the formation and evolution of the barrier islands of inhaca and bazaruto mozambique abstract the barrier islands of inhaca and bazaruto are related to the extensive coastal dune system of the mozambican coastal plain south east africa optically stimulated luminescence osl dating of key stratigraphic units indicates that accretion of sediment within these systems is episodic both islands appear to have been initiated as spits extending from structural offsets in the coastline superposition of significant quantities of sediment upon these spits during subsequent sea level highstands formed the core of the islands which were anchored and protected by beachrock and aeolianite formation at least two distinct dune building phases occurred during marine oxygen isotope stage mis 5 tentatively attributed to marine transgressions during sub stages 5e and 5c although some localized reactivation of dune surfaces occurred prior to the holocene large quantities of sediment were not deposited on either island during the low sea levels associated with mis 2 significant dune building and sediment reworking occurred immediately prior to and during the holocene though it is not clear whether these processes were continuous or episodic significant erosion of the eastern shoreline of bazaruto suggests that it is far less stable than inhaca and may suffer further large scale erosion a model is presented for the formation of barrier islands along the mozambican coastal plain

japan sea oxygen isotope stratigraphy and global sea level changes for the last 50 000 years recorded in sediment cores from the oki ridge abstract we obtained twenty ams accelerator mass spectrometry radiocarbon dates 2 tephra layer chronologies and a planktonic foraminiferal 18 o stratigraphy for the last 50 000 years from japan sea cores from the oki ridge in this paper we report ams 14 c results that allow us to reconstruct a high resolution chronology of the cores and discuss millennial scale climate changes recorded in japan sea sediments the sedimentation rate for the site increased dramatically from the glacial stage to the holocene as a result of significant hydrological changes associated with deglaciation and global sea level rise a lighter 18 o anomaly for the planktonic foraminifers was found during the lgm last glacial maximum this shift corresponds to a freshening of the japan sea surface waters and is mainly due to a global sea level drop rather than anomalously warm ssts sea surface temperatures as previously reported our record combined with the global sea level data suggests that the lgm started about 30 kyr ago and that the salinity of the japan sea became fresher than at present the ssts during mis marine oxygen isotope stage 3 were relatively stable and global sea level was not lower than ca 80 m the surface water of the japan sea attained normal saline levels following the younger dryas cold event and reached the present day 18 o values 7 kyr ago

late pleistocene coastal evolution of san giovanni di sinis west sardinia western mediterranean abstract the upper pleistocene succession of coastal deposits outcropping at san giovanni di sinis west sardinia has been studied since the 1960s however the absence of consistent radiometric ages has allowed the production of competing stratigraphic subdivisions of these deposits with different isotopic stage ois mis attributions the succession is composed of sandy to gravelly shallow marine coastal aeolian and alluvial fan plain deposits facies analysis and log correlations show the presence of three unconformities t1 t2 t3 always overlain by shallow marine deposits cutting through the substrate alluvial fan or aeolian sediments we have collected three samples for optically stimulated luminescence osl dating at the top of each shallow marine deposit the succession is composed of four unconformity bounded units u1 u2 u3 u4 and the new osl dates indicate the presence of three different sea level highstands the first unit u1 which is composed of shallow marine to aeolian deposits and overlies transgressive surface t1 is related to a marine transgression during ois 7 186 13 ky unit 2 is composed of continental deposits and formed during ois 6 unit 3 represents ois 5 and overlies a transgressive surface t2 more precisely subunit u3a is related to ois 5e 120 10 ky eu tyrrhenian or eemian sensu strictu and is characterized by shallow marine to aeolian deposits developed during both transgressive and highstand phases the following bay deposits of subunit 3b are associated with ois 5c 100 5 ky and record a second transgressive event t3 and highstand phase occurred during the neo tyrrhenian the succession of san giovanni di sinis ends with continental deposits of unit 4 associated to a sea level fall that took place at the beginning of the last glacial phase ois 4

new findings of bronze age homogenites in the ionian sea geodynamic implications for the mediterranean abstract holocene homogenites similar in character and stratigraphic position to those previously recorded in the ionian basin and related to the gigantic tsunami originating from santorini bronze age eruption are described from a core transect crossing the deformation front of the mediterranean ridge east of victor hensen seahill investigations on grain sizes and carbonate content carried out on three cores from three different areas of the ionian basin encompassing the bronze age homogenite revealed important similarities and some differences the most obvious difference concerns the carbonate content which is minimum at the base of the unit in a core close to the messina abyssal plain whereas it is maximum in cores from the western mediterranean and calabrian ridges characterized by the typical cobblestone topography a terrigenous versus pelagic nature of the components is documented and a distal versus local provenance is inferred homogenites are critically compared with unifites a type of re sediment recently described from the eastern mediterranean comparison includes in particular a source and sediment transport and b triggering mechanism a substantial difference exists between the sedimentation patterns of the ionian and levantine basins seaward of the calabrian and hellenic arcs in the latest quaternary and the difference contains a clear geodynamic message sedimentation rates increase from the late pleistocene to the holocene in the ionian basin whereas they decrease in the levantine basin the glacio eustatic signal is well expressed in the levantine basin where the source areas are situated consistently in the south or on a passive type aseismic continental margin north african margin in the ionian basin on the contrary the glacioeustatic signal is totally obscured by the strong tectonic signal from the active northern continental margin of the mediterranean

refined chronostratigraphy of a late quaternary sedimentary sequence from the yangtze river delta based on k feldspar luminescence dating abstract dating of sediments in the tidal dominated yangtze river delta remains a challenge because of extremely complicated processes during sediment transport and deposition in such a fluvial marine transition zone to better understand the late quaternary sedimentary history of the yangtze river delta we explore the applicability of k feldspar luminescence dating techniques to deposits through a case study on a 60 m long borehole core yz07 in the delta and then establish a spanning 50 000 year long chronological sequence a series of luminescence pre tests including dose recovery tests and determination of residual dose and fading rates were implemented using the modified single aliquot regenerative dose sar protocol for post infrared ir ir stimulated luminescence irsl measured at 150 c after prior irsl at 50 c pirir150 luminescence characteristics of the prior irsl ir50 and pirir150 were then analyzed to check their validity two fading correction models were utilized to correct apparent ages obtained from ir50 and pirir150 signals the newly obtained k feldspar luminescence ages were compared with quartz osl ages and 14c ages our results indicate that most of ages derived from pirir150 signals were overestimated due to incomplete bleaching in contrast the fading corrected ages from ir50 measured in pirir150 protocol are robust as they are consistent with quartz osl ages and 14c ages as well as the stratigraphy especially ir50 ages are characterized by negligible residual dose and thus reliably used for defining chronology of the chronological sequence over the past 50 ka our positive results of k feldspar dating shed light on further exploration of older unit in the yangtze river delta in combination with sedimentological and paleontological analyses of core yz07 we find fluvial to tide influenced fluvial deposits were emplaced during the period 30 50 ka which were then overlain by post glacial tidal river 13 11 5 ka and holocene estuarine shelf delta system and tidal flat deposits in the yangtze river delta together records of yz07 with other chronostratigraphy from the collected cores we confirm the existence of marine isotope stage mis 3 depositional units along the marginal coast of the yangtze river delta in relation to the interstadial sea level highstand our stratigraphic correlation based on the refined chronology reveals offshore transition of the mis 3 unit into facies deposited in deeper and offshore marine environments

using multiple logistic regression and gis technology to predict landslide hazard in northeast kansas usa abstract landslides in the hilly terrain along the kansas and missouri rivers in northeastern kansas have caused millions of dollars in property damage during the last decade to address this problem a statistical method called multiple logistic regression has been used to create a landslide hazard map for atchison kansas and surrounding areas data included digitized geology slopes and landslides manipulated using arcview gis logistic regression relates predictor variables to the occurrence or nonoccurrence of landslides within geographic cells and uses the relationship to produce a map showing the probability of future landslides given local slopes and geologic units results indicated that slope is the most important variable for estimating landslide hazard in the study area geologic units consisting mostly of shale siltstone and sandstone were most susceptible to landslides soil type and aspect ratio were considered but excluded from the final analysis because these variables did not significantly add to the predictive power of the logistic regression soil types were highly correlated with the geologic units and no significant relationships existed between landslides and slope aspect

coastal barrier dune construction during sea level highstands in mis 3 and 5a on tottori coast line japan abstract the southern coast of japan sea exhibits a number of late pleistocene coastal barrier dunes where the sediment record potentially provides important evidence for the palaeoenvironmental history of east asia the lack of direct dating of these barrier dunes however has veiled relationships between dune deposition sea level and other controlling factors quartz single aliquot regenerative optically stimulated luminescence osl dating was applied to the late pleistocene barrier dune at the tottori coast southern central japan sea we investigated a borehole drilled in a continuous ground penetrating radar gpr profile of the dune and an outcrop excavation where there has been recognised a sedimentary succession exposed of the pleistocene dune sand palaeosol daisen kurayoshi pumice dkp tephra palaeosol and holocene dune sand in ascending order the gradual transition from the pleistocene dune sand to palaeosol indicates a termination of the late pleistocene dune activity five osl ages from the uppermost pleistocene dune overlap within the period 48 2 51 4 ka which confirms that both deposition and termination of the dune occurred in early to mid marine isotope stage mis 3 another osl age from the lower section was 77 7 6 1 ka and indicates an earlier depositional stage in late mis 5a these reveal that the coastal dune deposition occurred in relation to the sea level highstands it would appear that a sea level of c 50 m relative to the present was the threshold for the dune activation morphology and sediment distribution of the modern shelf off the tottori coast suggest that the sea level lower than 50 m leads to increasingly unfavourable conditions for coastal dune activity due to longer sediment transport distances and decreased sediment supply these results have implications for the late pleistocene barrier dune along the southern japan sea coast and suggest that other dunes correlated with tottori based on the dkp tephra possibly would also have experienced a similar termination in relation to the sea level fall from mid mis 3 results also demonstrate that the depositional setting of the late pleistocene dunes was different from those constructed in the holocene due to the lower interstadial sea level highstands and resultant longer distance to the shore during mis 3 and 5a as a result the pleistocene dune exhibits less pronounced stratification and in finer grain size than the outer holocene dune ridge where sand is directly fed from the shore the grain size of the inner holocene dune ridge in contrast is almost identical to the pleistocene dune suggesting that the inner ridge partly consists of sand reworked from the pleistocene dune

