hypsometric control on surface and subsurface runoff 1 a fundamental problem in hydrology is relating the basin hydrological response to the geomorphologic properties of a catchment in this technical note we show that the hypsometric distribution exerts control on surface and subsurface runoff partitioning by isolating its effect with respect to other basin characteristics we conduct simulations using a distributed watershed model for hypsometric realizations developed by modifying the contour line values of a real basin results indicate that the runoff components are a function of the basin hypsometric form in general a relatively less eroded convex basin exhibits higher total runoff that is more dominated by subsurface processes while a relatively more eroded concave basin shows less total runoff with a higher fraction of surface response hypsometric differences are also observed in the relations between base flow discharge and the mean groundwater depth and the variable source area furthermore the hypsometric form reveals clear signatures on the spatial distribution of soil moisture and runoff response mechanisms

geomorphic evidence for northeastward expansion of the eastern qilian shan northeastern tibetan plateau abstract the eastern qilian shan is a tectonically active region consisting of a series of faults with bounded intermountain basins and is located within the transition zone between the mainland tibetan plateau and the alax block active deformation affecting the topography in this region can be quantified based on geomorphic indices therefore we applied the geomorphic indices hypsometry and stream power incision model to evaluate the tectonic deformation pattern of the eastern qilian shan hypsometric curves and s a plots of the selected seven rivers were determined hi values of every single sub basins were also calculated the results show that the local topographic evolution of the eastern qilian shan is in pre steady state and will soon reach its equilibrium state according to the analysis of regional climate condition e g rainfall and glaciers distribution and fault characteristics it is suggested that abundant glacial snowmelt water sustains fluvial incision and tectonic deformation from sustained northeastward expansion of the tibetan plateau is the main reason for the landscape growth combining the research of the deep electric structure beneath the gulang boundary zone we claimed that the eastern qilian shan even the northeastern tibet has been growing and expanding northeastward since the middle miocene and its leading edge now is the hexibao sidaoshan fault on the premise of synthetically considering the western and middle parts of the qilian shan it is suggested that the hexibao sidaoshan fault area will rise into a mountain in 1 2 ma

salt pans as a new archaeological sea level proxy a test case from dalmatia croatia abstract reconstruction of paleo relative sea level rsl is based on multi proxy disciplines including archaeology saltpans like fish tanks which are considered a reliable method for acquiring rsl index points are also anthropogenic intertidal facilities used continuously in the mediterranean from early antiquity the dalmatian shore contains a large number of preserved and historically dated ancient saltpans now flooded by the rising sea providing great potential for past rsl indication the primary objective of this study is to develop a new holistic approach for producing high quality elevation measurements of the saltpan structures and estimating paleo rsl during the last 2 ka the study combined aerial photogrammetry of the site bathymetry acoustics scanning and underwater archaeological survey of the man made structures as well as sampling wood and mortar in situ where available evaluation of each site s rsl and the functional height is based on the same assumptions and interpretations made for fish tanks using elevation measurements on the top of the separation walls and the bottom of the sluice gates in all the sites analyzed here we achieved reliable digital surface models with continuous high resolution data on the indicative structures with single centimeters level of accuracy the study finds that during the 5th 6th centuries rsl was 92 25 cm increased to 62 21 cm during the 7th 11th centuries and decreased to 104 20 cm in the 14th century medieval rsl can be explained either by strong tectonic subsidence post 1300 ad or by fluctuations as observed in the east mediterranean which requires validation by further medieval indicators

demise of the last two spire bearing brachiopod orders spiriferinida and athyridida at the toarcian early jurassic extinction event brachiopods were severely hit by several mass extinctions which fundamentally shaped their long evolutionary history after the devastating end permian extinction the fate of the four surviving orders differed significantly during the triassic and jurassic two orders the rhynchonellids and terebratulids are extant today whereas spiriferinids and athyridids which possess spiral brachidia suffered heavy losses at the end of the triassic and became extinct in the early jurassic toarcian event although the doom of the spire bearing orders has been thought to be related to physiological traits extinction selectivity across the end triassic and toarcian event has not been rigorously assessed previously and the reasons for their demise at the later and lesser toarcian event rather than at the earlier and greater end triassic crisis remained unexplored using primarily the paleobiology database we constructed diversity curves estimated taxonomic rates and assessed the temporal changes in geographic distribution of the two spire bearing and two other orders in the triassic jurassic interval after shared trends and similar origination rates in the post permian recovery leading to a late triassic diversity maximum the end triassic extinction was selective and preferentially eliminated the spire bearers in contrast to the rebound of rhynchonellids and terebratulids spire bearers failed to recover in the early jurassic and their repeated selective extinction at the toarcian event led to their final demise the end triassic event also terminated the worldwide geographic distribution of spire bearers confining them to the western tethys whereas the other groups were able to re establish their cosmopolitan distribution the morphologically diverse spire bearers represent specialized adaptation which further increased their extinction vulnerability compared to the other groups with conservative biconvex shell morphology another key difference is the physiological disadvantage of the fixed lophophore and passive feeding of spire bearers which became critical at times of increased environmental stress the spire bearing spiriferinids and athyridids were dead clades walking in the early jurassic and their disappearance in the early toarcian represents the last major order level extinction event for the brachiopods

new insights into the palaeoenvironmental evolution of magdala ancient harbour sea of galilee israel from ostracod assemblages geochemistry and sedimentology abstract despite several studies have focused on the past bio sedimentary response of the mediterranean coastal areas to ancient seaport activities only few geoarchaeological and palaeoecological data are available on strictly lacustrine harbours to date at the archaeological site of magdala taricheae sea of galilee north israel an interdisciplinary study combining ostracod fauna composition and shell chemistry with sedimentology geochemistry of sediments and archaeological data was undertaken on the sedimentary succession buried beneath the roman harbour structures in correspondence of two key sections this approach provided detailed information about past environmental changes otherwise not visible into a high resolution pottery based chronological framework at the transition from a natural pre harbour to anthropogenically influenced harbour lacustrine depositional setting new bio sedimentary and archaeological pottery data document that remarkable hydrodynamic and hydrochemical changes took place during the hellenistic period from the 3 rd 2 nd century bc to the first half of the 1 st century ad in response to the construction of the oldest magdala harbour installations and possibly to the following hasmonean structures the high v cr concentrations observed in the harbour sediments and the substantial increase of ostracod species pseudocandona albicans preferring slow moving waters and fine grained substrates point to the establishment of a semi enclosed shallow and organic rich setting coupled ostracod geochemical analyses also testify to an alkali ions na and k enrichment within whole sediment samples reasonably driven by increasing evaporation in response to the partial isolation of the lake margin the increase in sodium and potassium concentrations is accompanied by the sudden appearance of heterocypris salina a brackish tolerant species and by the almost absolute dominance of noded valves of cyprideis torosa whose shells are enriched in na k and cl the positive covariance between na 2 o k 2 o values and the frequencies of noded c torosa seems to confirm the relation between node development and changes in ionic concentration within hypohaline settings

coastal reconstruction of vista alegre an ancient maritime maya settlement abstract past coastal reconstruction is useful for understanding archaeological coastal settlements and predicting how coastal change might affect modern populations the ancient maritime maya inhabitants of vista alegre in the northeastern yucatan were active seafaring peoples however the past coastal landscape environmental history is unknown previous research concentrated on the fully terrestrial component of the site and did not approach the issue from an earth sciences sedimentological perspective in this study a sediment core campaign in the shallow offshore of vista alegre aimed to reconstruct the coastal and environmental changes that occurred over the past 3000 years and specifically identify the changes in sea level nine cores were analyzed using a multi proxy approach including a range of sedimentological parameters such as granulometry micropaleontology foraminifera radiocarbon dating and loss on ignition the sediment cores provided an archive of environmental changes related to sea level change anthropogenic influence and shifting microenvironments which can be associated with cultural time periods the environmental phases and shifts show some linkage to the archaeological chronology suggesting an association between the environmental conditions and human activities sea level changes and shifting shorelines have always been and still are a challenge for coastal settlements and ancient sites can be a harbinger of what to anticipate in the future in addition to this current natural and anthropogenic pressures on coastlines are placing archaeological sites at increasing risk and thereby threatening this important scientific and cultural archive therefore efforts to identify characterize and record natural and anthropogenic pressures prior to destruction are increasingly important

palaeobiogeographic patterns of the brachiopod assemblages of the iberian subplate during the late toarcian early aalenian jurassic abstract late toarcian aalenian brachiopod assemblages recorded in different basins located in and around iberia present a pattern of spatial and temporal distribution which enables two palaeobiogeographic biochoremas to be differentiated the iberian atlantic district iad which includes the lusitanian basin asturias and the basque cantabrian basin on one hand and the iberian mediterranean district imd the latter basically comprises the iberian range and the tortosa platform of the catalonian basin changes in the composition of the assemblages throughout the stratigraphical interval studied have enabled three main stages characterizing each palaeobiochorema to be recognized the first two assemblages reflect gradual individualization and isolation with frequent endemisms these two stages correspond to the iad1 iad2 imd1 and to the imd2 assemblages respectively as from the pseudoradiosa chronozone and during the aalensis and opalinum chronozones an increase in communication between the two districts can be observed as well as between these and other remote areas this stage is represented by the iad3 and the imd3 assemblages some of the brachiopods colonizing the districts are widely dispersed due to their capacity for expansion they have been found in other tethysian basins other species are exclusive to the district basins and appear to have originated in the areas close to them for the latter species the existence of two different evolutionary factories is proposed one that supplies species to the iad mainly from generic stocks as neozeilleria soaresirhynchia or praemonticlarella and another for the species reaching the basins of the imd clearly shared by other european and north african basins the atlantic evolutionary factory remains active until the aalenian and part of the early bajocian while the mediterranean is diluted since the aalenian

the effect of spatial heterogeneities on geomorphic expression in a model of basin evolution spatial variability is a basic component of all natural systems the system being studied here is the topography of an evolving drainage basin spatially heterogeneous erosivity within the drainage basin influences the structure of the drainage network the roughness of small scale features and the overall appearance of the simulated topography the presence of heterogeneities does not simply blur and smear analytical relationships the heterogeneities themselves introduce new structure to the organization of the drainage basin three measures the slope area relationship the cumulative area relationship and the hypsometric distribution are all systematically affected by spatial heterogeneity we will demonstrate how and why these relationships are affected and also how different structures in the heterogeneities themselves are manifested in the resulting simulated topography

palynological and sedimentological records of holocene human impact from the etang de berre southeastern france pollen and sedimentological analyses of holocene sediments from the etang de berre close to the rhone delta allow human impact on the holocene vegetation and hence on the landscape of the lower r

evolution of the last koninckinids athyridida koninckinidae a precursor signal of the early toarcian mass extinction event in the western tethys abstract koninckinids are a suitable group to shed light on the biotic crisis suffered by brachiopod fauna in the early jurassic koninckinid fauna recorded in the late pliensbachian early toarcian from the easternmost subbetic basin is analyzed and identified as a precursor signal for one of the most conspicuous mass extinction events of the phylum brachiopoda a multi phased interval with episodes of changing environmental conditions whose onset can be detected from the elisa mirabile subzones up to the early toarcian extinction boundary in the lowermost serpentinum zone t oae the koninckinid fauna had a previously well established migration pattern from the intra tethyan to the nw european basins but a first phase with a progressive warming episode in the pliensbachian toarcian transition triggered a koninckinid fauna exodus from the eastern central tethys toward the westernmost mediterranean margins a second stage shows an adaptive response to more adverse conditions in the westernmost tethyan margins and finally an escape and extinction phase is detected in the atlantic areas from the mid polymorphum zone onwards up to their global extinction in the lowermost serpentinum zone this migration pattern is independent of the paleogeographic bioprovinciality and is unrelated to a facies controlled pattern the anoxic suboxic environmental conditions should only be considered as a minor factor of partial control since well oxygenated habitats are noted in the intra tethyan basins and this factor is noticeable only in the second westward migratory stage with dwarf taxa and oligotypical assemblages the analysis of cold seep proxies in the subbetic deposits suggests a radiation that is independent of methane releases in the subbetic basin

