coastal seismic wipe outs distribution controlled by pore water salinity abstract the relationship between seismic wipe outs methane accumulation and pore water salinity was investigated using high resolution seismic profiles pore water geochemical measurements and sediment property data from the white oak river estuary north carolina the estuary is a broad shallow drowned river valley filled with organic rich sediment where the salinity changes from fresh to sea water within 10 km uniboom seismic reflection profiles indicate a distinct pattern in the distribution of seismic wipe outs wipe outs dominate the upper estuary but are not observed in the lower estuary sediment pore water chlorinities decrease upstream but the sharpest gradients occur with depth at 50 cm depths in the upper half of the estuary pore waters typically have less than 100 mmol l 1 chloride even though overlying estuarine waters have 300 400 mmol l 1 chloride concave chloride profiles demonstrate that sediments in the upper estuary are actively flushed with fresh water moving upward through the sediments from underlying aquifers the associated decrease in interstitial sulfate concentrations combined with high organic carbon content provides favorable conditions for methane production and accumulation seismic wipe outs are correlated with areas of high methane concentrations and with sediments containing low pore water salinities

landslides and climate change in the italian dolomites since the late glacial abstract the paper deals with the relationship between the temporal occurrence of landslides and climatic changes in the italian dolomites since the late glacial after an introduction on the state of the art with particular reference to the alpine region the results of recent investigations in the two study sites are illustrated at cortina d ampezzo several landslides were dated mainly by the radiocarbon method the most ancient landslide event there involved large rock slides which affected the dolomitic slopes following the withdrawal of glaciers after the last glacial maximum lgm and also slides and flows mainly occurring in pelitic materials of the valley floors from 13 000 to 10 000 cal bp a later series of flows occurred between 5500 and 2500 cal bp in the upper badia valley alta badia the most ancient events go back to 10 000 and 9000 cal bp and correspond with earth flows that followed vast rotational slides affecting the bedrock up to a depth of about 50 m more recent earth flows involving more modest amounts of material took place between 6500 and 2300 cal bp by analysing the dates from the two study areas it was possible to correlate the recorded increase of landslide activity with the climatic changes occurring at the boundary between the late glacial and the holocene and between the atlantic and the subboreal and to compare the results with those derived from other european regions the types and causes of landslides taking place in these two periods were substantially different reflecting the different morphoclimatic conditions that existed in the two areas when these mass movements were triggered finally notwithstanding the importance of non climatic causes such as geological structural factors and possible human influences it is concluded that many of the dated landslides can be considered as indicators of climatic change

onset and timing of deep seated gravitational slope deformations in the eastern alps italy abstract a previously unrecognised complex of deep seated gravitational slope deformations dsgsd extends 20 km along upper venosta valley in the eastern alps italy mt watles exhibits spectacular features indicative of dsgsds including double ridges trenches and counterscarps the slope deformation occurs along a nappe boundary now corresponding to the schlinig normal fault is also conditioned by recent faults marked by shallow earthquakes and shows glacial paraglacial controls on slope evolution the mt watles dsgsd is a complex deep seated compound slide along a basal shear zone involving the schlinig fault gravitational reactivation of ne trending fractures formed gravitational scarps counterscarps and half grabens in the upper slope whereas the lower part of the slope partially collapsed although our work indicates the importance of the schlinig fault and recent fracturing on slope failure the trigger seems to be postglacial debuttressing of the valley walls radiocarbon dating of peat deposits within one of the major counterscarps indicates that slope deformation started during the lateglacial period and continued during the holocene in several slope sectors

tectonic controls on a large landslide complex williams fork mountains near dillon colorado abstract an extensive 25 km2 landslide complex covers a large area on the west side of the williams fork mountains in central colorado the complex is deeply weathered and incised and in most places geomorphic evidence of sliding breakaways hummocky topography transverse ridges and lobate distal zones are no longer visible indicating that the main mass of the slide has long been inactive however localized holocene reactivation of the landslide deposits is common above the timberline at about 3300 m and locally at lower elevations clasts within the complex as long as several tens of meters are entirely of crystalline basement proterozoic gneiss and granitic rocks from the hanging wall of the laramide late cretaceous to early tertiary west directed williams range thrust which forms the western structural boundary of the colorado front range late cretaceous shale and sandstone compose most footwall rocks the crystalline hanging wall rocks are pervasively fractured or shattered and alteration to clay minerals is locally well developed sackung structures trenches or small scale grabens and upslope facing scarps are common near the rounded crest of the range suggesting gravitational spreading of the fractured rocks and oversteepening of the mountain flanks late tertiary and quaternary incision of the blue river valley just west of the williams fork mountains contributed to the oversteepening major landslide movement is suspected during periods of deglaciation when abundant meltwater increased pore water pressure in bedrock fractures a fault flexure model for the development of the widespread fracturing and weakening of the proterozoic basement proposes that the surface of the williams range thrust contains a concave downward flexure the axis of which coincides approximately with the contact in the footwall between proterozoic basement and mostly cretaceous rocks movement of brittle hanging wall rocks through the flexure during laramide deformation pervasively fractured the hanging wall rocks

a giant deep seated slope deformation in the italian alps studied by paleoseismological and morphometric techniques this work proves the existence of a large deep seated gravitational slope deformation dgsd in a hilly region of the southwestern alps whereas dgsd are usually linked with high relief energy in mountain environments moreover we describe the usefulness of applying paleoseismological techniques by means of trench excavation to date and understand the deformation history and genesis of recent morphostructures and we found evidence of causative relationships between dgsd and surface landslides the studied dgsd of mt croce della tola mt scincina italy is the largest of the western alps it is 7 km long and involves a minimum area of 16 km2 with a volume 3 5 km3 probably extending further ne beneath lake maggiore surface several parallel scarps representing the surface expression of slip planes affect the upper part of the slope whereas the lower part presents a convex profile dgsd at mt croce della tola started in the last interglacial period 120 40 ka bp and the following glacial phase was not able to significantly modify the general slope geometry post glacial deformation also occurred especially at mt scincina after 25 ka bp post glacial and active surface landslides developed on the convex lower part of the slope suggesting that they resulted from instability due to the new profile assumed by the slopes during the deep seated deformation the occurrence of mt scincina dgsd with a very low topographic gradient is interpreted as an effect induced by on other large dgsd

quaternary environmental evolution in the south carpathians reconstructed from glaciokarst geomorphology and sedimentary archives abstract the carpathian island type glaciokarst has a great potential of preserving signals of past environments archived in cave deposits like speleothems and clastic infills we present here the geomorphology and structural control of several relict alpine caves and the surrounding glaciated marble karst in the f g ra mountains four truncated and partially unroofed caves remained on the ridge top of mu eteica mountain above the glacial cirque while a ponor cave that developed on the cirque bottom could be related to the last glacial period structural measurements and cave morphology showed that the conduits formed at the intersection of foliation planes and tectonic fractures on the ne sw and nw se directions cave development reflects three speleogenetic stages 1 texture and fabric controlled dissolution and distension 2 structurally controlled breakdown and 3 truncation unroofing and cave infilling with sediments slow diffuse dissolution was typical for the ridge top caves whereas m1 cave developed by pressure flow further we report the first u th speleothem ages related to the evolution of alpine caves and island glaciokarst in the south carpathians during the middle and late pleistocene dating results show a minimum estimated age of 560 ka for the ridge top caves and that speleothem deposition met optimal conditions only during warmer periods largely corresponding to interglacials stable carbon isotope values in speleothems range between 9 96 and 4 11 indicating the presence of plant and soil organic activity at the time of deposition in total five speleothem growth phases were distinguished during the last 560 ka we excavated the sediment infill of a ridge top doline down to a 2 m depth radiocarbon dating revealed that it was deposited during the late holocene and preliminary pollen analysis identified a plant assemblage dominated by grasses using the relationships between karst development glaciation and cave sedimentary archives we present a time slice chronology of alpine landscape evolution at 560 ka 400 ka 330 ka the last glacial period 70 12 ka and the late holocene our geomorphological isotopic and geochronological results also support the existing hypothesis that the south carpathians may have experienced at least two glacial phases during the pleistocene glacial erosion rate during the last glacial period and most likely during the penultimate glaciation averages around 0 6 mm yr 1

the case against vast glaciation in valles marineris mars abstract the valles marineris of mars form the largest system of interconnected canyons in the solar system where morphological mineralogical and structural evidence of widespread glaciation has been recently reported however neither precipitation models nor global water budgets can account for such a colossal fill and the hypothesis has thus far remained unchallenged by additional scrutiny here we present the first thorough case against a valles marineris glaciation by describing new evidence that precludes the existence of a glacier most crucially we review high resolution imaging science experiment hirise images of chaos terrain in candor chasma previously interpreted as remnant glacial ice and identify layered boulder rich scarps bearing no similarity to scarps of massive ice in promethei terra or the north polar layered deposits we also find no significant differences in the structure morphology and composition of chaos terrain in candor and the chryse planitia region which suggests candor s chaos like chryse s is fractured highland terrain we also review several other key supports for the glacial hypothesis including the coincidence of an apparent glacial trimline with the water bearing mineral jarosite and the apparent presence of glacial features including kettle holes and sandur plains these too are found to have more plausible explanations with non glacial origins including tectonic reorganisation groundwater sapping and chaotic fracturing we conclude that the valles marineris glacial hypothesis is inconsistent with both observed morphology and our understanding of the ancient martian climate and we find no evidence to support its existence