channel width flow discharge relationships for rills and gullies abstract research conducted during the first half of the last century has shown that a strong power relationship exists between channel width and total flow discharge in streams recent studies have shown that this power relationship can be theoretically derived for bankfull discharge in channels the relationship has been extended empirically to rills and gullies revealing that the discharge exponent for rills and gullies is significantly smaller than that for rivers however water flow in rills and gullies is only rarely bankfull indicating that the theoretical explanation for the power relationship found for rivers does not apply to rills and gullies in order to investigate the width discharge relationships for rills and gullies a new method is proposed based on field measurements of widths of concentrated flow erosion channels both upstream and downstream of channel junctions although the method only allows the determination of the exponent of the power relationship it is easy and inexpensive to apply a total of 322 rill and gully channel junctions with various soils and land use types were investigated in belgium italy and spain the obtained data confirmed the existence of the power relationship for rills and gullies with the exponent varying from 0 43 for small rills about 3 cm in width to 0 5 for gullies about 50 to 100 cm in width the data did not allow deciding whether the exponent varies consistently with channel width or in a step wise fashion the exponent values obtained in this study are larger than those reported in previous studies but this may result from differences in the definition of the discharge that eroded the channel to its current width

catchment scale analysis of the effect of topography tillage direction and unpaved roads on ephemeral gully incision high resolution airphotographs and digital elevation models dems were used to study areas prone to gully incision in a small agricultural catchment in northern israel data are analyzed to understand better the integrated effect of environmental and human factors on gully incision the effect of flow accumulation slope unpaved roads density and tillage direction on gully width and length is found discontinuous and topography in the form of the topographic threshold was found to be the most dominant factor on gully incision in the catchment scale the topographic threshold coefficients observed in yehezkel catchment were lower than those found in previous studies due to the effect of large rainfall events during the early winter season when the soil in fields is still unprotected by crops in addition a survey of previous studies shows that in cultivated areas there is relationship between the topographic threshold coefficients a multiplier and b exponent the influence of unpaved roads and tillage direction on gully incision was also found significant and consistent during the two seasons observed while the non parametric test showed that it added to the prediction in 15 of the gullies incision points density plot show that of the two parameters the unpaved roads were found to have greater influence on gully head location than tillage direction studying the phenomenon on the catchment scale allows better understanding of the effect of spatial variation on gully head location copyright 2009 john wiley sons ltd

late pleistocene and halocene sea level changes in japan implications for tectonic histories and mantle rheology abstract it is very important to separate the tectonic and glacial isostatic components in the observed holocene and late pleistocene sea level changes in tectonically active areas such as japan for studying tectonic processes and for constraining mantle rheology the separation can be achieved by considering the spatial dependence of the relative sea level on the geometry of the coastline around the site where sea level is evaluated in fact the relative sea level caused by the last deglaciation at sites in the embayment such as tokyo and osaka has a sea level curve with a high stand at mid holocene and that site situated on the tip of peninsula has a sea level curve culminating towards the present the geometric effect also causes the regional difference of the sea level variations in the late glacial phase in the japanese islands the regional difference of the predicted relative sea level is about 5 m at 6000 years ago 20 m at 10 000 years ago and 30 m at 18 000 years ago comparison between observations and predictions indicates that the observations at several sites in japan are consistent with the predicted sea level variations more systematic data is required for the period 18 000 years ago to the present in order to examine tectonic processes and mantle rheology

late holocene aeolian sedimentation in the tottori coastal dune field japan sea affected by the east asian winter monsoon many dune fields that have formed along the southern coast of the japan sea are influenced by the north westerly winter monsoon which transports beach sand landwards the tottori coastal dune field of the japan sea has not been disturbed much by human activities until the 20th century and thus is expected to provide a continuous record of the relationships between the winter monsoon and aeolian sedimentation we examined new ground penetrating radar profiles and optically stimulated luminescence osl ages of quartz sand from transverse dune ridges in the western part of the dune field in addition to existing data in the eastern part this allowed us to extend the study period to cover the past 1000 years and to effectively compare the sedimentary record with other coastal dune fields in east asia and other palaeoenvironmental proxies osl ages from older dune sediments suggest considerable aeolian activity from the 10th to 12th century ad whereas a hiatus of dune sediment record between the 12th and 15th centuries was detected these results suggest that during the medieval period aeolian activity was low or that extensive erosion removed most of the deposits since the late 15th century dune sedimentation has apparently been broadly continuous though with periods of higher and lower activity in both of the eastern and western parts most of the dune ridges accreted landwards but clear seaward accretion occurred during the 18th century possibly reflecting a decrease in wind strength that restricted sand transport in contrast two significant landward accretion events are inferred to have occurred from the late 15th to 17th centuries and around 1840 corresponding to periods of increased dust fall in china which suggests an enhanced winter monsoon and to cold periods suggested by the decline of the sunspot number the timing of periods of inactive and active dune sedimentation inferred from alternations of organic soil and aeolian sand in other coastal dune fields of east asia appears to be concordant with corresponding periods in the tottori dune field we thus propose that other japan sea dune fields may also provide a valuable record of east asian winter monsoon fluctuations

a gis based approach for gully erosion susceptibility modelling a test in sicily italy the aim of this study is to analyze the susceptibility conditions to gully erosion phenomena in the magazzolo river basin and to test a method that allows for driving the factors selection the study area is one of the largest 225 km2 watershed of southern sicily and it is mostly characterized by gentle slopes carved into clayey and evaporitic sediments except for the northern sector where carbonatic rocks give rise to steep slopes in order to obtain a quantitative evaluation of gully erosion susceptibility statistical relationships between the spatial distributions of gullies affecting the area and a set of twelve environmental variables were analyzed stereoscopic analysis of aerial photographs dated 2000 and field surveys carried out in 2006 allowed us to map about a thousand landforms produced by linear water erosion processes classifiable as ephemeral and permanent gullies the linear density of the gullies computed on each of the factors classes was assumed as the function expressing the susceptibility level of the latter a 40 m digital elevation model dem prepared from 1 10 000 scale topographic maps was used to compute the values of nine topographic attributes primary slope aspect plan curvature profile curvature general curvature tangential curvature secondary stream power index topographic wetness index ls usle factor from available thematic maps and field checks three other physical attributes lithology soil texture land use were derived for each of these variables a 40 m grid layer was generated reclassifying the topographic variables according to their standard deviation values in order to evaluate the controlling role of the selected predictive variables one variable susceptibility models based on the spatial relationships between each single factor and gullies were produced and submitted to a validation procedure the latter was carried out by evaluating the predictive performance of models trained on one half of the landform archive and tested on the other large differences of accuracy were verified by computing geometric indexes of the validation curves prediction and success rate curves roc curves drawn for each one variable model in particular soil texture general curvature and aspect demonstrated a weak or a null influence on the spatial distribution of gullies within the studied area while on the contrary tangential curvature stream power index and plan curvature showed high predictive skills hence predictive models were produced on a multi variable basis by variously combining the one variable models the validation of the multi variables models which generally indicated quite satisfactory results were used as a sensitivity analysis tool to evaluate differences in the prediction results produced by changing the set of combined physical attributes the sensitivity analysis pointed out that by increasing the number of combined environmental variables an improvement of the susceptibility assessment is produced this is true with the exception of adding to the multi variables models a variable as slope aspect not correlated to the target variable the addition of this attribute produces effects on the validation curves that are not distinguishable from noise and as a consequence the slope aspect was excluded from the final multi variables model used to draw the gully erosion susceptibility map of the magazzolo river basin in conclusion the research showed that the validation of one variable models can be used as a tool for selecting factors to be combined to prepare the best performing multi variables gully erosion susceptibility model

middle and late quaternary depositional sequences and cycles in the eastern mediterranean although most of the quaternary sediments of the eastern mediterranean appear reworked extensive areas of hemipelagic sediments occur mainly in the central part of the basin mediterranean ridge the most obvious character of these muddy sediments is the numerous changes in colour they result from the organic carbon content as well as from concentration and chemical form of metallic elements mn fe cu zn the succession of coloured layers is arranged into sequences developed between two sharp contacts a complete sequence involves five lithofacies from an oxidized layer at the base to a reduced sapropel at the top and displays progressive internal changes of colour from ochre beige greyish beige grey and black layers several sequence variants top truncated base truncated recurrent are identified these sequences are a consequence of changes in oceanographic conditions i e from oxidizing to reduced environments resulting in different organic and mineral contents based on detailed studies of quaternary sediments collected by coring a synthesized standard succession representative of the ordered sequences in the eastern mediterranean is proposed from about 650 000 yr as deduced from the calculated rate of sedimentation of 1 7 mm 1000yr 1 this succession appears modulated by cyclic events large scale periods 200 000 yr of reduced and oxidized sequences correlate with major alternate phases of flooding and reduced flow of the nile river during the quaternary subsequent sequences of shorter time scale 20 000 50 000 yr results from two factors heaviest monsoons leading to an increase of the influx of the nile river and global climatic changes eurasian ice sheet meltwater these two factors act synchronously or independently along the studied time span these interplaying factors result in periodic stages of increasingly restricted conditions in the basin and explain the complexity of the eastern mediterranean succession at least since 650 000 yr ago

