time constraints for the evolution of a large slope collapse in karstified mountainous terrain of the southwestern crimean mountains ukraine abstract deep seated gravitational deformations are significant denudational agents of rock slopes at the margins of karstified plateaus of the crimean mountains ukraine the aim of this article is to study long term evolution of a giant rock slope failure close to the black sea coast in the southwestern tip of the mountains near foros town the failure evolved in highly anisotropic limestones overlying plastic flysch layers where the main headscarp follows a strike slip fault we tested a new chronological strategy based on 14 c and u th series dating of speleothems from unroofed caves exposed in the headscarp area of the slope failure this approach made it possible to state maximum age of the slope collapse in individual parts of the deformed slope obtained results indicate that extension of discontinuities together with their karstification can be traced to 300 ka bp whereas evolution of the main headscarp started 110 ka bp and since then it has propagated in the eastward direction the youngest slope failure in the easternmost part of the studied collapse is of late holocene age our study indicates that conditions for large rock slope failures in carbonate areas can be prepared by speleogenesis or combined effects of propagation of cracks and their solution based expansion furthermore large rock slope failures can be important factors for the genesis of unroofed caves

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

nature and timing of large landslides in the himalaya and transhimalaya of northern india four large landslides each with a debris volume 10 6 m 3 in the himalaya and transhimalaya of northern india were examined mapped and dated using 10 be terrestrial cosmogenic radionuclide surface exposure dating the landslides date to 7 7 1 0 ka darcha 7 9 0 8 ka patseo 6 6 0 4 ka kelang serai and 8 5 0 5 ka chilam comparison of slip surface dips and physically reasonable angles of internal friction suggests that the landslides may have been triggered by increased pore water pressure seismic shaking or a combination of these two processes however the steepness of discontinuities in the darcha rock slope suggests that it was more likely to have started as a consequence of gravitationally induced buckling of planar slabs deglaciation of the region occurred more than 2000 years before the darcha patseo and kelang serai landslides it is unlikely that glacial debuttressing was responsible for triggering the landslides the four landslides their causes potential triggers and mechanisms and their ages are compared to 12 previously dated large landslides in the region fourteen of the 16 dated landslides occurred during periods of intensified monsoons seismic shaking however cannot be ruled out as a mechanism for landslide initiation because the himalaya has experienced great earthquakes on centennial to millennial timescales the average holocene landscape lowering due to large landslides for the lahul region which contains the darcha patseo and kelang serai landslides is w0 12 mm yr previously published large landslide landscape lowering rates for the himalaya differ significantly furthermore regional glacial and fluvial denudation rates for the himalaya are more than an order of magnitude greater this difference highlights the lack of large landslide data lack of chronology problems associated with single catchment large landslide based calculations and the need for regional landscape lowering determinations over a standardized time period

erosional processes topographic length scales and geomorphic evolution in arid climatic environments the lluta collapse northern chile the lluta collapse of northern chile is one of the oldest recognizable landslides 2 5 ma in a hyperarid continental setting this paper develops a conceptual landscape evolution model of the lluta collapse and analyzes the controls of mass wasting and erosion sediment transport in channels on the topographic development the data presented here imply that high relief along a topographic scarp surface fracturing elevated groundwater table during a more humid climate and an aquitard underlying permeable ignimbrites are preparatory causal factors for landsliding 2 5 ma ago a strong seismic event then possibly resulted in the displacement of ca 26 km3 of mass subsequent modification of the landslide scar occurred by backward erosion resulting in the establishment of a dendritic drainage network and the removal of an additional ca 24 km3 of material it appears that this mass was produced by mass wasting in the headwaters and exported by high concentrated debris flows in channels in addition morphometric information suggest that whereas the geometrical development of the lluta collapse has been controlled by gravitational mass wasting the rates of the development of this geomorphic unit have been limited by the export rates of mass and hence by the transport capacity of the flows

prediction of the behaviour of landslide dams using a geomorphological dimensionless index landslide dams are a common phenomenon they form when a landslide reaches the bottom of a river valley causing a blockage the first effect of such a dam is the infilling of a lake that inundates the areas upstream while the possibility of a sudden dam collapse with a rapid release of the impounded waters poses a higher flood risk to the downstream areas the results of the main inventories carried out to date on landslide dams have been examined to determine criteria for forecasting landslide dam evolution with particular emphasis on the assessment of dam stability not all landslides result in the blockage of a river channel this only occurs with ones that can move a large amount of material with moderate or high velocities in most cases these landslides are triggered by rainfall events or high magnitude earthquakes a relationship also exists between the volume of the displaced material and the landslide dam stability several authors have proposed that landslide dam behaviour can be forecast by defining various geomorphological indexes that result from the combination of variables identifying both the dam and the dammed river channel further developments of this geomorphological approach are presented in this paper by the definition of a dimensionless blockage index starting with an analysis of 84 episodes selected worldwide it proved to be a useful tool for making accurate predictions concerning the fate of a landslide dam copyright 2002 john wiley sons ltd

the formation and failure of natural dams of the numerous kinds of dams that form by natural processes dams formed from landslides glacial ice and late neoglacial moraines present the greatest threat to people and property landslide dams form in a wide range of physiographic settings the most common types of mass movements that form landslide dams are rock and debris avalanches rock and soil slumps and slides and mud debris and earth flows the most common initiation mechanisms for dam forming landslides are excessive rainfall and snowmelt and earthquakes landslide dams can be classified into six categories based on their relation with the valley floor type i dams 11 of 184 landslide dams from around the world that we were able to classify do not reach from one valley side to the other type ii dams 44 span the entire valley floor in some cases depositing material high on opposite valley sides type iii dams 41 move considerable distances both upstream and downstream from the landslide failure type iv dams 1 are rare and involve the contemporaneous failure of material from both sides of a valley type v dams 1 also are rare and are created when a single landslide sends multiple tongues of debris into a valley and forms two or more landslide dams in the same reach of river type vi dams 3 involve one or more failure surfaces that extend under the stream or valley and emerge on the opposite valley side many landslide dams fail shortly after formation in our sample of 73 documented landslide dam failures 27 of the landslide dams failed less than 1 day after formation and about 50 failed within 10 days over topping is by far the most common cause of failure the timing of failure and the magnitude of the resulting floods are controlled by dam size and geometry material characteristics of the blockage rate of inflow to the impoundment size and depth of the impoundment bedrock control of flow and engineering controls such as artificial spill ways diversions tunnels and planned breaching by blasting or conventional excavation glacial ice dams can produce at least nine kinds of ice dammed lakes the most dangerous are lakes formed in main valleys dammed by tributary glaciers failure can occur by erosion of a drainage tunnel under or through the ice dam or by a channel over the ice dam cold polar ice dams generally drain supraglacially or marginally by downmelting of an outlet channel warmer temperate ice dams tend to fail by sudden englacial or subglacial breaching and drainage late neoglacial moraine dammed lakes are located in steep mountain areas affected by the advances and retreats of valley glaciers in the last several centuries these late neoglacial dams pose hazards because 1 they are sufficiently young that vegetation has not stabilized their slopes 2 many dam faces are steeper than the angle of repose 3 these dams and lakes are immediately downslope from steep crevassed glaciers and near vertical rock slopes and 4 downstream from these dams are steep canyons with easily erodible materials that can be incorporated in the flow and increase flood peaks the most common reported failure mechanism is overtopping and breaching by a wave or series of waves in the lake generated by icefalls rockfalls or snow or rock avalanches melting of ice cores or frozen ground and piping and seepage are other possible failure mechanisms natural dams may cause upstream flooding as the lake rises and downstream flooding as a result of failure of the dam although data are few for the same potential energy at the dam site ownstream flood peaks from the failure of glacier ice dams are smaller than those from landslide moraine and structed earth fill and rock fill dam failures moraine dam failures appear to produce some of the largest downstream flood peaks for potential energy at the dam site greater than 1011 1012 joules differences in flood peaks natural dam failures appear to be controlled by dam characteristics and failure mechanisms

correlation between climate man and debris flow events a palynological approach abstract debris flows occur frequently in the high alpine catchment area of lake lago di braies 1492 m a s l the sediments of the lake are used for detecting and dating past debris flow events during the last 4000 years and their driving factors comparing palynological and sedimentological data the results suggest that mainly heavy precipitation in winter and summer as well as snow melt events in spring enhance the release of debris flow events therefore especially longer periods with humid and cool climate conditions show a clearly higher debris flow activity the pollen diagram documents human impact on the catchment area since the late neolithic but the anthropogenic activities influenced the event activity only indirectly grazing and deforestation reduced the retention of debris by vegetation and results in thicker debris flow layers in the lake sediments

recent tectonics and slope failures in the western carpathians we describe several examples of recent tectonics and related slope failures from the western carpathians of slovakia the monitoring data confirm the idea of non uniform geodynamic behaviour of individual tectonic units as well as the idea that even an extremely low rate of displacement both in landslides and along active faults may endanger human life and property the crack gauge tm 71 is adopted as the monitoring device in our study and we confirm its reliability for measuring in plane displacements in severe conditions with a resolution of 0 1 mm year simple manipulation minimum maintenance requirements and reasonable price