comments on structural tectonic controls and geomorphology of the karst corridors in alpine limestone ridges southern carpathians romania by l tirlă and i vijulie geomorphology 197 2013 123 136 abstract in the recently published paper by tirl and vijulie 2013 the authors interpret the abundant trenches affecting the limestone ridge of the v nturari a buila massif southern carpathians romania as bogaz like landforms syn kluftkarren karst corridors karst streets zanjones etc these karst features originated according to the authors through the corrosion of structurally anisotropic limestone bedrock this proposed origin is supported by a comparison of the rose diagrams of the directions of both bogaz and tectonic discontinuities by a morphometric analysis and by observations of the speleothem remnants covering the exposed fault surfaces furthermore the authors described the typically karstic settings of the area such as extremely poor surface drainage subterranean connections between the karst corridors and karst springs in pocket valleys we disagree with their main interpretations and argue that the presumed bogaz are gravitationally induced grabens and trenches created by mass movement activity namely by deep seated slope failures the speleothem remnants are interpreted as flowstones deposited during the subsurface widening of the joints by gravitational activity these speleothem remnants became fossil and even rotated from the original position after sufficient widening of the joints and subsequent exposure of the crevices to the surface due to slope failure progression the morphology of the slope failure along the v nturari a buila massif is similar to numerous other elevated ridges within the carpathian mountains

the interaction between active normal faulting and large scale gravitational mass movements revealed by paleoseismological techniques a case study from central italy paleoseismological techniques have been applied to characterize the kinematic behaviour of large scale gravitational phenomena located in proximity of the seismogenic fault responsible for the mw 7 0 1915 avezzano earthquake and to identify evidence of a possible coseismic reactivation the above mentioned techniques were applied to the surface expression of the main sliding planes of the mt serrone gravitational deformation located in the southeastern border of the fucino basin central italy the approach allows us to detect instantaneous events of deformation along the uphill facing scarp these events are testified by the presence of faulted deposits and colluvial wedges the identified and chronologically constrained episodes of rapid displacement can be probably correlated with seismic events determined by the activation of the fucino seismogenic fault affecting the toe of the gravitationally unstable rock mass indeed this fault can produce strong short term dynamic stresses able to trigger the release of local gravitational stress accumulated by mt serrone s large scale gravitational phenomena the applied methodology could allow us to better understand the geometric and kinematic relationships between active tectonic structures and large scale gravitational phenomena it would be more important in seismically active regions since deep seated gravitational slope deformations can evolve into a catastrophic collapse and can strongly increase the level of earthquake induced hazards

rainfall infiltration derived submarine groundwater discharge from multi layered aquifer system terminating at the coastline this article investigates the quantity of submarine groundwater discharge sgd from a coastal multi layered aquifer system in response to constant rainfall infiltration the system comprises an unconfined aquifer a leaky confined aquifer and an aquitard between them and terminates at the coastline an approximate analytical solution is derived based on the following assumptions i flow is horizontal in the aquifers and vertical in the aquitard and ii flow in the unconfined aquifer is described by nonlinear boussinesq equation the analytical solution is compared with numerical solutions of the strictly two dimensional nonlinear model to validate the model assumptions used for the analytical solution the sgd from the leaky confined aquifer increases with the inland rainfall infiltration recharge and the specific leakage of aquitard the maximum sgd ranges from 1 87 to 10 37 m3 per day per meter of shoreline when rainfall infiltration ranges from 18 2 to 182 mm year and the specific leakage of aquitard varies from 10 9 to 10 1 l day copyright 2011 john wiley sons ltd

intercomparison of submarine groundwater discharge estimates from a sandy unconfined aquifer summary recent studies suggest that chemical loading from submarine groundwater discharge sgd may rival other major sources such as rivers in many coastal areas sgd can occur as terrestrially derived typically fresh groundwater discharge or by seawater circulation through aquifer sediments because both terrestrial and recirculated seawater sgd can be significant sources of chemical loading to coastal waters appropriate methods are needed to properly assess and quantify the rates and distribution of these different inputs although many techniques exist to quantify sgd each method samples different components of sgd e g fresh versus saline discharge over different temporal and spatial scales the result is that confusion exists about how to use the different methods in this study we investigate the applicability of a variety of techniques for estimating sgd from an unconfined sandy coastal aquifer physical methods are first used to understand the spatial variability of discharge this information is then used with physical and geochemical data to estimate sgd investigative methods include direct measurement via seepage meters hydrogeologic estimation using darcy s law and tracer based estimates using radon and radium isotopes at our field site on cape cod massachusetts nearshore landward topography appears to exert a significant control on the spatial variability of fresh groundwater discharge presumably through its effects on evapotranspiration and hence recharge rates the darcy estimate of fresh sgd 4 0 m 3 m 1 d 1 is similar to a previous estimate made using a seepage meter transect that spans the seepage face radon serves as a valuable estimator of total sgd fresh plus saline 5 6 m 3 m 1 d 1 the difference between the total and fresh sgd estimates is in good agreement with the radium based sgd estimate 0 56 m 3 m 1 d 1 which primarily measures saline circulation through coastal sediments thus we conclude that the hydrogeologic estimate and radon and radium techniques are complimentary for estimating different components of total sgd at our field site

plio quaternary thin skinned tectonics along the crustal front flexure of the southern central andes a record of the regional stress regime or of local tectonic driven gravitational processes we present here a record of plio pleistocene deformations above the flexural front of the southern central andes of argentina we combine a seismic profile with structural and geomorphological observations to show that thin skinned extension located on top of the crustal front flexure is coeval with thin skinned shortening at the toe of the topographic bulge the seismic line shows that a flat zone with no internal deformation separates the stretched and shortened domains such features are usually interpreted as the result of strike slip faulting along basement faults or tangential longitudinal strain folding in the soft sedimentary cover above crustal bending we propose an alternative linking extension at the apex of the crustal anticline to basal contraction by the downslope translation of a rigid thin nappe of sediments 30 30 km2 in area above evaporites at a depth of 700 900 m the size of such a process is unusually large onshore 630 810 km3 but mimics the gravity gliding observed in deltas and passive margins since this process disconnects zones with a shallow stress field from deeper crustal levels it could allow extension above a compressive deformation front and should not be interpreted merely as a record of the crustal stress regime large scale gravity gliding of the cover down the slope of a structural high could also explain some of the extension observed in mountain hinterlands

reply to comments on structural tectonic controls and geomorphology of the karst corridors in alpine limestone ridges by l tirlă and i vijulie geomorphology 197 2013 123 136 by j lenart and t panek abstract lenart and panek 2014 disagree with the term bogaz which we have attributed to the main structural discontinuities in the v nturari a buila massif southern carpathians they also insist upon the mass movements as being the defining processes which generate them finally the authors explain the genesis of fossil speleothems found in abundance on the exposed walls of the former crevice type caves we essentially followed within our study two aspects similarities met by the studied tectonic karst corridors and typical bogaz as classically described in literature and their connection with the basic structural and tectonic frame the spatial context of the described landforms was not ignored as we constantly mentioned the role of compressional forces in building a favorable environment for their occurrence tirl and vijulie 2013 neotectonics and structural frame particularly the strike slip fault systems are the major control factors in driving the evolution of the v nturari a buila massif and the formation of the bogaz like forms supplementary evidences for attesting reverse and strike slip faulting were provided slope failures by gravitational collapse prevail and rotational landslides are only isolated the origin of discussed exposed speleothems was correctly explained in the comment except that they were formed on fault walls not on fractures of gravitational origin

uphill facing antislope scarps in the coast mountains southwest british columbia uphill facing scarps are examined at affliction creek a glacierized area within the meager creek volcanic complex of southwest british columbia scarps occur directly downslope of tension cracks and are considered to have developed from a combination of 1 antithetic movement between partly toppled slices of rock defined by a master joint set dipping into the slope and 2 erosion of the upslope face of each tension crack leaving the downslope face prominent as an antislope scarp a kinematic test for toppling failure is described glacial erosion and rapid glacial downwasting are probable causes of toppling lichenometric data indicate significant scarp development since affliction glacier attained its maximum neoglacial dimensions about 140 yr ago dilatancy is cited as a possible mechanism for scarp stabilization

the upper pleistocene ice lateral till complex of cerler esera valley central southern pyrenees spain abstract sedimentological studies of the upper pleistocene ice lateral till complexes have been applied in the last years in order to define the glacial phases and reconstruct the glacial dynamics during the last glacial cycle in the southern pyrenees these sedimentary complexes are formed by different till types and related deposits glaciolacustrine and glaciofluvial sediments they were formed when the main valley glacier blocked up the drainage of tributary valleys either occupied by small local glaciers e g the cerler sedimentary complex in the esera basin or devoid of glaciers e g the llestui sedimentary complex in the noguera ribagorcana basin the study of the different lithofacies and their lateral and vertical relationships allows us to reconstruct the evolution of the cerler sedimentary complex since the early premaximum phase to the late deglaciation phases