stratigraphy facies analysis and chronology of quaternary deposits at capo s marco sinis peninsula west sardinia italy abstract capo s marco is the southernmost termination of the sinis peninsula in the northwestern border of the oristano gulf western sardinia italy in the area there are some of the most controversial and debated quaternary deposits of sardinia consisting of beach aeolian and slope sediments whose chronological attribution changed according to different authors and in different times by the same authors these discrepancies have not been solved by new radiometric dates as radiocarbon and optically stimulated luminescence osl methods provided ages that are significantly different during recent investigations at capo s marco beach notches filled with bioclastic sands gravels and boulders were discovered up to an elevation of 4 5 m which is the highest elevation of the known beach notches these sediments rest on aeolian deposits and form a marine terrace in two sites in some places these sediments also include small colonies of the coral cladocora caespitosa in living position that have been recently dated by u th at 70 4 ka and attributed to the end of mis 5 here we report new u series analyses of two samples of c caespitosa collected on the uppermost part of the sequence the u th ages of 153 0 8 and 149 0 6 ka would correspond to mis 6 but the high values for the initial 234u 177 and 179 compared to the modern seawater value 147 point to an open system addition of 234u and or 230th the corrected ages using the open system model of thomson et al are 141 6 2 and 132 2 ka however these deposits and the beach notches are not buried under aeolian or colluvial sediments as are almost all the tyrrhenian marine deposits found in sardinia they also rest on aeolian sediments which at san giovanni di sinis were dated to mis4 or late mis2 by osl and radiocarbon dating of buried organic palaeosols respectively accordingly the stratigraphic evidence would suggest their attribution to the holocene although this contrasts with the holocene sea level models available and the u th dating results

paleoenvironmental changes in the japan sea during the last 85 000 years five distinct changes in the paleoenvironment of the japan sea within the last 85 000 years are revealed from the sedimentary record of a piston core recovered from the oki ridge changes in both surface and deepwater conditions are registered by changes in lithology calcium carbonate content organic carbon content oxygen and carbon isotope ratios and microfossil assemblages including calcareous nannoplankton diatoms radiolaria and foraminifera between 85 and 27 ka the warm tsushima current did not flow into the japan sea and cold surface water conditions prevailed environments at the seafloor fluctuated between dysaerobic to weakly oxic conditions between 27 and 20 ka freshwater input to the japan sea probably from the huang ho river in china stratified the water column and the severe anoxic conditions eliminated most benthic fauna between 20 and 10 ka the cold oyashio current flowed into the japan sea through the tsugaru strait reestablishing deepwater ventilation shallow water benthic assemblages of the north pacific ocean subsequently colonized the japan sea and occupied the vacant niches of the deep basins between 10 and 8 ka the foraminifer compensation level fcl gradually rose to a depth shallower than 1000 m and bottom conditions changed from dysaerobic to oxic at 10 ka the warm tsushima current started to flow into the japan sea through the tsushima strait to establish the modern oceanographic regime which has existed since 8 ka the eustatic sea level during the last glacial maximum was above the sill depths 130 m of the tsushima and tsugaru straits assuming that tectonic movements at these straits were negligible for the last 20 ka

understanding geomorphic responses to environmental change a 19 000 year case study from semi arid central texas usa understanding the impact of past climatic changes on landscape stability is crucial in order to predict and mitigate the effects of future changes however in arid and semi arid environments reconstructions are often hampered by a poor understanding of the relationship between sediment deposition and climate we present here data from central texas a region that is sensitive to environmental change but has received relatively little attention the study integrates a chronology of 29 optically stimulated luminescence osl ages from six sedimentary sites in a range of depositional contexts with a 19 000 a climate record derived from pollen extracted from the adjacent boriack bog by comparing the two records we aimed to assess the relationship between climate change and geomorphic activity data show that extensive aeolian and colluvial deposition occurred during the mid to late holocene with sedimentation generally increasing during more arid phases however a number of depositional events on slopes were associated with moister episodes and sediment was also deposited in a summit setting immediately after phases of increased precipitation linkages between climate change and geomorphic response were therefore complex being controlled by both sediment supply and transport energy the climatic fluctuations identified in the boriack bog record highlight the sensitivity of central texas to environmental change while disparities in conditions recorded between it and other palaeoenvironmental sites in the southern usa emphasise the need for further work in order to enhance understanding of landscape sedimentary response to climate copyright c 2010 john wiley sons ltd

quartz and polymineral luminescence dating of japanese loess over the last 0 6 ma comparison with an independent chronology there are only a few luminescence dating studies of loess sediments in japan but interleaved with these deposits are many well described tephras of known age based on 14c and fission track analysis these independent age controls provide an opportunity to test the reliability of loess luminescence ages this study provides such a comparison at two sites in central honshu the largest island in the japanese archipelago samples were collected from sequences of interleaved volcanic tephra and loess deposited on a middle pleistocene river terrace in the niigata prefecture and on an early to middle pleistocene dissected fluvial surface at in the tochigi prefecture honshu equivalent doses de were estimated from fine grains 4 11 m using both polymineral ir osl and post ir blue osl and quartz blue osl the blue stimulated luminescence signals could be represented by up to three exponentially decaying components only the most light sensitive of these components was used in the final de estimation almost all the estimates of de from polymineral ir osl are smaller than those from polymineral post ir blue osl and quartz blue osl whereas the latter two are in good agreement the blue light stimulated luminescence ages using the most light sensitive component are shown to be in good agreement with the independent control up to 500 ka although the ir osl signals underestimate the known age a simple laboratory fading test is found empirically to correct for this underestimation we conclude that the most rapidly blue stimulated luminescence signals from quartz extracted from our loess samples give reliable ages and that future loess dating studies should concentrate on these signals

spatial variation of bed roughness in eroding rills and gullies when overland flow concentrates rill and gully channels can be formed if a series of thresholds are exceeded these thresholds are more or less explicitly linked to the erosion resistance of the topsoil moreover flow velocity and channel width depend on total flow discharge more recently also bed roughness in eroding channels has been attributed to the eroding effect of flow discharge while channel width was shown to be the result of the interplay between erosion resistance of the topsoil and flow discharge see channel junction approach torri et al 2006 which could be described by a modified leopold and maddock s relationship the objective of this paper is to investigate the spatial variability of channel bed roughness in rills and gullies using an approach based on these findings field data confirm the various aspects reported so far hence these were used to develop a new equation allowing one to predict bed roughness in eroding rill and gully channels each of the new aspects introduced into the channel width flow discharge equation by the channel junction approach is discussed and verified with new data the validity of this approach is tested against channel data from mars finally an equation predicting bed roughness and based on stream power is developed and compared with measured rill and gully bed roughness successfully confirming that 1 bed roughness if generated by concentrated flow increases with stream power 2 channel width local bed slope topsoil cohesion at saturation and grain size are all important factors controlling channel bed roughness and 3 these variables as well as soil characteristics all measurable in the field after a rill or gully forming event are sufficient to determine channel bed roughness therefore one may expect that bed roughness of an eroded channel and consequently hydraulic roughness or friction will generally increase with bed gradient erosion resistance of the soil and grain size following a logic which is best expressed by the final equations described in this paper

deposition of sand in a trench slope basin by unconfined turbidity currents abstract site 181 of the deep sea drilling project is located on the seaward margin of a small basin which formed on the accretionary lower slope of the eastern aleutian trench sand layers recovered from this basin display an unexpected degree of compositional heterogeneity evidently all of the detritus was not derived from a single point source or submarine channel instead unconfined turbidity currents must have converged on the site of deposition from initiation points which were widely spaced across the hinterland of the gulf of alaska most of the unconfined flows probably were deflected around larger bathymetric obstacles however the bathymetric relief associated with many ridges appears to be insufficient for complete blockage of turbidity currents ridge bypassing can also occur by direct upslope flow over the ridge crests and we believe this mechanism represents an important element of forearc sedimentation

the distribution of carbonate eolianite abstract carbonate eolianite forms distinctive coastal landforms on many mid latitude continents and islands numerous studies of extensive continental and smaller island deposits in both hemispheres have shown the eolianites are predominantly pleistocene in age the coorong coastal plain of south australia contains the world s longest record of eolianite deposition revealing that major phases of carbonate accumulation occurred during interglacial and some interstadial sea level highstands throughout the quaternary similarly the well studied eolianite islands of bermuda and the bahamas record a close match between dune accretion and sea level highstands since the middle pleistocene several other eolianite deposits appear to have formed at least partially during glacial periods the glacial age deposits are eolian reworked relict shelf or coastal sediments or remnants of former highly mobile coastal dunes sourced from low sea level shorelines the distribution and bioclastic composition of large scale eolianite deposits suggests carbonate production on shallow shelves and banks is the ultimate control on the formation of eolianite the bulk of the carbonate comprising those eolianites is heterozoan being produced where there is low terrigenous sediment input in dominantly temperate cool water and subtropical carbonate provinces quaternary cyclical movements of sea level have also controlled the form and rate of coastal carbonate deposition with repeated pulses of sedimentation during highstands forming laterally coalesced vertically stacked or composite dune successions major unconformities within the deposits are marked by paleosols which record hiatuses in coastal sedimentation in several regions major eolianite units overlie coastal deposits of terrigenous sediment those successions suggest that the trend towards aridity and reduction in the supply of terrigenous sediment to shelves during the quaternary has enhanced the production of carbonate and the deposition of eolianite