in search of pollentia s southern harbour geoarchaeological evidence from the bay of alcudia mallorca spain the roman city of pollentia was founded on the north eastern coast of mallorca balearic archipelago after the roman conquest of the island in 123 bce there is evidence that the city had two harbours a small harbour located to the north whereas the main harbour was located to the south of pollentia our study focuses on the southern harbour on a coastal plain in proximity to the ancient city four sedimentary cores were taken and bio sedimentological analysis was performed here we describe the palaeogeographical changes in this area evolving from an open lagoon environment between ca 3200 and ca 500 cal years bce to a semi enclosed lagoon during roman times progressively the lagoon became silted and was isolated from the sea by the development of a large sand spit probably during the second half of the first millennium ce we also discuss the water depth linked to the palaeosea level which is important in defining the possible ancient harbour location

carbon isotope record of the early jurassic toarcian oceanic anoxic event from fossil wood and marine carbonate lusitanian basin portugal thetoarcianoceanicanoxicevent oae intheearlyjurassic 183maago wascharacterizedbywidespreadnear synchronous deposition of organic rich shales in marine settings as well as perturbations to several isotopic systems characteristically two positive carbon isotope excursions in a range of materials are separated by an abrupt negative shift carbon isotope profiles from toarcian fossil wood collected in england and denmark have previously been shown to exhibit this large drop 7 i n 13 c values interpreted as due to an injection of isotopically light co2 into the ocean atmosphere system however the global nature of this excursion has been challengedonthebasisofcarbon isotopedatafromnektonicmarinemolluscs belemnites whichexhibitheavierthanexpectedcarbonisotope values here we present new data principally from fossil wood and bulk carbonate collected at centimetre scale from a hemipelagic section at peniche coastal portugal this section is low in organic carbon average toc 0 5 and the samples should not have suffered significant diagenetic contamination by organic carbon of marine origin the carbon isotope profile based on wood shows two positive excursions separated by a large and abrupt negative excursion which parallels exactly the profile based on bulk carbonate samples from the same section albeit with approximately twice the amplitude 8 in wood versus 3 5 in carbonate these data indicate thatthe negative carbon isotope excursion affected the atmosphereand by implication the global ocean as well the difference in amplitude between terrestrial organic and marine carbonate curves can be explained by greater water availability in the terrestrial environment during the negative excursion for which there is independent evidence from marine osmiumisotope records and plausibly changes in atmospheric co2 content for which independent evidence is also available the peniche succession is also notable for the occurrence of re deposited sediments their lowest occurrence coincides with the base of the negative excursionandtheirhighestoccurrencecoincideswithitstop thus slopeinstabilityandsedimentsupplycouldhavebeenstronglylinked to the global environmental perturbation an association that may misleadingly simulate the effects of sea level fall

changes in size and growth rate of lilliput animals in the earliest triassic abstract marine invertebrate taxa that survived the late permian latest changhsingian mass extinction event are all much smaller than they were prior to the event an example of the lilliput effect new taxa that first appeared in the immediate extinction aftermath are also small compared to their size in younger strata the lilliput effect is a temporary phenomenon with most surviving taxa returning to pre extinction size in the first two conodont zones of the triassic in this study the growth rates of some of the early triassic lilliput animals estimated by growth line analysis were compared from different stratigraphic levels to determine how this variable fluctuated as body size returned to pre extinction values after the event specimens were collected from the mazzin and siusi members of the werfen formation in northern italy from facies deposited in a tropical mixed siliciclastic carbonate ramp setting measurements of the bivalves unionites and claraia the gastropod bellerophon and the brachiopod lingula were made in the field with subsequent growth line analysis conducted on well preserved specimens of lingula specimens collected from the basal triassic mazzin member were smaller than those from the younger siusi member growth line analysis indicates that the smaller mazzin member specimens had a greater number of more closely spaced growth lines than the larger siusi member specimens the small lilliput animals living in the immediate aftermath of the late permian event therefore suffered more interruptions to growth and had overall slower growth rates than larger individuals living in later recovery times frequent interruptions to growth and an overall slower growth rate in specimens from the hindeodus parvus and isarcicella isarcica zones of the mazzin member lower induan reflects suboptimal environmental conditions such as the frequency or severity of low oxygen episodes temperature extremes and or disruptions to primary productivity

a new procedure for gridding elevation and stream line data with automatic removal of spurious pits abstract a morphological approach to the interpolation of regular grid digital elevation models dems from surface specific elevation data points and selected stream lines is described the approach has given rise to a computationally efficient interpolation procedure which couples the minimization of a terrain specific roughness penalty with an automatic drainage enforcement algorithm the drainage enforcement algorithm removes spurious sinks or pits yielding dems which may be used to advantage in hydrological process studies the drainage enforcement algorithm has also been found to significantly increase the accuracy of dems interpolated from sparse but well chosen surface specific elevation data moreover it facilitates the detection of errors in elevation data that would not be detected by more conventional statistical means and forms a sound physical basis for cartographic generalization

magdala harbour sedimentation sea of galilee israel from natural to anthropogenic control recent excavations undertaken within the framework of the magdala project in the ancient city of magdala tarichaee located on the western shore of sea of galilee northern israel have unearthed a harbour structure extending for more than 100 m dating from the late hellenistic 167 63 bc to the middle roman 70 270 ad period with well preserved quays and mooring stones an integrated sedimentological micropalaeontological and archaeological study of the late holocene sedimentary succession buried beneath the ancient harbour area reveals the harbour s main evolutionary stages shedding new light on the natural versus anthropogenic control on sedimentation three sedimentary sequences a few decimeters thick reflect the recent palaeoenvironmental evolution of the magdala area these include 1 a pre harbour foundation sequence 2 a harbour sequence and 3 a harbour abandonment sequence above the natural sandy beachface deposits subject to wave reworking pre harbour facies the abrupt transition to dark silty sands with high metal concentrations reveals the onset of an anthropogenic control on coastal sedimentation through the construction of harbour structures harbour facies the overlying vertically stacked sand and gravel beach deposits post harbour facies record harbour siltation and abandonment at the transition from the middle to the late roman period 270 350 ad

a geochemical and sedimentological perspective of the life cycle of neapolis harbor naples southern italy since the discovery of the ancient harbor of naples in 2004 during construction work on an underground railway geoarchaeological studies undertaken on the archaeological excavation have revealed the main stratigraphic and paleo environmental levels of the harbor site near the piazza municipio however knowledge of the dynamics and paleoenvironmental changes in the water column of the harbor as well as the processes of transport and deposition of sediments that led to siltation and infilling of the harbor basin has been lacking due to the absence of high resolution data to fill these gaps we have undertaken a threedimensional study longitudinal transverse and vertical of the harbor deposits by carrying out geochemical and sedimentological analyses of four stratigraphic sections of the archaeological excavation the results show that after a phase of relative calm during the first half of the 1st c ad siltation of the harbor progressed exponentially up to the 5th c ad when dredging operations were carried out to obtain a water level sufficient for the development of maritime and harbor activities we attribute this acceleration of siltation to a combination of climatic anthropic and volcanic factors volcanic activity was responsible for a high energy tsunami type event during the eruption of vesuvius in 79 ad from the 5th c ad onwards the harbor basin of neapolis does not appear to have been functional as evidenced by its transformation into a lagoon following coastal progradation the last stage of infilling was the development of a flood dominated fan delta under the combined influences of climatic cooling in the early medieval cool period and agro pastoral activities in the catchment area of the harbor several generations of paleo channels containing flash flood deposits as well as sheet wash from sheet floods are indicative of high environmental instability in this period

tracking geomorphic signatures of watershed suburbanization with multitemporal lidar abstract urban development practices redistribute surface materials through filling grading and terracing causing drastic changes to the geomorphic organization of the landscape many studies document the hydrologic biologic or geomorphic consequences of urbanization using space for time comparisons of disparate urban and rural landscapes however no previous studies have documented geomorphic changes from development using multiple dates of high resolution topographic data at the watershed scale this study utilized a time series of five sequential light detection and ranging lidar derived digital elevation models dems to track watershed geomorphic changes within two watersheds throughout development 2002 2008 and across multiple spatial scales 0 01 1 km 2 development induced changes were compared against an undeveloped forested watershed during the same time period changes in elevations slopes hypsometry and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes replacing smoothly varying hillslopes and leading to greater variation in slopes examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre and post development stream maps these results suggest that topographic modification in addition to impervious surfaces contributes to altered hydrologic dynamics observed in urban systems this work highlights important considerations for the use of repeat lidar flights in analyzing watershed change through time novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future research directions for development based watershed studies

alexander the great s tombolos at tyre and alexandria eastern mediterranean tyre and alexandria s coastlines are today characterised by wave dominated tombolos peculiar sand isthmuses that link former islands to the adjacent continent paradoxically despite a long history of inquiry into spit and barrier formation understanding of the dynamics and sedimentary history of tombolos over the holocene timescale is poor at tyre and alexandria we demonstrate that these rare coastal features are the heritage of a long history of natural morphodynamic forcing and human impacts in 332 bc following a protracted seven month siege of the city alexander the great s engineers cleverly exploited a shallow sublittoral sand bank to seize the island fortress tyre s causeway served as a prototype for alexandria s heptastadium built a few months later we report stratigraphic and geomorphological data from the two sand spits proposing a chronostratigraphic model of tombolo evolution

the tiber river delta plain central italy coastal evolution and implications for the ancient ostia roman settlement geomorphologic stratigraphic faunistic palynological and carbon isotope analyses were carried out in the area of the tiber river mouth the results depict a complex palaeoenvironmental evolution

the ancient harbour parasequence anthropogenic forcing of the stratigraphic highstand record abstract unique chronostratigraphic similarities are observed in recent geoscience literature on ancient mediterranean harbours from these empirical port data a clear pattern of millennial anthropogenic forcing marked by a fining up sequence can be discerned in coastal stratigraphy the stratigraphic peculiarity of this artificial or human modified parasequence leads us to define a new working model the ancient harbour parasequence

late quaternary alluviation and soil formation in the southern argolid its history causes and archaeological implications in the context of an archaeological survey of the southern argolid greece studies have been carried out to elucidate the evolution of the landscape since its earliest known human occupation about 50 000 years ago one of these studies was a detailed geological mapping of the late quaternary alluvium and soils in the area dated by means of thorium uranium disequilibria archaeological finds and historical information seven periods of alluviation were identified each of short duration relative to long intervening periods of stability and soil formation the three earliest alluvial phases falling before and during the last glacial interval range from about 330 000 to 32 000 years in age no alluviation accompanied the last glacial maximum around 20 000 years ago in fact a stable landscape persisted until about 4500 years ago when debris flows and widespread aggradation in the valleys resulted from major slope destabilization and soil erosion probably as a result of extensive land clearance in the early bronze age a subsequent stable period lasted through the many upheavals of the later bronze age the dark ages and the early historical period it came to an end with a brief phase of alluviation between about 300 and 50 bc stability returned through the late roman period notwithstanding considerable expansion of the settled area another period of destabilization this one marked by debris flows and hence major soil erosion is poorly fixed in time but probably coincides with expanded maquis clearance accompanying the resettlement of the area around ad 1000 subsequent events of soil erosion and aggradation vary in nature and timing from one drainage to the next and in some areas continue today nature and chronology of the soil forming and alluviation events show that simple correlations with climatic events do not suffice to explain them for the latter ones past about 2500 bc human activity seems to be the dominant cause but once again the relation between cause and effect is not straightforward land clearing or neglect of soil conservation efforts during economic downturns appear to have a more devastating effect upon the landscape than do intensive land use or total land abandonment

