changing perspectives in the concept of lago mare in mediterranean late miocene evolution abstract the cenozoic alpine orogeny caused the partition of tethys into several basins during the late neogene the mediterranean attained its final configuration whereas eastwards the paratethys isolated from the world ocean disintegrated progressively into a series of smaller basins as a result an endemic fauna developed in these basins mainly composed of brackish to freshwater faunas indicating an environment affected by changes in water salinity these small basins of the paratethys were named sea lakes by andrusov andrusov d 1890 les dreissenidae fossiles et actuelles d eurasie geol min 25 1 683 in russian subsequently this name was translated into lac mer gignoux m 1936 geologie stratigraphique 2 edition masson paris in the mediterranean isolated from the atlantic at the end of the miocene messinian thick evaporites deposited consisting of a marine lower evaporite unit and an upper evaporite unit mainly of continental origin ruggieri ruggieri g 1962 la serie marine pliocenica e quaternaria della val marecchia atti acad sci lett arti palermo 19 1 169 used the term lago mare to characterize the brackish to fresh water environment which occurred within the mediterranean at the end of the messinian during recent decades numerous scientific investigations concerning the history of the messinian within the mediterranean were devoted to the understanding of conditions prevailing after the deposition of the marine evaporites brackish to freshwater faunas are found in several outcrops and boreholes in the mediterranean both in the uppermost beds of gypsum and inter bedded within the clastic sediments of the upper evaporite unit immediately preceeding the flooding by the marine pliocene waters these faunas because of their similarities with the fauna described in the paratethys were named paratethyan or caspi brackish fauna this leading some authors to imply a migration of these fauna from paratethys to the mediterranean however others refute this hypothesis new data induced some researchers to consider that exchanges existed between the mediterranean and the eastern paratethys and also between the mediterranean and the atlantic ocean at the miocene pliocene transition these investigations now take advantage of the accurate time scales established by authors biostratigraphy cyclostratigraphy magnetostratigraphy allowing good stratigraphic correlations between the mediterranean and the paratethys and precisions on the geodynamic evolution of this area furthermore sediments at the base of the zanclean mpl1 locally containing brackish to fresh water faunas conducted authors to attribute this formation to an infra or pre pliocene and also to a lago mare event thus the lago mare concept drifted from its original meaning and is evolving because of progresses in the understanding of the mediterranean geodynamics and the adjacent areas during the miocene pliocene transition

chronology of neogene and quaternary uplift and magmatism in the caucasus constraints from k ar dating of volcanism in armenia abstract the greater caucasus is one of earth s highest actively uplifting mountain ranges the adjoining caspian sea basin contains a substantial proportion of its hydrocarbon reserves like other parts of the former soviet union the neogene and quaternary chronology of these important regions has not previously been well defined it has thus been impossible to obtain reliable estimates for rates of processes such as uplift of the caucasus and sedimentation in the caspian sea previous studies have established the relative timings of events in the region using correlation schemes between volcanism glaciations and the stratigraphy of the caspian basin however a range of absolute chronologies has previously been proposed for these sediments and igneous rocks based mainly on different interpretations of their magnetostratigraphic records by k ar dating we determine the ages of volcanism at three localities in armenia as 1 1 0 8 and 0 8 ma using these data and other evidence we propose a revision to the chronology of this region in which a distinctive brief interval of normal magnetic polarity in the local sedimentary and volcanic magnetostratigraphic records is matched to the cobb mountain event in the global record rather than the olduvai event or an earlier subchron as had previously been thought we thus interpret a 1 5 ma timing for the start of volcanism in the lesser caucasus and also suggest a 1 2 ma timing for the late akchagyl transgression of the caspian sea a key event in the regional stratigraphy when this water body reached its greatest extent we tentatively correlate this transgression with the melting event following glaciation during stage 36 of the oxygen isotope timescale which was thus the first time during the pleistocene when eastern europe was covered by a lowland ice sheet time averaged since 1 ma the flanks of the eastern greater caucasus mountains are shown to have uplifted at 0 6 mm a 1 and the lesser caucasus at 0 3 mm a 1 we show that the rate and spatial scale of this uplift are too great to be the result of plate convergence and suggest instead that this uplift is caused by crustal thickening due to inward lower crustal flow to beneath these mountain ranges at the start of magmatism in both the greater and lesser caucasus the estimated crustal thickness was 45 km we thus suggest that this magmatism has been caused by heating of the mantle lithosphere due to earlier crustal thickening the temperature rise required to initiate magmatism being the same in both cases