aeolianite and barrier dune construction spanning the last two glacial interglacial cycles from the southern cape coast south africa the southern cape region of south africa has extensive coastal aeolianites and barrier dunes whilst previously reported limited knowledge of their age has precluded an understanding of their relationship with the climatic and sea level fluctuations that have taken place during the late quaternary sedimentological and geomorphological studies combined with an optical dating programme reveal aeolianite development and barrier dune construction spanning at least the last two glacial interglacial cycles aeolianite deposition has occurred on the southern cape coast at ca 67 80 88 90 104 128 160 189 and 200 ka before the present using this and other published data coupled with a better understanding of late quaternary sea level fluctuations and palaeocoastline configurations it is concluded that these depositional phases appear to be controlled by interglacial and subsequent interstadial sea level high stands these marine transgressions and regressions allowed onshore carbonate rich sediment movement and subsequent aeolian reworking to occur at similar points in the landscape on a number of occasions the lack of carbonates in more recent dunes oxygen isotope stages 1 2 and 4 5 is attributed not to leaching but to changes to carbonate production in the sediment source area caused by increased terrigenous material and or changes in the balance between the warm agulhas and nutrient rich benguela ocean currents

pleistocene coastal stratigraphy sea level highstands and neotectonism of the southern australian passive continental margin a review located in a tectonically stable intraplate setting and in the far field of former ice sheets the southern australian passive continental margin represents a globally important region for quantifying sea level during pleistocene highstands the stratigraphical record of the southern australian margin is dominated by geographically extensive coastal barrier estuarine and peritidal landforms of bioclastic temperate carbonate affinity a function of regional aridity siliciclastic successions dominate the eastern australian coastline despite the generally high level of tectonic stability regional contrasts are evident in the elevation of pleistocene shoreline deposits that largely relate to pre quaternary geotectonic setting the most complete record of pleistocene highstand deposits occurs in the murray basin coorong coastal plain region and indicates that interglacial sea level highstands for at least the past 11 interglacials did not deviate by more than 6 m from present sea level the pleistocene marginal marine record of southern australia is dominantly represented by coastal successions deposited during marine oxygen isotope stages 5e and 7 equating with relative sea level maxima of 2 6 m and greater than 1 m above present sea level apsl respectively intertidal facies of late pleistocene interstadial successions rarely occur above present sea level the most reliable record of glacio eustatic ice equivalent sea level is registered on coastlines developed on stable precambrian cratons such as the gawler craton eyre peninsula where a consistent elevation of 2 m apsl is registered for over 500 km for the last interglacial shoreline 125 ka copyright 2002 john wiley sons ltd

tectonics and sedimentation in the gulf of corinth and the zakynthos and kefallinia channels western greece abstract single channel seismic reflection profiling data are presented from the gulf of corinth and from the continental margin outside the gulf of patras different tectonic styles are exhibited in the two regions the gulf of corinth is occupied by a complex asymmetrical graben structure with major faults trending nearly perpendicular to the local tectonic zones of the internal hellenides the gulf is interpreted to have formed during the quaternary in response to approximately north south extensional stress the deep floor of the gulf is underlain by a sequence of turbidites up to 1 km thick affected by normal growth faulting that extends up to the sea floor the sea areas inside the ionian islands of zakynthos and kefallinia zakynthos and kefallinia channels occupy a broad structural depression that trends parallel to the local tectonic zones of the external hellenides and is situated on the continental side of the strophades continental margin rise the channels contain local nw se trending structural basins zakynthos and kefallinia basins whose geometry is controlled by reverse faults or thrusts with associated diapirism in triassic evaporites hydra bank is interpreted as a tilted fault block with a diapiric core and its faulted western margin can be traced into the zone of thrusting and diapirism in southeast kefallinia at the boundary between the ionian and pre apulian paxos zones of the external hellinides the zakynthos and kefallinia structural basins are filled with a variety of sediments including prodeltaic deposits in front of the modern delta complex of the acheloos river slumped masses and debris flow deposits and in the zakynthos basin occasional turbidites the boundary separating zones of extensional and compressional focal mechanisms for shallow earthquakes crosses the gulf of patras the inner part of which exhibits wnw ese trending graben tectonics apparently related to the gulf of corinth tectonic province onshore neotectonic studies around the gulf of patras are required in order to understand the nature and cause of the westward tectonic transition from wnw ese graben structures in the gulfs of corinth and patras to nw se oriented zones of subsidence with associated compressional tectonics and diapirism in the zakynthos and kefallinia channels

deep sea tsunami deposits triggered by the explosion of santorini 3500 y bp eastern mediterranean abstract the collapse of the santorini caldera after the catastrophic eruption of the bronze age 3500 y bp caused a tsunami wave that had catastrophic effects in the ionian basin including its deepest parts pelagic turbidites of local origin were deposited on the bottom of small perched basins of the southern calabrian western and central mediterranean ridges type a homogenite whereas a megaturbidite of distal origin presumably triggered by the tsunami wave hitting the shoreline of the sirte gulf was deposited on the ionian and sirte abyssal plains extending eastwards as far as the western herodotous trough depositing a thick acoustically transparent layer type b homogenite three core transects crossing the deformation front of the mediterranean ridge are presented and discussed a fourth transect of giant piston cores was collected on the abyssal plains located to the south of the mediterranean ridge all those to the west of the collision zone contain the holocene homogenite with a thickness in excess of 20 m whereas the cores taken from the herodotous abyssal plain east of the collision zone are devoid of the homogenite sedimentological analyses were performed on the only giant core that penetrated the sandy base of the homogenite and the underlying pelagic sediments of late pleistocene last glacial age the african provenance of this typical type b homogenite is corroborated by shallow water fauna derived from the north african shelf no sedimentological characteristics peculiar to tsunamiites are observed in the deep sea homogenite of the eastern mediterranean

luminescence dating of interglacial coastal depositional systems recent developments and future avenues of research abstract luminescence dating offers new opportunities to explore the evolution of quaternary marine coastal facies and landforms this review highlights the main advances in luminescence geochronology of interglacial coastal sediments through the analysis of 547 luminescence ages most of which were published during the last decade the majority of these reported luminescence investigations have been carried out along passive margin coasts since the turn of the century the discovery of a normalization procedure known as single aliquot regeneration sar has drastically reduced data scatter and improved precision with the consequence that quartz sar optically stimulated luminescence osl has become the dating protocol of choice for the last interglacial lig period a more complex technique known as thermally transferred osl tt osl is presumably proposed for dating older interglacials of the mid pleistocene and beyond feldspar luminescence is increasingly being applied to dating pleistocene sea level high stands due to a much higher dose saturation level than quartz osl the use of feldspar irsl infrared stimulated luminescence is limited by the occurrence of variable but ubiquitous anomalous fading af following the advent of af correction methods several middle pleistocene sites have been amenable to dating albeit with significant related uncertainties recently new protocols involving the measurement of post ir irsl at elevated temperatures have yielded relatively coherent ages for interglacial sediments up to ca 300 ka quartz osl tt osl af corrected irsl and post ir irsl ages are generally correlated with periods of sea level high stands a few ages are reported from the early and middle part of the middle pleistocene as mis11 9 and more commonly mis7 high stands are documented in strongly uplifting active margin coasts however by far the most obvious age peak corresponds to the end of the lig the mis5e shoreline is probably the most studied and luminescence dated coastal feature of all as the chronology of the sea level markers is crucial to assess global eustatic sea level variations through the course of the last interglacial nevertheless the observed abundance of young 100 120 ka luminescence ages for presumed mis5e sediments may underline methodological issues and or reflect the higher preservation potential of late regressive sequences on the other hand the occurrence of geographically distant reports of mis5a high stand might reflect a true eustatic origin for this event age analysis supports the impression of general reliability of luminescence for the timing of former sea level high stands there is a clear need to address issues in dose rate variability in the phenomenology of fading in feldspar and in the behaviour of luminescence growth with dose both in laboratory and natural conditions these could be addressed and properly evaluated by dating different minerals as multiple or single grains with consequent variable internal dose rates more robust practices in the application of luminescence dating techniques could eventually constrain the age uncertainties to no better than 2 3 therefore the strength of luminescence as a dating tool is more in terms of its extended age range and the ubiquity of datable material

building of shore oblique transverse dune ridges revealed by ground penetrating radar and optical dating over the last 500 years on tottori coast japan sea abstract coastal dunes provide valuable information on the past aeolian activity better characterization of internal dune structures and their chronology potentially can greatly improve the interpretation of past environmental changes ground penetrating radar gpr and optically stimulated luminescence osl dating was applied to two transverse dune ridges which are arranged obliquely to the shoreline on the tottori coast japan sea data shows that the inner ridge has a core of pleistocene dune draped with holocene sand while the outer ridge consists only of holocene sand the holocene dune is generally dominated by landward migration but the outer ridge shows a clear seaward accretion during the 18th century ad osl dating showed concordant results with radar stratigraphy and topographic changes since ad 1932 revealed by maps from this we were able to present the first detailed report of the multi decadal to centennial scale dune formation for the last 500 years in east asia contemporaneous with the little ice age during which many european coastal and inland dunes were activated in east asia it is thought that the winter monsoon plays an important role for aeolian processes the seaward migration during the 18th century reflects a decrease in wind capacity which restricted sand transport nearshore being related to decline in winter monsoon revealed by chinese historical documents in contrast two remarkable events of landward accretion occurred in ad 1580 1640 and around ad 1840 respectively corresponding to periods of increased dust fall in china which suggest enhanced winter monsoon the zone of maximum sedimentation shifted through time from the inner to outer ridges and also towards the seaward end of the shore oblique dune ridge reflecting an expansion of the dune field caused by shoreline progradation these suggest that the effective combination of gpr and osl dating was critical in detailed characterization of the complicated depositional pattern of the transverse dune ridge and thus in reconstruction of the past aeolian activity