late quaternary deposition and facies model for karstic lake estanya north eastern spain lake estanya is a small 19 ha freshwater to brackish monomictic lake formed by the coalescence of two karstic sinkholes with maximum water depths of 12 and 20 m located in the pre pyrenean ranges north eastern spain the lake is hydrologically closed and the water balance is controlled mostly by groundwater input and evaporation three main modern depositional sub environments can be recognized as i a carbonate producing littoral platform ii a steep talus dominated by reworking of littoral sediments and mass wasting processes and iii an offshore distal area seasonally affected by anoxia with fine grained clastic sediment deposition a seismic survey identified up to 15 m thick sedimentary infill comprising i a basal unit seismically transparent and restricted to the depocentres of both sub basins ii an intermediate unit characterized by continuous high amplitude reflections and iii an upper unit with strong parallel reflectors several mass wasting deposits occur in both sub basins five sediment cores were analysed using sedimentological microscopic geochemical and physical techniques the chronological model for the sediment sequence is based on 17 accelerator mass spectrometry 14c dates five depositional environments were characterized by their respective sedimentary facies associations the depositional history of lake estanya during the last ca 21 kyr comprises five stages i a brackish shallow calcite producing lake during full glacial times 21 to 17 3 kyr bp ii a saline permanent relatively deep lake during the late glacial 17 3 to 11 6 kyr bp iii an ephemeral saline lake and saline mudflat complex during the transition to the holocene 11 6 to 9 4 kyr bp iv a saline lake with gypsum rich laminated facies and abundant microbial mats punctuated by periods of more frequent flooding episodes and clastic dominated deposition during the holocene 9 4 to 0 8 kyr bp and v a deep freshwater to brackish lake with high clastic input during the last 800 years climate driven hydrological fluctuations are the main internal control in the evolution of the lake during the last 21 kyr affecting water salinity lake level changes and water stratification however external factors such as karstic processes clastic input and the occurrence of mass flows are also significant the facies model defined for lake estanya is an essential tool for deciphering the main factors influencing lake deposition and to evaluate the most suitable proxies for lake level climate and environmental reconstructions and it is applicable to modern karstic lakes and to ancient lacustrine formations

using multiple geochemical tracers to characterize the hydrogeology of the submarine spring off crescent beach florida abstract a spectacular submarine spring is located about 4 km east of crescent beach fl in the atlantic ocean the single vent feature of crescent beach spring provides a unique opportunity to examine onshore offshore hydrogeologic processes as well as point source submarine ground water discharge the floridan aquifer system in northeastern florida consists of tertiary interspersed limestone and dolomite strata impermeable beds confine the water bearing zones under artesian pressure miocene and younger confining strata have been eroded away at the vent feature enabling direct hydrologic communication of eocene ground water with coastal bottom waters the spring water had a salinity of 6 02 which was immediately diluted by ambient seawater during advection mixing the concentration of major solutes in spring water and onshore well waters confirm a generalized easterly flow direction of artesian ground water nutrient concentrations were generally low in the reducing vent samples and the majority of the total nitrogen species existed as nh 3 the submarine ground water tracers rn 222 1174 dpm l 1 dpm methane 232 nm and barium 294 5 nm were all highly enriched in the spring water relative to ambient seawater the concentrations of the reverse redox elements u v and mo were expectedly low in the submarine waters the strontium isotope ratio of the vent water 87 sr 86 sr 0 70798 suggests that the spring water contain an integrated signature indicative of floridan aquifer system ground water additional sr isotopic ratios from a series of surficial and lower floridan well samples suggest dynamic ground water mixing and do not provide clear evidence for a single hydrogeologic water source at the spring vent in this karst dominated aquifer such energetic mixing at the vent feature is expected and would be facilitated by conduit and fractured flow radium isotope activities were utilized to estimate flow path trajectories and to provide information on potential travel times between an onshore well and the spring using either 223 ra and 224 ra or 228 ra and qualifying this approach with several key assumptions estimates of water mass travel times from an upper floridan well in crescent beach to the submarine vent feature distance 4050 m are in the order of 0 01 0 1 m min 1

genesis types and evolution of crevice type caves in the flysch belt of the western carpathians czech republic abstract crevice type caves are among the least investigated natural phenomena connected with the development of slope failures these caves present complex and peculiar underground systems with their own development and resulting landforms we investigated eight caves in the czech part of the outer western carpathians to determine their genesis types and evolution crevice formation is predisposed according to the lithological tectonic and morphological characteristics of the landslide body including the position and location of bedding planes joints and faults we performed several analyses including speleological mapping evaluation of high resolution topography above the caves geophysical ert measurements and structural investigations within cave passages in accordance with these analyses various mechanisms responsible for cave development were revealed an intra bed translation is responsible for the creation of regularly shaped passages with flat ceilings toppling as well as back and horizontal rotation of rock blocks determine the specific morphology and shapes of passages a relatively novel aspect of the current study is the identification of the subsidence of massive rock wedges due to the widening of cracks all of these mechanisms control the specific morphological characteristics within crevices e g typical shapes of passages cave level ordering and ceiling types some of these processes also influence topography above the caves finally the different phases of evolution of these caves were determined

a methodological approach for the analysis of the temporal occurrence and triggering factors of landslides the temporal occurrence of landslides in an area of the cantabrian range during the last 120 000 years is analyzed an initial relative chronology was established on the basis of aging degree and spatial relationships between landslides and glacial and fluvial features ten landslide classes were thus identified and their chronological limits defined on the basis of 19 14c age determinations on fluvial and glacial deposits including eight new ones the chronology was tested with 14c dates obtained on landslide deposits 10 from previous work and nine new ones the chronological classes identified were compared with existing climate models for the region the type and spatial distribution of landslides in each class were also analyzed the approach made it possible to identify periods during which landslides were triggered mainly by channel incision seismic activity and rainfall increase human activity played a significant role after 5000 bp and especially in the last few centuries mobilization of materials by slope movements has increased in the region by a factor of 10 compared to pre neolithic rates

structural constraints on deep seated slope deformation kinematics abstract a significant sackung type deep seated slope gravitational deformation dsgsd was recognised for the first time by the authors in the middle part of valfurva east of bormio rhaetian alps italy the reconstruction of its kinematics age and state of activity is presented through a detailed description of its morphological geomechanical and structural features an integrated multi disciplinary approach was performed to achieve a clear comprehension of the phenomenon field surveys and aero photo interpretation were carried out in order to clarify the structural geological and geomorphological setting in which the dsgsd developed a kinematic conceptual model of the slope deformation was developed through the analysis of morpho structures of their significance and relationships with lithological markers and quaternary deposits after a geomechanical characterisation of the rock mass involved in the slope deformation numerical modelling was performed to verify the hypotheses made on kinematics and driving factors of the phenomenon the sackung affects pre permian metapelites metabasites and marbles belonging to the upper austroalpine basement of the campo nappe as well as late pleistocene and holocene glacial and rock glacier deposits the deformation started after the late wurmian age 15 000 11 000 years b p and continued until few centuries ago not excluding a present day low rate activity deformation consists in a large oblique sagging along a deep confined sliding surface associated with gravitational reactivation of pre existing late alpine and recent tectonic brittle structures leading to the formation of n s and wnw ese trending gravitational morpho structures the evolution of the wnw ese trending system resulting in asymmetric trenches led to progressive failure of the lower part of the slope during the last 10 000 years as testified by large paleo landslide accumulations and it is still in progress numerical modelling indicates post glacial unloading as the main triggering factor of the slope deformation the importance of this deep seated slope deformation is enhanced by the occurrence of the 30 mm 3 active ruinon landslide in the lower part of the slope such landslide is subjected to rapid evolution and threatens the valley floor establishing an important risk factor connected to human lives and socio economic activities

late quaternary sackungen in the highest mountains of the carpathians sackungen represents a common mode of deep seated rock slope failures in alpine landscapes but proof of their temporal and causal relationship to extrinsic factors such as climatic changes glacier retreat or seismic activity remains elusive based on the terrestrial cosmogenic nuclide tcn dating of 18 sackung scarps supported by one radiocarbon dated scarp we reconstructed the post glacial chronology of sackungen in the tatra mts central europe slovakia and poland the highest part of the carpathians the obtained ages 15 7 4 3 ka indicate that sackungen post date the regional lgm and some of them originated soon after the glacier withdrawal from adjacent valleys furthermore systematic decrease of scarp ages with their increasing altitude suggests a direct link between sackung origin and post lgm glacier thinning however substantial lag 5 ka of some sackungen in respect to glacier retreat implies complex relationships between sackung onset and deglaciation where retreat of glaciers acted predominantly as a preparatory not a triggering factor during the genesis of these slope deformations they originated either as a consequence of stress relaxation within the rock mass lasting several ka or alternatively could be triggered by climatic processes or seismicity indeed a significant part of sackung activity took place during predominantly warmer and more humid periods with some dates coinciding with the belling allerod chronozone but especially with the onset of the holocene and the holocene climatic optimum earthquake triggering is less probable as the tatra mts lack significant modern and historic seismic activity and there is no geomorphic evidence of fault offsets on the late quaternary landforms in concert with other recent studies we propose that large rock slope failures in high mountains seldom react immediately to glacier withdrawal but could display temporal delay lasting up to several millennia c 2017 elsevier ltd all rights reserved