kinematics triggers and mechanism of majiagou landslide based on fbg real time monitoring reservoir landslide as one of the most serious geohazards is worldwide distributed to investigate its triggering factors and mechanisms that underlie its propagations a real time monitoring system based on fiber bragg grating fbg technology was designed for the majiagou landslide in the three gorges reservoir tgr region through analyses of inclinometer data it is found that there are two sliding surfaces existed in the majiagou landslide and that the deeper sliding surface is the critical one it accounts for nearly 80 of the deformation of the landslide this information necessitated the recording of the displacement at the deeper sliding surface together with the rainfall water level pore water pressure temperature of the landslide using a real time monitoring system after analyzing the multi parameter data in detail it is found that observed deformation is mainly governed by reservoir water levels while precipitation has some minor effects the reservoir water level is the determining factor of landslide deformation when it exceeds 160 m or lower than 150 m whereas the reservoir water level varies from 150 m to 160 m the fluctuation velocity plays a dominant role the relationship between the variation of seepage field and kinematic evolution of majiagou landslide is recognized the average displacement rate of majiagou landslide is within 0 1 mm day signifying that the landslide is still creeping presently the results are significant with respect to stability evaluation and formulation of early warning plans for the reservoir landslide

changing seas in the late miocene northern aegean a paratethyan approach to mediterranean basin evolution abstract the northern aegean region evolved during the miocene as a restricted land locked basin with small ephemeral connections to both the eastern paratethys former black sea and mediterranean its biostratigraphic data show mixed paratethys mediterranean components but the paratethys fauna has generally been neglected for chronologic reconstructions here we review this biostratigraphic data from a paratethyan perspective and present revised paleogeographic reconstructions of the northern aegean throughout the late miocene in the tortonian all sub basins show mainly fluvio deltaic terrestrial environments with a series of scattered lakes that are predominantly fed by local rivers and short lived paratethys connections the first persisting marine conditions still alternating with brackish paratethyan environments indicate a middle messinian late maeotian age 6 9 6 1 ma when the region formed a semi isolated egemar sea with multiple marine influxes the termination of marine conditions is very well documented by a marked palaeoenvironmental change to the brackish water environments that correlate to the maeotian pontian boundary 6 1 ma in eastern paratethys during the messinian salinity crisis 5 97 5 33 ma the northern aegean was a brackish water system lake egemar that formed a passageway for paratethyan overspill waters towards the mediterranean we conclude that the thick evaporites of the northern aegean domain do not reflect the classic mediterranean msc sequences but are more likely related to older badenian or maeotian salinity incursions

monitoring landslide displacements with the geocube wireless network of low cost gps abstract the analysis of landslide hazard requires continuous and high frequency surface displacement monitoring at numerous and geomorphologically relevant locations ground based geodetic methods gnss tacheometry allow very accurate and high frequency temporal observations while remote sensing methods insar terrestrial and satellite photogrammetry lidar allow spatially distributed observations at high spatial resolution a single surface deformation monitoring technique coupling all these capabilities is still missing the geocube system has been designed to partly overcome this pitfall by creating a low cost flexible easy to install and wireless gps receiver dense geocube monitoring networks can be set easily for operational observations furthermore the monitoring of other landslide properties micro seismicity seismic waves or triggering factors meteorology slope hydrology is possible with the capacity of integrating additional sensors to the geocube this work presents the geocube system and the results of a field campaign performed during the summer 2012 at the super sauze landslide southern french alps with a network of wireless low cost gps the objective was to assess the performance of the geocube system in real field monitoring conditions our results document the spatial and temporal evolution of the landslide during a period of 40 days landslide acceleration periods are detected and correlated to rainfall events

the pre messinian deep sea neogene echinoid fauna of the mediterranean surface productivity controls and biogeographical relationships abstract autochthonous deep water echinoid faunas are very rare in the fossil record a well preserved bathyal echinoid assemblage is described from the middle miocene pakhna formation of southern cyprus this low diversity fauna is dominated by just two genera of spatangoid palaeobrissus and heteropneustes and implies a water depth of 200 1000 m echinoids occur in modest abundance but are restricted to a small number of intervals where sapropels are numerous and thick although never in the sapropels themselves this suggests that echinoids in the deep pre messinian mediterranean were surviving at depth by exploiting raised levels of nutrient input driven by milankovitch forcing but being excluded at times of peak carbon settlement in contrast to the modern depauperated deep water fauna of the mediterranean which has atlantic affinities these two species show strongest phylogenetic affinities with bathyal caribbean fauna caribbean and mediterranean deep sea macrobenthic faunas were thus closely connected until just before the gibraltar sill formed