frictionite as evidence for a large late quaternary rockslide near kanchenjunga sikkim himalayas india implications for extreme events in mountain relief destruction abstract we present sedimentologic and petrographic field evidence of an extremely large 2 5 109 m3 late quaternary rockslide around dzongri 24 km s of kanchenjunga 8585 m a s l widespread occurrence of shattered leucogranites and migmatites deposited discordantly on top of undisturbed augen gneisses and separated by micro brecciated sliding surfaces indicate rapid movement during a large rockslide event occurrence of frictionite hyalomylonite in mineral samples indicates short term temperatures of 600 c in the moving rockslide mass along a 12 sliding plane from a sw direction of movement we infer a source 8 km ne of the deposit 5 km s of pandim 6691 m a s l where today a thick leucogranite intrusion marks a zone of weakness and failure of a postulated former mountain crest the mechanism of movement the dip of the sliding surface and the deposit preservation along ridge tops require that the dzongri rockslide ran out over an ice filled prek chu valley hence we prefer earthquake shaking over undercutting and glacial debuttressing as a possible trigger mechanism a regional review of other similarly large and catastrophic himalayan rockslides indicates that leucogranite intrusions are highly conducive to large scale failure in the higher himalayan crystalline hhc importantly high erosion rates have rendered this large rockslide deposit undetectable by remote sensing or digital elevation data which are commonly used for identifying evidence of such extreme events quantifying the contribution of such giant landslides in destroying some of the highest relief on earth will thus need further research attention

a lacustrine record of early holocene watershed events and vegetation history corvara in badia dolomites italy the early middle holocene lacustrine succession of corvara in badia italian dolomites 1521 m a s l records landslides and other watershed events before the onset of human pressure the sensitivity of this archive to relate climate change watershed processes and vegetation dynamics in the catchment has been explored through a stratigraphic study including the analysis of sedimentological features magnetic properties palaeobotanical records and radiocarbon dating a palaeolake existed between 10 1 k and 7 k cal yr bp and was surrounded by a dense conifer forest long term forest dynamics driven by ecological processes and by climatic conditions favourable to upward forest expansion is recorded throughout the pollen record within the fine clastic sedimentation distinct layers enriched in organic debris of terrestrial origin have been attributed to instant events produced by mass movements their age fits the chronology of large landslide events already known in the catchment enabling correlation of the field evidence of landslides with the lacustrine record landslide frequency is controlled by geological and structural factors but it is significantly modulated by the centennial millennial climatic phases that characterise the holocene in the alps the taphonomical properties of pollen and macroremains provided valuable insight on the mechanism of watershed processes copyright 2006 john wiley sons ltd

predesign failure and displacement mechanisms of large rockslides in the annapurna himalayas nepal abstract the paper analyses and compares four major mass movements rockslides and rock avalanches with volumes of 1 to 5 km3 around the annapurna himalayan region from engineering geological quaternary geological and geomorphological viewpoints it shows how paleotectonic and neotectonic predesign as well as morphological overprint caused by glacial activities are the main preparatory causal factors for the sliding events that is why giant failures of mountain crests have mainly occurred in areas of tectonic activity the mechanism of failure and displacement of the resulting large mass movements also strongly depends on this litho tectonic predesign and continues in giant translational rockslides in which the primary rock structure or fabric is preserved but shattered by mechanical stress during the sliding event

how unusual is the long runout of the earthquake triggered giant luanshibao landslide tibetan plateau china abstract in the tibetan plateau active tectonic deformation triggers frequent earthquakes and giant landslides associated with active faults produce serious consequences a study of the characteristics and mechanism of a historical long runout landslide in luanshibao lsb tibetan plateau china finds a maximum sliding distance l of 3 83 km with an elevation drop h of 820 m the landslide volume v was 0 64 0 94 10 8 m 3 and it produced a long runout h l 0 21 recent surface offset along the sinistral strike slip litang dewu fault passes through the middle part of the landslide which initiated on the hanging wall of the fault geological mapping geophysical prospecting trenching and 14 c dating together indicate that the lsb landslide occurred in jointed granite ca 1980 30 ybp probably triggered by a large earthquake compilation of volume and runout distance data for this landslide and other previously published data for volcanic and nonvolcanic long runout landslides yields a composite runout length volume relation l 12 52 v 0 37 that closely predicts runout of the lsb landslide although substantial variation is noted in runout length around the central tendency

the hattian bala rock avalanche and associated landslides triggered by the kashmir earthquake of 8 october 2005 the kashmir earthquake of the 8 october killed an estimated 87 350 people 25 500 through co seismic landslides the largest landslide associated with the earthquake was the 68 106 m3 hattian bala rock avalanche that destroyed a village and killed around 1000 people the deposit blocks the valley to a depth of 130 m impounding a lake that reached the dam crest in april 2007 an outburst flood now threatens a major settlement 3 km downstream a series of space images reveals landslide clusters in the rock avalanche source area prior to the earthquake the images also reveal a large slow moving landslide with its toe in the lake failure of this landslide may induce dam failure through overtopping and scour eighty five landslides in the hattian bala catchment predate the shaking of 8 october 2005 a further 73 are co seismic with the main shock and 21 postdate it in the period up to october 2006 landslide magnitude frequency distribution plots derived from satellite images allow an assessment of the contribution of seismically triggered events as compared to background rates of activity

the magnitude of error in conventional bulk sediment radiocarbon dates from central north america abstract although the carbon reservoir problem with bulk sediment radiocarbon dates from lakes has long been recognized many synoptic studies continue to use chronologies derived from such dates for four sites in central north america we evaluate chronologies based on conventional radiocarbon dates from bulk sediment versus chronologies based on accelerator mass spectrometry ams radiocarbon dates from terrestrial plant macrofossils the carbon reservoir error varies among sites and temporally at individual sites from 0 to 8000 yr an error of 500 2000 yr is common this error has important implications for the resolution of precise event chronologies

landslides and quaternary climate changes the state of the art abstract climatic factors are considered major causes and triggers of slope instability but the palaeoclimatic implications of landslides have not yet been systematically reviewed as inferred from landslides dated to the late glacial and holocene glacial interglacial transitions are the major intervals of enhanced landsliding but the length of this interval varies between distinct types of landscapes mass movements in non glaciated temperate mountain ranges arid and tropical regions and coastal areas intensified soon after the onset of the holocene alongside the warming and wetting of the climate whereas large rock slides in areas within the limits of pleistocene glaciations mostly show a millennial scale time lag with respect to glacier withdrawal although the incidence of landslides was ubiquitous throughout the holocene the mid to late holocene transition 5 4 ka was especially favourable for the origin of landslides across distinct types of landscapes indicating a strengthened role of mass movements during the culmination phases of interglacial climate optima in addition growing evidence suggests that the enhanced activity of landslides occurred during warmer interstadial conditions which is best demonstrated in the temporal coincidence of arid zone landslides with quaternary pluvials future progress in the understanding of the relationships between landslides and quaternary climate changes should benefit from the i extension of datasets of dated landslides ii geographical expansion of dating studies to regions with a lack of chronologically determined landslides e g tropics iii improvement of landslide dating strategies involving the incorporation of independent palaeoclimatic proxies and iv wider incorporation of numerical modeling within landslide dating studies

surface exposure dating of the flims landslide graubunden switzerland abstract sixteen boulder and bedrock surfaces related to the flims landslide volume 8 12 km3 were dated with 36cl and 10be exposure ages range from 4900 250 yr to 15 440 1480 yr including corrections made due to snow cover and karst erosion ages of 11 410 590 yr and 13 340 1090 yr were obtained on bedrock surfaces outside of the landslide zone these are minima for deglaciation of segnes valley and provide constraints on possible amounts of inherited nuclides based on seven boulder ages which range from 8200 260 to 9520 990 yr a mean of 8900 700 years is calculated for the flims landslide we exclude three outliers one significantly older and two significantly younger than the others and the ages from the cassons bedrock site from the mean calculation the latter is excluded as shielding due to snow and vegetation cover is difficult to constrain there the oldest boulder on the landslide yielded an age 15440 1480 yr more than 5000 years older than any other boulder age suggesting that it included the surface of the pre slide bedrock the exposure ages are consistent with a single failure event the erratics and patches of till lying on the landslide debris must have been carried piggy back on top of the landslide rather than having been deposited by the late pleistocene vorderrhein glacier the flims rockslide is about the same age as the kofels 9800 yr and kandertal 9600 yr rockslides all three occurred during the marked transition to warmer wetter conditions during the early holocene

the contribution of landslides to landscape evolution in europe abstract after a review of some analytical and conceptual models of slope evolution with the intervention of mass movements a proposal is made of a series of indicators for the quantitative description of landscape evolution in relation to mass movements the ratio between landslide mobilisation rate and downwearing rate is proposed as a quantitative measure of the significance of mass movements in landscape evolution a subdivision of european regions with respect to their susceptibility to landsliding as a process of landscape evolution is proposed the role of landsliding for the evolution of landscape in some regions is described the data presented show that landsliding may in some cases be the main contributor to landscape change

landslide dynamics from high resolution aerial photographs a case study from the western carpathians slovakia abstract the ubietova landslide is one of the largest landslide events in the central slovakia neogene volcanic field area its present morphology resulted from several reactivation events the latest one took place in 1977 we applied archive digital photogrammetry to build the historical topography of the landslide area and reconstructed its evolution from 1969 to 1998 at approximately decadal scale four sets of aerial photos of the area taken in 1969 scale 1 16 000 1977 scale 1 14 000 1988 scale 1 17 000 and 1998 scale 1 20 000 were processed using a digital photogrammetric workstation elevation data were extracted from all the photo sets then four high resolution digital elevation models dems were generated and compared particular interest was placed on quantification of vertical ground displacements and volumetric mass redistribution both of them were calculated by subtracting two subsequent dems consequently distribution and temporal variation of the landslide activity over three decades are outlined through differential raster images differential dems and cross sections according to our results the 1977 reactivation event caused considerable vertical displacements up to 5 7 m in the peak areas of depletion and accumulation zones accordingly large volumes of material 148 000 m3 84 000 m3 were redistributed during this event the dynamics of the 1977 reactivation event shows some specific features that are discussed within the broader context besides the new quantitative data reconstruction of 3d topography of the site before and after the 1977 reactivation brought geomorphic evidence that the area was affected by more than one landslide event in the past