the influence of basin morphology on groundwater outflow twenty geomorphologic parameters which constitute a well balanced representation of the area length elevation form and shape aspects of watersheds as well as the texture of their drainage networks were considered on the basis of groundwater theory and the results of previous related studies eight of these parameters were identified as being relevant to the process of groundwater discharge values of the selected parameters were obtained for representative watersheds located in a section of the appalachian plateaus the data which were generated from u s geological survey topographic maps were then subjected to a factor analysis to assess the relative importance of the parameters with respect to their influence on groundwater outflow behavior the analytical results and their interpretation showed that among the parameters that are related to groundwater outflow total length of perennial streams average basin slope and drainage density are the ones that are most closely related to the process the influences of these parameters on groundwater outflow behavior are independent of each other thus in relating groundwater outflow characteristics to basin morphology only these parameters need be considered and the inclusion of additional parameters does not necessarily yield a better relationship and may result in redundancy the findings of the study are consistent with existing concepts regarding base flow or drought flow and have been confirmed by an independent study that investigated the process based on a more mechanistic approach

rapid strand plain accretion in the northeastern nile delta in the 9th century a d and the demise of the port of pelusium an unusually large 1 km 3 and rapid influx of nile river sediment in the early 800s a d resulted in accretion of an extensive strand plain 6 to 15 m thick 35 km long and as much as 12 km wide on the subsiding northeastern nile delta margin egypt this event is related to blockage of the pelusiac branch and breaking through of a new distributary to the west of present day port said probably representing initiation of the damietta branch the sand is of analytically identical age throughout the area and was deposited within less than 60 yr as indicated by 14 c and amino acid racemization analyses of donax shells from a series of cores radiocarbon dates in combination with historical accounts by al jakubi who found the strand plain already in existence when he visited the area in the late 800s place this event in the early 800s nilometer flood records suggest that the sequence of great floods of 813 816 and 820 may have been the triggering events this sudden displacement of sand caused pelusium then the principal port and fortified city of the northeastern nile delta located at the mouth of the pelusiac branch to be cut off from both the nile and the mediterranean and led to its decline and eventual abandonment by the 12th century when the crusaders arrived

warming driven mass extinction in the early toarcian early jurassic of northern and central spain correlation with other time equivalent european sections abstract causes of the major mass extinction recorded during the early toarcian early jurassic are controversial many authors have concluded that the mass extinction is caused by the widespread oceanic anoxia derived from a postulated early toarcian oceanic anoxic event etoae supposedly synchronous in all basins and global in extent another group of papers links the mass extinction with a major climate change that occurred synchronously with the mass extinction the results of the study of five sections of the uppermost pliensbachian and lower middle toarcian deposits located in northern and central spain are presented detailed ammonite based biostratigraphy coupled with stable isotope analysis of belemnite calcite and bulk carbonates as well as total organic carbon toc analyses have been performed in all sections records of the vertical distribution of mainly benthic fossils have been compiled in four of the studied sections results obtained in the spanish outcrops have been compared and correlated with other european sections the excellent mutual relation between the patterns of the early toarcian progressive warming and the concomitant progressive losses of species evidences a cause and effect relationship between the increase of temperature and the mass extinction from an uppermost pliensbachian cooling interval warming started at the lower toarcian tenuicostatum zone increase of average seawater palaeotemperature is associated with a progressive and substantial drawdown in the number of species of nektonic planktonic and benthic organisms representing the extinction interval a prominent increase in seawater temperature occurred around the lower toarcian tenuicostatum serpentinum zonal boundary average temperatures at the serpentinum zone increased about 7 c marking the extinction boundary the high temperatures continued during the middle toarcian bifrons chronozone representing the repopulation interval the anoxia linked to the postulated etoae cannot be the responsible for the mass extinction because it has been synchronously recorded in the oxygenated environments of many european and northern african platforms deposition of laminated organic rich black shale facies above 5 wt toc indicating anoxic environments was mostly confined geographically to the western europe euxinic basin and mainly deposited after the extinction event during the interval of faunal recovery

pennsylvanian sea level cycles nutrient availability and brachiopod paleoecology abstract as with modern organisms the spatial and temporal distribution of fossil communities was controlled by both the physical setting in which the organisms lived and by the organisms physiology and interactions by studying the sedimentological and geochemical context of fossil communities it is possible to assess the relative importance of the physical setting and the organisms physiology comparison of pennsylvanian brachiopod associations with changing sedimentological context water depth facies and nutrient availability indicates that body size is a function of water depth and nutrient availability for most spire bearing athyridids and spiriferids brachiopods but rarely for productid brachiopods spire bearing brachiopods dominate the associations in high nutrient settings and productid brachiopods dominate the associations in low nutrient settings this difference suggests that physiological differences between brachiopod orders such as lophophore filtering efficiency play an important role in controlling their distribution

brachiopod miniaturization and its possible causes during the permian triassic crisis in deep water environments south china abstract brachiopod miniaturization is both the reduction in size of individuals of a species over time and where one brachiopod fauna dominated by larger individuals was replaced by a brachiopod fauna dominated by smaller individuals over time this paper investigates this phenomenon prior to and during the end permian crisis in a deep water setting in south china based on precise measurements of brachiopod body size and on the abundance and diversity of brachiopod species the process of miniaturization near the permian triassic boundary in deep water environments is characterized by 1 larger species including martinia sp costatumulus dongpanensis and anidanthus mucronata reduced in average body size and abundance over time towards the end permian brachiopod extinction event 2 small species including attenuatella mengi and spinomarginifera semicircridge showed a mixed response with either no size change or a reduction in average body size while these species increased in abundance over time indicating they were less sensitive to the stressed environmental setting 3 both the total abundance and the diversity of this brachiopod fauna decreased over time towards the end permian crisis regression an increased input of terrestrial material and productivity decline are considered to all have contributed to brachiopod miniaturization based on the biotic replacement and changes in sea water chemistry among these factors the fall in sea level is perhaps the primary factor and led to a decline in productivity and an increased input of terrestrial material into the marine setting

geomorphic controls on regional base flow the subsurface hydrological response plays an important role in the hydrology of humid regions in particular the physical relationship between base flow dynamics and the fluctuations in spatially averaged water table depth as described by the groundwater rating curve determine to a significant extent the nature of statistical persistence of hydrological anomalies in the unconfined aquifers level and river flow in this paper we propose that the scale and shape of the groundwater rating curve reflect some of the geomorphological characteristics of the region such as relief drainage density and the hypsometric distribution of the elevation field these connections between geomorphology and hydrology of river basins are investigated using a simple model of unconfined groundwater flow applied to synthetic basins as well as observed basins from illinois

revisiting the hypsometric curve as an indicator of form and process in transport limited catchment hypsometry has historically been used as an indicator of geomorphic form of catchments and landforms yet there has been little work aimed at relating hypsometry to landform process and scale this paper uses the siberia catchment evolution model to explore linkages between catchment process and hypsometry siberia generates results that are qualitatively and quantitatively similar to observed hypsometric curves for physically realistic parameters however we show that not only does the hypsometry reflect landscape runoff and erosion process but it is strongly dependent on channel network and catchment geometry we show that the width to length ratio of the catchment has a significant influence on the shape of the hypsometric curve though little on the hypsometric integral for landforms dominated by fluvial sediment transport the classic strahler mature hypsometric curve is only generated for catchments with roughly equal width and length narrow catchments show a hypsometric curve more similar to strahler s monadnock form for landscapes dominated by diffusive transport the simulated hypsometric curve is concave down everywhere this being consistent with curves reported for some example catchments in france because the transition between diffusive dominance to fluvial is scale dependent with larger catchments exhibiting greater fluvial dominance then the hypsometric curve is a scale dependent descriptor of landforms experimental results for simulated landforms from a small scale rainfall erosion simulator are reported it is shown that siberia yields satisfactory fits to the data confirming its ability to predict the form of the hypsometric curve from a simple model of geomorphic processes 1998 john wiley sons ltd

watershed morphometry and time to hydrograph peak abstract morphometric complexities often render geomorphic parameters ineffective in maintaining stable relationships over space with various aspects of hydrograph shape drainage density for example may relate either directly or indirectly with time to hydrograph peak depending upon environmental characteristics variations in climate geology and degree of geomorphic development in large measure stimulate morphometric complexities the suggestion is made in this research that the hypsometric curve an expression of overall basin slope be combined with basin area and or relief to promote transferable hydrologic models three aspects of hypsometric curve form are compared to time to peak following intense storms in small agricultural experimental watersheds in west virginia oklahoma and vermont a significant multiple regression correlation relationship is forthcoming between time to peak and hypsometric form with no direct control for basin area relief relief ratio or drainage density hypsometric skewness is related to headward drainage development mid basin slope is assessed through hypsometric density kurtosis and the rate of change in upper and lower basin slope is quantified by hypsometric density skewness while it is not suggested that hypsometry preclude the use of other important watershed parameters like drainage area it is proposed that hypsometric techniques might be employed along with basin area and or relief to increase the predictive power and transferability of rainfall runoff models

role of hypsometry and planform in basin hydrologic response the effects of variations of drainage basin morphometry and relief characteristics on flood peak magnitude and time to peak are investigated using simulated stream networks the networks are produced by three models headward growth systematic capture and minimum power relaxation translational and kinematic wave flood routing were used to generate synthetic hydrographs peak discharge and time to peak are predictable to a high degree by five different sets of morphometric relief parameters in order of decreasing order of importance in predictive ability the parameters characterize basin size relative relief basin concavity and basin shape both simulated and natural stream networks exhibit strong dependence of planimetric morphometry upon basin concavity the effect of this dependency is to increase the effect of basin concavity upon flood hydrographs

palaeogeography physiography palaeoenvironments and brachiopod communities example of the liassic brachiopods in the western tethys abstract within the western different and characteristic brachiopod communities as well as other benthic and necto benthic faunas have evolved in various palaeoenvironments resulting from the differentiation of a highly controlled submarine topography this physiography depends on palaeogeographical conditions which were induced by eustatic changes exaggerated or lessened by local tectonic movements the characteristics of brachiopod communities their location in the tectono sedimentary context the reconstruction of biotooe conditions from the study of sediments allow us to propose a pattern in which the relationships between the various characteristic brachiopod communities and the different palaeoenvironments are established these environmental settings include 1 inner carbonate platforms 2 protected carbonate ramps and mud flats 3 hinge zones between mud flats and basins 4 low energy outer platforms and gentle slopes 5 medium to high energy outer platforms 6 episodically waved and winnowed outer platforms and shoal borders 7 slopes transitional to basin 8 umbilicus and narrow troughs 9 epioceanic basins then according to this model the recognition and the distribution through time and space of these different brachiopod communities makes it possible to reconstruct the palaeogeographical evolution and to give a more accurate of the tectonic framework buried antithetic faults when the palaeogeographical evolution is mainly due to tilted blocks tectonic example of the portuguese lias

body size changes of latest permian brachiopods in varied palaeogeographic settings in south china and implications for controls on animal miniaturization in a highly stressed marine ecosystem abstract research on the dynamics of body size changes in varied water depths can provide important insights into the evolution of palaeoenvironments through time this paper attempts to investigate how the body sizes of two most commonly found chonetid brachiopod species in the uppermost permian in south china varied with palaeo bathymetry the result shows that there is a broadly negative correlation between the latest permian brachiopod body size and water depth there is no simple singular variable that could explain this correlation because bathymetry is correlated either linearly or nonlinearly to food availability redox condition and habitat temperature as well as substrate conditions overall we found that both oxygen and food availability played a more important role in controlling the differences of body sizes and specifically several depressed factors low food availability anoxia or abnormal temperature have compounded and caused small body sizes in deeper waters during the latest permian we propose that the brachiopod miniaturization during the permian triassic crisis in south china was collectively driven by anoxia food restriction and high temperature