permanent scatterers for landslide investigations outcomes from the esa slam project within the slam project service for landslide monitoring launched in 2003 by the european space agency esa the permanent scatterers ps technique a multi image interferometric approach coupled with the interpretation of aerial photos and optical satellite images was carried out for landslide investigations the ps analysis was applied at a regional scale as support for landslide inventory mapping and at local scale for the monitoring of single well known slope movements for the integration of the ps measurements within a landslide inventory the arno river basin italy was chosen as test site for the presence of a high number of mass movements to date about 300 areas at high landslide risk and more than 27 000 individual landslides mapped by the institutional authorities about 350 sar images have been interferometrically processed by means of the ps technique with the detection of about 600 000 ps the use of optical images contributed spatial meaning to the point wise information provided by the ps making it easier to identify terrain features related to slope instability and the landslide boundaries here we describe the employed methodology and its impact in the updating of a preexisting landslide inventory 6 8 of the total number of landslides were characterized by ground displacement measurements from the ps 6 1 of already mapped landslides and 0 8 of new unstable areas detected through the ps analysis moreover most of the ps are located in urban areas showing that the proposed methodology is suitable for landslide mapping in areas with a quite high density of urbanization but that over vegetated areas it still suffers from the limitations induced by the current space borne sar missions e g temporal de correlation on the other hand the use of insar for the monitoring of single slow landslides threatening built up areas has provided satisfactory results allowing the measurement of superficial deformations with high accuracy on the landslide sectors characterized by a good radar reflectivity and coherence

the link between tectonics and sedimentation in back arc basins new genetic constraints from the analysis of the pannonian basin the architecture of sedimentary basins reflects the relationship between accommodation space and sediment supply their rates and localization being variable during basin evolution the mechanisms driving the interplay between tectonics and sedimentation in extensional back arc basins overlying rheological weak zones inherited from an earlier orogenic evolution are less understood a typical example is the pannonian back arc basin of central europe it is floored by continental lithosphere and was affected by large amounts of extension driven by the subduction rollback that took place in the carpathians and or dinarides a novel kinematic and seismic sequence stratigraphic interpretation calibrated by wells allows the quantification of the link between the formation of half grabens and coeval sedimentation in the great hungarian plain part of the basin while the lower order tectonic induced cycles characterize the main phases of extension in various subbasins the higher order cyclicity and associated unconformities define individual moments of fault re activation our novel interpretation of a temporal and spatial migration of extension during miocene times explains the contrasting present day strike of various subbasins as a result of their gradual clockwise rotation incorporating the observed asymmetry in particular the associated footwall exhumation infers that the amount of extension is much larger than previously thought the quantitative link between tectonics and sedimentation has allowed the definition of a novel model of sedimentation in asymmetric basins that can be ported to other natural scenarios of similarly hyperextended back arc basins observed elsewhere

field measurement and failure forecast during the remediation of a failed cut slope a large number of deep cuts are formed during the construction of expressways in mountainous areas inadequate interpretation of ground conditions is a major contributing factor to the failure of cut slopes this study focuses on the hongyan landslide along the s26 expressway due to lack of an adequate pre construction investigation a landslide was triggered by small scale excavation at the toe part of the slope the potential slip surface was incorrectly located consequently two rows of stabilizing piles were not long enough to reach stable rocks to overcome the mistake two additional rows of piles were installed during construction both slope deformation and the stress of reinforced bars in piles were monitored for safety considerations a verhulst model based failure forecast was also utilized to insure the stability of the slope during remedial works reviewing this landslide reveals a number of lessons first sufficient geological investigation and careful interpretation of ground conditions are mandatory prior to the design of a cut slope second systematic field monitoring is strongly recommended especially when the geology of the slope is complex and it is difficult to determine failure patterns third the failure forecast can serve as a supplementary measure to insure the safety of workers and slopes last it always takes some time for stabilizing piles to mobilize

late cenozoic base level variations of the caspian sea a review of its history and proposed driving mechanisms abstract the caspian sea is characterized by significant variations in its base level during the late cenozoic and provides an important repository for long term records of both regional climate and tectonics due to its position within the interior of the eurasian continent and at the northern margin of the ongoing arabia eurasia collision zone the caspian also serves as an important moisture source for eastern eurasia including the northern tibetan plateau and thus the history of caspian base level variations represents an important and poorly understood constraint on paleoclimate reconstructions throughout eurasia prior work in the caspian region has largely focused on developing biostratigraphic age divisions and investigating the history of connection between the caspian black and mediterranean seas as well as the global ocean recent geochronologic work in the caspian and related basins has questioned previous correlations of hydrologic events in these different basins as a result prior estimates of the chronology and magnitude of caspian sea level variations may be incorrect here we synthesize previous work to develop a new caspian base level curve starting at the beginning of the meotian regional stage 7 ma we also present a new synthesis of potential driving mechanisms for the large variations in caspian base level and speculate on a possible cause for the enigmatic akchagyl transgression this synthesis highlights the dynamic range of caspian sea level which varied from 200 m above to in excess of 1000 m below its current level during the late cenozoic and provides a basis for future work investigating the tectonic and climatic drivers behind variations in caspian base level