gigantic low gradient landslides in the northern periphery of the crimean mountains ukraine abstract large scale low gradient ancient landslides estimated at 5 4 18 9 km 2 in area and 0 2 1 2 km 3 in volume have been studied in the northern hilly periphery of the crimean mountains ukraine they originated on slopes along wide water gaps of rivers belbek kacha alma and biyuk karasu crossing the cuestas of the northern foothills the slopes generally consist of slightly northward tilting miocene mainly sarmatian limestones overlying weak clay rich lower neogene palaeogene substratum with a significant content of smectite although the region is characterised by the least active contemporary morphodynamics within the crimean mountains the landslides which were studied are of the same size or even larger than various types of landslides occupying active geomorphic domains of the highest mountain range in the southernmost part of the peninsula the landslides are generally a spreading type but the sliding mechanics were probably very complex involving toppling rotational slides gravitational folding and translational block slides all the landslides which were studied are located in the vicinity of regional faults and three of them have headscarps aligned along faults a common feature is also a location close within several km to the mesozoic suture zone which is the most important tectonic feature in the northern periphery of the crimean orogene this suture was formerly classified as aseismic however evidence of strong low frequency palaeoearthquakes was collected during the last decade within both the mesozoic suture and the low lying northern part of the crimean peninsula radiocarbon dating of deposits associated with the landslides has revealed at least two phases of increased landslide activity during the late glacial chronozone and holocene epoch the main landslide phase presumably took place at some time between the late glacial and atlantic chronozones minor reactivation of landslide toes occurred during the subatlantic chronozone and some of them have been active up to recent times the first major landslide phase was possibly triggered by an earthquake whereas late holocene activity can be attributed both to seismic and hydroclimatic factors

classic and new dating methods for assessing the temporal occurrence of mass movements abstract establishing landslide chronologies is essential both for understanding causes of mass movements as part of fundamental geomorphological research and for the assessment of landslide hazards as part of applied geomorphology we discuss the applicability of different methods for determining landslide chronologies frequencies and dynamics in relation to the type of material being dated sampling location and type of mass movement the emphasis is on the possibilities and limitations of the different dating methods established methods such as radiocarbon dating lichenometry and dendrochronology are briefly discussed the paper focuses however on 1 new analytical techniques like accelerator mass spectrometry ams thermally ionising mass spectrometry tims and laser fusion which have led to significant improvements of established dating methods and on 2 new dating methods like optically stimulated luminescence osl dating and alpha recoil track art dating

late holocene evolution of a floodplain impounded by the smrduta landslide carpathian mountains czech republic we present here a detailed study of the sedimentary archive within a landslide controlled impounded floodplain smrduta site czech flysch carpathians using geochronological 14c and 137cs sedimentological and pollen evidence a sedimentary sequence deposited above the landslide dam points to three highly discontinuous and instantaneous depositional events dated to 4 6 and 2 0 cal ka bp whereas the last cycle started approximately in the 17 18th centuries and has continued to recent times stages of mass movement activity revealed by the smrduta landslide correlate well with major humid late holocene oscillations suggesting its high sensitivity to century scale climatic deteriorations the character of lithological units forming individual sedimentary pulses erosional hiatuses and sedimentary traces caused by the july 1997 extreme flood indicate a decisive role of large flood events during accretion and erosion of the floodplain impounded section

holocene reactivations of catastrophic complex flow like landslides in the flysch carpathians czech republic slovakia catastrophic complex flow like landslides cflls are characterised by a deep seated retrogressive landslide of structurally unfavourably oriented rocks and earthflows that occupy the lower slope positions and originate due to the liquefaction of material accumulated on the upper slopes these landslides are locally important geomorphic agents of late quaternary mountain evolution in the flysch belt of the outer western carpathians czech republic slovakia most of the cflls dammed and steepened adjacent valleys radiocarbon dating suggests that a majority of them moved repeatedly throughout the holocene namely approx every 1 2 ka dated events occurred during humid phases of the younger dryas holocene transition 11 5 9 4 cal ka bp atlantic chronozone 7 4 6 6 cal ka bp the beginning of the subboreal chronozone ca 4 6 cal ka bp and primarily within the subatlantic chronozone at ca 2 0 8 cal ka bp 50 of all events our study suggests that slopes based on an unfavourable structural setting and affected by long term deep seated gravitational deformations may produce cflls even if they are located in medium high mountains although our chronological dataset is influenced by the erosion of older landforms most of the dated reactivations correlate with regional increase in precipitation identified by previous palaeoenvironmetal studies

comparison of oxygen isotope records from the gisp2 and grip greenland ice cores recent results1 2 from the greenland ice core project grip summit ice core suggest that the climate in greenland has been remarkably stable during the holocene but was extremely unstable for the time period represented by the rest of the core spanning the last two glaciations and the intervening eemian inter glacial here we present the complete oxygen isotope record for the greenland ice sheet project 2 gisp2 core drilled 28 km west of the grip core we observe large rapid climate fluctuations throughout the last glacial period which closely match those reported for the grip core however in the bottom 10 of the cores spanning the eemian interglacial and the previous glacia tion there are significant differences between the two records it is possible that ice flow may have altered the chronological sequences of the stratigraphy for the bottom part of one or both of the cores considerable further work will be necessary to evaluate the likelihood of this and the extent to which it will still be possible to extract meaningful climate information from the lowest sections of the cores

river response to variations of periglacial climate in mid latitude europe abstract the last glaciation was characterised by considerable changes in climate many european river basins reacted to these changes by initial incision and subsequent pattern change earlier research explained this by the time lag of vegetation development after a climatic change which considerably affected the sediment load however since some river basins react differently or do not react at all this model needs to be refined this paper deals with the fluvial evolution of several rivers in northern and central europe during the last glaciation and two of them the weise elster river in the leipzig area and the spree river in the niederlausitz germany are discussed in more detail the vegetation cover on the floodplain in combination with the presence of frozen ground which affects the discharge characteristics largely determines the river type nevertheless when the sequences are compared not only synchronous changes in fluvial development may be observed but also distinct differences in fluvial development by analysing the different rivers in their varying geomorphological settings it appears that grain size basin configuration and catchment size are important parameters also which can determine whether a threshold is exceeded or not

deep seated landslides affecting monoclinal flysch morphostructure evaluation of lidar derived topography of the highest range of the czech carpathians abstract the recent launch of national scale lidar derived topographic data provides an opportunity for re evaluating the geomorphic imprint of landslides in forested mountains a lidar based inventory of deep seated landslides dsls in the highest part of czech outer western carpathians moravskoslezske beskydy mts reveals that nearly 20 of the territory is affected by ancient dsls rather than the topography itself we show that the geological characteristics of flysch rocks control the density scaling relationships and morphometry of dsls they reveal a strong tendency to clustering in areas with favourable structural conditions such as cataclinal slopes of individual monoclinal ridges formed by thick bedded sandstones in comparison with high mountain areas and regions dominated by weaker lithology e g claystone dominated flysch sandstone dominated monoclinal structure of the moravskoslezske beskydy mts features predominantly short travelled dsls that are arrested on slopes and thus reveal a higher slope gradient than non landslide terrain finally we propose a conceptual model for the evolution of dsls on monoclinal flysch morphostructures particularly where coherent sandstone caps overlie weak claystone siltstone dominated flysch in these conditions we distinguish between low and high monoclinal ridges where the former is capped by relatively thin sandstones overlying claystone formations and sandstones predominate in the structure of the latter we show that the density of dsls on the cataclinal dip slopes is similar on both types of monoclinal ridges but that major differences exist in the evolution of anaclinal escarpment slopes here low monoclinal ridges are highly affected by dsls but escarpments of high monoclinal ridges are nearly devoid of any dsls

large holocene landslides from pylon peak southwestern british columbia mount meager massif the northernmost volcano of the cascade volcanic belt has been the site of very large 10 7 m 3 landslides in the holocene epoch we document two complex landslides at pylon peak one of the peaks of the mount meager massif about 7900 14 c and 3900 14 c years ago about 8700 and 4400 calendar years ago together the two landslides displaced 6 1 0 8 m 3 of volcanic rock from the south flank of pylon peak into nearby meager creek valley each landslide consisted of at least two phases an early debris flow resulting from failure of hydrothermally altered pyroclastic rock at mid levels on the mountain and a later rock avalanche from a higher source both debris flows likely traveled down meager creek and preliminary evidence from drilling indicates the 4400 year old event traveled down lillooet river into areas that are now settled and where population density is increasing rapidly the mobility of the debris flows was due to the high content of fine weathered volcanic sediment and the availability of sufficient water the causes of the landslides are a wet climate and the presence of weak hydrothermally altered volcanic rock containing abundant phreatic water on glacially oversteepened slopes the landslides may have been triggered by earthquakes or by upwelling of magma to shallow depths within the volcano however they may also have occurred without specific triggers following extended periods of progressive weakening of the volcanic rocks

change in the frequency of extreme events as the indicator of climatic change in the holocene in fluvial systems abstract the transformation of natural systems of climatic origin in the holocene may be realised by a change in the type of extreme events or by a change in their frequency or by both the rapid warming at the younger dryas preboreal transition exemplifies a parallel drop in frequency and a change in the type of events several wetter phases of the holocene are characterised by rises in frequency of various types of extreme rainfalls the fragmentary records of events in the fluvial and slope systems coincide with smoothed variations in stable ecosystems and shifts of ecotonal zones such as tree line and lake levels