geoarchaeological evidence for dredging in tyre s ancient harbour levant abstract chrono stratigraphic data from tyre s ancient northern harbour delineate extensive dredging practices during the greco roman and byzantine periods radiocarbon dates from four cores consistently cluster between ca 500 b c and 1000 a d and indicate rapid rates of sedimentation in the basin namely 10 mm yr during the greco roman and byzantine periods compared to 0 5 1 mm yr for the period 6000 4000 b c absence of strata between 4000 b c and 500 b c is not consistent with a natural base level sediment sink and cannot be interpreted as a depositional hiatus in the high stand systems tract ancient dredging is further corroborated by persistent age depth inversions within the fine grained harbour facies these data support removal of middle bronze age to persian period sediment strata with deliberate overdeepening of the harbour bottom by greco roman and byzantine societies

changes of relative sea level during the past 5000 years in the ancient harbor of marseilles southern france in the ancient harbor of marseilles marine fauna fixed upon archaeological structures as well as bio sedimentary units document a 1 5 m steady rise in relative sea level during the past 5000 years followed by a near stable level at present datum from about 1500 years ad to the last century this trend is similar to the one previously documented along the rocky coasts of the same region field observations inside and outside the harbor confirm that no sea level stand higher than the present ever occurred during the studied period in contradiction with the numerical model of peltier but in agreement with the glacio hydro isostatic models of lambeck and johnston and lambeck and bard q 2001 elsevier science b v all rights reserved

the sensitivity of catchment hypsometry and hypsometric properties to dem resolution and polynomial order abstract derivation of the hypsometric curve of a catchment and properties relating to that curve requires both use of topographical data commonly in the form of a digital elevation model dem and the estimation of a functional representation of that curve an early investigation into catchment hypsometry concluded 3rd order polynomials sufficiently describe the hypsometric curve without the consideration of higher order polynomials or the sensitivity of hypsometric properties relating to the curve another study concluded the hypsometric integral hi is robust against changes in dem resolution a conclusion drawn from a very limited sample size conclusions from these earlier studies have resulted in the adoption of methods deemed to be sufficient in subsequent studies in addition to assumptions that the robustness of the hi extends to other hypsometric properties this study investigates and demonstrates the sensitivity of hypsometric properties to dem resolution dem type and polynomial order through assessing differences in hypsometric properties derived from 417 catchments and sub catchments within south australia the sensitivity of hypsometric properties across dem types and polynomial orders is found to be significant which suggests careful consideration of the methods chosen to derive catchment hypsometric information is required

geoarchaeology of tyre s ancient northern harbour phoenicia tyre s ancient northern harbour has been a source of scientific intrigue and debate for many centuries today an insignificant fishing harbour looking north and sheltered from the dominant winds by a sandstone reef system is all that remains of the famous bronze age phoenician hellenistic roman and byzantine anchorage havens in light of this many scholars have long questioned whether the modern port corresponds to its counterpart in antiquity here we provide litho and biostratigraphical evidence for an ancient harbour approximately twice as large as the present comprising the modern day harbour and city centre four distinct sedimentary units have been identified translating the different holocene palaeoenvironments 1 the holocene transgressive contact is dated ca 7800 bp and lies at the base of a silty clay lithodependant unit our proxies are consistent with a low energy lagoonal type environment protected by an extensive reef system 2 transition to a coarse sand fraction after ca 5500 bp is concomitant with the accretion of a semi protected pocket beach this environment served as a proto harbour during the middle bronze age mba 3 after the mba artificial harbour sedimentation is represented by a fine grained silty sand unit with stress on the natural biosystem this unit attests to a closed marine lagoonal type environment which existed until around 1500 bp dredging activity during the roman and byzantine periods explains the absence of 1st millennium bc strata 4 the economic decline of the ancient city after the byzantine period is marked by the opening of the basin to greater marine influence with a progradation of the harbour coastline natural sediment infilling diminished the size of the harbour to its present dimensions lost until now beneath the medieval and modern centres

patterns of brachiopod faunal and body size changes across the permian triassic boundary evidence from the daoduishan section in meishan area south china abstract new analysis of permian triassic brachiopod assemblages and body size changes in south china provides insights into the process of the environmental crisis in the lead up to the end permian mass extinction the recently discovered daoduishan section of south china can be considered as an important auxiliary section for the study of brachiopods at the meishan section d of south china the gssp of the permian triassic boundary ptb this paper studied changes of the brachiopod assemblages and body sizes through the upper part of the changxing formation and basal yinkeng formation of daoduishan the results show that significant changes of brachiopod assemblages took place between beds 24e and 26 brachiopods prelissorhynchia sp and paracruirithyris pygmaea are the dominators in beds 14 24e while tethyochonetes pigmaea and paryphella spp are the dominators in beds 26 29 body sizes of brachiopods significantly decreased between beds 24e and 26 and then maintained smaller means in beds 27 29 studies of brachiopod morphological features indicate both tethyochonetes and paryphella had advantageous adaptations enabling them to copy with living in an anoxic dysoxic and or low productivity environment during the permian triassic crisis

geoscience of ancient mediterranean harbours abstract although much has been written on the subject of ancient mediterranean harbours the relatively new area of harbour geoarchaeology remains dispersed in the geoscience and archaeological literature over a decade of research has amassed rich and varied datasets of anthropogenically forced coastal evolution with a remarkable number of between site analogies this new research field also shows the rich potential of geoscience to reconcile important archaeological questions no single publication however has yet drawn on these geological patterns to yield a detailed overview suitable for geoscientists and environmental archaeologists the aim of this review article is to 1 discuss how ancient harbours have come to be preserved in the geological record 2 expound the basic principles and palaeoenvironmental tools underpinning ancient harbour geoarchaeology 3 outline some of the most significant research advances made and 4 discuss a new chrono stratigraphic model applicable to harbour sequences

the contribution of geochemistry to ancient harbor geoarcheology the example of ostia antica abstract once trapped in ancient harbor basins sediments form environmental archives that have been widely studied by geoarcheologists in recent decades especially to help reconstruct fluvio marine landscapes of the last millennia in some cases classic environmental markers cannot be used for this purpose either because of their scarcity in the sedimentary deposits or because analytical costs limit the resolution that can be achieved in order to remedy these shortcomings and to complement the more commonly used proxies elemental and isotopic geochemistry has been added to the geoarcheological toolkit here we show how to read the evolution of the paleo environmental dynamics in the water column of ostia antica rome s first maritime harbor using the geochemical and isotopic record of a 3000 year old sediment core drilled in the ancient harbor basin a comparison of the results obtained from ostia antica with those of other ancient mediterranean harbors reveals the nature of the main environmental processes operating during the formation of sedimentary deposits in harbor basins from this comparative approach it appears that the respective weight of each control factor is dependent on the coastal geomorphological context of the sites where the harbors were established since the discovery of the harbor of ostia antica in 2014 this method has provided the means for the first time to identify two distinct harbor basin regimes an initial marine dominated regime from the middle of the 4th c bc to the 3rd c bc and a later freshwater dominated regime up to the 2nd c bc more generally we observe the effects of the dynamics of the deltaic progradation of the tiber which very early on was subject to a hydro climatic component on the processes of alluviation of the harbor basin additionally and also for the first time in harbor geoarcheology pb isotope compositions measured specifically on uncontaminated sediments demonstrate their utility for both identifying the geological sources of the sediments of the tiber delta and discriminating finer from larger particles the present study further provides an opportunity to test the validity of two hypotheses recently put forward 1 that a series of three tsunamis is recorded in the harbor silts and 2 that an initial lagoon type harbor was constructed at ostia antica which later evolved into a fluvial harbor neither of these hypotheses are supported by the present data

nearshore offshore basin species diversity and body size variation patterns in late permian changhsingian brachiopods abstract body size is a fundamental and defining character of an organism and its variation in space and time is generally considered to be a function of its biology and interactions with its living environment a great deal of body size related ecological and evolutionary research has been undertaken mostly in relation to extant animals among the many body size related hypotheses proposed and tested the size bathymetry relationship is probably the least studied in this study we compiled a global body size dataset of changhsingian late permian ca 254 ma 252 ma brachiopod species from low latitude areas 30 s 30 n and analyzed their species diversity and body size distribution patterns in relation to the nearshore offshore basin bathymetric gradient the dataset contained 1768 brachiopod specimens in 435 species referred to 159 genera and 9 orders from 135 occurrences localities of 18 different palaeogeographic regions treating the whole of the changhsingian stage as a single time slice we divided the nearshore offshore basin bathymetric gradient into three broad depth related environments nearshore offshore and basinal environments and compared how the species diversity and body size varied along this large scale bathymetric gradient here we report an array of complex patterns first we found a clear overall inverse correlation between species diversity and water depth along the nearshore offshore basin gradient with most species concentrating in the nearshore environment second when the median sizes of all low latitude brachiopod species from the three environments were compared we found that there was no significant size difference between the nearshore and offshore environments suggesting that neither the wave base nor the hydrostatic pressure exerts a critical influence on the body size of brachiopods on the other hand the median sizes of brachiopods from the nearshore environment and to a lesser extent the offshore environment were found to be significantly larger than that of basinal brachiopods this trend of significant size reduction in basinal brachiopods mirrors the relative low species diversity in the basinal environment and neither can be easily explained by the tendency of decreasing food availability towards deeper sea environments rather both trends are consistent with the hypothesis of an expanding oxygen minimum zone omz in the bathyal slope to deepsea environments where hypoxic to anoxic conditions are considered to have severely restricted the diversification of benthos and favored the relative proliferation of small sized brachiopods finally a significant difference was also found between eurybathic and stenobathic species in their body size response to the nearshore offshore basin gradient in that eurybathic species species found in all three environments did not tend to change their body size significantly according to depth whereas stenobathic forms species restricted to a single environment exhibit a decline in body size towards the basinal environment this pattern is interpreted to suggest that bathymetrically more tolerant species are less sensitive to depth control with respect to their body size change dynamics in contrast to stenobathic species which tend to grow larger in shallower water depths

structural control on drainage network and catchment area geomorphology in the dead sea area an evaluation using remote sensing and geographic information systems in the wadi zerka ma in catchment area jordan the geology of jordan is characterized by fault systems with three major trends 1 nw se the oldest 2 wnw ese and 3 nnw sse the youngest the drainage network of the wadi zerka ma in catchment area located in the middle of the dead sea rift parallels these structural orientations a regional transtensive fault with embedded normal faults bounds the lower and middle part of the catchment area the topographic profile of the zerka ma in river exhibits two major knickpoints where it crosses two major embedded normal faults the second major knickpoint developed as a result of the dramatic lowering of the lisan lake water level a lake that pre dates the dead sea the decreased water level triggered river incision into the clastic sandstone units of wadi zerka ma in we performed a morphotectonic analysis study to investigate how the rock structures control the drainage network and the catchment area geomorphology according to the transverse topographic symmetry factor t the catchment area is highly asymmetric the major basin asymmetry trend is se oriented parallel to the oldest set of fault systems the catchment area displays a convex hypsometric curve indicating a very recent stage in the geomorphologic cycle our study indicates that the lisan lake catchment area shrinkage and structures growth controlled and shaped the wadi zerka ma in catchment area geomorphology the combined use of a geographic information system gis and remote sensing was shown to be very efficient in unraveling the evolution of the drainage network and catchment area geomorphology