using tdr cables and gps for landslide monitoring in high mountain area time domain reflectometry tdr is performed as a complement to the monitoring methods in subsurface deformation in slope together with the global positioning system gps to monitor ground deformation of high altitude landslides in li shan four tdr cables were installed in drill holes near the monitoring stations in the landslide area according to the recorded tdr waveforms there were shear and tensile zones under the b 5 b 9 c 1 and c 2 stations a comparison of the tdr waveforms with the monitored data and boring log revealed that the subsurface sliding occurred between layers of colluvium and strongly weathered slate three gps receivers were installed to measure ground displacement in the landslide area the results from the gps were compared with the surface extensometers data on site the two initial baseline lengths were 451 188 10 and 908 212 4 mm respectively the optimal data reduction achieved used a 3 h session with moving average for each hour s gps data the standard deviation values of the gps were 2 16 and 2 44 mm respectively on site the results of tdr and gps measurements showed their applicability in the deformation monitoring of high mountain landslides

deformation mechanisms and evolution of a pile reinforced landslide under long term reservoir operation abstract stabilizing piles are widely used for reinforcing landslides in the three gorges reservoir area china due to reservoir operations long term water level fluctuations wlfs may cause instability or failure of the reservoir landslide and piles system rlps this study experimentally investigated the deformation characteristics and mechanisms of the rlps under long term wlfs the results showed that long term wlfs led to loading and unloading cycles and consequently a weakening of the slope stability where retrogressive failure and system instability were observed retrogressive failure at the slope toe was caused by topographical variation and physical and mechanical deterioration which may be a result of the long term wlfs system instability was accompanied by a stress release process above the new slip surface and was determined to be dependent on the geological structure of the rlps based on this investigation the evolution model of the pile reinforced landslide under long term wlfs was proposed even though the rlps was adversely affected by the long term wlfs it maintained a relatively steady state due to the reinforcement of the piles effective pile installation changed the development of the reservoir landslides and prevented the entire slip surface from reaching a critical state thus a catastrophic consequence was avoided except for the local failure through physical modeling this study experimentally provided a deeper understanding of the deformation mechanisms and evolution of the rlps influenced by the long term wlfs

the paleogeography of late neogene central crete inferred from the sedimentary record combined with albinaria land snail biogeography abstract phylogenetic and geographic relations of recent land organisms often agree with results from tectonical and paleogeographic reconstructions in the hellenic island arc greece albinaria land snails gastropoda pulmonata clausiliidae are used to provide paleogeographical information in a combined analysis of their present distributional ranges and the sedimentary record late tertiary neogene islands in the region of present day crete existed for 6 9 myear before the arc was uplifted 3 2 myear ago pliocene the albinaria fauna of crete is known to be relictual in central crete an area of 3800 km2 the distributional ranges of 15 parapatrically dispersed albinaria species were determined based on differences in their ecological behavour the species are subdivided into two groups group 1 exclusively living on pre neogene substrate is believed to have largely conserved pre pliocene ranges and group 2 partly living on neogene partly on pre neogene substrates is assumed to have occupied the land which appeared after late neogene uplift events together with the sedimentary record albinaria helps to reconstruct the dynamic paleogeographic developments and block movements in central crete since the serravallian the conclusions imply 1 that some of the involved populations have been separated from each other for up to 11 myear and 2 that providing information on paleoislands recent land snails may contribute to geoscientific questions concerning the rate and timing of uplift and erosion

boundary effect on the hydraulic characteristics of gravelly soil slopes in physical model tests abstract the stability of a residual gravelly soil slope during heavy rainfall is closely related to the seepage field which is directly affected by the seepage boundaries of the slope to examine the boundary effect a novel model flume that can implement permeable and impermeable boundary conditions was designed with this flume hydraulic model tests of a gravelly soil slope considering those two seepage boundaries were carried out the results show that distinct spatial morphology of seepage fields is reflected by the hydraulic characteristics of the slope models with different seepage boundaries the slope with permeable boundaries generally exhibits a larger average infiltration rate as well as a relatively smaller moving speed of wetting front in the lower part compared to the slope with impermeable boundaries the residual moisture content in the deep lower part of the slope with permeable boundaries is 6 6 cm3 cm3 smaller than that of the slope with impermeable boundaries nevertheless the maximum pore water pressure in the middle part of the slope with permeable boundaries is 1 2 kpa higher than that in the corresponding part of the slope with impermeable boundaries it is noted that regional pore water pressures in the shallow lower and shallow middle parts of the slope with impermeable boundaries exhibit large fluctuations with an amplitude over 0 5 kpa the seepage field in the slope with permeable boundaries presents a multi dimensional development which may lead to a local failure of the slope the results are of great significance in studying the similarity of seepage boundary condition in the field of similarity theory on landslide model tests and provide an experimental basis for establishing rainfall induced landslide theory