high rates of sea level rise during the last interglacial period sea level during the last interglacial stood at least 4 m higher than at present with evidence of short term fluctuations of up to 10 m a new continuous sea level record from the red sea and coral ages suggest that during these fluctuations sea level changes were on the order of 1 6 m per century

sea level and deep water temperature changes derived from benthic foraminifera isotopic records we show that robust regressions can be established between relative sea level rsl data and benthic foraminifera oxygen isotopic ratios from the north atlantic and equatorial pacific ocean over the last climatic cycle we then apply these regressions to long benthic isotopic records retrieved at one north atlantic and one equatorial pacific site to build a composite rsl curve as well as the associated confidence interval over the last four climatic cycles our proposed reconstruction of rsl is in good agreement with the sparse rsl data available prior to the last climatic cycle we compute bottom water temperature changes at the two sites and at one southern indian ocean site taking into account potential variations in north atlantic local deep water 18o our results indicate that a last glacial maximum lgm enrichment of the ocean mean oxygen isotopic ratio of 0 95 is the lowest value compatible with unfrozen deep waters in the southern indian ocean if local deep water 18o did not increase during glacials with respect to present such a value of the lgm mean ocean isotopic enrichment would impose a maximum decrease in local bottom water 18o at the north atlantic site of 0 30 during glacials

effects of holocene climate change on mercury deposition in elk lake minnesota the importance of eolian transport in the mercury cycle sediments in elk lake minnesota consist of 10 400 varve layers that provide a precise chronology for holocene fluctuations in climate and biota recorded in the strata progressively greater concentrations and accumulation rates of mercury since ca a d 1875 reflect deposition of anthropogenic mercury additions to the atmosphere within the holocene record are numerous short intervals in which mercury concentrations and accumulation rates exceed the modern values the highest mercury concentrations formed ca 8 ka coincident with a rapid change from cool moist conditions to warm dry conditions a related change in flora from pine forest to prairie caused destruction of organic forest soils and the release of mercury that had been sequestered in them resulting in a short lived pulse of mercury to the lake accumulation rates of mercury were highest during the 4 k y mid holocene dry interval and show a correlation with periods of rapid deposition of eolian dust the mercury was probably bound to wind borne mineral particles which were derived from an unidentified mercury rich source region west of elk lake

trench floor sedimentary sequences in a palaeozoic subduction complex eastern australia abstract late palaeozoic rocks of the new england fold belt in eastern australia preserve from west to east a continental volcanic chain a forearc basin and a subduction complex the gundahl complex and the coffs harbour sequence are two tectono stratigraphic units in the subduction complex that consist of contrasting trench floor sedimentary sequences the gundahl complex is a tectonic melange containing slabs and blocks of greywacke greywacke argillite argillite argillite tuff bedded chert and greenstone some slabs have representative sections of the pre melange stratigraphic sequence that resemble trench floor deposits other slabs have thick sequences of argillite and argillite tuff and are probably trench slope basins kneaded into the subduction complex the coffs harbour sequence is a faulted folded assemblage of turbidites the structural style regional extent and near strike parallel sediment movement directions suggest it was probably deposited in a trench probable environments of turbidite deposition are starved trench non channelized trench and outer fan submarine settings the facies differences between the two units reflect slower subduction rates and higher sedimentation rates for the coffs harbour sequence

sedimentation on the ionian active margin hellenic arc provenance of sediments and mechanisms of deposition abstract lithological sedimentological mineralogical and faunal analyses of twenty cores from the western peloponnesus margin and adjacent matapan trench permit the origin of the sediments and the processes of sedimentation to be defined in some detail except for the ash layers derived from the ischian province the major part of the sediment is local in origin peloponnesus analyses of heavy light and clay minerals enable three main provinces to be distinguished each of these provinces includes one or more slope basins and a portion of trench without lateral connection between them and mixing of inputs the diversity and complexity of sedimentary structures the granulometric characters the mixed fauna molluscs and ostracods and the variability of rates of sedimentation all testify to the prevalence of reworking phenomena and gravitative processes these data confirm and elaborate on the model of sedimentation deduced from seismic studies in which sediments are successively trapped released by the slope basins and transferred via channels and canyons towards the underlying trench basins this cascade feeding appears characteristics of this subductive sedimentary environment

the evolution of coastal barrier systems a case study of the middle late pleistocene wilderness barriers south africa abstract barrier systems contain lengthy but complex records of long term environmental fluctuations the wilderness embayment south africa contains a system of shore parallel barriers reaching up to 200 m above modern sea level this study reports the results of chronological topographical both on and off shore sedimentological and micromorphological analyses within the wilderness embayment sixty one new luminescence ages from sixteen sites in unconsolidated dunes and three separate barriers are presented which when combined with previously published luminescence ages from the area provide a high resolution chronological framework for the emplacement and evolution of the barrier system the preserved barriers have been constructed within at least the last two glacial interglacial cycles with notable phases between 241 221 ka 159 143 ka 130 120 ka 92 87 ka and post 6 ka multiple phases of barrier construction occurred during sea level highstands with sediment deposition on each individual barrier occurring over at least two interglacials holocene evolution of the system sheds light on earlier events with dune preservation occurring only during early regression from the mid holocene highstand tectonic stability at wilderness allowed glacio eustatically formed shorelines to occupy similar positions on multiple occasions this in conjunction with a relatively humid climate and a well vegetated landscape enabled deflated sediment from beaches to form dunes which stacked upon each other to form an extensive and complex vertical accretionary sequence repeated erosion and recycling of pre existing barriers as well as barrier construction on what is currently the off shore platform during still stands in sea level regressional cycles when sea levels dropped below ca 50 m from the present day has added to the complexity of the preserved terrestrial barrier record the wilderness barrier system contrasts with barriers developed elsewhere in the world where higher rates of crustal uplift have allowed preservation of a more complete and more widely spaced palaeorecord this research also shows the utility of integrating off shore topography as revealed by bathymetry with terrestrial topographic data for the better understanding of the evolution of palaeo coastlines and the preserved dune record found on present day coastal plains local variation in the topography of the continental shelf at wilderness has generated spatial and temporal complexity within the sedimentary records of individual barriers as well as having a significant influence on preservation

seasonal control on coastal dune morphostratigraphy under a monsoon climate mui ne dunefield se vietnam abstract having developed in the later quaternary period the mui ne dunefield representing the upper most portion of a major coastal barrier complex in se vietnam formed by wind regimes associated with the asian monsoon climate the barrier complex is 100 km long and higher than 150 m in elevation but despite its large dimensions research on its geomorphological and geological characterization is limited several active dune fields extend 2 10 km landwards from the coast while the rest of the barrier surface is stabilized we applied ground penetrating radar gpr and quartz optically stimulated luminescence osl dating to the transverse dunes of the mui ne dunefield to characterize the morphostratigraphy and recent aeolian sedimentation history currently the dunes have a relief of typically 5 10 m and a wavelength of 50 100 m they are driven by the northeasterly winter monsoon winds and reversed with minor relief in response to the southwesterly summer monsoon gpr profiles and osl ages define three morphostratigraphic units the modern holocene and pleistocene dune units the gpr data of the modern dune unit is dominated by a series of steep reflections that dip exclusively towards the west reflecting the winter monsoon and is punctuated by reactivation surfaces evidence for the wind reversal is not preserved in the sediment successions but is represented by reactivation surfaces thus a subunit bounded by the reactivation surfaces defines annual deposition the preservation potential of a subunit varies with the migration rate of the transverse dune and in the fastest migrating dunes approximately one subunit was preserved every year 1 1 0 6 subunit yr the modern dunes are generally younger than 100 years and have migrated wsw at net rates of 0 6 2 5 m yr the holocene dune unit is as thick as the modern unit although it spans a period ten times longer reflecting the lower preservation potential of the transverse dunes as sedimentary records due to erosion associated with their migration the rate of dune migration suggests that an aeolian contribution of coastal sands has occurred following the sea level highstand of the middle holocene accounting for the extent of the active dunefields this mode of the barrier accumulation is considered as an analogue for earlier highstand events however the dunefields only cover a fraction of the entire barrier it is thus inferred that barrier formation occurred over a long period probably encompassing several glacial interglacial cycles sand accumulation during the lowstand either by transport of sand from the subaerially exposed shelf and or reworking of sand emplaced during the prior highstand may contribute significantly to the barrier development

mechanisms of sediment transport and dispersion in a tectonically active submarine valley canyon system zakynthos straits nw hellenic trench abstract physical oceanographic and geophysical data sets are used to examine sediment transport processes currents were directed generally along the axis of the valley canyon system and in an area of low tidal range are attributed to regional weather patterns near bed and near surface currents are opposed both in terms of instantaneous observations and net lagrangian drift near bed down canyon water movement provides a mechanism for the offshore movement of fine grained sediment slope failures have been identified in the geophysical records and are considered to be controlled by earthquakes and salt diapirism in a tectonically active area these failures as mass displacement or slow down slope creep result in debris infill and the generation of turbidity currents fine grained sediments resuspended by the turbidity currents would be transported down canyon by the slowly moving near bed residual water movement hence the dominant transport mechanisms in the valley canyon system are 1 frequent mass sediment failure and 2 nearly continuous down channel fine grained suspended sediment movement