long term dynamics of rockslides and damage propagation inferred from mechanical modeling 1 long term observations of large active rockslides show accelerating deformation over many thousands of years since the last deglaciation the effect of deglaciation on slope stability is however poorly understood due to 1 limited long term observations and 2 a complex interaction between glacier retreat and hydrogeological mechanical and morphological processes to assess the sensitivity of rockslide dynamics to these different processes a model of progressive damage through intact rock mass is developed in this study based on the finite element method this model uses time to failure laws based on rock laboratory creep experiments it is able to reproduce progressive damage localization along shear bands associated with strain rate acceleration as observed during tertiary creep the model reproduces the different phases of deformation associated with morphologies typical of large rockslides this model is thus suitable for simulating the dynamics of large rockslides and the transition from initiation to rapid sliding the sensitivity of rockslide kinematics and morphology to different mechanical properties is analyzed this analysis shows that the time evolution of the rockslide can be inferred with the knowledge of only one time parameter independent of the knowledge of the mechanical properties of the rock mass this parameter is here chosen as the time when the summit slope displacement has reached 10 m a parameter that can be estimated with cosmogenic dating the model is then used to study the effects of deglaciation on the valley flank stability and the formation of large rockslides this study shows that the deglaciation velocity can affect the morphology of the rockslide with the shear band of the rockslide emerging at higher elevation as the velocity decreases we also show that the response to the deglaciation can last several thousands of years after the glacier retreat

geomorphology and geochronology of sackung features uphill facing scarps in the central spanish pyrenees abstract the paper analyses uphill facing scarps and associated troughs developed in the oversteepened slopes of two neighbouring glacial valleys in the central spanish pyrenees previous studies of sackung landforms in the pyrenees have argued for deglacial unloading as the genetic mechanism but this causal and temporal relationship has not been proved due to the lack of chronological data the antislope scarps in the two studied locations vallibierna and estos are developed in palaeozoic metasedimentary rocks parallel to the contour lines and the structural grain occur in the intermediate sector of the hillslope and are up to 0 5 km long and several meters high a trench was excavated in a sackung trough fill in each of the valleys in order to gain information about their chronology and genesis charcoal from the lowermost unit in vallibierna provided an age of 5 9 cal ka for the sackung and extrapolation of the three dates obtained in estos indicates that the trough formed ca 7 6 7 8 cal ka deglaciation of the studied sectors of the valleys occurred between 16 and 13 ka the time lag of 5 ka suggests that glacial erosion and the subsequent debutressing of the oversteepened valley walls created slopes predisposed to sackung development but did not initiate the movement seismic shaking is proposed as a probable triggering factor this hypothesis although supported by the sudden deformation event recorded by a failure plane exposed in vallibierna trench and by the seismic and neotectonic activity of the area cannot be proved due to the lack of chronological information about paleoearthquakes

deep seated gravitational slope deformation large scale rock failure and active normal faulting along mt morrone sulmona basin central italy geomorphological and paleoseismological analyses abstract active faulting is one of the main factors that induce deep seated gravitational slope deformations dgsds in this study we investigate the relationships between the tectonic activity of the nw se normal fault system along mt morrone central apennines italy and the evolution of the associated sackung type dgsd the fault system is considered to be the source of m 6 5 7 earthquakes our investigations have revealed that the dgsd began to affect the mt morrone sw slope after the early pleistocene this was due to the progressive slope instability arising from the onset of the younger western fault with the older eastern fault acting as the preferred sliding zone paleoseismological investigations based on the excavation of slope deposits across gravitational troughs revealed that the dgsd was also responsible for the displacement of late pleistocene holocene sediments accumulated in the sackung troughs moreover we observed that the investigated dgsd can evolve into large scale rock slides therefore as well as active normal faulting the dgsd should be considered as the source of a further geological hazard overall our approach can be successfully applied to other contexts where active normal faults control the inception and evolution of a dgsd

deep seated gravitational slope deformations in the highest parts of the czech flysch carpathians evolutionary model based on kinematic analysis electrical imaging and trenching deep seated gravitational slope deformations dsgsds played an important role during the quaternary evolution of mountain ridges formed by anisotropic flysch rocks of the outer western carpathians owc four dsgsd affected ridges in the highest part of the czech sector of the owc have been subjected to multidisciplinary investigation involving mapping structural and kinematic analysis geoelectrical imaging trenching and dating all the studied dsgsds are strongly predisposed by regional structural fabric given by the intersection of bedding planes joint sets and faults performed research suggests high diversity of mechanisms leading to the origin of individual dsgsds the area of a single dsgsd can be affected by various types of movements such as sackung lateral spreading toppling or incipient sliding electrical imaging and trenching revealed that besides these mechanisms anisotropic flysch massifs formed by thick bedded sandstones are strongly exposed to subsurface opening of air filled voids related to widened crevices such a process is driven by deep seated creep and translational sliding of sandstone beds upon plastic claystones whose strength has been reduced to residual values of the angle of internal friction performed radiocarbon and osl dating revealed that some of the studied dsgsds originated in the holocene period particularly in the atlantic and subboreal chronozones

a late holocene deep seated landslide in the northern french pyrenees abstract a very large deep seated landslide dsl in the northern pyrenees with over 1 4 10 9 m 3 was mapped and dated based on sedimentation rates and 10 be terrestrial cosmogenic radionuclide surface exposure cre dating our analysis on the landslide reveals the role of inherited structures in the landslide process and highlighted typical gravitational morpho structures and a small lake trapped at the toe of the landslide head scarp the rate of lake sedimentation 0 86 0 57 mm yr 1 also provided us with the approximate age of the landslide 1106 540 yr the cre dating result highlights two main slope destabilization phases then we discussed the history of dsl activity and its controlling factors information related to historic markers and the absence of particular climate markers and changes during the medieval dark ages point to a single event in ad 1380 due to a major seismic event lavedan earthquake

a carbon isotope method to quantify groundwater discharge at the land sea interface we present a new method to characterize and quantify groundwater discharge to estuaries and the coastal ocean using data from the pages creek estuary in the cape fear region of southeastern north carolina we show that the concentration and carbon isotopic composition d 14 c and d 13 c values of dissolved inorganic carbon dic can provide a tracer of a single well defined component of the surface water groundwater system in coastal regions the integrated freshwater discharge to an estuary from confined aquifers groundwater from the two shallowest confined aquifers in the cape fear region the castle hayne and the peedee has dic d 14 c values ranging from 2282 to 2829 significantly lower than the radiocarbon content of surficial water table groundwater rivers and streams and seawater in the area d 14 c 52 38 to 197 dic additions from salt marsh decomposition and dic removal via photosynthesis and gas evasion can influence estuarine dic concentrations and dic d 13 c values however none of these processes results in strongly depleted dic d 14 c values because artesian springs are the only significant low d 14 c dic input to the pages creek estuary flood ebb 14 c budgets provide a direct measure of the fraction of the total freshwater inputs to the pages creek estuary that is derived from artesian discharge with this method we have observed a striking range in the relative contribution of artesian flow to the pages creek estuary freshwater budget during november 1999 and april 2001 both periods of low precipitation in southeastern north carolina artesian groundwater discharge could account for essentially all of the pages creek freshwater inputs in contrast during july 2000 a period of high precipitation in this region artesian groundwater made a negligible contribution to the creek s freshwater budget

integrated geophysics and soil gas profiles as a tool to characterize active faults the amer fault example pyrenees ne spain the combined use of geophysical and soil gas composition exploration methods allows to rapidly obtain at relative low cost information that might be related to seismic activity conditions in this study we carried out geochemical soil gas sampling 222rn 220rn and co2 electrical resistivity tomography and seismic refraction profiles in two selected zones near the town of amer in the spanish pyrenees where the presence of recent fractures is evident in the field data analysis clearly reveals anomalous values for each gas at specific positions along the electrical imaging transects geomorphologic and hydrogeologic data and the integration of geophysical data and soil gas measurements indicate that 1 endogene gases radon 222rn and carbon dioxide co2 are released from the meta sedimentary basement rocks across the main fractured zones with higher permeability values while lower cenozoic detrital sedimentary formations act as an impervious boundary 2 sites with highest radon concentrations 52 kbq m 3 coincide with the zones in the amer fault showing more recent geomorphic evidence of activity and more specifically with those areas covered by thinner surficial formations 3 the lowest 222rn values 0 2 0 4 kbq m 3 were recorded just on the master active fault plane this pattern could be explained by a dilution effect resulting from high rates of soil co2 efflux 267 g m 2 day 1 4 soil thoron 220rn activity is maximum 143 kbq m 3 in areas with high surficial fracturing 5 groundwater pumping may cause important distortions in the natural flow dynamics and in the measured concentrations of gases the agreement between the different data geochemical geophysical and hydrogeological and field observations geology and geomorphology leads us to propose a preliminary tectonic gravitational model for the study area

