two magmatic series with island arc affinities within the vourinos ophiolite within the vourinos ophiolite evidence of two magmatic series has been preserved in cognate cumulates and in effusive and hypabyssal rocks which constitute the earlier krapa sequence and the younger asprokambo sequence the asprokambo dyke basic magmas which are poor in incompatible elements and relatively ni and cr rich bear some resemblance to very low ti basalts transitional to boninites found in subduction related arcs or interarc basins krapa series magmas from sills massive and pillow lavas are best equated with low k tholeiites of island arc suites compositions of al and ti poor cpx in lavas from both series are comparable to those in island arc basalts the asprokambo cpx being richer in ca and cr than those from krapa the large volume of cumulates from the krapa sequence displays the following crystallization order ol sp cpx pl opx mt periodic influx of fresh magma batches into the magma chamber occurred mainly during the formation of the lower cumulates wehrlite ol clinopyroxenite and melagabbro the upper cumulates gabbronorite and leucogabbronorite with minor mt bearing gabbronorite crystallized in the upper levels of a magma chamber which became progressively smaller with time in the asprokambo sequence ol sp opx cpx pi and amph are the successively crystallizing phases the ortho to heteradcumulates consist of websterite pl websterite gabbronorite amphibole bearing leuconorite diorite and granophyre in cumulates especially in the lower krapa sequence significant subsolidus reaction was probably induced by the persistence of high geothermal gradients linked to continuous magmatism petrological features indicate that the evolution of the krapa series is more compatible with an intermediate fractional equilibrium crystallization history in an initially open system whereas nearly perfect fractional crystallization in closed system may have occurred in the small asprokambo magma chambers chemical variations in the lavas of both series can be explained in terms of crystallization of the observed cumulates significantly the asprokambo intrusives have igneous mg hornblende and vanadium bearing chromian aluminous titaniferous magnetite crystallization of which is responsible for the calcalkaline evolutionary trend of these rocks major and trace element modelling necessitates a two stage model for the petrogenesis of the vourinos parental melts involving high degree remelting of previously depleted mantle sources favoured by the influx of subduction derived hydrous fluids the primary magmas parental to the krapa and asprokambo series could have been derived respectively by 20 and 30 equilibrium partial fusion of variably depleted lherzolitic sources leaving residua having a harzburgitic to dunitic composition

evolution of the eclogites in the rhodope zone of northern greece abstract the polymetamorphic complex of rhodope in the southern balkan peninsula has been affected by three successive metamorphic episodes these are 1 a high pressure 2 a barrow type and 3 a greenschist facies retrograde metamorphic episode based on the different metamorphic grades of the barrovian metamorphism the rhodope zone can be subdivided into two tectonic units a lower and an upper one commonly amphibolitised eclogites of probable mesozoic age occur in both units a in the shape of lenses b as concordant interbeds with other rock types such as gneisses and marbles and c as metagabbroic dykes the high pressure mineral assemblage is garnet omphacite quartz ca amphibole clinozoisite zoisite rutile kyanite in eclogites of gabbroic origin igneous relics such as igneous plagioclase augite and ilmenite are sometimes preserved pt conditions of 14 kbar and 550 600 c were determined for the high pressure metamorphism in the lower tectonic unit symplectites of clinopyroxene plagioclase ca amphibole plagioclase biotite plagioclase and spinel plagioclase are common and are attributed to post eclogitic reactions during uplift changes in mineral composition of high pressure phases such as garnet ca amphibole and na pyroxene reflect a re equilibration tendency during unloading