cre dating on the head scarp of a major landslide sechilienne french alps age constraints on holocene kinematics cosmic ray exposure cre dating applied to the active sechilienne landslide romanche valley belledonne massif french alps provides information about its holocene dynamics from initiation to present day activity glacier retreat at 1100 m a s l is estimated at 16 6 0 6 10be ka from glacially polished bedrock samples with total deglaciation of the valley achieved at least by 13 3 ka application of the cre method along vertical profiles sampled with a high spatial resolution of 3 m on the head scarp yields 1 an initiation of the rock slope failure at 6 4 1 4 10be ka and 2 a continuous rock slope failure activity with a mean head scarp exposure rate of 0 6 cm yr the data suggest an increase of the head scarp exposure rate between 2 3 and 1 0 ka after this acceleration phase the exposure rate is similar to that obtained by the present day monitoring data over 20 years in the depletion zone 1 3 cm yr since the failure initiation occurred more than 5400 yr after the total deglaciation of the valley the slope failure does not appear as an immediate consequence of debutressing in the romanche valley this result is consistent with studies of other large alpine rockslides in the alps failure initiation of the sechilienne landslide occurred during the holocene climatic optimum a hot and wet period the temperature and precipitation changes of this climatic optimum seem to have a worsening effect at the regional scale to trigger large mass wasting in this glacial alpine valley

origin of a boreal birch bog woodland and landscape development on a warm low mountain summit at the carpathian pannonian interface we analysed two peat cores of late glacial origin from a bog woodland in the male karpaty mts sw slovakia using plant macrofossil pollen peat chemistry and charcoal analyses to trace local successional patterns regional vegetation development and occurrence of rare species

catastrophic rock slope failures and late quaternary developments in the nanga parbat haramosh massif upper indus basin northern pakistan abstract the nanga parbat haramosh massif has some of the greatest relief on earth and highest measured rates of uplift denudation and river incision in bedrock many studies have sought to understand how its morphology relates to geotectonic evolution and glaciations however few catastrophic rock slope failures had been recognised and many of their impacts had been attributed to other processes recently more than 150 of these landslides have been found within a 100 km radius of nanga parbat 8125 m new discoveries are reported east north and west of nanga parbat along the indus streams most generated long run out rock avalanches that dammed the indus or its tributaries some impounding large lakes they initiated episodes of intermontane sedimentation followed by trenching and removal of sediment valley floor features record a complex interplay of impoundment and sedimentation episodes superimposition of streams in pre landslide valley floors and exhumation of buried features these findings depart from existing reconstructions of quaternary events a number of the rock avalanche deposits were previously misinterpreted as tills or moraine and their associated lacustrine deposits attributed to glacial lakes features up to 1000 m above the indus formerly seen as tectonically raised terraces are depositional features emplaced by landslides or erosion terraces recording the trenching of valley fill in landslide interrupted river reaches unquestionably tectonics and glaciation have been important but decisive and misread formative events of the holocene involve a post glacial landslide fragmented fluvial system the latter has kept valley developments in a chronic state of disequilibrium with respect to climatic and geotectonic controls accepted glacial chronologies are put in doubt particularly the extent and timing of the last major glaciation the pace and role processes in the holocene have been seriously underestimated

structural control and types of movements of rock mass in anisotropic rocks case studies in the polish flysch carpathians abstract types of gravitational movements in the flysch carpathians are related to tectonic and lithologic anisotropy of rock massifs this article presents the main types of mass movements in the highly anisotropic flysch massifs lateral spreading and rock flow topple translational rotational and compound sliding and complex type of mass movements which are illustrated by chosen forms described using structural analysis joints faults and other structural planes orientation topple is the typical mass movement for double ridges and top trenches e g gaworzyna in the beskid s decki mts translational landslides with flat structural sliding surfaces typical for shallow forms can develop along bedding planes e g duszatyn western bieszczady mts as well as along joints opuszna gorce mts and fault planes rzeki gorce mts currently used classification of the structural landslides is applied only to translational landslides shearing zones of deep seated landslides are composed of structural sections of joints faults bedding planes and shearing elements consequently most of the carpathian landslides have developed as compound type with non circular sliding zones representing complex movements combined with various types of displacement rotation translation and or topple purely rotational movements with circular failure typical for isotropic material have developed in the flysch where thick bedded hard sandstones are underlain by plastic shales e g mt kostrza in the beskid wyspowy mts the influence of anisotropy of these rocks on sliding surface is significantly reduced and plastic type rocks stimulate rock flow development which is usually later transformed into complex landslides with predominant rotational movement e g rotational landslide with topple and flow elements on mt muronka in the beskid l ski mts compound landsliding on mt lubon wielki beskid wyspowy mts represents an antithetic rotational slide with topple and rotational type movements

paleoenvironmental evolution of the eastern mediterranean during the messinian constraints from integrated microfossil data of the pissouri basin cyprus abstract integrated data of calcareous nannofossils as well as planktonic and benthic foraminifera from the pissouri motorway section on cyprus allow the reconstruction of surface and bottom water paleoenvironments of the eastern mediterranean during the interval preceding the messinian salinity crisis msc contrary to deeper water locations where benthic foraminifera faunas are suppressed or absent just after the tortonian messinian boundary sediments deposited at intermediate water depths do contain benthic assemblages from the earliest messinian onwards a development towards increasingly unfavourable paleoenvironments is reflected in the planktonic and benthic microfossil records of the pissouri section and proceeds with rather discrete time steps that can be correlated to sequences throughout the mediterranean shortly after the tortonian messinian boundary a transition is recorded in the sedimentology and the open marine deeper water taxa disappear from the benthic foraminifera assemblages subsequently the diversity of all fauna groups diminishes the changes recorded at species level in both surface water and sea floor dwelling taxa suggest decreasing circulation of the bottom waters associated with changes in the surface waters most likely due to increasing stratification from 6 73 ma onwards our data indicate a prominent change to more restricted conditions and increasing salinity at the sea floor together with intermittently rising surface water salinity the dominance of oligotypic and monospecific assemblages and the frequent shifts in assemblage compositions of all microfossil groups indicate severely stressed environments after 6 4 ma probably related to increased salinity the major changes in paleoenvironmental conditions including oxygen deprivation due to stagnation and hypersalinity can be explained by hydrographical changes in the mediterranean basin which are probably caused by tectonic movements in the rif corridor acting in concert with astronomical cyclicity evaluation of the paleodepth proxies indicates that the depth of the pissouri basin remained rather constant at 300 500 m with a minimum of 200 m until deposition of the barre jaune the transitional interval towards the evaporites and that early shallowing to neritic depths as was proposed before is highly unlikely

last glacial interglacial cycle in the evolution of river valleys in southern and central poland abstract the last glacial interglacial cycle is represented usually by several cuts and fills which have formed 2 3 terrace steps from the last cold stage and by two or more fills of lateglacial holocene age their number depends on the size of the river valley and the position in the longitudinal profile the sequence of changes reflects shorter stadial interstadial climatic fluctuations generally aggradation dominates during the cooler phases of the vistulian and during the interpleniglacial the most distinct erosional phases occurred during the change from a more oceanic to a more continental climate before the maximum extension of the ice sheet 25 20 ka bp and during the upper pleniglacial lateglacial transition 15 13 ka bp the second phase coincides with the rapid downcutting in the lower course of the main vistula valley which had been blocked earlier by the scandinavian ice sheet in the holocene aggradation prevailed accelerated by anthropogenic soil erosion it was only in the mountain foreland that shorter lived hydrological changes resulted in well expressed several cuts and fills

large rockslides in the southern central andes of chile 32 34 5 s tectonic control and significance for quaternary landscape evolution abstract the distribution and age of large 0 1 km2 pliocene to recent rockslides in the chilean cordillera principal 32 34 5 s the southern central andes has been analyzed to determine the rockslide triggering mechanisms and impact on regional landscape evolution most of the rockslides appear in the western cordillera principal and cluster along major geological structures variographic analyses show spatial correlation between rockslides geological structures and shallow seismicity a relative chronosequence was calibrated with existing 14c and 40ar 39ar dates and new cosmogenic nuclide exposure ages for selected rockslides rockslide induced sediment yield was estimated with empirical relations for rockslide area distributions throughout the quaternary rockslides have delivered sediment to streams at rates equivalent to denudation rates of 0 10 0 06 mm a 1 while estimates using short term 20 a seismicity records are 0 3 0 2 0 6 mm a 1 the estimates of sediment transfer and the spatial distribution of rockslides reflect a landscape in which tectonic and geological controls on denudation are more significant than climate

landslides increased holocene habitat diversity on a flysch bedrock in the western carpathians abstract landslides are an important natural phenomenon of the flysch outer western carpathians that diversify the local topography and provide valuable microrefugia in the geomorphologically uniform region for the first time we reconstructed the continuous history of carpathian landslide wetland the kotelnice mire which initiated at the pleistocene holocene transition using joint analysis of abiotic proxies pollen plant macrofossils and testate amoebae ta we utilised modern training datasets of plants and ta to define ecological requirements of species and to determine indicators of either bog or fen habitats we further compared pollen representation of selected woody species between two landslide related wetlands and two spring fens not related to landslides within the study region the unique feature of the kotelnice mire is the development of a nearly ombrotrophic bog at 2500 cal bp that was after 1500 years reversed to a poor fen by intense deforestation and pastoralism pollen analysis and its intra regional comparison demonstrate a dual refugial role of landslides in the carpathians in the early holocene and perhaps even in the late glacial landslides provided refugia for warmth and moisture demanding species e g lime elm hazel beech maple on the contrary they provided shelter for cold demanding boreal species e g spruce eriophorum vaginatum sphagnum medium divinum in the middle and late holocene because the analogous refugial role of landslides at both the recent and the quaternary time scales has been reported from the flysch like and volcanite bedrocks across the northern hemisphere landslides deserve more attention in searching for regionally or even globally crucial refugia