10be ages reveal 12 ka of gravitational movement in a major sackung of the western alps france abstract the rognier sackung which extends ne sw for more than 9 km is a major gravitational morpho structure located in the western alps we used the 10 be cosmic ray exposure dating method on 23 samples to unravel its history and better understand its genetic mechanism we found that the average slip rate on sackung faults varies from 0 3 to 3 2 mm yr 1 conjugate sackung faults are contemporaneous in agreement with a model in which the whole mountain ridge is involved in the gravitational deformation 600 m thick multiple samples on single faults suggest that the development of this sackung started before 12 ka and that it is still active we cannot exclude the possibility that the dissolution of the underlying triassic evaporites participated in the sagging of mt rognier however the age of this sackung and the presence of the lauziere sackung on the other side of the arcs valley support glacial erosion and debuttressing following the retreat of the valley glacier as the main causes of these large gravitational structures the long and permanent activity of the rognier sackung contrasts with that of the neighbouring arcs sackung which we previously dated using the same method and showed that it is a result of flexural toppling along with the proximity of the rognier sackung to the belledonne border active fault its long history suggests that earthquake shaking contributed to maintain its activity additionally two ages confirm that in the western alps rock glaciers formed mainly during the younger dryas this study allowed the determination of the best sampling strategy for future cre dating of these types of gravitational structures

using the radium quartet for evaluating groundwater input and water exchange in salt marshes the fluxes of 226ra half life 1600 years and 228ra half life 5 7 years from the north inlet salt marsh to the sea are much larger than can be supported by decay of their th parents in the surface marsh sediments these fluxes are sustained almost entirely by groundwater flow through the marsh an average groundwater flow of approximately 10 cm3 cm 2 day 1 is indicated if the groundwater activities we have measured are representative the fluxes of 223ra half life 11 4 day and 224ra half life 3 6 day are factors of 22 and ten more than those expected from the flux of 226ra groundwater also sustains most of the flux of the short lived isotopes the measured ra activity ratio pattern in the marsh creeks matches the groundwater signature but is distinct from the pattern of the parent thorium isotopes in the sediment we present a model to explain the anomalous distribution pattern of these isotopes despite their large throughput the inventories of desorbable 226ra and 228ra in the top 15 cm sediment layer are very low nevertheless the activities of 226ra and 228ra in the porewaters are large indicating a low distribution coefficient 10 for radium and a short retention time 10 days in the surface sediment layer we surmise that groundwater flow may be a significant source of radium isotopes in the waters of shallow estuaries and coastal margins this source must be recognized while considering mass balance of any tracer be it radium nutrients other metals or 18o

terrestrial originated submarine groundwater discharge through deep multilayered aquifer systems beneath the seafloor a large quantity of submarine groundwater discharge sgd of about 1000 m3 day 1 m 1 of the 600 km long shoreline of south atlantic bight has been estimated by moore global biogeochemical cycles 2010b 24 gb4005 doi 10 1029 2009gb003747 however there is great uncertainty in estimating the percentage of net land originated groundwater recharge of sgd moreover most previous studies considered the homogeneous case for the coastal superficial aquifers here we investigated the terrestrial originated sgd through a multilayered submarine aquifer system which comprises two confined aquifers and two semi permeable layers the inland recharge includes a constant part representing the annual average and a periodical part representing its seasonal variation an analytical solution was derived and used to analyse the distributions of the terrestrial originated sgd from the multilayered aquifers along the winyah bay transect south atlantic bight it is found that the width of the zone of sgd from the upper aquifer ranges from 0 8 to 8 0 km depending on the leakance of the seabed semi permeable layer a head of the upper aquifer at a coastline 1 0 m higher than the mean sea level will cause a sgd of 1 82 18 3 m3 day 1 m 1 from that aquifer as the seabed semi permeable layer s leakance varies from 0 001 to 0 1 day 1 providing considerable possibility for considerable land originated sgd seasonal terrestrial originated sgd variations predicted by the analytical model provide consistent explanation of the seasonal variation of 226ra observed by moore journal of geophysics 2007 112 c10013 doi 10 1029 2007jc004199 the contribution of the lower aquifer to sgd is only 1 2 12 of that of the upper aquifer copyright 2014 john wiley sons ltd

groundwater seawater interactions off the coast of southern taiwan evidence from environmental isotopes abstract we have conducted detailed hydrochemical surveys off the pingtung plain coast sw taiwan using environmental isotope compositions d 18 o 13 c dic tritium and 14 c as the main tracers to investigate groundwater seawater interactions in the region the 18 o values of seawater in this area show significant variability with heavy isotope enrichment relatively to groundwater the d and 18 o data also confirmed that submarine groundwater discharge sgd originated from meteoric water and were mixed with seawater due to an overdraft of groundwater seawater has intruded inwardly through the offshore outcrops for both the unconfined and confined aquifers at a depth of 300 m however 18 o depleted layer is found along deep parts of kaoping canyon this result provides evidence for sgd in this region this phenomenon is also reflected in depleted 13 c dic and lower 14 c values in deep canyon water than in adjacent seawater and indicating that the discharge zone extends over a considerable distance to the offshore area 25 km based on these three parameters 18 o 13 c dic and 14 c we used two end member mixing model to estimate that fresh submarine groundwater constitute the submarine fresh groundwater contributed about 3 and the estimated submarine fresh groundwater discharge was calculated as 4 5 10 9 m 3 per year this result is comparable with groundwater annual loss in the pingtung plain as documented by the isotopic composition of the collected samples detailed results show that sgd in the pingtung coastal zone raises a potential environmental concern and provides implication for the management of groundwater resource in the region

deep structures of slopes connected with sandstone crags in the upland area of the świetokrzyskie holy cross mountains central poland abstract deep seated gravitational deformations of slopes are commonly observed and described in mountains but faintly manifested and thus neglected in upland areas thanks to the geophysical methods e g ert as well as detailed surface surveys and studies in caves such deformations have been discovered and described in the region of the wietokrzyskie holy cross mountains central poland which is an upland area of usually gentle slopes of a height of several tens of metres the deformations which have been studied on 20 30 m high slopes formed of sandstone series alternating with claystone siltstone and heterolithe series represent various movements from slight rotational and translational ca 1 m movements through horizontal and vertical shifts of several metres to significant dislocations of sandstone corestones embedded within the regolith forming the slopes the last mentioned structures are currently relics completely masked by subsequent slope processes and their origin should be related to specific periglacial and even sub glacial conditions of the pleistocene on the other hand as confirmed by radiocarbon dating and other mapping slight movements of relatively low slopes can even be active nowadays these deformations that occur in regions of a relatively low relief and have so far been neglected or considered to be unique are possibly even more frequent and should be studied using modern geophysical and other methods

identification prediction and mitigation of sinkhole hazards in evaporite karst areas sinkholes usually have a higher probability of occurrence and a greater genetic diversity in evaporite terrains than in carbonate karst areas this is because evaporites have a higher solubility and commonly a lower mechanical strength subsidence damage resulting from evaporite dissolution generates substantial losses throughout the world but the causes are only well understood in a few areas to deal with these hazards a phased approach is needed for sinkhole identification investigation prediction and mitigation identification techniques include field surveys and geomorphological mapping combined with accounts from local people and historical sources detailed sinkhole maps can be constructed from sequential historical maps recent topographical maps and digital elevation models dems complemented with building damage surveying remote sensing and high resolution geodetic surveys on a more detailed level information from exposed paleosubsidence features paleokarst speleological explorations geophysical investigations trenching dating techniques and boreholes may help in investigating dissolution and subsidence features information on the hydrogeological pathways including caves springs and swallow holes are particularly important especially when corroborated by tracer tests these diverse data sources make a valuable database the karst inventory from this dataset sinkhole susceptibility zonations relative probability may be produced based on the spatial distribution of the features and good knowledge of the local geology sinkhole distribution can be investigated by spatial distribution analysis techniques including studies of preferential elongation alignment and nearest neighbor analysis more objective susceptibility models may be obtained by analyzing the statistical relationships between the known sinkholes and the conditioning factors chronological information on sinkhole formation is required to estimate the probability of occurrence of sinkholes number of sinkholes km2 year such spatial and temporal predictions frequently derived from limited records and based on the assumption that past sinkhole activity may be extrapolated to the future are non corroborated hypotheses validation methods allow us to assess the predictive capability of the susceptibility maps and to transform them into probability maps avoiding the most hazardous areas by preventive planning is the safest strategy for development in sinkhole prone areas corrective measures could be applied to reduce the dissolution activity and subsidence processes a more practical solution for safe development is to reduce the vulnerability of the structures by using subsidence proof designs

great earthquakes in low strain rate continental interiors an example from se kazakhstan the lepsy fault of the northern tien shan se kazakhstan extends e w 120 km from the high mountains of the dzhungarian ala tau a subrange of the northern tien shan into the low lying kazakh platform it is an example of an active structure that connects a more rapidly deforming mountain region with an apparently stable continental region and follows a known palaeozoic structure field based and satellite observations reveal an 10 m vertical offset exceptionally preserved along the entire length of the fault geomorphic analysis and age control from radiocarbon and optically stimulated luminescence dating methods indicate that the scarp formed in the holocene and was generated by at least two substantial earthquakes the most recent event dated to sometime after 400 years b p is likely to have ruptured the entire 120 km fault length in a m w 7 5 8 2 earthquake the lepsy fault kinematics were characterized using digital elevation models and high resolution satellite imagery which indicate that the predominant sense of motion is reverse right lateral with a fault strike dip and slip vector azimuth of 110 50 s and 317 343 respectively which is consistent with predominant n s shortening related to the india eurasia collision in light of these observations and because the activity of the lepsy fault would have been hard to ascertain if it had not ruptured in the recent past we note that the absence of known active faults within low relief and low strain rate continental interiors does not always imply an absence of seismic hazard