representative rainfall thresholds for landslides in the nepal himalaya measuring some 2400 km in length the himalaya accommodate millions of people in northern india and pakistan nepal bhutan and parts of other asian nations every year especially during monsoon rains landslides and related natural events in these mountains cause tremendous damage to lives property infrastructure and environment in the context of the himalaya however the rainfall thresholds for landslide initiation are not well understood this paper describes regional aspects of rainfall thresholds for landslides in the himalaya some 677 landslides occurring from 1951 to 2006 were studied to analyze rainfall thresholds out of the 677 landslides however only 193 associated with rainfall data were analyzed to yield a threshold relationship between rainfall intensity rainfall duration and landslide initiation the threshold relationship fitted to the lower boundary of the field defined by landslide triggering rainfall events is i 73 90d 0 79 i rainfall intensity in mm h 1 and d duration in hours revealing that when the daily precipitation exceeds 144 mm the risk of landslides on himalayan mountain slopes is high normalized rainfall intensity duration relationships and landslide initiation thresholds were established from the data after normalizing rainfall intensity data with respect to mean annual precipitation map as an index in which ni 1 10d 0 59 ni normalized intensity in h 1 finally the role of antecedent rainfall in causing landslides was also investigated by considering daily rainfall during failure and the cumulative rainfall to discover at what point antecedent rainfall plays an important role in himalayan landslide processes rainfall thresholds presented in this paper are generalized so they can be used in landslide warning systems in the nepal himalaya 2008 elsevier b v all rights reserved

a review of recent work on mass movements on slopes and on rock falls abstract this paper reviews the recent developments in the field of mass movements on slopes the subjects treated include surface slips deep seated soil creep rock mass creep surficial landslides mud flows and alpine debris flows in this instance the paper supplements the chapter accidents on slopes in the author s book physical aspects of natural catastrophes 1975 by new data published mainly between 1976 and 1983

sediment dynamics and hydrologic events affecting small lacustrine systems on the southern central tibetan plateau the example of tt lake a sedimentological geochemical micropaleontological and palynological study of a lacustrine sediment record from the small tt lake southern central tibetan plateau shows that the background sedimentation was frequently interrupted by event related deposits these event related deposits are interpreted as the result of hydrologic events that are triggered by above average precipitation events in total 11 events were recorded in the tt lake sequence two types can be differentiated fluvial runoff events caused by precipitation that carried sediment in suspension into the lake and a sediment mass transport caused by torrential precipitation the hydrologic events appear to be decoupled from long term climate and environmental variations but there is evidence that anthropogenic impact in terms of pastoralism might have favored the runoff events the multi proxy approach proved to be valuable and allowed for a detailed study of sedimentary processes within the lake and its watershed in order to asse

field variability of landslide model parameters a data set of parameters slope soil depth and soil shear strength relevant to spatially distributed modelling of shallow landslides triggered by rain and snowmelt events was determined from field measurements in 250 grid elements of dimensions 25 m downslope 10 m across slope in an area of 250 m 250 m on a hillslope in scotland these data provide an unusually detailed basis for the evaluation of spatial variability and uncertainty in model parameterisation the variations in slope and soil strength are represented adequately by normal distributions a weibull distribution is suggested for the soil depth data the factor of safety calculated at each point in the grid was shown partially to identify observed landslides with a number of false predictions of occurrence trend analysis and semivariogram analysis of the data set suggest that the use of kriging could improve upon this approach to landslide prediction by providing areal estimates of parameters at the grid element scale with associated error bounds

the thrace basin in the rhodope province of ne greece a tertiary supradetachment basin and its geodynamic implications abstract detailed tectonic analysis and geological mapping on the tertiary molassic and volcanosedimentary rocks of the thrace basin in northeastern greece allowed us to reconstruct the structural evolution of the basin and its geotectonic setting as well as the orientation of the regional paleostress field sedimentation was linked with a calc alkaline and locally shoshonitic magmatism associated with the tertiary syn to late orogenic extension in the rhodope province we interpret the molassic tertiary greek part of the thrace basin as a supradetachment basin associated with sedimentary and volcanic infilling five 5 deformational events t1 to t5 have been distinguished during basin evolution from eocene to quaternary time t1 is related to a low angle normal detachment fault zone with a top to the sw to ssw sense of movement and initial basin subsidence during middle late eocene to oligocene time simultaneously with uplift and exhumation of the footwall rhodope metamorphic rocks stacking and crustal thickening in the more external parts of the hellenic orogenic belt have taken place during the same time t2 evolved during oligocene miocene time it was characterized by transpressional tectonics and formation of large strike slip faults and extensional fractures as well as conjugate thrust faults and folds with n nw or s se sense of movement during miocene pliocene time the third t3 event took place it was responsible for the high angle normal faults dismembering the eocene oligocene molassic basin into neogene grabens the t4 event affected the neogene sediments of the basin with minor reverse strike slip faults as well as normal faults the following t5 event is related to large normal active faults they coincided with the active tectonics of the study area defined by the earthquake focal mechanisms

