in northwestern jefferson county ohio the coal body originated as a pod shaped peat body of 60 km2 trees are rooted at several levels within a thin 15 40 cm bone coal directly above the banded coal they extend upward up to 15 cm into overlying flat bedded carbonaceous mudstones that coarsen up from a maximum basal diameter of 1 2 m stumps taper upward to diameters no less than 0 3 m within single entry transects 6 m wide that total 2585 m in length stumps are randomly distributed the trees are identified as lepidodenrids on the basis of gross morphology external stem patterns and attached stigmarian root systems and provisionally as lepidophloios or lepidodendron by associated palynology of the enclosing matrix palynological analyses of incremental seam samples indicate an initial dominance of lycopsid spores with lepidodendracean affinities lycospora granulata from lepidophloios hallii replaced upwards by tree fern spores with a reoccurrence of lepidodendracean spores in the upper benches spores of sigillaria crassispora are abundant only at the base of the coal petrographic analyses indicate a prallel trend from vitrinite rich to inertinite and liptinite rich upward in the coal body all data indicate that the peat represented by the mahoning coal was drowned slowly during the earliest stages of inundation a lycopsid forest was re established only to be subsequently drowned

wave ripple dynamics and the combined flow modification of wave ripples in the intertidal zone of ariake bay kyushu japan abstract intertidal sand bars occur as rhythmic features on the mesotidal foreshore in ariake bay in kyushu southern japan superimposed on the low gradient foreshore 2 1000 are seventeen low amplitude many wave ripples are constructed on the intertidal rhythmic bars by wind waves during high tide the crest line of the wave ripples is long parallel and straight to gently curved with bifurcation but often oblique to the crest of these rhythmic bars peaked crests of wave ripples on the gentle seaward slope of the bars are modified by combined flow of borelike waves and the return flow just before emergence and become rounded or flattened in contrast wave ripples on the landward slope are only slightly deformed through this process as the result the form of the wave ripples is diagnostic of the position on the rhythmic bars this difference in form is important as a criterion for discriminating the landward and seaward directions for such intertidal deposits

new insights into embayed beach rotation the importance of wave exposure and cross shore processes although embayed beach rotation has been viewed and modeled as an alongshore sediment transport process acting on a uniform beach profile recent research suggests a more complex response whereby alongshore variability in cross shore sediment fluxes may be more significant this study utilizes 5 years of fully three dimensional beach surveys at narrabeen collaroy beach se australia to quantify the control of alongshore nonuniform wave exposure and cross shore processes on embayed beach rotation empirical orthogonal function analysis of the alongshore variability in subaerial beach volume width and berm slope confirms that the dominant mode of subaerial beach variability is an onshore offshore sediment exchange that is strongly controlled r 0 8 by the alongshore gradient in breaker wave height and coincides with a uniform flattening steepening of the berm slope a secondary rotation like signal is observed in both the subaerial beach volume width data and significantly the berm slope this inverse flattening steepening of the berm slope between beach extremities is most likely a proxy for differing cross shore processes within the surf zone between the exposed and sheltered ends of the embayment particularly with regards to dissipation of storm wave energy by offshore sandbars and beach recovery following storms analysis of the corresponding wave data reveals two distinct time scales of wave forcing characteristic of short term erosion and longer term recovery processes a new conceptual model is presented of three differing modes of embayed beach rotation with the newly identified beach rotation mode controlled by offshore sandbars considered of particular importance at embayments where headland sheltering of oblique waves is pronounced

sheltered sandy beaches of southwestern australia four beach types were identified from field surveys of beach profiles on low energy sandy beaches in cockburn sound a micro tidal semi enclosed basin in southwestern australia these were delineated by an exposure factor ef which provided a surrogate for the relationship between incident wave energy and attenuation as a result of structures banks and shoals the four beach profiles identified were exponential segmented concave curvilinear and convex curvilinear in form whether the different profile shapes occurred in environments subject to different degrees of sheltering and protection under the same tidal regime was open to question beach profiles were examined for como beach and princess royal harbour in western australia and compared with observations from cockburn sound to test this proposition cockburn sound and princess royal harbour are subject to minimal penetration of swell waves whereas como beach in the swan river estuary is wholly fetch limited profile forms identified in each environment were consistent with those described from cockburn sound similar profile types had similar exposure values for all sites such that ef 2 of convex curvilinear although this approach requires further testing in low energy environments subject to different tidal ranges and fluctuations in sea level use of the exposure factor for delineation of low energy sheltered beach types appears to be a robust procedure