depositional architecture and transgressive regressive cycles within liassic backstepping carbonate ramps in the basque cantabrian basin northern spain an integrated stratigraphical sedimentological geochemical and sequential analysis has been carried out on the liassic rocks of the basque cantabrian basin in northern spain using outcrop and subsurface data the study documents the progressive drowning and backstepping of an epeiric carbonate ramp that originated during the worldwide late triassic early jurassic transgression two major carbonate depositional systems have been recognized within the drowning succession 1 a late triassic early sinemurian shallow marine ramp which reflects a progressive marine transgression over triassic continental deposits 2 a late sinemurian toarcian set of hemipelagic ramps which recorded the progressive drowning and backstepping of the ramp system during a second major event of marine flooding sequence stratigraphic analysis of the liassic succession has revealed that transgressive regressive trends constitute the most evident cyclicity a major transgressive regressive cycle and six subsidiary transgressive regressive facies cycles have been defined in the basin and compared with those defined in other european basins although a good correlation exists for the major transgressive regressive cycle significant discrepancies have been found for the number limits and extent of the transgressive regressive facies cycles reflecting the effects of local tectonics the overall backstepping within the basque cantabrian basin resulted in a dominance of transgressive episodes across a range of different scales accordingly regressive intervals are less well developed except during limited periods of active tectonics as occurred in the mid sinemurian these progressively longer and deeper marine flooding intervals followed by relative stillstand or minor sea level falls are interpreted to reflect high thermal subsidence rates coupled with a liassic eustatic transgression

geoarchaeology of beirut s ancient harbour phoenicia abstract this paper presents geoarchaeological results from the ancient harbour of beirut lebanon as at sidon knowledge of beirut s ancient tell has advanced significantly over the past decade thanks namely to redevelopment of the city centre and excavations centred on the modern port in spite of this research understanding of the city s coastal palaeoenvironments during antiquity is poor buried iron age harbourworks presently 300 m from the sea attest to pronounced coastal changes during the past 3000 years these processes have been significantly accentuated during the last two centuries by redevelopment of the port which remains in use some 5000 years after its foundation here we elucidate the coastal stratigraphy east and west of the bronze age tell to yield new insights into the evolution of the beirut seaboard in addition to the complex history of human environment interactions these chronostratigraphic data are subsequently used to 1 precisely locate the main anchorage haven during antiquity and 2 propose a chronology for its evolution

biological evidence of sea level rise during the last 4500 years on the rocky coasts of continental southwestern france and corsica on the rocky coasts of the northwestern mediterranean basin biogenic littoral rims built by the coralline rhodophyte lithophyllum lichenoides develop whose remains may be preserved for millennia when submerged in a rising sea environment these remains can be used as biological indicators of recent sea level variations our survey of the continental coasts of var and bouches du rhone west of marseilles southern france and of northern corsica shows that relative sea level rose about 1 6 m in the study area during the last 4500 years without exceeding the present datum the rate of sea level rise was 0 4 mm per year between 4500 and 1500 yr b p and slowed down to 0 2 mm per year from 1500 yr b p to present time there are also morphological indications of an acceleration of the rate of sea level rise during the last century supporting the evidence of tide gauges regions at the periphery of the above zone alpes maritimes italian border zone and the french and spanish catalonia regions were also surveyed but a weaker development of lithophyllum rims and bad preservation of algal remains led to unconvincing dates which could also be linked to regional tectonic trends

linking western tethyan rhynchonellide morphogroups to the key post palaeozoic extinction and turnover events abstract genetic control undoubtedly plays the most decisive role in the development of characters in rhynchonellides especially in those structural features such as shell microstructure and brachidial architecture however considering the relationship between shell microstructure and type of crura in post palaeozoic rhynchonellides supported by recent growing research the present study links this striking matching to the distribution of rhynchonellide morphogroups around the main post palaeozoic mass extinction and diversification events innovatively introducing the ribbing pattern as a feature widely argued as indicator of deeper shallower habitats and particular ecological conditions the analyses performed on the western tethys rhynchonellide database and directly on 28 species from the peri iberian margins around selected post palaeozoic extinction diversification episodes reveal a recurrent distribution pattern according to the habitat considered epicontinental vs epioceanic the smooth eurinoid septifal arcual body plan is the distinctive inhabitant of deeper epioceanic environments also being the last to withdraw from the epicontinental platforms when the environmental conditions were adverse and the pioneers or opportunistic taxa conducting repopulation of these epicontinental habitats when the conditions were re established after crises the ribbed eurinoid falciform morphogroup seems to be the more resilient stock on epicontinental platforms in relation to ecological crises conversely the ribbed leptinoid raducal group is typical inhabitant of epicontinental seas when normal conditions prevail and shows an uneven distribution unlinked to critical events suggesting a more specialist pattern with a diversification related with a secondary differentiation it is suggested that this distribution dynamic of morphogroups was controlled by the availability of requirements to generate each type of crura and microstructure in epicontinental epioceanic habitats such as metabolic or oxygen restrictions or the filter feeding efficiency of the lophophore a research line starting point is thus herein introduced which can lead to shed light into the adaptive strategies of rhynchonellides relating particular morphotypes with potential triggering factors of mass extinction events

geoarchaeology of sidon s ancient harbours phoenicia abstract geoarchaeological data from sidon s ancient harbour areas elucidate six evolutionary phases since the bronze age 1 at the time of sidon s foundation during the third millennium bc medium sand facies show the city s northern and southern pocket beaches to have served as proto harbours for middle to late bronze age societies 2 towards the end of the late bronze age and the early iron age expanding international trade prompted coastal populations into modifying these natural anchorages in sidon s northern harbour transition from shelly to fine grained sands is the earliest granulometric manifestation of human coastal modification the lee of zire island was also exploited as a deep water anchorage or outer harbour at this time 3 although localised sediments evoke developed port infrastructure during the phoenician and persian periods high resolution reconstruction of the northern harbour s iron age history is problematic given repeated dredging practices during the roman and byzantine periods 4 fine grained silts and sands in the northern harbour are coeval with advanced roman engineering works significantly deforming the coastal landscape bio and lithostratigraphical data attest a leaky lagoon type environment indicative of a well protected port 5 the technological apogee of sidon s northern harbour is recorded during the late roman and byzantine periods translated stratigraphically by a plastic clays unit and brackish lagoon fauna 6 a final semi abandonment phase comprising coarse sand facies concurs silting up and a 100 150 m progradation of the port coastline after the seventh century ad we advance three hypotheses to explain these stratigraphic data namely cultural tectonic and tsunamogenic finally our results are compared and contrasted with research undertaken in sidon s sister harbour tyre

holocene coastal change in the ancient harbor of yenikapi istanbul and its impact on cultural history an extensive rescue excavation has been conducted in the ancient harbor of istanbul yenikapi by the sea of marmara revealing a depositional sequence displaying clear evidence of transgression and coastal progradation during the holocene the basal layer of this sequence lies at 6 m below the present sea level and contains remains of a neolithic settlement known to have been present in the area indicating that the sea level at 8 9 cal ka bp was lower than 6 m below present sea level advanced to its maximum at 6 8 7 cal ka bp drowning lykos stream and forming an inlet at its mouth after 3 cal ka bp coastal progradation became evident subsequent construction of the byzantine harbor theodosius 4th century ad created a restricted small basin and accumulation of fine grained sediments the sedimentation rate was increased due to coastal progradation and anthropogenic factors during the deposition of coarse grained sediments at the upper parts of the sequence 7th 9th centuries ad the harbor was probably abandoned after the 11th century ad by filling up with lykos stream detritus and continued seaward migration of the coastline

adaptive strategies and environmental significance of lingulid brachiopods across the late permian extinction abstract linguliform brachiopods are traditionally considered a conservative group which seems to pass through the late permian extinction without any significant loss and even appear to thrive immediately after the extinction peak in the southern alps lingulids are very common in the post extinction mazzin member early induan of the werfen formation sparse occurrences are also known in the overlying siusi and gastropod oolite members late induan and early olenekian in age respectively the recent discovery of well preserved specimens from a pre extinction bed of the bellerophon formation changhsingian has permitted a detailed comparative analysis mostly based on the interior characters preserved in the lingulid succession from across the extinction beds the following effects on the lingulid populations have been analyzed i change in taxonomic assessment ii adaptive strategies during the surviving and recovery phases and iii environmental proxy connected with the killing mechanisms of the late permian extinction the pre extinction individuals belong to lingularia cf smirnovae biernat and emig a species that is characterized by large sized shells with a short lophophoral cavity the post extinction populations belong to different species and probably even to a different genus the first post extinction population early induan with small sized shells and long lophophoral cavity has been referred to lingularia yini peng and shi it records the most severe effects of the late permian extinction on the marine ecosystems the late induan olenekian lingularia borealis bittner with large sized shells and long lophophoral cavity appears during the first phase of the triassic biotic recovery the main adaptive strategies of lingularia yini in comparison with the permian species include i shell miniaturization ii increasing of the lophophoral cavity surface respiratory surface and iii increasing of shell width length ratio these modifications are interpreted as adaptations towards warming and hypoxia two main killing mechanisms of the marine biota the recovery species lingularia borealis maintains a large lophophoral cavity indicating an adaptation towards predominant low oxygenated bottom marine waters the appearance and the great abundance of lingularia yini in the mazzin member early induan represent a proxy of dysaerobic conditions which determined the appearance of the second phase of the lilliput biota characterized by the definitive disappearance of the rhynchonelliform brachiopods and calcareous algae in the southern alps

population response during an oceanic anoxic event the case of posidonotis bivalvia from the lower jurassic of the neuquen basin argentina abstract benthonic marine species show a wide range of biological reactions to seawater chemical changes through time from subtle adjustments to extinction the early toarcian oceanic anoxic event t oae was recently recognized in the neuquen basin argentina confirming its global scope the event was identified chemostratigraphically on the basis of a relative increase in marine organic carbon and a characteristic negative carbon isotope excursion 13corg in bulk rock and fossil wood in the upper pliensbachian lower toarcian interval in the arroyo lapa section neuquen simultaneously with collection of lithological samples a high resolution biostratigraphical survey was carried out and the scarce benthonic fauna was collected in order to check the biotic response to changing marine geochemical conditions we present here an analysis of size and abundance data from the t oae interval in the neuquen basin for the dominant bivalve species the paper clam posidonotis cancellata leanza and relate these data to geochemical proxies toc and 13corg obtained at the same locality the abundance of p cancellata increased when the rest of the benthos diminished reaching a maximum at the onset level of the t oae and then decreasing size frequency distributions show a noteworthy lack of juvenile shells shell size shows a positive correlation with toc in the whole section though over the t oae interval proper it decreases below the level where the maximum toc value is attained and increases above it posidonotis cancellata shows features of opportunistic species such as high tolerance to hypoxia strong dominance in impoverished environments and a strong dependence on primary productivity but at the same time had a reproductive strategy more similar to equilibrium species with relatively low juvenile mortality rates several anatomical features suggest adaptation to permanently dysaerobic environments the species disappeared just before the minimum negative carbon isotope value was reached and by the same time the genus became extinct worldwide

history and influence of the danube delta lobes on the evolution of the ancient harbour of orgame dobrogea romania on the coast of northern dobrogea south of the danube delta the greek settlement of orgame was founded in the mid 7th c bc probably by milesian colonists the ancient city was located on the cape dolojman which today overlooks a large lagoon complex we undertook a chronostratigraphic study to i understand coastal changes around cape dolojman since ca 5000 years bp in connection with the construction of the danube delta lobes and ii identify potential sediment impacts related to human occupation of the site three cores were extracted from the lagoon area sedimentological and biological analyses were undertaken to reconstruct the evolution of the coastal palaeoenvironments the results show a closure of the marine bay around 3500 cal bp and its transformation into a lagoon environment the first major environmental change was due to the construction of the lobe st george i and the formation of the barrier lupilor around 2000 cal bp the formation of an intra lagoonal lobe the dunavatz led to the gradual transformation of the lagoon into a fluvial dominated system paradoxically lagoon waters today still wash the ancient greek harbour environment which has not been totally infilled by alluvial sediments to understand this paradox in a context of coastal progradation we compared and contrasted the geomorphological data with the nearby city of istros histria which was already landlocked at this time the location of these two greek colonies relative to the coastal sediment cell and barriers partly explains their contrasting palaeoenvironmental evolution until 2650 cal bp the increase in charcoal and organic matter in sedimentary archives is interpreted as an anthropogenic signal for a more extensive use of the vegetation cover following the foundation of the city of orgame e g for domestic use and funeral rites