the gundahl complex of the new england fold belt eastern australia a tectonic melange formed in a palaeozoic subduction complex abstract the new england fold belt of eastern australia preserves a palaeozoic fore arc terrain with a magmatic arc fore arc basin and a subduction complex the gundahl complex is a tectonic melange of regional extent in the subduction complex the matrix and slabs of the gundahl complex have six mappable lithofacies argillite greywacke argillite greywacke argillite tuff bedded chert and greenstone the argillite matrix is pervasively sheared with many slickensided shear fractures locally the matrix is formed by highly sheared greenstone greywacke and greenstone blocks are affected by internal shear zones and the blocks themselves pinch and swell folds in places with axial surface spaced cleavage are common within those slabs comprised of well bedded sequences bedding plane shear and faulting at a high angle to bedding also occur in these slabs on a map scale much of the gundahl complex comprises slabs up to 10 km long in imbricate fault bounded slices which repeat the disrupted pre melange stratigraphic sequence elsewhere there are lithologically distinctive blocks containing thick coherent sequences which are structurally incorporated into the gundahl complex the unit is believed to have formed by accretion imbrication and subsequent tectonic disruption of arc derived sediments and less abundant pelagic sediment and greenstone in an ancient subduction complex

sedimentation and deformation in the amlia fracture zone sector of the aleutian trench abstract a wedge shaped landward thickening mass of sedimentary deposits composed chiefly of terrigenous turbidite beds underlies the west south west trending amlia sector 172 20 173 30 w of the aleutian trench pacific oceanic crust dips northward beneath the sector s sedimentary wedge and obliquely underthrusts 30 off normal the adjacent aleutian ridge the trench floor and subsurface strata dip gently northward toward the base of the inner trench slope the dip of the trench deposits increases downsection from about 0 2 at the trench floor to as much as 6 7 just above basement the wedge is typically 2 2 5 km thick but it is thickest 3 7 4 0 km near the base of the inner slope overlying the north trending amlia fracture zone and also east of this structure slight undulations and relatively abrupt offsets of the trench floor reflect subsurface and generally west trending structures within the wedge that are superimposed above ridges and swales in the underlying oceanic basement the southern or seaward side of some of these structures are bordered by high angle faults or abrupt flexures across these offsets the northern side of the trench floor and underlying wedge is typically upthrown west flowing turbidity currents originating along the alaskan segment of the trench 1200 km to the east probably formed the greater part of the amlia wedge during the past 0 5 m y the gentle northward or cross trench inclination of the trench floor and underlying wedge probably reflects regional downbending of the oceanic lithosphere and trench floor basement faulting and rotation much of the undulatory flexuring of the trench wedge can be attributed to differential compaction over buried basement relief however abrupt structural offsets attest to basement faulting faulting is associated with extensional earthquakes in the upper crust the west trending basement offsets are probably normal faults that dip steeply south or antithetic to the north dip of the subducting oceanic crust up to arc extensional faulting can be attributed to the downbending of the pacific plate into the aleutian subduction zone the rupturing direction and dip is controlled by zones of crustal weakness that parallel north pacific magnetic anomalies which were formed south of a late cretaceous early tertiary spreading center kula pacific ridge the strike of these anomalies is fortuitously nearly parallel to the amlia sector the up to arc fracturing style may locally assist in elevating blocks of trench deposits to form the toe of the trench s landward slope which is in part underlain by a compressionally thickened accretionary mass of older trench deposits compressional structures that can be related to underthrusting are only indistinctly recorded in the turbidite wedge that underlies the trench floor

modelling palaeosol preservation in aeolian dunes in some of the world s desert and desert marginal areas e g simpson strzelecki australia dunefields preserve well developed palaeosols whereas in other regions with broadly similar climatic regimes and topography e g southwest kalahari the dunes are characterized by very poorly developed internal stratigraphy it has been postulated that dunes such as those in the kalahari may never have had conditions conducive to soil formation or that soils once formed but any evidence of palaeosols has been lost due to reworking this study develops and applies a one dimensional numerical model to simulate dune development soil formation and soil preservation variables in the model allowed experimentation on the influence of sediment supply the time taken for soil to form and the additional resistance to erosion offered by the soil reduced sediment supply plays a vital role in landscape development during periods of initial pedogenesis although re exhumed palaeosols influence sediment supply the effect is minimal although under almost all parameterized conditions more than half and up to 80 90 of those soils initially formed are lost due to reworking evidence of their past formation remains in the large majority of profiles and the dominant factor in controlling the preservation of palaeosols is the frequency of their formation the implication is that where dunes are found without palaeosols the most likely albeit not certain inference is that they have never formed counter intuitively the limited sediment supply means their additional resistance to erosion becomes almost inconsequential to their preservation at least until the unit approaches complete invulnerability short chronostratigraphic hiatuses around palaeosols are normal and although long gaps can occur they are extremely infrequent where such gaps are observed in field studies external forcing factors e g climatic or environmental changes are implied as they are highly unlikely to result from stochastic net preservation copyright 2014 john wiley sons ltd

modelling the occurrence of gullies in rangelands of southwest spain gully erosion has been recognized as an important soil degradation process in rangelands of southwest spain in this paper a relatively new data mining technique called multivariate adaptive regression splines mars was applied to construct a model capable of predicting the location of gullies a large database was used to support the model composed of a target variable presence or absence of gullies and 36 independent variables related to topography lithology soils rainfall land use and vegetation cover the performance of the model was evaluated using the receiver operating characteristic roc curve for five external datasets the model had high predictive power with values for the area under the roc curve of the external validation datasets varying from 0 75 to 0 98 1 0 being perfect prediction the most important variables explaining the spatial distribution of gullies were lithology and soil type finally the model was compiled and implemented into a geographical information system to obtain maps of susceptible areas for gully erosion these maps show that approximately 7 of the study area presents favourable conditions for the development of gullies the results demonstrate that mars constitutes a valuable model in geomorphic research and could also be a useful tool for assessing the impacts of changing climate and land use on gully erosion copyright 2009 john wiley sons ltd

sedimentation in the zakynthos channel a conduit link to the hellenic trench eastern mediterranean abstract sedimentological oceanographic and geophysical data sets are used to examine contemporary and past transport processes in a tectonically active submarine valley canyon which acts as a feeder area to a trench system around 4000 m in depth provinces are identified together with the major redistribution processes active over the area the conclusions are that 1 the zakynthos channel is a major proximal source for a transport system which has its distal end in the north matapan trench basin 2 tectonically induced movement is the major mechanism triggering down slope mass gravity flow 3 the holocene late pleistocene facies associated with the upper reaches of the valley canyon system are dominated by local terrigenous sources and 4 sedimentation rates vary from being moderately high in the shallow water continental shelf feeder provinces low along the conduit axis high in the perched basin and extremely high at the distal end

active faults deformation rates and quaternary paleogeography at kyparissiakos gulf sw greece deduced from onshore and offshore data abstract kyparissiakos gulf forms a 45 km long zone located at 70 80 km east from the hellenic trench with a general direction nnw sse onshore studies show the existence of several neotectonic horsts and grabens bounded by e w trending normal faults thrust sheets of the underlying hellenides crop out within the horst areas and younger sediments mostly lower pleistocene have been deposited in the grabens the age of the marine sediments is mostly lower pleistocene throw rate on the normal faults varies between 0 7 and 1 0 mm yr accommodating extension in the n s direction subsidence rates during early pleistocene are between 0 1 and 0 3 mm yr whereas uplift rates during middle pleistocene present are between 0 18 and 0 50 mm yr offshore data were obtained using bathymetric and air gun litho seismic profiles the shelf has been disrupted by active faults with several meters of throw average holocene throw rates are 0 4 0 6 mm yr but in some areas adjacent filiatra and olympia values greater than 3 mm yr are detected holocene and upper pleistocene marine sediments thicken gradually to the north as do the marine lower pleistocene sediments onshore a nnw sse offshore longitudinal fault parallel to the kyparissiakos coast with throw rate above 3 mm yr is the dividing structure between the uplifted coastal area and the present day gulf this indicates a major change in paleogeography between early and middle pleistocene present day transition from e w compression in the hellenic trench to e w extension in the kyparissiakos gulf and to n s extension in western peloponnesus is discussed the development of e w structures in western peloponnesus since latest pliocene may be related to the central hellenic shear zone which accommodates differential gps rates between northern greece and southern peloponnesus

recent gravitative mass movements in a highly tectonically active arc system the hellenic arc abstract the hellenic arc system is located within one of the world s most seismically active areas and has experienced extreme tectonism throughout tertiary and quaternary times this paper discusses the various types of gravitative mass movements that have been detected and examines their causative factors in environments of high tectonic and seismic activity the areas surveyed are the sporadhes and corinth grabens in the back arc basin the zante cephalonia shelf on the inner slope of the hellenic trench and the kythera ridge in the outer island arc the various types of gravitative mass movements that have been documented include i sliding of large masses with no or only slight internal deformation ii sliding of masses with disintegration of the sediment fabric to debris flows and iii slow downslope creep the mass movements are associated with fault escarpments delta fronts and well stratified slopes with slope gradients ranging from 2 to 40 earthquakes seem to be the main mechanism initiating mass movement but other mechanisms such as increasing topographic gradient gas in the sediment pores and heavy rain can also independently trigger and or contribute to the initiation of mass movements