mechanism and failure process of qianjiangping landslide in the three gorges reservoir china the qianjiangping landslide is a large planar rock slide which occurred in july 14 2003 shortly after the water level reached 135 m in the three gorges reservoir china the landslide destroyed 4 factories and 129 houses took 24 lives and made 1 200 people homeless field investigation shows that the contributing factors for the landslide are the geological structure of the slope the previous surface of rupture the water level rise and continuous rainfall in order to reveal the mechanism and failure process of the landslide numerical simulation was conducted on qianjiangping slope before sliding based on the characteristics and the engineering conditions of the landslide the topography and the geological profiles of qianjiangping slope before sliding is reconstructed the seepage field of qianjiangping slope before sliding was simulated with the geostudio software the results show that ground water table rises and bends to the slope during the rise of water level and the slope surface becomes partially saturated within the period of continuous rainfall using the ground water table obtained above the failure process of qianjiangping slope is simulated with the flac3d software the results demonstrate that the shear strain increment displacement and shear failure area of the slope increased greatly after the water level rose and continuous rained and the landslide was triggered by the combined effect both of water level rise and continuous rainfall the development of shear strain increment displacement and shear failure area of the slope shows that the landslide was retrogressive in the lower part of the slope and progressive in the upper part of the slope

strain distribution based geometric models for characterizing the deformation of a sliding zone abstract distributed optical fiber sensing technology was used to establish a deformation monitoring system for the majiagou landslide in the three gorges reservoir area china the monitoring methods were introduced the strain distribution of the optical sensing cables can be utilized to accurately detect the position of the sliding zone and to reveal the movement of the landslide which was verified by comparisons with gps and inclinometer data it was found that the strain distributions of the optical sensing cable in the sliding zone were different in order to reasonably explain the shear deformation of the sliding zone based on the strain distribution and its changes three geometric models reflecting the spatial relationship between the sliding zone and the optical cable were proposed the results indicate that the strain distributions depend on the angle between the optical sensing cable and the sliding zone the position of the main slip surface within the sliding zone as well as the shear deformation of the sliding zone the correctness of the geometric models is verified by the monitored strain distribution of the sensing cable the proposed geometric models can be used to precisely describe the deformation of the sliding zone and reveal the evolutionary stage of the landslide

behavior and analysis of stabilizing piles installed in a cut slope during heavy rainfall abstract in this study the behavior of stabilizing piles installed in a cut slope is investigated using a field measurement system and analyzed considering the infiltration depth of environmental rainfall two cut slopes located on an express highway construction site in donghae korea were selected for this study landslides with some tension cracks were found in the upper part of these cut slopes during the cutting process as the primary method of slope enforcement four rows of stabilizing piles were created and a series of field monitoring systems was installed to measure the movements of the stabilizing piles and the slope according to the field monitoring results the deflection of the stabilizing piles and the deformation of the slope were significantly affected by heavy rainfall lumb s theory 1975 was used to calculate the depth of the wetting front for the case in which the rainfall intensity is equivalent to the coefficient of permeability of the soil a slope stability analysis was performed and the calculated depth of the wetting front and the measured groundwater level were considered in this analysis the behavior of the stabilizing piles was calculated by the slopile program ver 3 0 which was used to analyze and design the slope and the piles the expected deflections of the piles obtained from the analysis are similar to measured deflections therefore the rainfall intensity can be used to calculate the depth of the wetting front and this analysis technique very effectively calculates the slope stability and the behavior of stabilizing piles

a thermomechanical model for saturated clays a thermomechanical model for saturated clays is proposed within the framework of recent extensions of the cam clay model the results of some tests found in the literature are analyzed and the main features of the thermomechanical behaviour of clays are identified the effect of the overconsolidation ratio ocr on the volume change of a soil expansion contraction submitted to heating is well established using experimental data obtained for selected soils by various authors however existing models need to be modified to correctly model this feature for this reason a new volumetric thermal plastic mechanism is developed that allows for the prediction of plastic strains at higher ocr values the overconsolidation effect observed when heating a normally consolidated soil is also modelled particular attention is paid to the coupling and hardening phenomena related to the combined effects of stress and temperature a qualitative validation is made by examining the response of the model under a given th