debris flow run out and landslide sediment delivery model tests five models are investigated for determining the percentage delivery of sediment to streams for shallow landslides that evolve into debris flows models i iii are based on debris flow run out distance model iv on snow avalanche run out distance for these it is assumed that percentage delivery is 100 for slopes above 10 and zero for slopes below 4 for intermediate slopes delivery is based on the run out distance estimate model v derived from field data estimates percentage delivery directly without the need for slope conditions the model performances are investigated using 100 hypothetical hillslopes and a limited database on landslide sediment delivery in idaho model iv performs best but model i is a close second and its design run out distance varying with elevation drop may be preferable for modeling purposes model ii run out distance varying with debris flow slope and volume provides a conservative upper limit on percentage delivery parallel use of models to provide bounds on the perc

late cenozoic extension in northeastern greece strymon valley detachment system and rhodope metamorphic core complex the strymon valley detachment system accommodated at least 25 km of extension at the northern margin of the aegean extensional province from middle miocene through early pliocene time the primary detachment surface is exposed as a gently southwest dipping low angle normal fault similar to those widely known in core complex settings of the u s basin and range province for more than 150 km along strike from the aegean sea coast in northeastern greece northward into the struma valley of southern bulgaria hanging wall rocks in the strymon valley detachment system moved in a s53 w direction relative to the footwall resulting ultimately in the tectonic unroofing of the rhodope metamorphic core complex several segments of the strymon valley detachment have previously been interpreted as thrust faults formed during a miocene compressional event our results negate the principal evidence for this event and imply instead that extensional deformation has characterized the northern aegean region since at least middle miocene time displacement ceased on the strymon valley detachment with the late pliocene development of the strymon and drama basins we propose that those basins together with the other principal basins of the northern aegean region are subsiding above an active northeast dipping extensional detachment zone that forms a unified kinematic system with the western offshore continuation of the dextral north anatolian strike slip fault the north aegean trough if this hypothesis is correct then the north aegean trough the western strands of the north anatolian fault and the principal modern depocenters of the northern aegean region may all have originated no earlier than late pliocene time

a view from the roof magmatic stoping in the shallow crust chita pluton argentina nearly 2 km of vertical relief and exposure of continuous pluton roof wall corners around the chita pluton northwest argentina provides constraints on the 3 d host rock displacement field attending magma emplacement in the shallow crust the pluton is rectangular in crosssectional view and consists of weakly to non deformed granite to granodiorite structures in surrounding metasedimentary host rocks are truncated at a knife sharp contact and are only weakly deflected from their regional orientations final emplacement occurred by stoping together with minor doming of the earth s surface structural restoration of a cross section indicates that host rocks above the pluton may have been domed upwards during emplacement by as much as a few hundred meters accounting for up to 20 of the exposed pluton volume the remaining 80 of the space for pluton emplacement was made by downward removal of host rock from the present level of exposure although mechanisms such as floor subsidence are permissive late stoping has destroyed evidence for the early emplacement history however geometrical constraints provided by exposure of continuous wall to roof contacts indicate that early emplacement mechanisms at this level in the crust and immediately below were also dominated by the downward displacement of host rocks through a conduit that now is represented by the solidified pluton q 2002 elsevier science ltd all rights reserved

debris flow phenomena in the central apennines of italy the results of a research project on the extent of debris flow processes in the monti sibillini area central italy are presented debris flows have greatly contributed in shaping the landscape of the monti sibillini territory based on the dominant active process they can be subdivided into three sections a source area a transport area and a depositional area four environments can be identified as source areas landslide deposits highly fractured rocks scree or talus deposits and glacial deposits the evolution of some of the largest features present in the area is examined these may have developed from an initial stage of mostly gully erosion and minor landsliding through an intermediate stage characterized by extensive mass movement to a final stage dominated by fluvial processes lastly generalizations on the debris flow hazard in the study area are made