the episodic rise net growing rate and kinematics of radial faults of the salinas de oro diapir using paleoseismological techniques ne spain salt upwelling versus karstic subsidence abstract this paper explores the use of trenching and paleoseismological techniques to determine salt flow rates into a salt diapir for the first time in the literature the salinas de oro diapir located in the northern spanish pyrenees is an oval shaped triassic salt stock that extends vertically for 7 km down to the paleozoic basement salt dissolution subsidence and diapir growth are coeval active processes karstification is responsible for the development of large sinkholes a thick caprock and the monocline folding and ring faulting of the cretaceous and early tertiary limestone rim the evaporite karstic aquifer discharges high concentration water of up to 137 g l of total dissolved solids and a conductivity over 200 ms cm into the salado creek which drains the diapir top the salinity monitoring of this drainage provides a maximum karstic surface lowering rate of around 2 8 mm yr salt upwelling has caused the 150 m uplift of the annular limestone escarpment and the development of 3000 m long radial grabens with up to 90 m of vertical offset that disrupt drainages displace quaternary deposits and overprint concentric faults the 260 cm drag folding of lacustrine facies exposed in a 42 m long and 6 5 m deep trench due to the creep motion of the western radial fault of azanza graben yielded a minimum short term uplift slip rate of 1 75 mm yr for the last 1485 years and provides a minimum salt supply rate of over 5 mm yr considering karstification lowering this value that is several hundred times higher than average evidence the discontinuous growth of salinas de oro diapir

influence of inherited geologic framework on barrier shoreface morphology and dynamics abstract passive margin coastlines with limited sand supplies such as much of the u s atlantic margin are significantly influenced by the geologic framework of older stratigraphic units that occur beneath and seaward of the shoreface many u s east coast barrier islands are perched barriers in which the underlying pre modern sediments determine the morphology of the shoreface and strongly influence modern beach dynamics and composition perched barriers consist of varible layers of beach sand on top of older eroding stratigraphic units with highly variable compositions and geometries along many parts of the coastal system stratigraphically controlled bathymetric features on the inner shelf modify waves and currents and thereby effect patterns of sediment erosion transport and deposition on the adjacent shoreface it is essential to understand this geologic framework before attempting to model the large scale behavior of these types of coastal systems in north carolina most shoreline features are controlled by the pre holocene stratigraphic framework of the shoreface the beaches are perched on top of pre existing pleistocene tertiary and cretaceous sediments the surficial geology of the coastal zone is subdivided into two distinct provinces resulting in different stratigraphic controls of the shoreface north of cape lookout the geological framework consists of a quaternary sequence that fills a regional depositional basin called the albemarle embayment the coastal zone south of cape lookout is dominated by tertiary and cretaceous units that crop out across the coastal plain and continental shelf with very thin quaternary units only locally preserved superimposed upon this regional stratigraphy is an ancient drainage system resulting in a series of fluvial valleys filled with younger coastal sediments separated by large interfluve areas of older stratigraphic units this results in a coastal system in which the shoreface is either nonheadland or headland dominated respectively headland dominated shorefaces are further divided into subaerial and submarine categories nonheadland dominated shorefaces are further divided into those influenced primarily by transgressive or regressive processes or channel dominated depositional processes i e inlet migration or stream valley fill examples of each of these six types of shorefaces are presented to demonstrate the control that the geologic framework exhibits on shoreface morphologies and processes

influence of structural framework on mountain slope deformation in the maiella anticline central apennines italy abstract relationships between tectonic framework and gravity driven phenomena have been investigated in an area of the central apennines italy characterised by high relief the north south half dome shaped maiella anticline lies in the easternmost part of the apennine fold and thrust belt its backlimb is bordered by the caramanico fault a normal fault with a maximum downthrown of about 3 5 km that separates the western slope of the maiella massif from the caramanico valley the southwestern maiella area is affected by deep seated gravitational slope deformation indicated by major double crest lines down hill and up hill facing scarps a pattern of crossing trenches bulging at the base of slopes and the presence of different types of landslide and talus slope deposits the onset and development of deep seated gravitational slope deformations and the location of quaternary massive rockslope failures have been strongly influenced by the structural framework and tectonic pattern of the anticline deep seated gravitational slope deformation at mt macellaro mt amaro ridge has developed along the maiella western reverse slope in correspondence with the anticline axial culmination it is bordered at the rear by a nnw sse oriented dextral strike slip fault zone and has an e w direction of rock mass deformation closer to the southern plunging area of the anticline gravity driven phenomena show instead a n s and nw se direction influenced by bedding attitude 3d topographic models illustrate the relationship between deep seated gravitational slope deformation and massive rockslope failures the campo di giove rock avalanche a huge quaternary failure event was the result of an instantaneous collapse on a mountaine slope affected by a long term gravity driven deformation

reconstructing the geochronological evolution of large landslides by means of the trenching technique in the yesa reservoir spanish pyrenees abstract detailed geomorphological mapping has revealed that the slopes upstream of the yesa dam are affected by several flysch landslides the largest landslides correspond to la refaya rotational slide 11 million m3 situated just upstream of the spillway and el vertedero translational slide 6 million m3 located 1 5 km upstream of the dam a portion of el vertedero landslide 3 million m3 was reactivated in 2006 due to overloading caused by an earth heap a higher earth dam will be built on the downstream side of the existing gravity concrete dam to raise the maximum water level of the reservoir by 23 m the retrodeformation analysis of the deposits exposed in two trenches excavated in the upper part of these landslides together with the obtained absolute ages c14 and osl have provided information on the kinematics and evolution of these slope movements the main findings derived from the 45 m long trench dug in the closed depression developed at the foot of the head scarp of la refaya landslide include 1 the landslide is older than 12 ka and has undergone a cumulative rotation higher than 17 yielding a mean rotation rate of about 1 4 millennium 2 most of the rotation 14 occurred before 5 8 ka and according to the trench stratigraphy the kinematics of the landslide has been dominated by progressive displacement no evidence of catastrophic reactivation has been found the 45 m long trench excavated across the scarp and bench situated at the head of the non reactivated portion of el vertedero translational slide reveals that 1 the landslide is older than 38 ka 2 the trenched portion has undergone at least one reactivation subsequent to 20 ka and has remained inactive for a long time as suggested by the highly degraded bedrock scarp with a slope of 18 compared to the 60 dip of the underlying failure plane based on this study corrective measures with an estimated cost of 11 5 million euros have been designed for this slope the investigation illustrates the usefulness and cost effectiveness of the trenching technique allied with geochronological methods to obtain information on the precise limits age failure mechanism kinematics progressive vs episodic displacement movement rate and chronological evolution of landslides

predynastic human presence discovered by core drilling at the northern nile delta coast egypt a small but significant find made during a geological survey provides evidence of the oldest human presence yet discovered along the northernmost margin of egypt9s nile delta a manuport a rock fragment carried by human agency to the site was discovered in a sediment core section north of burullus lagoon near the mediterranean coast accelerator mass spectrometry ams radiocarbon analysis of plant rich matter in the mud surrounding the object provides a date calibrated to 3350 3020 b c the late predynastic period this long thin manuport formed of dolomite had not been deposited by the nile or the sea but was collected and transported from an outcrop exposure positioned at least 160 km south of the core site the fragile manuport used for an undetermined function lay buried at a depth of 7 4 m in dark olive gray mud deposited in a shallow brackish lagoon setting close to a marsh this fortuitous find documents an early human presence in the middle holocene wetlands along the delta9s paleocoast a sector where traditional excavation and augering are normally incapable of reaching occupation levels or zones of activity at considerable subsurface depths core drilling provides a means to help archaeologists locate undetected and potentially important sites

asynchroneity of maximum glacier advances in the central spanish pyrenees the deglaciation history of the escarra and lana mayor glaciers upper gallego valley central spanish pyrenees had been reconstructed on the basis of detailed geomorphological studies of glacier deposits sedimentological and palynological analyses of glacial lake sediments and an accelerator mass spectrometry ams 14c chronology based on minimum ages from glacial lake deposits the maximum extent of the pyrenean glaciers during the last glaciation was before 30 000 yr bp and pre dated the maximum advances of the scandinavian ice sheet and some alpine glaciers a later advance occurred during the coldest period around 20 000 yr bp synchronous with the maximum global ice extent but in the pyrenees it was less extensive than the previous one later there were minor advances followed by a stage of debris covered glaciers and a phase of moraine formation near cirque backwalls the deglaciation chronology of the upper gallego valley provides more examples of the general asynchroneity between mountain and continental glaciers the asynchroneity of maximum advances may be explained by different regional responses to climatic forcing and by the southern latitude of the pyrenees copyright 2002 john wiley sons ltd

deep seated rockslide avalanches preceded by mass rock creep of sedimentary rocks in the akaishi mountains central japan abstract seven large rockslide avalanches of sedimentary rocks are known in japan almost all of these major landslides were preceded by gravitational deformation of rocks mass rock creep mrc as inferred from geologic and geomorphic investigations of five rockslide avalanches in the akaishi mountains the mrc that preceded the rockslide avalanches in the akaishi mountains was characterized by a slow but steady downslope bowing of steeply dipping foliations which accompanied intensive deformation and fragmentation of the rock mass by shearing along foliations this deformation and fragmentation of the rock mass provides a basic cause for the occurrence of rockslide avalanches which occur when a creeping rock mass has lost its support from the lower part of a slope by stream erosion this type of mrc continues for a long time after a part of the creeping area has slid and results in longterm generation of debris by the landslide sear of the rockslide avalanche