in situ monitoring platform and preliminary analysis of monitoring data of majiagou landslide with stabilizing piles abstract reservoir landslide evolution is a complex multi fields dynamic process which involves the interaction of the seepage field stress field displacement field and temperature field after installing the stabilizing structure into landslide the landslide and stabilizing structure will establish the landslide stabilization system and lead to a more complex multi fields evolution process under the reservoir operation to study this complex problem this paper designs and establishes a comprehensive in situ multi fields information monitoring platform which has been installed on majiagou landslide in three gorges reservoir area the multi fields information monitoring platform has four components the landslide stabilization system the in situ multi field monitoring system the data transmission and receiving system and the database management system the landslide stabilization system includes majiagou landslide and two experimental reinforced concrete piles the in situ monitoring system consists of landslide surface deformation monitoring system experimental piles monitoring system and boreholes monitoring system the landslide surface deformation monitoring system includes gps stations and fiber lines the experimental pile monitoring system consists of earth pressure cells around piles stress and strain gauges on steel bars and strain and temperature fiber sensors in piles the borehole monitoring system includes boreholes with inclinometers water pressure and water level gauges fiber sensors therefore the in situ monitoring system can monitor the seepage stress displacement and temperature fields in the landslide as well as the force and deformation in the experimental piles currently the data transmission and management system is under construction and will be finished soon current monitoring results show that the landslide moves along three slip surfaces and the deformation of the experimental piles is influenced by reservoir operation this platform can provide multi fields data for scholars to study the evolution of landslide stabilization system

paleoceanography and climate of the badenian middle miocene 16 4 13 0 ma in the central paratethys based on foraminifera and stable isotope δ 18 o and δ 13 c evidence benthic foraminifera and stable isotopes analyses revealed changes emerging in the paleoceanographic scenery in the paratethys the percentage of inbenthic oxyphylic taxa and diversity in the benthic foraminiferal assemblage showed increasing food supply organic matter decreasing oxygen level and growing stress on the sea floor oxygen isotopes measured in planktonic and benthic foraminifera pointed to strengthening stratification during the badenian period the carbon isotopes indicated intensified accumulation of light marine organic matter this increasing stratification trend is especially pronounced by late badenian 13 5 13 ma when surface water oxygen isotope values are rather negative a simple two layer circulation model was worked out for the badenian paratethys explaining these characteristic environmental changes an antiestuarine lagoonal circulation is assumed for the central paratethys during the early 16 4 15 ma and mid badenian 15 13 5 ma the mid badenian period of time comprises the short episode of evaporite formation in the carpathian foredeep and the transylvanian basin evidence presented here supported a reversal of circulation to estuarine type after the deposition of salts by late badenian 13 5 13 ma the early badenian antiestuarine circulation is suggested to associate with the high temperatures of the mid miocene climatic optimum and the late badenian estuarine circulation with the cooler period following it

centrifuge model test on the retrogressive landslide subjected to reservoir water level fluctuation abstract geological disasters have occurred frequently in the three gorges reservoir area therefore the stability and failure mode research on riverside landslides has become increasingly important taking the toe of liangshuijing landslide as a case study and combining the geological conditions of the three gorges reservoir area a centrifuge slope model is constructed in addition the fluctuation of the water level is simulated in the centrifuge model test based on the digital photography laser displacement sensors lds pore pressure transducers ppt and earth pressure sensors e multi physical data are obtained finally numerical simulation is carried out to analyze the stability and deformation characteristics of the slope model the results indicate that 1 at the water level rise stage the model is dominated by the vertical displacement and the horizontal displacement is much larger than the vertical displacement at the drainage stage 2 cracks first appear at the toe of the slope and extend to the middle and rear of the model gradually then deformation occurs in the middle platform of the slope 3 at the water level rise stage the factor of safety increases rapidly when the reservoir water level remains stable the stability of the slope decreases slowly and at the drainage stage the factor of safety decreases first and then increases 4 there is a significant positive linear correlation between the decline rate of the safety factor and the drainage rate over a certain test range and the stability of the landslides on the reservoir banks would become worse gradually during the long term cyclic operation of the three gorges reservoir

response of a landslide to reservoir impoundment in model tests abstract landslides are often induced or activated by reservoir impoundment within the reservoir area in this paper a physical model test was conducted and compared with another published test to investigate the deformation characteristics and failure behavior of a colluvial landslide for conditions with and without reservoir impoundment the laboratory landslide model represented the lower part of a landslide in the three gorges reservoir area a thrust load was applied to represent the upper part of the landslide the thrust load surface deformation pore water pressure and soil pressure were recorded during the experiments the results show that the effect of the reservoir impoundment reduces the time to failure of the landslide and the load causing the failure as expected when water submerged the lower part of the landslide the shearing resistance was reduced the slip surfaces and failure behavior of the landslide under the two conditions are different the entire landslide mass slid along the contact between the colluvium and the bedrock under reservoir impoundment however without a reservoir the landslide slides partially along this contact and multiple slip surfaces through the colluvium