the lilliput effect in the aftermath of the end permian extinction event early triassic animal body fossils and trace fossils are small relative to those in older and younger intervals size decreases sharply through the end permian extinction event and permian triassic boundary and the smallest sizes are encountered in the parvus and isarcica zones of the earliest induan animals appearing within these two zones are also exceedingly small compared to younger congenerics and conspecifics temporary dramatic size decrease of surviving taxa in the immediate aftermath of the extinction event is an example of the lilliput effect coined by urbanek a 1993 biotic crises in the history of upper silurian graptoloids a palaeobiological model historical biology 7 29 50 body size increases somewhat from the carinata zone mid induan but remains depressed for the duration of the early triassic and pre extinction sizes are not commonly recorded until at least the middle triassic marine and terrestrial faunas appear to be similarly affected the lilliput effect and longer term size reduction could be the result of several factors environmental parameters such as marine anoxia due to low atmospheric concentrations of oxygen at this time coupled with sluggish ocean circulation in a greenhouse world and food shortage are the likely proximal causes for the early triassic lilliput effect no single cause can explain all the observations and a combination of factors are likely to be involved

changes in brachiopod body size prior to the early toarcian jurassic mass extinction abstract herein we analyze the shell length as estimation of the body size of several brachiopod assemblages recorded into the extinction interval prior to the early toarcian mass extinction they were collected from representative localities around the iberian massif spain and portugal presenting different paleoenvironmental conditions the analysis performed has revealed two different trends of spatial and temporal changes in body size 1 mean size decreases in the assemblages following an anticlockwise pattern from iberian to lusitanian basins in relation to the progressive environmental stress caused by shifts on terrigenous input and in depth this diminution results from changes in the relative abundance of bigger or smaller species in each area rather than from miniaturization of the taxa 2 some new evolved or more resilient species show increasing sizes over time along the extinction interval this increase affects both big spiriferinides in the iberian basin and small rhynchonellides and koninckinides in the lusitanian basin and runs in parallel to the drop in diversity and the progressive warming of the sea water in this interval in all the localities this increase in body size has been related to the changes in diversity that could have favored the access to resources for resilient or new evolved species the observed patterns are comparable with those detected in the end permian crisis and might indicate a generalizable response to similar biotic crises

late holocene coastline and landscape changes to the west of ephesus turkey abstract palaeogeographical research regarding coastline and landscape changes has been conducted in the kucuk menderes graben and the environs of the ancient city of ephesus in western turkey for a few decades based on geophysical data multi proxy and microfaunal analyses of sediment cores 14 c ams age estimates and diagnostic ceramics this study presents for the first time results of an area close to the present coastline where a byzantine church is located on top of a small hill the results reveal that this mica schist hill turned into an island during the 2nd 1st millennium bce it was reconnected to the mainland via a tombolo during the 5th century ce drill cores and geophysical measurements surrounding the hill show massive stone layers which were deposited intentionally during the 5th 6th century ce when the byzantine church was built geophysical images point to wall structures in the surroundings of the hill the area to the northeast hosts a small harbour site when the coastline continued to shift further to the west this site was still connected to the sea by the kucuk menderes river

geoscience rediscovers phoenicia s buried harbors after centuries of archaeological debate the harbors of phoenicia9s two most important city states tyre and sidon have been rediscovered and including new geoarcheological results reveal how where and when they evolved after their bronze age foundations the early ports lie beneath their present urban centers and we have indentified four harbor phases 1 during the bronze age tyre and sidon were characterized by semi open marine coves that served as protoharbors 2 biostratigraphic and lithostratigraphic data indicate the presence of early artificial basins after the first millennium b c 3 the harbors reached their apogees during the greco roman and byzantine periods 4 silting up and coastal progradation led to burial of the medieval basins lost until now

foraminifera as markers of holocene sea level fluctuations and water depths of ancient harbours a case study from the bay of elaia w turkey abstract the absence of common sea level indicators in the study area of elaia pergamum s harbour city in hellenistic and roman times forced to establish a new reliable indicator which was found in the foraminifera associations in connection with the transgressive contact the strength of this indicator is the exclusion of post depositional compaction accompanied by a well dated archaeological index point at a breakwater the micropalaeontological indicator enabled the establishment of a reliable regional sea level curve rsl curve for the bay of elaia it is in good agreement with other curves for the aegean region and in general agreement to the glacio hydro isostatic model for the region our sea level curve proves for the first time at a continental site on the turkish aegean coast the today s sea level peak water depth modelling for the so called closed harbour of elaia reveals the capacity to fully accommodate the common ship classes of hellenistic and early roman times until around 150 ce while water depth estimates for the so called open harbour of the city verifies the usage of the adjacent ship sheds during elaia s prime

physiographic and climatic controls on regional groundwater dynamics the main goal of this study is to explore whether the ideas established by surface water hydrologists in the context of pub predictions in ungauged basins can be useful in hydrogeology the concrete question is whether it is possible to create predictive models for groundwater systems with no or few observations based on knowledge derived from similar groundwater systems which are well observed to do so this study analyses the relationship between temporal dynamics of groundwater levels and climatic and physiographic characteristics the analysis is based on data from 341 wells in southern germany with ten year daily groundwater hydrographs observation wells are used in confined and unconfined sand and gravel aquifers from narrow mountainous valleys as well as more extensive lowland alluvial aquifers groundwater dynamics at each location are summarized with 46 indices describing features of groundwater hydrographs besides borehole log derived geologic information local and regional morphologic characteristics as well as topography derived boundary and climatic descriptors were derived for each well regression relationships were established by mining the data for associations between dynamics and descriptors with forward stepwise regression at a confidence level 95 the most important predictors are geology and boundary conditions and secondarily climate as well as some topographic features such as regional convergence the multiple regression models are in general agreement with process understanding linked to groundwater dynamics in unconfined aquifers this systematic investigation suggests that statistical regionalization of groundwater dynamics in ungauged aquifers based on map derived physiographic and climatic controls may be feasible

stratigraphy of late holocene deposits of the ancient harbour of marseilles southern france the late holocene stratigraphy of marseilles harbour is presented together with archaeological evi dence and radiocarbon data an anthropogenic oyster midden dated between c 4260 and 3400 14 c yr bp is followed by a period of siltation that ended the accretionary growth of an algal marl deposit this event was caused by early human settlement subsequently the coastline was subject to progradation it is argued here that the development of the e rst town of marseilles c 2600 years ago accelerated soil erosion and sediment deposition in the harbour area

sedimentological evidence of an assumed ancient anchorage in the hinterland of a phoenician settlement guadiana estuary sw spain abstract as bays lagoons and estuaries ensure protection from wind and a hinterland rich in natural resources is most enticing during the early iron age the seafaring phoenician settlers chose such locations all over the mediterranean for their seaports establishing pan mediterranean trade from the late 9th century bce onwards despite the difficult nautical conditions phoenician sailors had conquered the strait of gibraltar by the end of the 9th century bce today many of these sites along the mediterranean and atlantic coasts are located several kilometers inland due to coastal progradation this paper investigates whether the wetlands of the estero de la nao a tidal channel and small tributary within the lower guadiana estuary gulf of cadiz sw iberia were able to serve as a potential natural harbor location and port of trade for the seafaring phoenician population the focus of this study is set on a systematic analysis of sedimentological data the lithostratigraphy of three sediment cores shows that at least 8000 years ago open water conditions existed within a marine embayment characterized by sedimentation under estuarine conditions this situation prevailed for several millennia from the early bronze age silting up processes of the former navigable areas occurred additionally a distinct stratigraphic gap within the sedimentary sequence of one particular sediment core provides strong evidence of ancient dredging activities that attempted to cope with the local siltation processes in the most recent strata badly sorted sediments intercalated with brick and shell fragments provide evidence of a high energy event probably triggered by the great lisbon earthquake in 1755

human influence and the changing geomorphology of mediterranean deltas and coasts over the last 6000 years from progradation to destruction phase the present geomorphology of the mediterranean s coasts is largely a product of an intricate long term relationship between nature and human societies a cradle of ancient civilisations the mediterranean has seen its shores occupied by humans since prehistory and is therefore a particularly pertinent unit of analysis the morphotectonic context and other forcing agents e g climate shaped out a highly diversified coastal morphology and generated a sediment supply regime potentially favourable to the formation of numerous open coast deltas and bay head deltas in infilled rias as sea level stabilised during the mid holocene this supply of riverine sediment has also been the key agent in mediating human occupation of the mediterranean s clastic coasts expressions of this relationship have been extensively archived in clastic coastal deposits including base level deltaic and estuarine sedimentary sinks which comprise records to explore the interactions between geosystems and the human environment the stratigraphic sequences in these coastal sedimentary archives comprise in many places a clearly identified anthropogenic signature notably in ancient harbours some of which underwent extremely rapid silting up due to massive sediment sourcing generated by new agricultural practices from the neolithic onwards increasing human influence especially over the last 3000 years has been in turn an important driver of changes in sediment supply strongly modulating deltaic development pulses of sediment supply from catchments rendered vulnerable by human perturbations during the roman period resulted in a new cycle of inception of many other deltas and in rapid delta growth e g the ebro the po the arno and the ombrone another progradation dynamic during the little ice age at a time of strong rural population growth river discharge increases technological developments and urbanisation further consolidated delta growth understanding the life cycle of these deltas since their initial formation is in turn key to unravelling the relative role of natural and anthropogenic forcing agents rapid climate changes are deemed to have contributed through both the stripping of landscapes rendered fragile by human activities and active fluvial sediment transport to the coast but disentangling climate change effects from human impacts in the mediterranean remains a challenge the patterns of subsequent deltaic growth and delta morphodynamics reflect adaptations to pulsed sediment supply river discharge variations the microtidal fetch limited context of the mediterranean and direct engineering interventions the progradation dynamic of the roman period and little ice age contrasts markedly with the situation of common coastal destabilisation over the last two centuries particularly well documented for the last 50 years this period has been characterised by reduced sediment flux to base level geosystems due to catchment reforestation retenion within reservoirs fluvial regulation and dredging resulting in the erosion of deltas and barrier lagoon and beach dune systems large stretches of shoreline and narrow coastal plains have been massively engineered for coastal defence and protection against erosion but also for the construction of marinas leisure harbours and artificial beaches resulting in the emergence of veritable artificial seafronts these interventions have collectively and progressively raised societies to a pervasive and overarching position in the geomorphic stability instability of the mediterranean s coasts a situation that will be exacerbated by pressures from sea level rise paving the way for rampant coastal erosion and delta destruction