calcareous nannofossil paleoecology in the sapropel s1 of the eastern ionian sea paleoceanographic implications a high resolution study performed by means of calcareous nannofossils on two box cores located in the south eastern ionian basin allowed recognition of fluctuations in the assemblage which can be related to the climatic and paleoceanographic changes that occurred during the deposition of the holocene sapropel s1 this study reports a decrease of the coccolith abundance and of the genus reticulofenestra in the s1 sapropel interval considered as whole with its mn and fe oxidized intervals florisphaera profunda shows an increase at the base of the dark corg rich interval while helicosphaera carteri and rhabdosphaera claviger show an increase in abundance within the fe enriched interval of the oxidized sapropel braarudosphaera bigelowii is very rare in the interval studied as a whole however it shows a small but significant increase in abundance in the mn enriched interval of the oxidized sapropel sapropel deposition is probably related to important climatic changes that influenced the abundance of the various nannofossil species as a function of their paleoecological preferences our results indicate that three different paleoceanographic phases exist in s1 suggesting eutrophication at the beginning of s1 deposition followed by an intermediate stage characterized by nutrient depletion and finally by stagnation

timing of the tsergo ri landslide langtang himal determined by fission track dating of pseudotachylyte abstract fission track dating was carried out on zircon grains from pseudotachylyte associated with a late pleistocene landslide tsergo ri landslide in langtang himal nepal zircon grains were separated from an injection pipe of glassy and vesicular pseudotachylyte about 10 cm in diameter the resulting age of 51 13 ka lies between the two subpeaks 70 and 20 ka of the wurm glacial period and is concordant with the previous age estimate from geomorphological evidence i e older than 25 30 ka this is the first reliable isotopic age for a landslide generated pseudotachylyte excluding the possibility of contamination by an inherited age

a complete holocene climate and environment record for the western carpathians slovakia derived from a tufa deposit calcareous tufas are great archives of geochemical information for the reconstruction of past climate their importance increases in the regions where other proxies are rare such as western carpathians here we present the first whole holocene palaeoclimatic reconstruction for this region based on geochemical proxies we analysed o 18 c 13 and mg ca ratio on tufa calcite of the mituchovci site white carpathian mountains w slovakia and compared these with pollen plant macrofossil and mollusc data according to o 18 two distinct thermal maxima occurred in the region around 11 4 ka and between 7 3 and 6 9 ka bp according to c 13 and mg ca ratio a steep increase in moisture and rainfall took place around 8 5 ka cal bp preceded by a cold and dry event these events are well reflected in the biotic proxies and are suggested also by other palaeoenvironmental studies from the carpathians we found some later fluctuations with dry and warm bronze age ca 3 6 ka cal bp cold and wet urnfield period ca 2 8 ka cal bp warm roman period ca 2 ka cal bp and cold but humid migration period ca 1 5 ka cal bp we observed extreme abruptness and amplitude of the variation in all geochemical proxies in the last 500 years when biotic proxies imply a very intense human deforestation land use changes may have altered both the temperature regime in the studied fen and the carbon cycle in the recharge area

recent climatic change and catastrophic geomorphic processes in mountain environments climatic warming during the last 100 150 years has resulted in a significant glacier ice loss from mountainous areas of the world certain natural processes which pose hazards to people and development in these areas have accelerated as a result of this recent deglaciation these include glacier avalanches landslides and slope instability caused by glacier debuttressing and outburst floods from moraine and glacier dammed lakes in addition changes in sediment and water supply induced by climatic warming and glacier retreat have altered channel and floodplain patterns of rivers draining high mountain ranges the perturbation of natural processes operating in mountain environments caused by recent climatic warming ranges from tens of decades for moraine dam failures to hundreds of years or more for landslides the recognition that climatic change as modest as that of the last century can perturb natural alpine processes has important implications for hazard assessment and future development in mountains even so these effects are probably at least an order of magnitude smaller than those associated with late pleistocene deglaciation ca 15 000 to 10 000 years ago

a mass movement origin for cirques the glacial process of cirque initiation whereby small initial hillslope hollows grow by nivation until snow can form glacier ice and ice motion then enlarges the hollow to a fully developed cirque appears to have difficulty explaining the creation of large cirques in the time available during quaternary glaciations at the rates at which glaciers are reported to erode rock and in rapidly uplifting mountain ranges it also has difficulty explaining the striking proliferation of cirques in fiordland south island new zealand an area of harder rock and less glaciation than the nearby cirque poor area of south westland here we show that cirques can be initiated as large deep seated often coseismic rock slope failure source area depressions in which snow may accumulate to form cirque glaciers which can then remove detritus from smooth and enlarge the cirque we present an example of a classically shaped cirque that has never held a glacier we show that many similarities between the locations sizes and shapes of rock slope failure source area depressions and cirques are understandable on this basis as is the occurrence of cirques in presently aseismic intraplate locations and their relative paucity in actively uplifting ranges the extent to which cirques may be of mass movement origin has implications for their value as palaeoclimatic indicators copyright 2006 john wiley sons ltd

orbitally controlled oscillations in planktic communities and cyclic changes in western mediterranean hydrography during the messinian we use quantitative analyses of the planktic foraminiferal assemblages and stable isotope analyses of the sorbas section in the western mediterranean to reconstruct the cyclical changes in surface and deep water hydrographic conditions during the late miocene prior to the messinian salinity crisis oscillations in winter and summer temperatures linked to cyclical fluctuations in the hydrographic conditions and nutrient availability were the main mechanisms driving the cyclical changes in the planktic foraminiferal assemblages during the messinian the winter intensification and southward expansion of the northern cool and dry winds during precession maxima lowered sea surface temperatures below 14 15 c favoring water convection and the upward mixing of nutrients with the consequent increase in the proportion of cold eutrophic water foraminifera the low summer temperatures below 24 c inhibited the growth of warm oligotrophic water foraminifera as occurs today in the mediterranean by contrast at times of precession minima the low influence of the high latitude air masses caused winter temperatures to remain relatively high which combined with the lower surface salinities led to the formation of a permanent pycnocline winter conditions prevented the growth of cold eutrophic water foraminifera while high summer temperatures and the formation of a permanent pycnocline stimulated the growth of warm oligotrophic water foraminifera the prevalence of stable water stratification during winter due to the large density gradient between the surface and intermediate waters prevented deep water formation and slowed down the rates of oxygen supply to the bottom resulting in the formation of the sapropels a sharp decrease in 13c of benthic and planktic foraminifera that occurred between 6 8 and 6 7 myr is related to an increase in the residence time of mediterranean waters because similar changes have been observed in other regions of the mediterranean we conclude that this change records a significant reduction in the atlantic mediterranean water exchange at that time mediterranean climatic amplification increased throughout the messinian as the atlantic mediterranean water exchange was progressively more limited and oscillations in the ratio of planktic benthic foraminifera and of warm oligotrophic cold eutrophic species are good records of this increasing amplification which culminated at 5 95 myr with the deposition of gypsum pelitic layers that mark the onset of the messinian salinity crisis

ancient landslide dam events in the jishi gorge upper yellow river valley china some scholars have argued that the formation and outburst of an ancient dammed lake in the jishi gorge at ca 3700 cal yr bp resulted in the destruction of lajia the site of a famous prehistoric disaster in the guanting basin upper yellow river valley china however the cause of the dammed lake and the exact age of the dam breaching are still debated we investigated ancient landslides and evidence for the dammed lake in the jishi gorge including dating of soil from the shear zone of an ancient landslide sediments of the ancient dammed lake and loess above lacustrine sediments using radiocarbon and optically stimulated luminescence osl dating methods six radiocarbon dates and two osl dates suggested that the ancient landslides and dammed lake events in the jishi gorge probably occurred around 8100 cal yr bp and the ancient dammed lake was breached between 6780 cal yr bp and 5750 cal yr bp hence the outburst of the ancient dammed lake in the jishi gorge was unrelated to the ruin of the lajia site but likely resulted in flood disasters in the guanting basin around 6500 cal yr bp

lake sediments deposited on the flims rockslide mass the key to date the largest mass movement of the alps long piston cores taken from the subsurface of two mountain lakes of the eastern swiss alps recovered sediments which overlie the flims rockslide deposits these sediments provide new information on the chronology of the largest known alpine rockslide and can be used to reconstruct the post landslide environmental evolution the oldest 14 c date of the lake sediments yields a minimum age of the rockslide at 9660 9430 cal yr bp in addition the dating of a wood fragment contained in the rockslide deposits directly below the lake sediments shows a maximum age of 9480 9120 cal yr bp the overlap of the maximum and minimum ages 9480 9430 cal yr bp approximates the age of the flims rockslide this early holocene range coincides with a period of higher frequency of large mass movements observed in the alps which could be related to climatic changes