mesozoic tertiary tectonic evolution of albania in its regional eastern mediterranean context abstract research carried out since the opening of albania to the western geological community in the 1990s allows the geology and tectonics of this small balkan country to be integrated into an overall interpretation of neotethys in the eastern mediterranean region specifically greece and the former yugoslavia region albanian geology is most famous for the occurrence of contrasting ophiolites of jurassic age the country is sub divided into three main geotectonic units those in the west i e sazani ionian kruja krasta cukali and the albanian alps relate to the western margin of apulia effectively part of north africa from early mesozoic time onwards in the east is the korabi zone interpreted as a microcontinent located further northeast within neotethys between the two is the mirdita zone dominated by two contrasting jurassic ophiolites the western type ophiolite and the eastern type ophiolite taking account of evidence from greece and former yugoslavia the following tectonic evolution is proposed from early mesozoic time onwards neotethys in albania existed as a northward continuation of the pindos oceanic basin in greece pindos mirdita ocean a korabi microcontinent was rifted off apulia in the early mid triassic followed by passive margin subsidence until late middle jurassic time a rifted slow spreading mor type ophiolite formed within the western pindos mirdita oceanic basin in late triassic early late jurassic time using present co ordinates the shkoder peje scutari pec lineament in the north of albania is interpreted as an important transform fault zone that influenced the regional tectonic evolution during the entire mesozoic early tertiary rift drift emplacement history of the pindos mirdita ocean taking account of evidence from the greek and former yugoslavia ophiolites the easterly albanian ophiolites formed within the pindos mirdita ocean above a westward dipping intra oceanic subduction zone in the early late jurassic metamorphic soles were formed during initial intra oceanic displacement ca 162 174 m y and underlying melanges originated as subduction accretion complexes the mor western type ophiolite evolved into the iat boninitic eastern type ophiolite after subduction began during tithonian berriasian time trench margin collision emplaced the ophiolites eastwards over the korabi margin coupled with redeposition of ophiolitic and continental margin material as exotic blocks debris flow deposits and turbidites these were emplaced onto the upper surface of the ophiolitic thrust sheet during the latest stages of emplacement onto the korabi microcontinent following collision in the east oceanic crust remained within a small remnant pindos mirdita oceanic basin passive conditions were restored in the mid late cretaceous with shallow water carbonate deposition on microcontinental units and both pelagic and redeposited carbonates in basinal settings from the maastrichtian onwards africa eurasia convergence resulted in large scale westward thrusting deforming the apulian foreland in oligo miocene time the suture zone was re activated in oligo miocene time as the albanie thassalie piggy back type basin in central and southern albania albania as a whole was rotated 45 clockwise as part of the western aegean arc in post eocene time coastal and offshore albania experienced strong subsidence after early miocene time forming the periadriatic basin including the tirana depression interpreted as a foredeep related to continuing regional convergence southern albania experienced extensional tectonics in plio quaternary time related to southward roll back of the aegean active margin

a fluidized landslide occurred in the loess plateau a study on loess landslide in south jingyang tableland abstract the south jingyang tableland is located on the southern loess plateau of china ever since the introduction of the water division project in the 1970s more than 40 loess landslides have occurred in this tableland terrace slope topography here on the morning of march 8 2016 a loess landslide induced by irrigation occurred in jiangliu village on the south jingyang tableland and around 20 000 m 3 of loess rapidly slid along a 65 m high slope for 260 m the moisture content of the slip mass displayed a dramatic change along the slip direction the water saturation degree in the landslide depression was relatively high and the leading edge was in a flow state there were some local natural sub areas but the overall area showed a characteristic fluidized a field investigation indicated that while macropores developed in the loess and deep joints provided a preferential passage for the infiltration of irrigation water which became a major water source for the slip mass the softening of the toe part of the slope caused by irrigation became the major factor resulting in the instability of the slip mass undrained triaxial shear tests on loess in natural water content and fully saturated state show that the enhanced saturation degree not only lowered the soil mass strength but also increased pore water pressure resulting in the zoning status of the jiangliu landslide the angle of reach formed during this landslide was approximately 14 which demonstrated motion characteristics of long runout further considering the standing water at the slope foot and unique properties of slip soils after the landslide occurred it is speculated that the motion mechanism of this high speed and long runout landslide was associated with loess liquefaction that led to sharp decrease in shear strength of the displaced landslide materials during the shear process