late triassic and early jurassic palaeogeographic evolution and depositional cycles of the western tethys iberian platform system eastern spain deposition of upper triassic and lower jurassic sediments on the iberian platform system took place in a post rift intraplate basin which formed part of the western tethys shelf nevertheless there is evidence for the tensional reactivation of a network of faults with associated magmatic activity early jurassic palaeogeographic reconstructions based on over 70 sections and 9 oil wells reveal the presence of a series of highs and lows depocentres two main highs referred to as the el maestrazgo high in the east and the la mancha high in the west where condensed sections were deposited were mainly controlled by syndepositional faults the main depocentres were situated between these two highs areas in a northwest trending belt in the central northern and southern areas despite partial fault control development of some early jurassic depocentres appears to be mainly controlled by thermal contraction of the lithosphere following triassic main rifting pulse the upper triassic lower jurassic succession of the iberian platform system was deposited during four transgressive and regressive cycles of 12 to 6 my duration the lowermost cycle lj 1 started in late norian and lasted until the sinemurian the second cycle lj 2 started in the sinemurian and ended in the pliensbachian davoei zone and can be subdivided into two minor cycles lj2 1 and lj2 2 the cycle lj 3 started with an extensive upper pliensbachian davoei zone transgression whereas the top of its regressive cycle is dated to the toarcian variablilis zone within cycle lj 3 three cycles can be distinguished maximum deepening was reached during the bifrons zone and active volcanism took place along the teruel and caudiel faults the transgressive phase of the cycle lj 4 started in the thouarsense zone and extended up to the insigne zone its regressive phase developed during the upper toarcian pseudoradiosa and aalensis zones and part of the aalenian opalinum and murchisonae zones this cycle can be subdivided in two minor cycles with their transgressive peaks occurring during the insigne zone and the aalensis zone respectively palaeogeographically this corresponds with the expansion of the marginal carbonate platforms over hemipelagic deposits the top of the cycle corresponds to a major unconformity with regional emersion during the aalenian murchisonae zone

early jurassic mass extinction a global long term event the end pliensbachian extinction event 187 ma has been interpreted either as one of 10 global periodically recurring mass extinctions of the past 250 m y or as a minor localized european event elevated levels of family extinction spanned five ammonite zones during the late pliensbachian and the early toarcian an interval of 7 5 m y and were distributed unequally in the boreal tethyan and austral realms detailed sampling of invertebrate macrofaunas through complete expanded sequences in northwest europe shows that most species extinctions occurred in the early toarcian following a regional anoxic event the early jurassic mass extinction event took place over a long time scale and it was global in extent

mass extinction and recovery of the early toarcian early jurassic brachiopods linked to climate change in northern and central spain abstract the early toarcian mass extinction event represented the most important mesozoic and cenozoic turnover of the population of brachiopods and severely affected other benthic fauna two main hypotheses have been proposed to explain the synchronous and global mass extinction an oceanic anoxic event or a warming episode to test both hypotheses the dynamics of the brachiopod assemblages below and above the extinction boundary are analyzed and compared with the seawater paleotemperature variations calculated from the 18 o data recorded in belemnite rostra five sections from northern and central spain well dated with ammonites have been selected for this study the sections show no indication of sedimentary breaks and contain abundant brachiopods which have been grouped into four assemblages the changes observed in the brachiopod assemblages show a close correlation with the changes in the seawater paleotemperatures the oldest assemblage assemblage 1 coincides with a cooling interval recorded to have taken place in the latest pliensbachian paleobiogeographical reconstruction shows that this assemblage was distributed at paleolatitudes between 30 and 45 n with a preference for relatively cool waters with the rise of temperatures that took place during the earliest toarcian tenuicostatum zone assemblage 1 was substituted by assemblage 2 which composed of different species of the same genera but considerably restricted to the warmer waters of lower paleolatitudes between 28 and 35 n coinciding with the rapid and pronounced increase in seawater temperature recorded at the tenuicostatum serpentinum zonal boundary all of these brachiopod species disappeared in the studied localities marking clearly the extinction boundary predominant southward currents through the laurasian seaway precluded the possible migration of the brachiopods to cooler northern waters the brachiopods disappearance is independent from the oxygenation degree of the sea bottom and therefore the rapid warming seems to be the most plausible cause of the mass extinction after the extinction event the recovery of the brachiopods was uneven subsequent to a brief pause recovery was rapid in central spain and in other southern areas of western tethys whereas in northern spain and in the whole of europe north of the french central massif brachiopods did not recover until the mid to late toarcian times

evolution of the rhone delta plain in the holocene abstract the delta plain of the rhone shows many sandy beach ridges cropping out at the surface we propose here a radiocarbon chronology for the accumulation of the sedimentary bodies and an interpretation of the morphology of the mouth lobes that they form morphologies of the lobes depend on four principal factors 1 the variation of the relative sea level which constitutes the morphogenic base level 2 the fluvial input volume of water discharge and sedimentary input number and position of the mouths 3 marine dynamics volume and direction of the longshore drift dominant wave direction 4 the accommodation space created by the rise of relative sea level along with the paleobathymetry onto which the lobe will prograde immediately in front of the delta and at sea our conclusions are the main holocene paleo delta lobes of ulmet and saint ferreol were contemporaneous being deposited from 4000 to 2000 yr bp however the fluvial style of their downstream channel meandering for ulmet channel and linear for saint ferreol and the lobe morphologies of both channels are contrasted rounded in the case of ulmet and elongated for saint ferreol the role of the accommodation space is confirmed by two recent drillholes traversing the entire holocene succession which reveal a prior stage of sedimentary filling in the case of the saint ferreol lobe thus limiting the accommodation space and favouring a rapid and pointed progradation of this lobe the decoupling between hydrological activity and progradation of lobe indicates the complexity of mechanisms in the large catchment basin of rhone however the high rate of progradation of saint ferreol lobe after 2900 bp is probably a consequence of the increase of human activity after this date the variation of relative sea level remains an important factor controlling the evolution of the rhone delta after 6000 bp the local stabilization of the relative sea level between 4585 bp and 3520 bp played an important role in the triggering of coastal progradation saint ferreol lobe eastern margin rhone delta

arab madagascan brachiopod dispersal along the north gondwana paleomargin towards the western tethys ocean during the early toarcian jurassic multiple approaches mainly focused on assessing the depositional environments paleotemperature chronostratigraphical and paleobiogeographical data morphometrical analyses and the study of the internal structure of spiriferinide brachiopods assigned to the genus calyptoria have revealed that this brachiopod fauna migrated from their arab madagascan homeland along the north gondwana paleomargin into the peri iberian epicontinental platform system in the same well known spreading episode suffered by the arab madagascan bouleiceras ammonite fauna over the worldwide distributed early toarcian platforms this brachiopod fauna has been so far overlooked as potential arab madagascan immigrant fauna as it was integrated together with diverse assemblages well established in the peri iberian basins dispersal of calyptoria stock was conditioned by the interplay of several factors such as the tectonic framework the development of epicontinental seas on both tethyan margins the early toarcian transgression the prevailing ocean current pattern and their limited ability for dispersal the revised chronostratigraphical framework of this dispersal episode reveals the coincidence with the thermal maximum recorded prior to the early toarcian mass extinction event etmee in the westernmost tethys ocean the concurrence of these factors played a significant role in the calyptoria spreading showing an inter tropical distribution between 0 and 30 in both hemispheres the taxonomical updating performed in the light of the current systematic trends support this adaptive strategy carried out by calyptoria species consisting of a sudden and practically synchronous dispersal without outstanding morphological changes instead of the diverse evolution of different brachiopod taxa in response to the environmental changes related to the etmee updating and rearranging of the species attributed to the genus calyptoria suggest a new systematic scheme for several former attributions supporting that lower toarcian occurrences of l undulata from westernmost tethyan areas belong to calyptoria thus pointing towards the dispersal from the northern peri gondwana seas to the westernmost tethyan epicontinental platforms similar adaptive strategies were linked to other extinction events supporting a possible pattern in the response of certain brachiopod populations to such biotic crises

human impact on holocene sediment dynamics in the eastern mediterranean the example of the roman harbour of ephesus during the past millennia many erosion and accumulation processes have been modified by anthropogenic impact this holds especially true for the environs of ancient settlements and their harbours along the mediterranean coasts our multi proxy investigations in the roman harbour and the harbour canal of ephesus western turkey reveals that humans have significantly triggered soil erosion during the last three millennia since the eighth century bc and especially since the hellenistic period a high sed imentation rate indicates fast alluviation and delta progradation of the kucuk menderes deforestation agriculture especially ploughing and grazing especially goats were the main reasons for erosion of the river catchment area one consequence was significant siltation of the hellenistic roman harbour basin this sediment trap archives the human impact which was strongly enhanced from hellenistic roman to byzantine times second first centuries bc to the sixth seventh centuries ad evidenced by high sedimentation rates raised values of heavy metal contaminations lead pb copper cu the occurrence of fruit tree pollen and of intestinal parasites from the middle to the end of the first millennium ad the influence of ephesus declined which resulted in a decrease of human impact studies of several ancient settlements around the mediterranean sea tell a comparable story they also confirm that during their most flourishing periods the human impact totally overprinted the climatic one to detect the latter geo bio archives of relatively pristine areas have to be investigated in detail

geomorphological origin of recession curves 1 we identify a previously undetected link between the river network morphology and key recession curves properties through a conceptual physical model of the drainage process of the riparian unconfined aquifer we show that the power law exponent of dq dt vs q curves is related to the power law exponent of n l vs g l curves which we show to be connected to hack s law where l is the downstream distance from the channel heads n l is the number of channel reaches exactly located at a distance l from their channel head and g l is the total length of the network located at a distance greater or equal to l from channel heads using digital terrain models and daily discharge observations from 67 us basins we find that geomorphologic estimates match well the values obtained from recession curves analyses finally we argue that the link between recession flows and network morphology points to an important role of low flow discharges in shaping the channel network

the role of climate in landscape morphogenesis since the bronze age in provence southeastern france between the rhone and the massif des maures geomorphological research radiocarbon dating and archaeological excavation has revealed synchronous variations in morphological evolution produced by changes in climate following one or more torrential protohistoric phases the later iron age and gallo roman civilizations were marked by a reduction in runoff from slopes and a lowering of the water level in marshy areas this was probably due to drier climatic fluctuations linked to a more even seasonal rainfall distribution the early middle ages and the beginning of modem times correspond to a renewed increase in rainfall the erosive effects of which have been exacerbated by human activity

changes in the hypsometric curve through mountain building resulting from concurrent tectonics and denudation abstract the stages of geomorphic development of mountains have sometimes been explained based on strahler s diagram of hypsometric curves although the japanese mountains are young they do not follow his diagram hypsometric curves simulated using empirical laws deduced from the japanese mountains indicate that mountain building resulting from concurrent tectonics and denudation does not produce convex curves but concave and or s shaped curves the hypsometric curve of a mountain changes from a concave curve to an s shaped curve in accordance with the increase in mountain altitude the succession of the hypsometric curve during concurrent tectonics and denudation is the reverse of strahler s diagram the hypsometric integral increases with the advance in stage which is evaluated based on the change in mountain altitude it has a relatively good correlation with the stage however the sequence of change in the hypsometric integral is different according to the extent of the terrain examined whether the terrain is restricted to the interior of a mountain or pertains to the whole mountain and whether it includes newly emerged land the stage should be evaluated based on the course of change in the integral characteristics for the extent of the mountain examined

dredging and canal gate technologies in portus the ancient harbour of rome reconstructed from event stratigraphy and multi proxy sediment analysis ancient harbours are rich archives of human environment interaction however dating harbour deposits and correlating their stratigraphy is a major challenge because of typically high sedimentation rates over short periods and possible curative dredging events portus the maritime harbour of rome at the height of the roman empire was a port complex composed of basins and canals connecting the commercial harbour to rome via the tiber river sediment core cps1 in the narrowest of these canals canale traverso is located centrally in what was the capital city s commercial hub and contains a continuous harbour depositional record with average sedimentation rates greater than 1 cm per year here we use piston coring high resolution core scanning and a multi proxy sediment analysis including for the first time paleo and rock magnetism and bulk and clay mineralogy in order to overcome the problems of dating harbour deposits and correlating their stratigraphy the method allowed precise identification of major reworked events including a dredged deposit and a hyperpycnal deposit which improve the chronostratigraphy and water depth reconstruction and sheds light on harbour technologies at the height of the roman empire a debris layer with abundant ceramic fragments and rocks marks the decommissioning of canale traverso and provides a new chronostratigraphic marker at portus multi proxy riverine input signatures point to the possible use of canal gate technology for water flow management