orbital and millennial scale variations in asian dust transport path to the japan sea abstract orbital and millennial scale variations in the asian monsoon and its probable association with the dansgaard oeschger d o cycles have been demonstrated by previous studies however the origin and nature of such variations are poorly understood the japan sea is located down wind of the arid areas of the eurasian continent and thus receives significant amounts of aeolian dust consequently the hemipelagic sediments of the japan sea are expected to record a continuous aeolian dust accumulation which may provide information about the past variations in asian monsoon grain size flux and provenance of aeolian dust in the sediments were examined using two sediment cores obtained from the northern and southern parts of the japan sea in order to understand the spatial variability of asian monsoon since the silt fraction of the detrital materials in hemipelagic sediments of the japan sea is composed predominantly of aeolian dust the grain size flux and provenance of the silt fraction were examined the taklimakan desert loess plateau and siberia northeast china areas were identified as possible source areas of aeolian dust in the sediments of the japan sea based on the electron spin resonance esr signal intensity and crystallinity of quartz moreover the relative contribution of aeolian dust from each source area was estimated based on the esr signal intensity and crystallinity of quartz aeolian dust fluxes from the two source areas at the southern site were then estimated grain size and flux of eolian dust at the northern site and fluxes of aeolian dust from two source areas at the southern site show orbital scale variations in harmony with the insolation change at 30 n in june these results indicate orbital scale changes in the extent of the arid area and or frequency of dust storms in the taklimakan desert loess plateau and siberia northeast china areas and suggest that southward northward shifts of the westerly jet axis occurred together with either intensified weakened winter monsoon decreased increased winter precipitation in the siberia northeast china area or southeastward northwestward shifts of summer monsoon limit during periods of smaller larger insolation at 30 n in june in addition to these orbital scale variations millennial scale variations possibly associated with the d o cycles are observed in the grain size record of aeolian dust at the two sites based on analogy with orbital scale variations these millennial scale variations are considered to reflect millennial scale changes in the position of the westerly jet axis together with the changes either in winter monsoon intensity winter precipitation or position of summer monsoon limit our results suggest n s oscillations in the westerly jet and summer monsoon limit and changes in the intensity of the winter monsoon on orbital and millennial timescales

the luminescence chronology of dune development on the maputaland coastal plain southeast africa abstract geomorphological and lithostratigraphic mapping of dune systems on the maputaland coastal plain of northeastern kwazulu natal province south africa has defined the relative age relationships between the complex pattern of quaternary parabolic and hummocky dunes sand megaridges and the composite coastal barrier dune cordon here infra red stimulated luminescence irsl ages are presented in the context of regional stratigraphic relationships and serve to bracket the period of accumulation of the main dune systems the luminescence ages challenge the widely held belief that the north south aligned dune pattern reflects a coastward younging sequence the framework of ages highlights the spatial variations in dune mobilization and long accretion history on some dune forms weathered dune and interdune wetland sediments spanning from prior to marine isotope stages mis 11 and up to mis 7 underlie the coastal plain at least two generations of decalcified aeolianite of mis 5 and 4 form the core of the complex coastal barrier dune on the coastal plain frequent sand mobilization events during mis 3 2 resulted in the development of discrete complexes of highly extended northward directed parabolic dune systems and reworking of the crest of the central sand megaridge the luminescence dated dune mobilization history brackets the period of formation of interdune and lacustrine peat and diatomite deposits during the holocene marine transgression at least four laterally extensive complex transverse ridges of coalesced ascending parabolic dunes accreted against the aeolianite core of the coastal barrier polyphase dune formation and remobilization is discussed in the context of the regional groundwater and vegetation responses to global climatic changes wind regimes and glacio eustatic sea level fluctuations

aeolian beach ridges and their significance for climate and sea level concept and insight from the levant coast east mediterranean abstract relict beach ridges of aeolian origin and associated soils are often used for inferring relative sea level and climate with contrasting results most studies link the aeolian coastal deposits to regressive phases some to high sea level stands and a few to intermediate relative sea level positions we interpret the apparent contradictions as indicating the lack of an over arching concept and the inconsistent usage of sea level related terms in this paper we present an integrated morpho sedimentological concept for a microtidal mid latitudinal coast and review existing data from the levant east mediterranean coast to evaluate the concept and to eliminate nomenclatural confusion a coastal depositional environment in a semi arid environment consists of shallow marine aeolian and alluvial facies which together form an aeolian beach ridge complex as a package of strata which respond simultaneously to sea level change a transgressive complex forms through reworking or overstepping of the coastal foredune and a regressive complex forms by downstepping under transgression the aeolian beach ridge represents the highstand deposit and its adjacent shallow marine sediment is the transgressive deposit under regression the complex represents the falling stage and the associated downdip surface marks the lowstand on the levant coast we find chronologically well constrained offlapping aeolian beach ridges as parts of six downstepping beach ridge complexes formed between 200 ka and 10 ka the complexes represent the falling stage systems tract fsst of a short lived 5th order depositional sequence when the shoreline shifted from a position close to the modern coastline to the shelf or below the shelf edge three of these fssts and their up dip and down dip super bounding surface together form the 4th order 100 ka sequence of the last interglacial glacial cycle the absence of transgressive highstand and lowstand systems tract is explained by the poor preservation potential due to the small sediment budget of the complex the falling stage complex has a high preservation potential because sediment source area increases while the sand drift potential remains above the local threshold on the levant coast sand delivery to the backshore continued during relative sea level falls for distances of up to 10 km between dune and coastline which is unprecedented in most modern analogues the significance of the dune soil succession for climate is limited because the dunes are governed by relative sea level change the vegetation response to changes in precipitation is non linear and the dune dynamics are characterised by low resilience and hysteresis

the effect of some watershed soil characteristics and morphometric factors on the relationship between the gully volume and length in fars province iran abstract a survey consisting of 146 first order gullies selected from five sites with different land use soil and watershed properties was carried out to estimate the parameters of the empirical power function in order to describe the relationship between the gully volume and length in fars province iran subsequently the gullies were clustered into seven groups a to g based on nine morphometric factors the linearized functions were fitted to the natural logarithms of the volume and length in each group and the parameters a and b were determined the obtained a and b parameters are in the ranges of 1 0 10 8 and 0 8 1 4 respectively comparison of a and b parameters in each group with the mean of nine factors and the mean soil watershed and land use characteristics in each group showed that the gully volume and average cross section are correlated with the gully depths in different sections and the gully head slopes also it was shown that the parameters of fitted functions to the plots of gully volumes versus gully lengths are proportional to width at the gully heads the gully widths at the top and bottom of the five meter sections are correlated with the average upstream watershed area of the gullies

geomorphological chemical and physical study of calanchi landforms in nw sicily southern italy abstract this work deals with an integrated geomorphological and chemical physical study of calanchi landforms in two sites ottosalme and catalfimo of nw sicily southern italy developed on dominant silty clay deposits the calanchi fronts are characterized by different morphological features and dominant geomorphic processes sharp knife edged ridges and concentrated water runoff dominate at ottosalme and smoother landforms affected by mass movements mud flows and translational slides prevail at catalfimo we focused on some geochemical and physical parameters such as ph total dissolved salts sodium adsorption ratio sar porosity plastic and liquid limits as possible causes of the above differences with special emphasis on their role in discriminating the behavior of peculiar microforms such as a weathered outer crust and the corresponding inner massive portion unweathered substrate our results show that the main chemical physical features of calanchi morphologies and microforms often display no clear correlations with respect to those reported in the existing literature pointing to a higher complexity of patterns and behaviors in particular all samples consist of dispersive material sar values 10 but a more plastic and liquid behavior at catalfimo can explain a higher occurrence of landslides and smoother morphology than at ottosalme higher sar values at ottosalme well explain the dominance of concentrated water erosion the chemical behavior of the studied microforms is better described by ph being alkaline with higher values in the inner substrate than the outer crust and appears to minimize the effects of all other parameters and their responses to other external controlling factors lower sar values in the crust suggest that clay dispersivity is not the prominent factor controlling its surface detachment and mobility downslope which is more likely promoted by its higher porosity and consequent water absorption than the inner portion with changes in the saturation state shear strength and water pressure

radiocarbon calibration curve spanning 0 to 50 000 years bp based on paired 230 th 234 u 238 u and 14 c dates on pristine corals abstract radiocarbon dating is the most widely used dating technique in the world recent advances in accelerator mass spectrometry ams and sample preparation techniques have reduced the sample size requirements by a factor of 1000 and decreased the measurement time from weeks to minutes today it is estimated that more than 90 percent of all measurements made on accelerator mass spectrometers are for radiocarbon age dates the production of 14 c in the atmosphere varies through time due to changes in the earth s geomagnetic field intensity and in its concentration which is regulated by the carbon cycle as a result of these two variables a radiocarbon age is not equivalent to a calendar age four decades of joint research by the dendrochronology and radiocarbon communities have produced a radiocarbon calibration data set of remarkable precision and accuracy extending from the present to approximately 12 000 calendar years before present this paper presents high precision paired 230 th 234 u 238 u and 14 c age determinations on pristine coral samples that enable us to extend the radiocarbon calibration curve from 12 000 to 50 000 years before present we developed a statistical model to properly estimate sample age conversion from radiocarbon years to calendar years taking full account of combined errors in input ages and calibration uncertainties our radiocarbon calibration program is publicly accessible at http www radiocarbon ldeo columbia edu along with full documentation of the samples data and our statistical calibration model

an absolute chronology for the raised beach and associated deposits at sewerby east yorkshire england the raised beach sediments revealed in the cliffs at sewerby east yorkshire are widely regarded as ipswichian in age previously reported evidence for this dating is reviewed and new results from a range of luminescence dating techniques applied to the blown sand deposit overlying the raised beach are reported these provide the first absolute date for the sewerby site of 120 84 11 82 ka which places the blown sand at the boundary between oxygen isotope stages ois 5e and 5d as the underlying raised beach is little older than the blown sand it probably formed during ois stage 5e as suggested by the faunal evidence