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

effect of quarrying on the slope stability in banasuramala an offshoot valley of western ghats kerala india the narippara area which is nestled in the banasuramala of wayanad district witnessed initiation of landslide which was manifested in the form of curvilinear cracks running for a length of 170 m in the event of continuous rainfall these cracks may get reactivated leading to a major landslide this could affect the life and livelihood of a large number of families living downslope and could cause extensive damage to property extensive mining for building stones in this area has been a cause for much concern amongst the local population this study aims at understanding the impact of quarrying on slope stability through geotechnical geophysical and environmental impact assessment eia geotechnical analysis shows that the area is stable under dry condition but parts of the area are critical under wet and saturated conditions moreover resistivity studies revealed that the cracks that had developed extend up to the bedrock and the suspected mechanism of failure will be translational in nature eia reveal that due to quarrying and mining operations the possibility of land disturbances cannot be ruled out during the monsoon season in the present study an attempt is also made to suggest management strategies for mitigating further effects of landslides in this area

origin and emplacement of the late cretaceous baer bassit ophiolite and its metamorphic sole in nw syria abstract the baer bassit ophiolite of inferred late cretaceous age was emplaced from the south tethys ocean onto the leading edge of the arabian continental margin in latest cretaceous maastrichtian time dismembered sequences in different thrust sheets can be correlated to produce a complete ophiolite sequence with a metamorphic sole at the base overlain in turn by upper mantle tectonite rare cumulates massive and layered gabbros localized high level plagiogranites sheeted dykes basic extrusives and minor fe mn sediments umbers the restored ophiolite sequence is similar to that of the more intact troodos and hatay ophiolites but dissimilar to oman the baer bassit extrusives are magnesian and strongly depleted comparable to primitive island arc tholeiites and some boninitic lavas which favours a subduction related origin a well developed metamorphic sole is divisible into high grade amphibolite facies assemblages in the north and lower grade greenschist facies assemblages in the centre of the region but no complete inverted metamorphic gradient is preserved in any one local area the protoliths of both the high grade amphibolites and lower grade rocks greenschists are interpreted as alkali basalts and pelagic sediments including chert similar to the volcanic rocks in an underlying unmetamorphosed melange the metamorphic fabrics progressively evolved from ductile to brittle during tectonic transport towards the southeast most of the metamorphic fabrics evolved during intense shearing but some of the alkaline metabasites apparently were metamorphosed under relatively static strain conditions the apparent absence of preserved inverted metamorphic gradients in baer bassit may reflect a complex deformation history during emplacement alternatively differing p t conditions may be recorded at different depths at the base of the over riding mantle wedge during emplacement the front of the ophiolite was tectonically imbricated and overthrust by the main ultramafic slab bassit massif the thickest massif baer is underlain by a high grade metamorphic sole and was internally shortened but without thrust duplication of the entire ophiolite sequence following covering by late maastrichtian palaeogene marine calcareous sediments the area was subjected to mid tertiary regional folding this was followed by neogene dominantly left lateral strike slip deformation along the african eurasian plate boundary extending from south of cyprus to the dead sea transform fault as a result the originally emplaced thrust sheets were dissected into three main composite units baer bassit and the southeastern units separated by strongly faulted and sheared ophiolitic blocks and unmetamorphosed volcanic sedimentary melange

late proterozoic and silurian basement units within the serbo macedonian massif northern greece the significance of terrane accretion in the hellenides