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

cenozoic tectonic evolution of liaodong dome northeast liaodong bay bohai offshore china constraints from seismic stratigraphy vitrinite reflectance and apatite fission track data abstract the liaodong dome is a region of localized uplift and deformation within the liaodong bay bohai offshore china 3 d seismic dataset vitrinite reflectance and apatite fission track data provide an exceptional opportunity to document the evolution of the liaodong dome which developed coeval with the tan lu strike slip fault zone with a rift system the 3 d seismic data demonstrates that the dome formed before the deposition stage of esm sequence 40 ma and it uplifted again during or after the depositional stage of ed sequence 32 24 ma apatite fission track and vitrinite reflectance data indicate that the dome experienced two stages of cooling episodes paleocene to early middle eocene 65 40 ma and late oligocene to late miocene 30 11 5 ma usually indicating uplifting both the seismic stratigraphy and thermal history analysis show that 1 the liaodong dome is part of the jiaoliao terrane 2 regional continental rifting climaxed during 65 40 ma as it did the rift shoulder uplift of the dome 3 the reactivation of the tan lu fault caused a second uplift processes of the liaodong dome during 30 11 5 ma 4 the liaodong dome uplifted independently and separated from the jiaoliao terrane our results also suggest that it is important to take uplifting evolution into consideration to target a potential petroleum reservoir

glaciation in the surroundings of prasilske lake bohemian forest czech republic abstract comprehensive geomorphological and sedimentological analyses confirmed three phases of wurm glaciation in the surroundings of prasilske lake and stara jimka in the bohemian forest sumava mountains glaciations were affected by a steep east facing slope by plateaus on the adjacent ridges and by local geological conditions a small valley glacier about 2 km long and 50 m thick occurred during the first phase in the second phase a glacier rock glacier developed probably based on remnants of the valley glacier during the last phase glacial activity was divided into stara jimka and the stepped cirque of prasilske lake a further shallow 3 m deep lake in stara jimka was dammed by slope movements after deglaciation 14 cal ka bp and survived until 4 cal ka bp the late pleistocene chronology of the bohemian forest seems to be related more closely to the alps than to northern europe in the mid mountains of central europe pleistocene glaciation decreases significantly eastward because of increasing continentality the presence of plateaus deflation areas around 1300 m altitude across the approach of westerly winds was important for the development of glaciers in the bohemian forest the termination of glaciation before the younger dryas is specific to the bohemian forest in comparison with the vosges and krkonose mountains

geology and radiometric 14c 36cl and th u dating of the fernpass rockslide tyrol austria abstract one of the largest mass movements in the alps the fossil fernpass rockslide in the northern calcareous alps tyrol austria was dated absolutely for the first time three independent radiometric dating methods were applied to geologically individual sample sites and enabled a cross checking of the results close to the scarp front rockslide dammed torrent deposits indicate a 14c minimum age of at least 3380 3080 cal yrs bp the chronostratigraphic base of this backwater sequence has not been dated yet but is assumed to date somewhat older into the middle holocene however this coincides with two cosmogenic radionuclide 36cl ages of sliding planes at the steep and rugged scarp exposure data thus obtained are 3400 900 and 4800 1200 yrs respectively with an arithmetic mean of 4100 1300 yrs additional age data were acquired from post depositional calcareous cements which locally lithified the rockslide debris these meteoric cements contain remarkably high uranium total contents and yielded a 230th 234u minimum age of about 4150 100 yrs for the accumulation of the rockslide deposits all dating data agree well and indicate that the fernpass rockslide is of subboreal age thus the intensively structured present morphology characterised by the well known cone shaped toma hills and several lakes in the depressions is indicative of primary rockslide morphology and clearly not shaped by late glacial ice as assumed formerly

landslides as a geomorphological proxy for climate change a record from the dolomites northern italy abstract this study investigates the relationships between climate changes and hillslope evolution in the dolomites eastern alps italy during the late quaternary with particular attention paid to landslide processes the basic premise is that modifications in landslide frequency may be interpreted as changes in the hydrological conditions of slopes which are in turn controlled by climate after the statistical analysis of a data set composed of 73 conventional radiocarbon ages obtained from 24 landslides four periods of enhanced landsliding have been identified i from 10 700 to 8400 cal bp between younger dryas and the preboreal ii from 8200 to 6900 cal bp during the older atlantic iii from 5800 to 4500 cal bp between atlantic and subboreal and iv from 4000 to 2100 cal bp between subboreal and subatlantic these periods have been compared with different lateglacial and holocene paleoclimatic records to check the correspondence between periods of enhanced landslide activity and cold and humid spells recognized at different spatial scales as the records show in the study areas slope instability processes can be considered geomorphological indicators of climatic changes and to a certain extent reliable proxies of environmental evolution

slope instability in relation to glacial debuttressing in alpine areas upper durance catchment southeastern france evidence from field data and 10be cosmic ray exposure ages the upper durance catchment is an area prone to rock slope failures such failures reflect the combination of high relief litho structural controls and paraglacial stress release the aim of this study is to determine the role of deglacial unloading and resulting paraglacial stress release in conditioning or triggering slope failure former dimensions of the durance glacier are reconstructed then combined with digital elevation model data in a raster geographic information system to quantify the spatial pattern of stresses associated with glacial loading at the last glacial maximum preliminary calculations suggest that major rock falls and rock avalanches are associated with areas subject to the highest decompression stresses focus on two case studies allows the consequences of paraglacial stress release on slope instability to be evaluated description of slope failure runout deposits allows reconstruction of the nature of slope failure surface exposure dates based on concentration of cosmogenic 10be allows the timing of both deglaciation and that of post glacial rock slope failures to be established it is shown that rock slope failures are concentrated on lower valley side slopes within the area occupied by ice at the last glacial maximum and that their locations coincide with zones of inferred high glacial loading stress consistent with interpretation of both bedrock disruption and large scale rock slope failures as paraglacial phenomena induced by stress release following deglaciation timing of initial rock avalanche runout deposition at one site is consistent with this conclusion though later instability episodes at the same site may have occurred independent of the influence of paraglacial stress release

depth related radiolarian assemblage in the water column and surface sediments of the japan sea plankton tows and surface sediments from the japan sea a marginal sea of the northwestern pacific were examined to study the depth distribution of modern radiolarians the depth distribution patterns between the living assemblage in the water column and the thanatocoenose in surface sediments are similar to each other indicating that the depth related assemblage in sediments is closely related to the living depths of major species four clear restrictions of many species to discrete depth zones are recognized in the water column from the surface down to 2000 m 1 upper subsurface water species which are abundant from 40 to 120 m larcopyle butschlii juvenile form spirocyrtis subscalaris spongodiscus resurgens and lipmanella virchowii 2 lower subsurface water species which are abundant from 40 to 300 m larcopyle butschlii adult form ceratocyrtis histricosa and spongotrochus glacialis 3 intermediate water species which have population maxima from 160 to 300 m ceratospyris borealis and 4 deep water species which have maxima between 1000 and 2000 m cycladophora davisiana and actinomma boreale only a few specimens of a boreale were found in the water column ranging from 1000 to 2000 m depth although this is a dominant species in surface sediments from depths below 2000 m of which the dominance increases with water depth a boreale may live mainly in the bottom water cycladophora davisiana and a boreale which characterize the japan sea deep assemblage are naturally shallow or intermediate dwellers in other oceans on the other hand the typical deep dwellers e g cornutella profunda cyrtopera languncula and peripyramis circumtexta of other oceans have not been found in the japan sea such a peculiar deep assemblage is a result of the deep circulation system in the japan sea and the shallow depths of the sills around it

precession related sapropelites of the messinian sorbas basin south spain paleoenvironmental significance abstract the sorbas basin southern spain is a narrow and elongated basin located in the betic corridor that formed the northern connection between the atlantic and the paleomediterranean during the late miocene in the centre of the basin about 120 m of well preserved cyclic marine sediments crop out ranging in age from 7 2 to 6 myr these cycles make up the abad member and are an excellent example of precession control over sedimentation in the upper part of the sequence upper abad member the cycles include organic rich laminated brown marls sapropelites alternating with homogeneous marls displaying diatomite layers the om rich laminated marls are the westernmost sapropelites of the mediterranean this paper is a geochemical mineralogical sedimentological and micropaleontological analysis of three cycles with sapropelites the data enable us to distinguish two main climatic scenarios the climate which dominated each of these scenarios regulated the sedimentology and the physico chemistry of the water column resulting in the sapropelite homogeneous marl cyclic alternations the sapropelites developed during a climate characterised by a long period of temperate and humid conditions that occur at times of precession minima these climatic conditions changed progressively to a subarid and drier weather during which homogeneous sediments were deposited the changes between these scenarios were gradual as expected from precession dynamics our data suggest that the change from the subarid to the humid climate transition from homogeneous marls to laminated sapropelites took place at a faster rate or at least was recorded more rapidly by the sediments than the transition from the humid interval to the sub arid period

geophysical anatomy of counter slope scarps in sedimentary flysch rocks outer western carpathians abstract a multidisciplinary geophysical survey consisting of electrical resistivity tomography ert ground penetrating radar gpr shallow seismic refraction ssr and gravity survey gs was used to investigate the counter slope scarps one of the typical manifestations of the relaxed zones of rock massifs and the possible initial stages of deep seated landslides dsls two upper parts of the extensive dsls within the moravskoslezske beskydy mountains outer western carpathians owc built by the sedimentary flysch rock were chosen as the testing sites a combined geophysical survey on the flysch rocks was performed on both localities to enhance our present findings the survey revealed that the ert is able to reliably detect underground discontinuities which are manifested at the ground surface by one of the typical landforms tension cracks trenches pseudokarst sinkholes double crested ridges and counter slope scarps previous studies suggested that bedrock discontinuities should be depicted by high resistivity features within ert surveying according to ssr and gs expected zones of weakened rock massif were not confirmed directly underneath the superficial landforms but they were shifted based on the ssr and gs measurements the depicted high contrast transitions between high and low resistivity domains within the ert profiles were newly identified as possible manifestation of bedrock discontinuities the results of gpr measurements give only limited information on the sedimentary flysch rocks due to shallow penetrating depth and locally strong signal attenuation the combined results of multidisciplinary geophysical surveying confirmed an importance of employing more than one geophysical technique for integrated interpretations of measured data integrated interpretations of the measured geophysical data provided a new insight into massif disintegration and the geomorphic origin of the landforms related to the dsl