emplacement of the recent sedimentary cover and processes of deposition on the matapan trench margin hellenic arc abstract high resolution seismic surveys across the southern peloponnesus margin help to define the configuration and geometry of the unconsolidated sedimentary cover on the basis of acoustic character structural framework and results of dsdp cores two sedimentary units are distinguished a well stratified quaternary unit and an acoustically transparent pliocene series overlying a deep acoustic unit of different nature and age the plio quaternary series appears highly discontinuous along most of the margin the slope displays a series of basins where locally sediment thicknesses exceed 1000 m these basins separated by structural ridges generally devoid of sediment are often connected to the trenches by canyons the mechanism of sedimentation termed cascade feeding consists in a succession of depositions and of removals of sediment from basin to basin until the trench basins are reached the major physiographic features involved in this mechanism slope basins canyons ridges depressions trenches are directly controlled by structural trends oriented n140 and n70 related with the neotectonic evolution of the hellenic arc

gully erosion susceptibility assessment by means of gis based logistic regression a case of sicily italy article i nfo article history this research aims at characterizing susceptibility conditions to gully erosion by means of gis and multivariate statistical analysis the study area is a 9 5 km 2 river catchment in central northern sicily where agriculture ac tivities are limited by intense erosion by means of field surveys and interpretation of aerial images we prepared a digitalmap of thespatial distribution of 260 gulliesinthestudy area inaddition fromavailable thematicmaps a 5 m cell size digital elevation model and field checks we derived 27 environmental attributes that describe the variability of lithology land use topography and road position these attributes were selected for their potential influence on erosion processes while the dependent variable was given by presence or absence of gullies within two different types of mapping units 5 m grid cells and slope units average size 2 66 ha the functional re lationships between gully occurrence and the controlling factors were obtained from forward stepwise logistic regression to calculate the probability to host a gully for each mapping unit in order to train and test the predictive models three calibration and three validation subsets of both grid cells and slope units were randomly selected results of validation based on roc receiving operating characteristic curves attest for acceptable to excellent accuracies of the models showing better predictive skill and more stable performance of the susceptibility model based on grid cells

land ocean linkages over orbital and millennial timescales recorded in late quaternary sediments of the japan sea late quaternary sediments of the japan sea are characterized by centimeter to meter scale alternations of dark and light layers which are synchronous basinwide high resolution analyses of the sediments from ocean drilling program site 797 reveal that deposition of the meter scale alternations reflect variations in paleoceanographic conditions which were closely associated with glacio eustatic sea level changes through the modulation of the volume and character of the influx to the sea through the tsushima strait the centimeter to decimeter scale alternations reflect millennial scale variations which are possibly associated with dansgaard oeschger d o cycles with each dark layer appearing to correspond to an interstadial this variability is attributed to the development of a humid climate in central to eastern asia and the consequent increase in discharge from the huanghe and changjiang rivers during interstadials this caused expansion of the east china sea coastal water ecscw which penetrated more strongly into the japan sea the increased influence of the lower salinity nutrient enriched ecscw reduced deep water ventilation and enhanced the surface productivity leading to the development of anoxic bottom waters and deposition of the dark layers thus the centimeter to decimeter scale alternations of the dark and light layers record wet and dry cycles in central to eastern asia possibly associated with d o cycles

low frequency current variability at the straits of crete eastern mediterranean current meter data from six moorings are analyzed to study current variability at the straits of the cretan arc which connect the south aegean sea with the eastern mediterranean the three layers in which the current meters were deployed show different current characteristics the upper layer shows evidence of the asia minor current in the rhodes strait and a clockwise eddy in the karpathos strait water in the middle layer moves slowly into the south aegean the bottom current meters in kassos and antikithira straits recorded currents steady in amplitude and direction with speeds equal to or higher than those observed in the upper layer the observations suggest a significant outflow 0 5 sv of cretan dense water cdw to the levantine and ionian seas rotary empirical orthogonal functions are used to extract and describe the coherent part of the variability forty four percent of the total variability is described by the first three empirical orthogonal functions less than 20 of the current variability of the western strait is coherent with variability of the eastern straits the coherent part of the variability refers mainly to periods longer than 20 days the current meter data are compared with atmospheric pressure showing good correlation during the first period of the measurements when a major atmospheric pressure low passed over the aegean

palaeoenvironmental reconstructions from linear dunefields recent progress current challenges and future directions abstract this paper reviews recent progress in the use of linear dunes as geoproxies of late quaternary environmental change summarises the challenges facing their use and explores some potential solutions to these challenges large areas of the swathes of linear dunes which occupy the continental interior of southern africa australia and parts of central asia and southern america currently have limited or negligible aeolian activity they have been recognised as offering potential information about past environments for more than a century but only with the widespread application of luminescence dating during the 1990s did they realistically start to offer the prospect of being an extensive dateable proxy of late quaternary palaeoenvironments and possibly palaeoclimates dating aeolian dune sands with luminescence methods is generally although not always relatively straightforward over the past twenty years a large number 1000 of luminescence ages have been added to the global dataset yet there has also been significant criticism of some of the rationale underpinning much of the interpretation of the records derived at the landscape scale developments of arguably equal importance have come from improved geomorphological understanding based on the wider availability of remotely sensed data and the paradigm of dunefield evolution as a self organising complex system current challenges are identified in three key regions incomplete understanding of how the process geomorphology of linear dunes affect the accumulation and preservation of sediment a lack of clarity regarding the temporal and spatial scale of the response in a dynamic environmental setting and uncertainty surrounding the drivers of changing rates of net accumulation solutions to these challenges lie within diverse research methodologies certainly further field study is required with improvement required in understanding system responses to changing environmental stimuli at scales from sedimentological to landscape in parallel the full implications of complex systems approaches to aeolian geomorphology for linear dunes lag behind the adoption of the concept to some other dune forms e g barchans the relationship between observed dune complexity and age from field data complicates previous suggestions that dune patterning may be purely a function of development time parallel to this lies the need to improve interpretation of the results of dune geochronological studies a suggestion is offered which aims to test the statistical significance of dune accumulation time series by comparison with a modelled system with unchanging external forcing despite the initial promise of linear dune records as a revolutionary source of palaeoenvironmental information in drylands the outcomes to date have been coarse although still valuable in resolution perhaps the most valuable realization has been that geomorphological understanding of these widespread landforms is incomplete

chronology of a late neolithic age site near the southern coastal region of fujian china an archaeological site at anshan in the coastal area of fujian province southern china was excavated in 2007 2009 and 2015 abundant artefacts including adzes cores bronze fishhook pottery an

measurements of rill and gully erosion in sicily this article reports the results of a field investigation aimed to characterize the morphology of both rills monitored at sparacia experimental area and two ephemeral gullies egs located in the tremamargi basin sicily italy at first the available literature data together with the measurements carried out in this investigation were used to show that the eg length is a key parameter for the estimation of the eroded volume then the comparison among the pairs length and volume corresponding to measured rills egs and gullies showed that the exponent of the power relationship is independent of the channelized erosion type rill eg and gully while a different scale factor has to be used for each erosion process finally a single relationship applicable to all channelized erosion processes was deduced applying the dimensional analysis and the self similarity theory copyright 2011 john wiley sons ltd

superficial and subterranean soil erosion in tabasco tropical mexico development of a decision tree modeling approach tropical countries suffer from a lack of financial resources to monitor and model sources and outcomes of soil degradation and therefore a scarcity of data in this study it was tried to model superficial and subterranean water erosion based on basic environmental variables such as geological formation soil type or vegetation cover data which are potentially available even in developing countries different forms of water erosion and karst or pseudokarst formations in tabasco southeastern mexico were estimated the study region 3500 km 2 consists of plain and hilly areas with an annual precipitation ranging from 2000 to 4000 mm main land use form is rangeland the area is geologically composed of sedimentary rocks limestone sandstone and conglomerates collecting data by field observations over the entire study area a cartography of different soil loss forms such as rill and gully erosion mass movement sinkholes and tunnels was created including field data from available maps of geological formation soil type precipitation and former land use 20 years ago additionally data collected in the field such as actual land use vegetation cover and inclination were added in the entire study area 1039 sites were affected by soil erosion with 2435 single manifestations of soil erosion 482 sites were found with one gully each 57 sites with erosion rills with a total of 416 392 sites with one mass movement each 85 sites with sinkholes with a total of 1122 and 23 sites with one tunnel each rendzic leptosols over oligocene limestone are strongly affected by sinkholes and tunnels in regions with inclinations of less than 5 this phenomenon is explained by karstic and pseudokarstic formation superficial erosion forms are mainly found on rendzic leptosols over shale sandstone and on eutric or peli eutric vertisols on andesit in areas with inclinations between 5 and 30 the application of classification trees allowed to successfully predict the occurrence of sinkholes and tunnels degree of agreement between prediction and observation very good to excellent even in areas with scarce data bases this could allow for easy identification of high risk areas predictive success of the occurrence of the different forms of superficial soil losses however is low superficial erosion seems to be mainly caused by more specific pedological factors nevertheless automated induction of classification trees can be a valuable tool for preliminary data analysis and hypothesis generation in areas with lack of local expertise and can guide erosion risk mapping and soil conservation planning 2007 elsevier b v all rights reserved

the lithinon slide a large submarine slide in the south cretan trough eastern mediterranean abstract twelve kilometers off the cretan south coast at water depths of 2000 2500 m a large slide mass covers part of the floor of the south cretan trough from four seismic reflection profiles it appears to cover over 100 km 2 the allochton which is called the lithinon slide consists of pliocene quaternary sediments vertical movements along a set of active normal faults delimiting the cretan margin and rapid loading of sediments on the cretan slope during quaternary glacio eustatic sea level changes played an important role in its genesis the slide is compared with analogues from other deeps its dimensions are best comparable to examples from the atlantic continental margins