constraints on the petrogenesis of evros ophiolite extrusives ne greece abstract the incomplete and dismembered evros ophiolite is situated in thrace ne greece and belongs to the circum rhodope belt crb its age is considered to be jurassic lower cretaceous the geotectonic setting of the ophiolite was a volcanic arc marginal basin system in the vardar oceanic realm in the uppermost level of the ophiolitic sequence volcanic and pyroclastic rocks of tholeiitic composition are underlain massive and pillow lavas with a few tuffaceous rocks and lava breccia all these rocks were involved in intense deformation and low grade metamorphic events during and after their formation the underlying tholeiites were regionally metamorphosed to greenschist facies lower metavolcanics lmv whereas the upper lavas were extensively recrystallized mainly by ocean floor metamorphism of prehnite pumpellyite facies upper metavolcanics ree data and wide ranges in zr y ti zr and al ti ratios suggest that the parental magma of the upper metavolcanics underwent extensive fractional crystallization tholeiitic basalts and mainly basaltic andesites to andesites were formed at the initial stages of the differentiation by crystal fractionation which involved olivine cr spinel clinopyroxene and occasionally plagioclase subordinate dacites to rhyodacites were created when plagioclase became the main fractionating phase the oxygen fugacity remained nearly stable during the formation of the main volume of the rock association but it changed when rhyodacitic rocks started to crystallize the protoliths of the upper metavolcanics was boninitic produced in the forearc area by about 30 partial melting of an already depleted mantle source this partial melting was induced by aqueous fluids and or melts from the subducting oceanic crust and its sedimentary cover the depleted mantle source of the upper metavolcanics was the residue of an earlier partial melting event that had generated the magma of the lower metavolcanic protoliths in an extensional regime

real time estimation of hazard for landslides triggered by rainfall landslide movements triggered by rainfall can be foreseen in real time by modelling the relationship between rainfall amount and landslide occurrence this paper deals with the problem of the reliability of the flair forecasting of landslides induced by rainfalls model when applied to forecasting landslide movements in the usual condition of poor historical information availability in this case the identification of the admissibility field for the model parameters instead of a point estimation leads to an improvement of the forecasting reliability moreover this approach makes the model capable of taking into account information embodied in periods of heavy rain but without movement the concepts of informative content and foreseeability of landslide movements are introduced and their duality is analyzed the effectiveness of the estimation procedure described has been tested by application on two landslides located in southern italy

the determination of statistical and deterministic hydrological landslide triggering thresholds hydrological landslide triggering thresholds separate combinations of daily and antecedent rainfall or of rainfall intensity and duration that triggered landslides from those that failed to trigger landslides they are required for the development of landslide early warning systems when a large data set on rainfall and landslide occurrence is available hydrological triggering thresholds are determined in a statistical way when the data on landslide occurrence is limited deterministic models have to be used for shallow landslides directly triggered by percolating rainfall triggering thresholds can be established by means of one dimensional hydrological models linked to the infinite slope model in the case of relatively deep landslides located in topographic hollows and triggered by a slow accumulation of water at the soil bedrock contact simple correlations between landslide occurrence and rainfall can no longer be established therefore real time failure probabilities have to be determined using hydrological catchment models in combination with the infinite slope model

early orogenic deformation in the ionian zone of the hellenides effects of slab retreat and arching on syn orogenic stress evolution abstract in this work we report on early orogenic fracture patterns affecting a cretaceous to eocene sedimentary succession exposed in western greece these rocks belong to the cenozoic external hellenides which form the western portion of the aegean orocline the analysis of fracture type orientation and crosscutting relationships provides constraints on the stress and strain patterns during the early stages of orocline formation the fracture patterns in the study area includes early orogenic extensional fractures arranged into two mutually orthogonal sets these developed during progressive burial in the forebulge foredeep system ahead of the advancing compressive front tectonic solution seams at a high angle to bedding postdate these extensional structures solution seams are arranged in different sets oblique to each other and developed in the early stages of thrusting and folding extensional structures and solution seams are oblique to each other their orientation and crosscutting relationships provide evidence for clockwise vertical axis rotation of stress directions with time this is consistent with the progressive arching of the forebulge thrust belt system during progressive slab retreat