evaluating quaternary activity versus inactivity on faults and folds using geomorphological mapping and trenching seismic hazard implications abstract the incorporation of active faults in seismic hazard analyses may have a significant impact on the feasibility design and cost of major engineering projects e g nuclear facilities dams especially when located in the site vicinity the regulatory definition of active versus inactive fault is generally based on whether the fault has ruptured or not after a specific chronological bound i e fault recency this work presents a methodology mainly based on geomorphological mapping and trenching for determining whether specific faults can be considered as active or inactive the approach is illustrated through the analysis of several faults located in the spanish pyrenees loiti leyre la trinidad ruesta faults the 29 km long loiti thrust was included in the neotectonic map of spain as a probable neotectonic structure previous works based on geomorphological investigations incorporated the 28 km long leyre thrust as a significant seismic source in a probabilistic seismic hazard analysis which challenged the seismic design of nearby large dams the production of detailed geomorphological strip maps along the faults allowed the recognition of specific sites where the faults are covered by quaternary deposits the establishment of chronosequences pediments terrace sequences and the available geochronological data helped identifying the most adequate morpho stratigraphic units for satisfactorily evaluating fault activity vs inactivity the excavation of trenches at the selected sites provided unambiguous information on the presence or lack of deformation in the quaternary cover overlying the fault and the origin of scarps tectonic versus erosional trenches were also useful for collecting samples and reliably measuring the relative height of terraces overlain by thick colluvium the evidence gathered by these methods were complemented with the numerical dating of non deformed slope deposits covering a fault the analysis of the longitudinal profiles of old pediment surfaces located in the proximity of a fault the examination of a cave situated next to a fault searching for speleoseismological evidence and regional geodetic and seismotectonic data gps measurements earthquake focal mechanisms the integration of all the data and especially the trenches dug in non deformed old terrace deposits 100 ka truncating the faults indicates that the analysed faults can be considered inactive and that previous neotectonic postulations were based on non valid geomorphological interpretations

deep seated gravitational slope deformations along the active bocono fault in the central portion of the merida andes western venezuela abstract two very large deep seated gravitational slope deformations in the highlands of the merida andes venezuela are herein described the mucubaji pass and cerro la camacha these slope movements have slid in post last glacial maximum times in addition both landslides are in very close association with the active bocono fault trace the cerro la camacha camacha range landslide is fault bounded along its northwest flank whereas the mucubaji pass mass movement is even cut by the active fault trace the almost 10 km long mucubaji slide mobilizes lgm moraine deposits along the unconformable basement contact la camacha slope movement is a sackung type landslide involving two huge masses that affect the entire northwestern slope of the la camacha range this sackung is at least 20 km long paralleling the active bocono fault trace combination of high relief energy gravitational forces and seismic shaking related to an on site active fault could be responsible for the destabilization of the slopes or massif in both cases although the seismically induced re activation of the la camacha landslide is very likely there is no proof for that yet conversely the mucubaji slide shows geomorphic geodetic and sedimentary evidence of episodic activity in recent times which could be ascribed to seismic triggering in the particular case of the la camacha sackung the combination of dextral slip along the bocono fault and a se dipping fault plane could additionally favor the destabilization of the nw slope of the la camacha range

differentiating between gravitational and tectonic faults by means of geomorphological mapping trenching and geophysical surveys the case of the zenzano fault iberian chain n spain abstract the zenzano fault scarp has been developed on the top of a 475 m high erosional escarpment underlain by an upper brittle sequence and a lower halite bearing evaporitic formation the 1850 m long fault with a maximum displacement of 45 m and parallel to the escarpment has offset the back of a dip slope generating an antislope scarp with prominent triangular facets up to 38 m high and obstructing consequent transverse drainages defeated streams both gravitational and tectonic interpretations were previously proposed for this active surface rupture the fault scarp has been investigated by detailed geological and geomorphological mapping geophysical surveys gpr and ert and two trenches excavated across the fault in disrupted drainages the geophysical profiles clearly imaged the fault helping to site the trenches and roughly estimate the thickness of the deposits accumulated in the downthrown block although the maximum displacement to length ratio dmax l of the fault fall within the range of tectonic faults of similar length according to the world database the geological and geomorphological context together with several parameters reveal that this structure corresponds to a gravitational failure 1 anomalously high vertical displacement per event 1 4 m 2 high apparent vertical slip rate 0 6 mm year and 3 short recurrence interval of faulting events the negligible horizontal displacement component on the dip slip fault as well as the presence of very large caprock collapse sinkholes and saline springs strongly suggest that interstratal karstification of the halite bearing evaporites has played a primary role in the development of the gravitational failure the formation of this morphostructure has been favoured by pre existing tectonic faults erosional unloading related to the removal of an overburden ca 800 m thick and enhanced groundwater recharge due to the blockage of the drainage this work illustrates that the proposed multidisciplinary approach allows the identification of features and calculation of parameters that may help to elucidate whether an active failure has a gravitational or a tectonic origin

cosmogenic 10be dating of a sackung and its faulted rock glaciers in the alps of savoy france sackungs are the largest gravitational deformation observed in mountains they are characterized by the long term slowness of the movements but their mechanism is still not well understood nowadays cosmic ray exposure cre dating methods allow dating the morphologic structures involved in sackung and can contribute at the understanding of their origin in the alps the 5 3 km long arcs sackung initiated during the activity of rock glaciers three samples from these faulted rock glaciers provide their first cre ages and show that at 2000 m elevation these block accumulations moved during the younger dryas and stopped in early holocene six 10be ages of fault scarps show that the arcs sackung lasted only a few thousand years and stopped at about 8462 432 10be yr they also reveal that deformation migrated upslope in agreement with a mechanism of flexural toppling of vertical layers this unique and long gravitational event characterized by migration of the deformation does not support earthquake shaking as triggering mechanism for individual faults it shows that in the upper isere valley slope deformation was delayed of several thousand years after glacial debuttressing and is not anymore active despite its fresh morphology

are sackungen diagnostic features of de glaciated mountains abstract deep seated gravitational slope deformations dsgsds with characteristic sackung landforms e g double crests trenches uphill facing scarps and toe bulging are considered by some researchers to be diagnostic features indicating past mountain glaciations however an extensive literature review on sackung features throughout the world reveals that in some regions paraglacial processes are not the causes of such phenomena sackungen occur across a diverse spectrum of mountain types with different morphoclimatic histories including regions that have never experienced glaciation to reinforce that sackungen may originate independently of glaciation we also include two case studies from the western carpathians czech republic and slovakia which are supported by detailed geomorphic mapping trenching and absolute dating 10 be 14 c and osl on the ond ejnik ridge outer western carpathians czech republic sackungen occur in the mid holocene in the medium high mountains which are beyond the pleistocene glacial limits on the salatin mt tatra mts slovakia the sackungen which occur in formerly glaciated terrain date between 7 5 and 4 2 ka bp representing a 4 ka time lag after the disappearance of glaciers this suggests that the direct link between the ice retreat and the onset of sackung formation is not obvious even in the case of the once glaciated mountain range although paraglacial stress release is undoubtedly one of the crucial causes of sackung genesis in many mountain regions it is not the only important mechanism therefore despite occurring in numerous de glaciated mountains sackung features cannot be considered as proof of past mountain glaciations e g during analysis of extra terrestrial settings

temporal behavior of deep seated gravitational slope deformations a review abstract deep seated gravitational slope deformations dsgsds are slow moving hillslope scale mass movements featuring characteristic landforms such as double crested ridges and upslope facing scarps that occur in diverse landscapes throughout the world although these deformations have been studied since the 1960s significant insights to the rates of dsgsds have only been gained within the last two decades owing to progress in geochronology remote sensing and instrumental monitoring absolute age and monitoring data indicate that dsgsd movements are observable over long term 102 years and short term future research directions include constraining the lifespan of dsgsds with absolute age dating and precise high resolution monitoring of spatio temporal displacement across dsgsd bodies it is of great importance to include absolute time scales in the numerical models of dsgsds furthermore combining remote sensing techniques such as synthetic aperture radar interferometry with high resolution lidar scanning and near surface geophysics offers a promising toolkit for collecting very detailed and accurate data on the short term deformation rates of dsgsds

rock slope movements along the mount currie fault scarp southern coast mountains british columbia rock slope movements are reported from mount currie ridge near pemberton in the southern coast mountains of british columbia the site displays linear trenches antislope scarps and tension cracks typical of mountain ridges undergoing slow deformation however the most prominent linear scarp on the ridge has been previously interpreted as a fault scarp kinematic tests on rock discontinuities demonstrate the feasibility of both toppling and plane sliding at this site ground motion vectors based on a 4 year laser electronic distance measurement edm record of slope movements are generally compatible with the results of the kinematic tests these results cast doubt on a strictly seismic interpretation of the mount currie scarp

deep seated gravitational slope deformations in western sicily controlling factors triggering mechanisms and morphoevolutionary models abstract a study of deep seated gravitational slope deformation dsgsd phenomena affecting areas of various geological and geomorphological settings in western sicily is described western sicily is underlain by a thin skinned imbricate wedge of meso cenozoic carbonate and siliciclastic rocks that formed by the stacking of several thrust nappes over the iblean foreland locally the original thrust sheets are folded and cut by high angle faults large areas of western sicily now display high relief energy due to plio pleistocene block faulting and uplifting and the quaternary morphogenetic phases are characterised by incision thereby triggering widespread dsgsds to identify controlling factors and triggering causes and to develop reliable morphoevolutionary models for the dsgsds of western sicily a geomorphological study based on field surveys and aerial photography interpretations was performed previous geomorphological data relating to well known examples of dsgsds were reconsidered leading to remarkable revisions of the interpretative models in certain cases new data were subsequently collected enabling recognition of additional dsgsd phenomena the whole body of data involves a total of 27 dsgsds affecting areas in two specific geological settings 1 areas with flat thrust surfaces where differential settlements back tilting lateral spreads in competent rocks overlying marls and clays large topples and or block type slope movements may develop and 2 areas where deep rooted carbonate units come into lateral contact with clayey marly units along high angle faults where lateral spreads in brittle homogeneous rocks sinking and or rock flows may occur these dsgsd phenomena are associated with different evolutionary stages allowing a morphoevolutionary model to be defined for the two geological conditions for these two different morphoevolutionary models the following structural features play an important role in the development of dsgsds 1 where carbonate bodies overlie clayey marly rocks triggering of the dsgsds traces back to deformation of a ductile substratum that follows the exhumation of the flat thrust planes and the underlying clayey marly rocks due to block faulting and or stream incision and 2 where homogeneous carbonate rocks hundreds of metres thick crop out the dsgsds are triggered by very high relief energy and tensile stress that follow the combined actions of quaternary block faulting and stream deepening associated with differential erosion