ostracodological studies in archaeological settings a review during recent years geo archaeology has been revitalised and much effort has been made to combine geo archaeological sciences like geomorphology sedimentology micropalaeontology and geochemistry with the cultural archaeological approach the first definition of geo archaeology dates back to the late seventies and since then has evolved to include more and more multidisciplinary studies in this perspective ostracods play a crucial role since they are valuable palaeoenvironmental indicators in all aquatic habitats from freshwater to marine despite their potential the integration of ostracods in archaeological studies has not been immediate only in the nineties did ostracod geo archaeology seem to finally take its place including a systematic approach to ostracod studies in archaeological excavations since then many geo archaeological investigations have included ostracod analyses exploiting their potential as multitask tools the research papers composing this special issue demonstrate that ostracods can be used in the most diverse settings as tracers of archaeological material provenance proxies for palaeoenvironmental and palaeoclimate reconstructions as well as clues to human impact

the environs of elaia s ancient open harbour a reconstruction based on microfaunal evidence during hellenistic and roman times elaia the harbour city of ancient pergamum was an important place of trading and traffic intense mercantile and military activities are documented by literary sources and archaeological evidences geomagnetic and geoelectric investigations detected building structures close to the ancient coastline which are interpreted as ship sheds the aim of this study was to reconstruct the coastal evolution particularly with regard to harbour related facilities for that purpose a 10 m long sediment core was drilled in the area of the ancient open harbour immediately in front of the supposed ship sheds it was studied with the tools of micropalaeontology geophysics sedimentology and geochemistry to improve the reconstruction of the palaeoenvironmental conditions reference samples of modern environments of the area were analysed as indicated by marine ostracod and foraminifer taxa the sediment core shows from bottom to top that the initially fully marine conditions changed to a more restricted fauna indicative for a more sheltered bay with brackish waters this layer dates to hellenistic times it can however be shown that the siltation process had produced a lagoon system already several hundred years bc the elaia embayment was first used as a natural harbour it was equipped with breakwaters in the hellenistic period the progressive siltation caused the abandonment of the harbour in late roman times

physical stratigraphy and sedimentology of the late pleistocene holocene tiber delta depositional sequence the tiber delta lies on the passive continental margin of central western italy the tiber delta is a late pleistocene holocene sedimentary succession and constitutes an incomplete high frequency depositional sequence 4th or 5th order which developed from the last post glacial rise in sea level to the present stillstand it is bound by a type 1 basal unconformity which cuts pleistocene deposits five depositional systems have been identified 1 coastal barrier lagoon 2 shelf transition 3 fluvial braided 4 tiber lagoonal deltas t1 t2 t3 and 5 tiber wave dominated delta the first four systems constitute the transgressive system tract tst which is characterized by a retrogradational parasequences set while the fifth system represents the highstand system tract hst characterized by only one parasequence progradational the evolution of these depositional systems has been mostly controlled by sea level rise which was not continuous but punctuated by eight minor stillstands and rapid rises this mechanism of sea level change led to the formation of parasequences that developed within the depositional systems from a palaeogeographical point of view the present tiber delta area was mainly characterized by a coastal barrier lagoon and tiber lagoonal deltas t1 t2 t3 which migrated landwards during the sea level rise throughout the time of the present stillstand the t3 lagoonal delta prograded rapidly into the lagoon reaching the coastal barrier and the lagoon was replaced first by marshes and then by the alluvial plain finally the tiber river overcame the littoral barrier supplying the coast giving rise to the present wave dominated delta

refining the eustatic sea level curve since the last glacial maximum using far and intermediate field sites the eustatic component of relative sea level change provides a measure of the amount of ice transferred between the continents and oceans during glacial cycles this has been quantified for the period since the last glacial maximum by correcting observed sea level change for the glacio hydro isostatic contributions using realistic ice distribution and earth models during the last glacial maximum lgm the eustatic sea level was 125 5 m lower than the present day equivalent to a land based ice volume of 4 6 4 9 107 km3 evidence for a non uniform rise in eustatic sea level from the lgm to the end of the deglaciation is examined the initial rate of rise from ca 21 to 17 ka was relatively slow with an average rate of ca 6 m ka 1 followed by an average rate of ca 10 m ka 1 for the next 10 ka significant departures from these average rates may have occurred at the time of the younger dryas and possibly also around 14 ka most of the decay of the large ice sheets was completed by 7 ka but 3 5 m of water has been added to the oceans since that time

the pliensbachian toarcian early jurassic extinction a global multi phased event abstract during the pliensbachian toarcian interval of the early jurassic there is a well known second order marine extinction that is observable at the species and genus levels ammonite diversity data from successions throughout europe and parts of the arctic suggest that this extinction may have been multi phased with diversity declining over six separate intervals the main phase of decline begins at the pliensbachian toarcian boundary and extends into the lower toarcian to a level that is correlative with the tenuicostatum serpentinum zone boundary to date only the main phase of extinction has been demonstrated as being global in extent and affecting multiple taxonomic groups this multi phased extinction has been attributed to regional and global controlling mechanisms that are associated with the volcanic greenhouse scenario which links the eruption of the karoo ferrar large igneous province lip to global warming and mass extinction we compare stratigraphic ranges of ammonite and foraminiferal species in pliensbachian toarcian successions of western north america to the record in europe and parts of the arctic in order to test the geographic extent of the multiple phases of extinction our results show six intervals of species level decline that correlate with those recognized in europe 1 middle of the lower pliensbachian middle whiteavesi middle freboldi zones 2 middle of the upper pliensbachian upper kunae lower carlottense zone 3 pliensbachian toarcian boundary into the lower toarcian upper carlottense middle kanense zones 4 middle toarcian upper planulata lower crassicosta zones 5 upper middle lower upper toarcian middle crassicosta hillebrandti zones and 6 upper toarcian lower yakounensis zone recognition of this multi phased event in three separate ocean basins paleo pacific paleo arctic and tethys oceans in at least two taxonomic groups greatly expands the known geographic extent of this multi phased event and argues for a controlling mechanism that is global in its reach in relation to the volcanic greenhouse scenario our study shows that four of the six pulses of extinction occur within the main phase of karoo magmatism the decline in the early pliensbachian previously thought to be separate from this event occurs within error range of the onset of karoo magmatism and the decline in the late toarcian coincides with the later stages of magmatism these observations extend the known duration of this multi phased extinction event to the early pliensbachian and support the volcanic greenhouse scenario specifically the eruption of the karoo ferrar lip as a preeminent factor driving the multi phased extinction of the pliensbachian toarcian

a statistic for testing the elevation characteristics of landscape simulation models there is an urgent need to test recently constructed conceptual models of landscape evolution and geomorphology against field data many statistics that have commonly been used such as strahler statistics are poorly suited to this testing being unable to potentially falsify the models when applied in controlled conditions the relations between these statistics and catchment mass movement processes are in many cases indirect moreover they are sensitive to unknowable inputs e g initial conditions one of the main differences among the competing landscape evolution models is their representation of mass movement and erosion processes so that statistics that are directly linked to these processes or their geomorphic signature are needed this paper examines the use of a log log linear relation between catchment area slope and elevation this relation has been previously derived quantitatively from the catchment erosion and hydrologic processes for dynamic and declining geomorphic equilibria using a catchment evolution model this paper shows that the relation is robust against deviations from the assumptions of spatial and temporal homogeneity of erosion climate and tectonic uplift made in its derivation the sensitivity of the geomorphology to time varying tectonic uplift and climate and spatially variable soil erodability is examined it is thus asserted that the relation between area slope and elevation is suitable for testing of models against field data where spatial and temporal homogeneity of erosion climate and tectonic uplift are only approximately true in the case of variable soil erodability planar drainage patterns exhibit self organization with the high elevation regions of the catchment having low soil erodability consequently a downstream increasing erodability of the soil material consistent with a downstream fining type of behavior is observed it is further argued that the equilibria relation is fundamental and uniquely defines the elevation form of catchments so that all other elevation statistics are derived from it

geoarchaeological sea level proxies from a silted up harbour a case study of the roman colony of luni northern tyrrhenian sea italy abstract the luni plain which faces the northern tyrrhenian sea underwent major landscape changes over the last 3000 years the coastline shifted south and west separating the ruins of the ancient roman colony of luni founded in 177 bc from the sea by means of a new coastal plain the precise location of the coastline during the main settlement phase as well as during the city s decline has never been established although partial and qualitative scenarios have been suggested by various authors according to these authors an indentation of the coastline west of the city formed a major water basin along the shores of which traces of pre roman settlements exist near the city two minor basins were present suitable for hosting harbour structures the city of luni was famed for its harbour portus lunae from which the marbles quarried in the apuan alps used to build many of the monuments in rome were delivered the traces of its port however are scattered and uncertain newly available subsurface data are presented associated with a revision of unpublished archaeological evidence of the ancient city topography progress in palaeoenvironmental reconstructions at luni has been possible thanks to the collection and analysis of ancient and recent cores supported by radiocarbon dates as well as the interpretation of archaeological findings suitable as markers for sea level recognition the main environmental changes in the area have been refined since a few centuries before the colony was founded the luni plain had been characterized by a complex architecture of swamps and marshes limited by dune ridges and fluvial sand bars the positions of these landforms were not fixed but shifted mainly depending on the spatial relationship between the coastline and the river mouths determining the precise position of the roman coastline is useful to constrain the area in which archaeological surveys should be concentrated in order to identify the harbour location moreover some of these results have been used to infer altitude constraints on the sea level position in roman times preliminary data are shown for constructing a late holocene local sea level curve in the area

palaeoenvironmental evolution of the ancient harbor of lechaion corinth gulf greece were changes driven by human impacts and gradual coastal processes or catastrophic tsunamis abstract the corinth gulf central greece is one of the most rapidly widening tectonic rifts on earth where large earthquakes with magnitudes of up 7 0 have been documented not only by instrumental records but also assessed from historical reports extending back to the 5th century bce several of these earthquakes were associated with tsunamis particularly in the western part of the gulf of particular interest is the ancient harbor of lechaion in the eastern side of corinth gulf we reexamine the hypothesis that lechaion was hit by high energy tsunami waves in the 8th 6th century bce 1st 2nd century ce and during the 6th century ce on the basis of sedimentological seismotectonic archaeological and historical data completed with field observations we support that there is no evidence for tsunami impact in lechaion local stratigraphy and environmental changes are rather interpreted by human impacts and gradual coastal processes such interpretations confirm that the tsunami potential in the east corinth gulf is relatively low

a two state integral balance model for soil moisture and groundwater dynamics in complex terrain a dynamical model is devised for a hydrologic system where unsaturated and saturated storage serve as the principal control on rainfall runoff and where complex topography drainage area and variable depth of moisture penetration describe the flow geometry the model is formed by direct integration of the local conservation equation with respect to the partial volumes occupied by unsaturated and saturated moisture storage respectively this yields an integral balance model in just two state variables the relationship of the dynamical model to field data in complex terrain is found through a joint probability density for terrain features this serves as a volume weighting function to construct conditional averages for the state variables and fluxes over a specified range of terrain features the scale of averaging could range from hillslopes to river basins two examples of the joint probability of terrain features altitude and aspect are demonstrated for valley ridge and appalachian plateau digital elevation models the strategy of a dynamical model formed by conditional averages of state variables with respect to terrain features is proposed as a way of simplifying the dynamics while preserving the natural spatial and temporal scales contributing to runoff response the parametric form of the storage flux or constitutive relationships for the proposed model is determined from numerical experiments in a simple hillslope flow geometry the results show that a competitive relation exists between unsaturated and saturated storage except for the lowest precipitation rates saturation overland flow is proposed to be a storage feedback relation solutions to the integral balance model are presented in terms of the phase portrait which represents all possible solution trajectories in state space the timing and magnitude of peaks in the runoff hydrograph from pulse type input events demonstrate quick flow from near stream saturated storage saturation overland flow including rejected rainfall storage feedback and late time infiltration from upslope subsurface flow