model tests of the evolutionary process and failure mechanism of a pile reinforced landslide under two different reservoir conditions abstract anti slide piles are widely used for stabilizing landslides and a large number of landslide piles systems were constituted in reservoir areas how these landslide piles systems evolve under reservoir effects is vital for the safe operation of dams in this study two reservoir conditions namely condition of static water level and water level fluctuations were considered for detailly exploring the influence of static and dynamic water pressure on a landslide piles system in physical model tests the pore water pressure surface deformation and photographs of visual observations were obtained for comparatively analyzing the deformation characteristic and failure mechanism of landslide piles models under the two conditions the results show that the soil deformation and failure around the piles were similar in the two tests due to the same pile arrangements however retrogressive deformation and two soil collapses occurred in the landslide front area under water level fluctuations instead of slight deformation and shallow erosion under the static water level the outward hydrodynamic pressure caused by reservoir drawdowns was the primary reason for the soil collapses in the landslide front area the progressively intensified deformation around the piles which indirectly decreased the soil stability in the landslide front area was the secondary cause for the collapses the majiagou landslide piles system in the field was identified as in the early period of the uniform deformation stage at present based on the field observations monitoring data and the test results under water level fluctuations

oxygen strontium and neodymium isotope composition of fossil shark teeth as a proxy for the palaeoceanography and palaeoclimatology of the miocene northern alpine paratethys the upper marine molasse sediments of southern germany were deposited during the early to middle miocene a period of significant change for the global miocene palaeoceanography palaeoclimate and the regional palaeogeography because of the ongoing alpine himalayan orogeny to address the influence of the alpine uplift on climate and oceanography of the northern alpine molasse basin a combined o sr and nd isotope study was undertaken on fossil teeth from sharks synodontaspis sp galeocerdo cf aduncus chaenogaleus sp and button like teeth from the bony fish of the upper marine molasse chrysophrys molassica average 18o values for hydroxyapatite of teeth from two sites are 20 3 1 0 6 and 21 2 1 0 5 while their average 87sr 86sr and 143nd 144nd ratios are 0 70850 0 00001 2 and 0 70882 0 00003 2 and 0 51220 and 0 51223 both at 0 00001 2 respectively by comparison to the sr evolution curve for the global ocean the sr isotope compositions suggest ages of about 22 and 17 ma for the teeth these ages are in good agreement with the depositional ages which suggests open marine conditions open marine conditions are also compatible with 1 lower average 18o values and 87sr 86sr ratios for the one site compared to higher 18o values and higher 87sr 86sr ratios for the other site 2 estimates for seawater temperatures which are similar to other estimates from deposits of similar latitude and age 3 a comparison of seawater temperatures with average ambient air temperature estimates deduced from continental palaeoclimate indicators nd isotope compositions are compatible with an influence of the north atlantic on the paratethys assuming constant salinity and seawater oxygen isotope composition a 4 c cooling can be inferred from average 18o values of the teeth between 22 and 17 ma this is similar to trends observed for foraminiferal records from the mediterranean tethys but different from foraminiferal and molluscan records of the north atlantic and the north sea during this period and allows for the possibility that the alpine orogeny had an influence on the regional circum alpine climate

landslide monitoring by using ground based sar interferometry an example of application to the tessina landslide in italy abstract an innovative technique based on radar interferometry and implemented using ground based instrumentation has been applied for monitoring the tessina landslide italy belluno the technique has allowed us to derive multitemporal surface deformation maps of the entire depletion zone of the landslide with a high spatial resolution and accuracy the portable device used in this application is known as linear sar lisa and it is able to provide measurements at 17 ghz with a synthetic aperture of up to 2 8 m the results have been validated by comparing the recorded pixel displacements with independent measurements carried out by a motorized theodolite and electronic distance meter edm on two benchmarks

patterns of movement in reactivated landslides abstract the primary aim of this research was to study the relationship between landslide motion and its causes with reference to large slow moving reactivated translational rock slides surface displacements of the 22 106 m3 utiku landslide in central north island new zealand were measured using continuous gps cgps for three years the nature of the movement of such slides has often been difficult to determine because of poor temporal and spatial monitoring resolutions after removal of tectonic plate motion the temporal pattern of the landslide s surface motion could be understood to arise from irregular episodes of faster up to 21 mm day and slower up to 26 mm yr post failure landslide displacement and seasonal cyclic displacements of about 20 mm yr 10 mm per half year in alternating directions intervals of faster motion gave rise to displacements of between 10 and 120 mm per event faster displacement was associated mostly with basal sliding mechanism 1 involving deformation within a thin clay seam as recorded by borehole inclinometer surveys slower surface displacement involved permanent internal deformation of the larger landslide mass consisting of plastic deformation within the landslide body and or slip along existing internal planes of weakness and slip on the slide base mechanism 2 it accounted for up to 26 mm yr of displacement at a mean angle of about 49 from the horizontal indicating that the slide mass was thinning as it moved down slope seasonal cyclic displacements were synchronous with changes in pore pressure suggesting that it is a shrink swell process mechanism 3 associated with wetting and recharge of groundwater during the wetter winter months leading to a downslope movement and soil shrinkage leading to upslope rebounds during the dryer summer months the brief periods of faster displacement were triggered by seasonal peaks in pore pressure linked to long periods 12 to 20 weeks of increased precipitation and lowered evapotranspiration faster displacement however was not arrested by lowering pore pressure or by any other monitored factor similarly periods of slower displacement did not correlate with pore pressure changes or with any other monitored factor this study has shown that the annual movement pattern of a reactivated landslide is a combination of these processes that generate a complex overall movement record the field measurements showed real variability arising from variations in rainfall and pore pressure which were overprinted with measurement noise that may mask some other processes