catastrophic slope failure and its origins case of the may 2010 girova mountain long runout rockslide czech republic abstract one of the largest long runout landslides in the modern history of the czech republic originated on the southern slopes of the girova mountain outer western carpathians at the end of extreme rainfalls in may 2010 the structurally predisposed girova mountain rockslide occurred very quickly within fault weakened deeply weathered flysch bedrock its main phase during which a wedge like block collapsed in the upper part of slope lasted for a few hours the overloaded slope collapsed and its motion lasted for the following 3 days the may 2010 girova mountain rockslide is an excellent case of a recurrent long runout landslide nested within a deep seated gravitational slope deformation with a long history of late quaternary mass movements the chronology of slope failures within the studied slope was reconstructed by means of radiocarbon dating and dendrogeomorphological analysis at least one holocene long runout landslide 7 4 cal ka bp and several smaller failures 1 5 and 0 6 cal ka bp preceded this recent catastrophic failure dendrogeomorphological analysis showed that the failure had been preceded by at least 80 year long creep movement that accelerated over the years due to extreme rainfall events despite the fact that extreme precipitation of may 2010 represented the last incremental change before catastrophic collapse of the slope its main reason was gradual weakening of rock massif and concentrated creeping with some accelerated phases in the upper part of the slope deformation

giant landslides topography and erosion abstract distributions of slope angles in tectonically active mountain belts point to the development of threshold conditions where hillslopes attain a critical inclination or height at which they fail readily because of limitations in material strength it has been proposed that hillslopes adjust to rapid uplift and bedrock incision through an increase in the rate of relief limiting landsliding rather than gradual slope steepening here we test this concept by investigating the relationship between mean local relief h which we take to be a proxy of long term erosion rates e and the occurrence of over 300 of the largest v 10 8 m 3 terrestrial landslides on earth we find that nearly two thirds of these giant landslides have occurred in the steepest 5 of the earth s land surface where relief is close to its proposed upper strength limit they are primarily located in deeply incised valleys along fault bounded fringes of active mountain belts and in volcanic arcs this distribution coincides with areas of high long term erosion rates 4 mm yr 1 confirming that giant landslides contribute to rapid denudation of mountains most of the eroded volume is concentrated in the smallest but steepest parts of mountain belts and volcanic arcs first order estimates of minimum erosion rates accomplished by the largest landslides are 0 01 mm yr 1 these rates are between 1 and 10 of the late pleistocene to holocene mean erosion rates in a given area importantly the landslide erosion rates show a nonlinear increase with mean local relief suggesting that the contribution of giant landslides in total and per event increases significantly with increasing overall erosion rates however giant landslides also occur in areas of lower than average relief h 300 700 m irrespective of whether threshold hillslopes have developed or not factors contributing to these failures include soft rocks extensive low angle discontinuities high rates of fluvial bedrock incision and tectonically driven deformation and slope loading

the origin of shallow landslides in moravia czech republic in the spring of 2006 abstract at the end of march 2006 the czech republic cz witnessed a fast thawing of an unusually thick snow cover in conjunction with massive rainfall most watercourses suffered floods and more than 90 shallow landslides occurred in the moravian region of eastern cz primarily in non forested areas this region geologically part of the outer western carpathians is prone to landslides because the bedrock is highly erodible mesozoic and tertiary flysch the available meteorological data depth of snow water equivalent of the snow cumulative rainfall air and soil temperatures from five local weather stations were used to construct indices quantitatively describing the snow thaw among these the total cumulative precipitation tcp combines the amount of water from both thawing snow and rainfall this concurrence of rain and runoff from snow melt was the decisive factor in triggering the landslides in the spring the tcp index was applied to data of snow thaw periods for the last 20 years when no landslides were recorded this was to establish the safe threshold of tcp without landslides the calculated safe threshold value for the region is ca 100 mm of water delivered to the soil during the spring thaw corresponding to ca 11 mm day 1 in 2006 10 of the landslides occurred under or at 100 mm of tcp the upper value of 155 mm covered all of the landslides

large and rapid climate variability during the messinian salinity crisis evidence from deuterium concentrations of individual biomarkers during the messinian 6 m y ago massive sea level fall and widespread deposition of evaporites occurred in the mediterranean sea when it became isolated from the world oceans here we present the first hydrogen isotope data from individual sedimentary biomarkers n alkanes and isoprenoids that tracked climatically driven hydrographic changes in response to extreme evaporation during the messinian salinity crisis the stable hydrogen and carbon isotope compositions of these biomarkers show a range of 160 in d values and 14 in 13 c values and roughly covary this indicates that the source waters of the biomarkers were therefore in some cases extremely enriched in deuterium having average d as great as 66 vsmow vienna standard mean ocean water such values are only known from desert climates today because the offset between the d values of n alkanes and isoprenoids preserved in the miocene sedimentary rocks is similar to the offset found in modern biological samples we conclude that diagenesis did not significantly affect the primary deuterium concentrations

use of lidar derived images for mapping old landslides under forest large deep seated landslides are common features in the flemish ardennes belgium as most of these old 100 years landslides are located under forest in this hilly region aerial photograph interpretation is not an appropriate landslide mapping method this study tested the potential of lidar light detection and ranging images for mapping old landslides under forest landslide inventory maps were created for a 125 km2 area by applying the expert knowledge of seven geomorphologists to lidar derived hillshade slope and contour line maps in a gis environment each of the seven lidar based landslide inventories was compared i with the other six ii with a detailed field survey based inventory and iii with a comparable study in which topographic data were extracted from a topographical map the combination of the percentage of field landslides indicated by an expert and the percentage of positional discrepancies expressed in terms of positional mismatch were used to evaluate the quality of the lidar based inventory maps high quality lidar derived landslide inventory maps contain more than 70 per cent of the landslides mapped during the field survey and have positional discrepancies smaller than 70 per cent when compared with the field survey based inventory map four experts and the combination map of all experts satisfied these criteria together the seven experts indicated all landslides mapped in the field importantly lidar enabled the experts to find ten new landslides and to correct the boundaries of eleven of the 77 landslides mapped during the field survey hence this study showed that large scale lidar derived maps analysed by experienced geomorphologists can significantly improve field survey based inventories of landslides with a subdued morphology in hilly regions copyright 2006 john wiley sons ltd

the largest prehistoric landslide in northwestern slovakia chronological constraints of the kykula long runout landslide and related dammed lakes abstract this study deals with the chronology of the largest long runout landslide in the northwesterrn part of the western flysch carpathians kysucke beskydy mts slovakia despite the impossibility of using direct radiocarbon dating method time constraints for the evolution of the landslide were determined on the basis of the dating of various sedimentological geomorphological elements situated on and adjacent to the landslide body the results show that the landslide evolved between 10 3 and 9 0 ka 14 c bp i e in the wider transitional phase between the late glacial lg and the holocene the main mass movement activity took place at the turn of the younger dryas preboreal chronozones whereas retrogressive activity continued up to the preboreal boreal transition radiocarbon dating together with pollen analysis and sedimentology of landslide dammed palaeolakes and colluvial peat bogs revealed almost continuous holocene palaeogeographical records between 10 3 and 3 3 ka 14 c bp periods of enhanced sediment supply to the reservoirs in 9 9 9 0 8 4 8 2 6 9 6 5 and 4 5 ka 14 c bp correlate well with palaeogeomorphic and palaeohydrological records from nearby polish carpathians the study confirms that the lg holocene transition represented a favourable period for the evolution of large landslides not only in glaciated high mountain areas but also in medium high mountains of central europe

10be dating reveals pronounced mid to late holocene activity of deep seated landslides in the highest part of the czech flysch carpathians abstract although the highest part of the czech outer western carpathians lacks significant recent landslide activity the vast area 20 of their territory is occupied by relict deep seated landslides and deep seated gravitational slope deformations dating these deformations might help to determine degrees of present day landslide hazard in that area based on the 10be exposure dating of eight rocky scarps and walls of ridge top trenches we estimated the minimal ages of the deep seated landslides dsls and one deep seated gravitational slope deformation dsgsd in the satina river basin in the moravskoslezske beskydy mts the obtained ages 9 7 2 9 ka suggest holocene slope instability in the area with a pronounced cluster of ages spanning from 6 0 to 2 9 ka except for one dsl the ages reveal rather episodic activity of gravitational movements mid to early late holocene activity of large landslides in the study area corresponds to the ages of several previously dated landslides both in an adjacent region as well as within the central european context with respect to the historical quiescence of the dsls and dsgsds in the area and because the slopes have not been destabilized even during the most extreme hydrometeorological events within the last few decades we infer that the hydrometeorological thresholds necessary for their activation are seldom exceeded in this area therefore the highest parts of the carpathians built by rigid thick bedded lithology reveal a rather lower frequency of events in comparison with adjacent parts formed by claystone dominated flysch where several large dsls originated in the last few decades as a consequence of heavy rainfalls

gigantic paleolandslide associated with active faulting along the bogd fault gobi altay mongolia on the basis of analyses of satellite imagery aerial photographs and field observations we describe the occurrence of one of the largest paleolandslides 50 km3 ever recognized in an intracontinental domain the slide occurred along the active bogd fault in the gobi altay mountain range in mongolia morphological and structural analyses of the relationships between the landslide and the area affected by active tectonics suggest that this gigantic mass movement was associated with surface faulting during a strong earthquake

bedload to suspended load ratio and rapid bedrock incision from himalayan landslide dam lake record about 5400 cal yr bp a large landslide formed a n400 m tall dam in the upper marsyandi river central nepal the resulting lacustrine and deltaic deposits stretched n7 km upstream reaching a thickness of 120 m 14 c dating of 7 wood fragments reveals that the aggradation and subsequent incision occurred remarkably quickly 500 yr reconstructed volumes of lacustrine 0 16 km 3 and deltaic 0 09 km 3 deposits indicate a bedload to suspended load ratio of 1 2 considerably higher than the 1 10 that is commonly assumed at the downstream end of the landslide dam the river incised a new channel through 70 m of greater himalayan gneiss requiring a minimum bedrock incision rate of 13 mm yr over last 5400 yr the majority of incision presumably occurred over a fraction of this time suggesting much higher rates the high bedload ratio from such an energetic mountain river is a particularly significant addition to our knowledge of sediment flux in orogenic environments 2007 university of washington all rights reserved