direct determination of total and fresh groundwater discharge and nutrient loads from a sandy beachface at low tide cape henlopen delaware total groundwater discharge from a sandy seepage site to the delaware bay at cape henlopen delaware was determined together with the associated nutrient loads by trapping the discharge from a length of the shoreline in a tidal pond at low tide and measuring the discharge of the trapped water through a weir at steady state salinity was used to parse the total groundwater discharge from the beachface at low tide into a recycled estuarine component and a new fresh groundwater component based on 16 measurements over 18 months average total discharge and average freshwater discharge at low tide were found to be 2 76 6 1 08 and 0 87 6 0 43 l min21 m21 of shoreline respectively the estuarine component of discharge varied with the maximum height of the immediately preceding high tide owing to the control of freshwater discharge by the average upland hydraulic gradient away from the beach individual measurements of freshwater discharge at low tide represent a good estimate of this discharge component over time scales of hours to days based on the nutrient concentrations in the discharge waters nutrient loads from the beach to the adjacent estuary at low tide were 148 6 79 7 5 6 5 1 and 197 6 101 mmol min21 m21 of shoreline for total dissolved n p and si respectively groundwater discharge and these nutrient fluxes contribute significantly to the unusually productive benthic communities that inhabit the seepage and nearby intertidal zones estuaries receive their primary inputs from fluvial discharges and exchange with the ocean but it is increasingly evident that atmospheric deposition and direct groundwater discharges from uplands also play a significant role in estuarine biogeochemical processes paerl 1997 burnett et al 2003 although groundwater discharge is thought to represent only a small fraction of the total freshwater discharge to estuaries and the ocean there is increasing evidence that nutrients and contaminants associated with this discharge may play a more significant ecological role than implied by the relatively small discharge valiela et al 1992 burnett et al 2003 shaw 2003 this is particularly true in coastal plain settings where nutrient and contaminant inputs to the groundwater from domestic industrial municipal and agricultural practices may be high the hydraulic conductivity of soils and aquifer sediments is large and the topographically driven groundwater flow to shallow upland streams is low submarine groundwater discharge in many settings appears to be associated with productive benthic communities johannes and hearn 1985 bussmann et al 1999 zipperle and reise 2005 and may influence sediment water exchange through the imposition of hydraulic gradients the modification of subbottom flow paths and the alteration of diagenetic reactions and rates moore

paraglacial slope failures in the aran valley central pyrenees abstract slope failures are widespread phenomena in mid latitude mountain environments that were glaciated during the last glacial cycle this is the case of the aran valley in the upper garonne catchment central pyrenees that included glaciers several hundred meters thick following postglacial warming and ice thinning the recently deglaciated slopes were subject to intense stress readjustments the so called paraglacial dynamics we have identified up to 135 major slope failures in the aran valley with only 10 units occurring outside the glaciated domain of the maximum ice extent of the last glacial the presence of polished bedrock surfaces till and moraine ridges next to some of these features evidence a close connection between glacial and slope processes we have detected different types of slope failures affecting both bedrock 12 large catastrophic rock slope failures 16 rock slope deformation 34 rockfalls and 49 rockslides and unconsolidated glacial sediments 14 slope readjustments on drift mantled slopes the average altitude of rock slope failures oscillates between 1551 and 1991 m with a mean length ranging from 147 to 905 m and a width between 247 and 513 m the affected surface is also highly variable oscillating between 0 02 and 126 2 ha slope failures occur in different lithological settings but they are most frequent in slate lutite and limestone bedrocks we conclude that most of the failures show a paraglacial origin though other factors i e lithology and topography promoted slope instability

variability of the northeast atlantic sea surface δ14c and marine reservoir age and the north atlantic oscillation nao abstract we compiled new 14 c analyses of mollusc shells bivalves and gastropods of known age from the collection of the museum national d histoire naturelle de paris and previously published data to investigate changes in the sea surface 14 c and reservoir age in the northeast atlantic sector nea between 1823 and 1952 ad the mollusc shells are mainly located off the atlantic margin between 45 n and 60 n downstream of the north atlantic current nac we show that the temporal variability of the nea 14 c is independent of the mollusc species depth habitat diet and latitudinal distribution the quasi null difference between mollusc 14 c and the marine model indicate that the mollusc 14 c reflects the 14 c values of open marine conditions between 1823 and 1850 ad the pre anthropogenic mean of 14 c is 45 5 corresponding to a reservoir age of 380 60 years and a r value of 7 50 years in agreement with previous estimates the 14 c values show a significant long term decrease of 12 from 1823 to 1952 ad attributed to changes in 14 c production between 1823 and 1900 ad and the suess effect between 1900 and 1952 ad between 1885 and 1950 ad 14 c fluctuations of 10 up to 18 occurred in the northeast atlantic corresponding to reservoir age variations of 90 years up to 170 years these fluctuations are very similar to changes of 14 c in the southern norwegian sea spectral analyses of the nea 14 c exhibit quasi periodic cycles of about 7 4 years almost equivalent to the quasi periodic cycles of the winter index of the north atlantic oscillation nao with a period around 6 5 years we find that changes of nea 14 c cannot be attributed to changes in river runoff or the precipitation evaporation budget the 14 c lows or high reservoir ages correspond to the more intense phase of the winter nao with a time lag of 1 3 years such a time lag may reflect the eastward transit time of upstream changes originating in the labrador sea then entrained within the nac along with the subpolar gyre into the northeast atlantic sector during these events we estimate that about 70 of the total transport in the nac was due to water originating in the labrador sea

hydrogeological characterization of southeast coastal plain aquifers and groundwater discharge to onslow bay north carolina usa summary the natural geochemical tracer 222 rn was used to quantify submarine groundwater discharge sgd onto the continental shelf of onslow bay north carolina water column samples were collected aboard the r v cape hatteras on july 21 26 2002 and an additional nearshore water column transect and groundwater samples were collected in 2005 2006 assessment of sgd was accomplished using a mass balance approach that quantified sources and sinks of radon including benthic flux exchange across the pycnocline or air sea interfaces horizontal transport into and out of the study area and a water column inventory four independent geochemical box models were developed to quantify sgd regionally and with distance from shore overall water column inventories and diffusion rates decreased with distance from shore average water column inventories were 8520 1310 7230 1190 and 760 510 dpm m 2 for three shore parallel boxes from nearshore to offshore and resulted in a regional average of 5800 1050 dpm m 2 for the regional box model diffusion rates of radon through the sediment water interface were 0 9 0 2 0 6 0 1 and 0 4 0 1 dpm m 2 min 1 for the near to offshore models and averaged 0 6 0 1 dpm m 2 min 1 for the regional box model sgd estimates were calculated using two end member 222 rn activities for the advecting fluids which allowed a distinction between terrestrially driven sgd and total sgd terrestrially driven and total sgd estimates averaged 0 2 and 0 7 cm d 1 respectively the calculated terrestrially driven sgd is as important in the delivery of fresh water as riverine sources to onslow bay and a significant contributor to the south atlantic bight

paraglacial slope adjustment since the end of the last glacial maximum and its long lasting effects on secondary mass wasting processes hauser kaibling austria abstract this study indicates the possible long lasting impacts of deep seated gravitational slope deformation dgsd on erosional and mass movement processes dgsd features are common large scale landforms in the crystalline basement rocks of the central alps of austria inactive forms are related to paraglacial nonglacial processes directly conditioned by former glaciation and deglaciation rock slope adjustment processes acting after glacier retreat towards the end of the late glacial period the near surface metamorphic bedrock of dgsd features is generally disintegrated such rock type favours erosion and the formation of small landslides field data laboratory analyses aerial photographs and gis based terrain analyses are used to describe the different geomorphic effects of an extremely disintegrated rock slope the studied dgsd hauser kaibling 13 6 km2 is located in central austria during the last glacial maximum the adjacent valley glacier reached an altitude of approximately 1900 m a s l glacier retreat in combination with the unfavourable tectono metamorphic setting caused gravity induced stresses to act subsequent sediment build up in the main valley restabilised the slope linear erosion cut a number of gullies into the lower part of the dgsd calculated mean erosional denudation rates at incised valley sections range from 0 5 to 2 6 mm a 1 since deglaciation smaller active landslides on the sides of the steep gullies draining the dgsd contribute to high denudation rates active landsliding is favoured by i fragmented rock ii steep slopes iii supply of surface and subsurface water by rain and snowmelt and iv human impact debris flows and debris charged flood events occurred frequently in the past during such events material was transported from the unstable slopes to the populated alluvial fans thus knowledge about the spatial distribution and the stage of development of dgsds active and currently inactive provides an important basis for risk management measures