distributed acquisition characterization and process analysis of multi field information in slopes the slope is a multiphase composite system including solid liquid and gas phases slope stability changes under the actions of stress temperature and seepage slopes will be very prone to landslide if in an unstable state in this paper considering the contributions of different fields to the landslide the distributed acquisition characterization and stability analysis of multi field information from slopes was studied systematically using distributed fiber optic sensing dfos technology a sensing system based on dfos was designed and developed for multi field information monitoring including stress temperature seepage and deformation the corresponding methods for data processing identification and methods for characterization description are also proposed on this basis the evolution of the slope is analyzed finally monitoring results of the dfos system from the majiagou landslide are shown as a case study for verification

geohazards in the three gorges reservoir area china lessons learned from decades of research abstract the impoundment of the 660 km long reservoir behind the huge three gorges dam the world s largest hydropower station increased regional seismicity and reactivated severe geohazards before the reservoir filling was initiated in 2003 the region had approximately two earthquakes per year with magnitudes between 3 0 and 4 9 after the full impoundment in 2008 approximately 14 earthquakes per year occurred with magnitudes between 3 0 and 5 4 in addition hundreds of landslides were reactivated and are now in a state of intermittent creep many landslides exhibit step like annual pattern of displacement in response to quasi regular variations in seasonal rainfall and reservoir level additional problems include rock avalanches impulse waves and debris flows the seriousness of these events motivated numerous studies that resulted in 1 better insight into the behavior and evolution mechanism of geohazards in the three gorges reservoir area tgra 2 implementation of monitoring and early warning systems of geohazards and 3 design and construction of preventive countermeasures including lattice anchors stabilizing piles rock bolts drainage canals and tunnels and huge revetments this paper reviews the hydro geologic setting of tgra geohazards examines their occurrence and evolution in the past few decades offers insight learned from extensive research on tgra geohazards and suggests topics for future research to address the remaining challenges

the geology of mount hasan stratovolcano central anatolia turkey mount hasan is a double peaked stratovolcano located in central anatolia turkey the magmas erupted from this multi caldera complex range from basalt to rhyolite but are dominated by andesite and dacite two terminal cones big mt hasan and small mt hasan culminate at 3253 m and 3069 m respectively there are four evolutionary stages in the history of the volcanic complex stage 1 kecikalesi volcano 13 ma stage 2 palaeovolcano 7 ma stage 3 mesovolcano and stage 4 neovolcano the eruptive products consist of lava flows lava domes and pyroclastic rocks the later include ignimbrites phreatomagmatic intrusive breccias and nuees ardentes sometimes reworked as lahars the total volume is estimated to be 354 km 3 the area extent 760 km 2 textural and mineralogical data suggest that both magma mixing and fractional crystallization were involved in the generation of the andesites and dacites the magmas erupted from the central volcanoes show a transition with time from tholeite to calc alkaline three generations of basaltic strombolian cones and lava flows were emplaced contemporaneously with the central volcanoes the corresponding lavas are alkaline with a sodic tendency

climatically driven sedimentary cycles in the late miocene sediments of the pannonian basin hungary abstract by detailed cycle analysis of marginal mostly delta plain facies successions of pannonian sediments the frequency of water level changes of the late miocene pannonian lake hungary can be identified cycle analysis is presented with the object of defining the orbital record preserved in the strata we use the bed thickness as input data for our cycle analysis statistical analysis revealed a slow upward increase of both the frequency and thickness of sand beds in the boreholes resulting from infilling of the lake by a basinward migration of the marginal facies cycles of different order were detected in the sediments the higher order cycles are very close to or are equivalent with the milankovitch climatic cycles 19 ka caused by precession 50 ka caused by obliquity and 400 ka is the longer period of eccentricity the longer 1 m y cycle is very poorly developed here it is probably the analogue of the 3rd order global climatic cycle cycle analysis suggests that one of the main controlling factors of the water level changes of the pannonian lake was high frequency climatic oscillations the long term climatic changes only had a faint impact on the sediments the record of the 3rd order water level changes is very subtle our results show that the water level changes followed the rhythm of that of the eustatic changes but being asynchronous to them i e at high sea level stage the pannonian lake level was low and vice versa