surface water dynamics and phytoplankton communities during deposition of cyclic late messinian sapropel sequences in the western mediterranean abstract distinctive precession scale sapropel marl sequences of late messinian age are found in several outcrops bordering the western mediterranean to examine the roles of stratification and productivity in driving this cyclic sedimentation we performed a high resolution analysis of calcareous nannofossil assemblages through four orbital sequences composed of sapropel marl diatomite marl from the sorbas basin in southern spain this effort also involved a detailed comparison between calcareous nannofossil abundances and other micropaleontological sedimentological and geochemical proxies to further understand the behaviour of some taxa for this period fluctuations in the depth and gradient of the pycnocline and the distribution and remobilization of nutrients seem to be the main factors controlling the calcareous nannoplankton assemblages with temperature of secondary importance in the sapropels the warm oligotrophic genus sphenolithus and discoaster are abundant especially significant is the progressive increase towards the top of discoaster pentaradiatus indicator of severe oligotrophic deep pycnocline conditions at the top of the sapropels peaks in reticulofenestra rotaria are interpreted here as the result of an increase of surface water temperatures although decreasing salinity may also play a role small reticulofenestra 5 m are more frequent in diatomites even considering conditions of extreme mixing and eutrophication occurred in the basin umbilicosphaera jafari peaks just after diatomites replacing small reticulofenestra probably as a response to an increase in salinity and or nutrient limitation species such as coccolithus pelagicus and helicosphaera carteri are abundant at the top of the diatomites and in the overlying marls indicating relatively mesotrophic and cool water conditions this succession shows similar characteristics in the four studied cycles allowing us to interpret surface water dynamics in this region on orbital time scales the top of the sapropel represents a warm low salinity and well stratified episode under a situation of maximum insolation a well developed pycnocline and oligotrophic conditions moderate production of calcareous phytoplankton coinciding with anoxic conditions at the bottom enhance the preservation of organic matter and consequently generate a sapropel diatomites are deposited under a situation of unstable pycnocline that produce an increase in productivity in surface waters diatoms significantly deplete limiting nutrients and consequently calcareous nannofossils start to be dominant again in the water column as result of a progressive stabilization of the pycnocline

seismic reflection imaging of a major strike slip fault zone in a rift system paleogene structure and evolution of the tan lu fault system liaodong bay bohai offshore china the tan lu fault system in the liaodong bay bohai offshore china affords an exceptional opportunity to document the structural features of a major strike slip fault using two and three dimensional seismic reflection data as well as evolution of a strike slip fault developed coeval with a rift system the fault zone displays a relatively straight throughgoing trace longitudinally bisecting the rift valley it consists of positive and negative flower structures and en echelon folds in the south bay and three parallel flower structure systems northward the middle fault bifurcates northward into two semiparallel vertical fault strands to the north the west strand bends clockwise and merges with the east strand the stepping pattern and orientation of en echelon structures indicate right lateral sense and about n10 35e azimuth of slip the fault apparently accrued about 30 40 km 20 25 mi of post early eocene slip based on the current distribution of deformation zones and depocenters tan lu fault segments with clockwise and counterclockwise orientation relative to the regional slip direction are characterized by divergent and convergent structures i e restraining and releasing bends respectively waning of rifting eliminated the cause of a major restraining bend putting an end to development of associated convergent structures in the south bay area near the central north bay deformation occurred along major normal faults related to the basin rifting although a prominent feature reflecting regional strain partitioning the tan lu fault apparently was not a major factor in the paleogene opening of the liaodong bay basin and the larger north china rift basin

dendrogeomorphic chronologies of landslides dating of true slide movements dendrogeomorphic chronologies of landslide movements are frequently used to investigate past landslide activity slide areas are often affected by other slope movements e g creep simultaneously trees growing on landslides record all types of ground movements which potentially creates significant noise in tree ring based chronologies of landslide movements the effect of creep movements on dendrogeomorphic landslide chronologies was evaluated in a block type landslide in the south western foreland of the orlicke hory mts in total 272 trees p abies and f sylvatica were sampled 1088 increment cores on the sub horizontal surfaces of rotated slide blocks which were presumably created only by slide movements and on the steep internal scarps separating landslide blocks which were presumably created and affected by a combination of slide and creep movements ground movements were dated based on growth disturbances identified in an analysis of eccentric tree growth the trees growing on the internal landslide scarps separating the rotated blocks exhibited a significantly higher number and frequency of growth disturbances than those growing on the sub horizontal block surfaces all eight dated block surface movements were also identified on the internal scarps creep based events represented as many as 70 of the dated movement events on the internal scarps varying the it thresholds did not filter out more than 40 of the noise without significantly reducing the number of true dated slide events a significant difference was observed between the ability of p abies and f sylvatica to record ground movements by eccentric growth probably due its shallower roots and weaker anchoring of the tree to landslide blocks p abies appears to be more sensitive to surficial ground movement which potentially increases the proportion of dated creep events noise thus the careful selection of sampled tree species with different physiologies should be considered during dendrogeomorphic field sampling

recurrent holocene landslides a case study of the krynica landslide in the polish carpathians situated in the southern part of the polish outer carpathians the development of the krynica lanslide is presented in detail head scarps slide shoulders and colluvial ridges connected with particular episodes of sliding occur on the western slope of the parkowa gora mountain peaty silts and calcareous tufa suitable for the radiocarbon dating fill depressions within colluvial masses calcareous deposits contain rich assemblages of molluscs characterizing changes of the climate and the environment during the late vistulian and the holocene four stages in the evolution of the landslide correspond with phases of increased mass movements distinguished elsewhere in the carpathians according to radiocarbon dating as well as palynological and malacological analyses the phases of enhanced mass movement correlate in turn with climatic changes

last glacial to holocene vegetation succession recorded in polyphase slope failure deposits on the malenik ridge outer western carpathians abstract structural settings and palaeoenvironmental reconstruction of a polyphase late pleistocene deep seated landslide at the malenik ridge in the eastern part of the czech republic are presented the deep seated rotational landslide is about 480 m long and 1540 m wide and it is a part of much larger landslide complex the depositional record of two generations of former near scarp depressions revealed a multiple deep seated landslide activity during the last quaternary climatic cycle with the minimum age of 47704 2346 cal b2k the landslide belongs among the oldest dated landslides in the outer western carpathians and carpathian foredeep in the czech republic the younger reactivation started at 12662 73 cal b2k during younger dryas the palaeobotanical and depositional record from the landslide brought unique palaeoenvironmental data for two time intervals of the last quaternary climatic cycle the reconstructed mis 3 forest vegetation with the predominance of stone pine larch pinus cembra larix taiga with pinus sylvestris and betula pendula pubescens are the first evidences of the forest vegetation for the gs13 to gi12 transition in outer western carpathians similarly documented events of mis 3 landslide activity from outer western carpathians are rather rare the late glacial to holocene record from the younger near scarp depression revealed vegetation and landscape changes during the pleistocene holocene transition the evidenced oldest parts of the landslide at the malenik ridge had to originate during more humid interpleniglacial conditions the geomorphological evidence for landslide activity from this period has almost completely disappeared from the ground surface topography due to intensive periglacial processes operating later during the last glacial maximum and subsequent fluvial and anthropogenic processes of the holocene the cold and relatively dry period of the pleniglacial is considered as a time when deep seated mass movements use to be halted and overprinted by shallow solifluction of the active layer masking former deep seated landslide features

past hydrological events reflected in holocene history of polish rivers abstract a database of 335 radiocarbon dates from holocene fluvial sediments in poland has been compiled each sample is characterized by 25 parameters all samples were grouped into one of 7 regions characterized by hydrological regime and one of 8 depositional environments statistical analysis was used to enhance the palaeoenvironmental data and 17 phases may be distinguished 10 of which have a distinct sharp peak abandoned paleochannels 149 dates clearly reflect the major wetter phases of the holocene an opposite picture is presented by overbank aggradation 86 dates connected mainly with expansion of agriculture preliminary correlations are made on peat bog records changes in vegetation lake water level rates calcareous tufa and speleothems growth landslides phases and debris flow phases these show many convergences explained by climatic fluctuations during the holocene

late holocene catastrophic slope collapse affected by deep seated gravitational deformation in flysch ropice mountain czech republic the region of the flysch western carpathians is characterized by abundant deep seated gravitational slope deformations dsgsds this study deals with a detailed analysis of late holocene catastrophic collapse of a fault created slope of mountain ropice in the moravskoslezske beskydy mountains eastern czech republic the catastrophic collapse was initialized by huge compound rotational slide toppling deformation which occurs on the upper part of the studied slope and affects tectonically weakened subhorizontally inclined sandstone beds detailed geomorphological mapping accompanied by morphotectonic analysis and geophysical sounding revealed at least two historic flowslides the older event f1 affected 0 5 0 8 mm3 of bedrock and created a 1000 m long and up to 150 m wide accumulation with abundant transverse steps and a carapace like surface the landslide toe blocked an adjacent valley which led to the development of a small impoundment with 4 m thick deposits containing lacustrine peat bog floodplain and alluvial fan facies radiocarbon dating and pollen analysis indicate the valley blockage at 1 5 ka bp the other flowslide f2 of much smaller dimensions 10 000 12 000 m3 overlaid the main landslide body and according to the dating of minerogenic horizon in the impoundment may have taken place 0 3 ka bp the organisation of landforms character of slope failures and dynamic back modelling point to a likely rock avalanche or combined rock slide debris avalanche mechanism of movement this case study shows that rapid rock avalanches can operate also in mountainous terrain with moderate relief if toppling together with deep seated gravitational deformation of slopes modifies the original stable position of bedding planes