a new classification of the turkish terranes and sutures and its implication for the paleotectonic history of the region abstract the turkish part of the tethyan realm is represented by a series of terranes juxtaposed through alpine convergent movements and separated by complex suture zones different terranes can be defined and characterized by their dominant geological background the pontides domain represents a segment of the former active margin of eurasia where back arc basins opened in the triassic and separated the sakarya terrane from neighbouring regions sakarya was re accreted to laurasia through the balkanic mid cretaceous orogenic event that also affected the rhodope and strandja zones the whole region from the balkans to the caucasus was then affected by a reversal of subduction and creation of a late cretaceous arc before collision with the anatolian domain in the eocene if the anatolian terrane underwent an evolution similar to sakarya during the late paleozoic and early triassic times both terranes had a diverging history during and after the eo cimmerian collision north of sakarya the kure back arc was closed during the jurassic whereas north of the anatolian domain the back arc type oceans did not close before the late cretaceous during the cretaceous both domains were affected by ophiolite obduction but in very different ways north directed diachronous middle to late cretaceous melange obduction on the jurassic sakarya passive margin senonian synchronous southward obduction on the triassic passive margin of anatolia from this it appears that the izmir ankara suture currently separating both terranes is composite and that the passive margin of sakarya is not the conjugate margin of anatolia to the south the cimmerian taurus domain together with the beydaglari domain part of the larger greater apulian terrane were detached from north gondwana in the permian during the opening of the neotethys east mediterranean basin the drifting cimmerian blocks entered into a soft collision with the anatolian and related terranes in the eo cimmerian orogenic phase late triassic thus suturing the paleotethys at that time the taurus plate developed foreland type basins filled with flysch molasse deposits that locally overstepped the lower plate taurus terrane and were deposited in the opening neotethys to the south these olistostromal deposits are characterized by pelagic carboniferous and permian material from the paleotethys suture zone found in the mersin melange the latter as well as the antalya and mamonia domains are represented by a series of exotic units now found south of the main taurus range part of the mersin exotic material was clearly derived from the former north anatolian passive margin huglu type series and re displaced during the paleogene this led us to propose a plate tectonic model where the anatolian ophiolitic front is linked up with the samail baer bassit obduction front found along the arabian margin the obduction front was indented by the anatolian promontory whose eastern end was partially subducted continued slab roll back of the neotethys allowed anatolian exotics to continue their course southwestward until their emplacement along the taurus southern margin mersin and up to the beydaglari promontory antaya mamonia in the latest cretaceous paleocene the supra subduction ocean opening at the back of the obduction front troodos type ocean was finally closed by eocene north south shortening between africa and eurasia this brought close to each other cretaceous ophiolites derived from the north of anatolia and those obducted on the arabian promontory the latter were sealed by a maastrichtian platform and locally never affected by alpine tectonism whereas those located on the eastern anatolian plate are strongly deformed and metamorphosed and affected by eocene arc magmatism these observations help to reconstruct the larger frame of the central tethyan realm geodynamic evolution

rainfall induced debris flows in pyroclastic deposits campania southern italy abstract a combination of empirical and physically based hydrological models has been used to analyze historical data on rainfall and debris flow occurrence in western campania to examine the correlation between rainfall and debris flow events rainfall data from major storms recorded in recent decades in western campania were compiled including daily series from several rain gauges located inside landslide areas supplemented by hourly rainfall data from some of the principal storms a two phase approach is proposed during phase 1 soil moisture levels have been modelled as the hydrological balance between precipitation and evapotranspiration on a daily scale using the method of thornthwaite geograph rev 38 1948 55 phase 2 is related to the accumulation of surplus moisture from intense rainfall leading to the development of positive pore pressures these interactions take place on an hourly time scale by the leaky barrel lb model described by wilson and wiezoreck env eng geoscience 1 1995 11 in combination with hourly rainfall records the lb model has been used to compare hydrological effects of different storms the critical level of retained rain water has been fixed by the timing of debris flow activity related to recorded storm events new rainfall intensity duration thresholds for debris flow initiation in western campania are proposed these thresholds are related to individual rain gauge and assume a previously satisfied field capacity condition the new thresholds are somewhat higher than those plotted by previous authors but are thought to be more accurate and thus need less conservatism

geology and geochronology of the arnea sithonia and ouranopolis intrusions chalkidiki peninsula northern greece abstract the chalkidiki peninsula comprises the greek geotectonic units of the vardar axios zone and the serbo macedonian massif several granitic bodies of various ages intrude this area and many of them are of unknown or disputed age the ages of the arnea sithonia and ouranopolis granitoids are investigated using 40 ar 39 ar stepheated mineral and rb sr whole rock analyses the arnea granite has experienced intense but variable deformation recrystallization and retrogression in general it lacks easily datable minerals because of it s highly evolved silica rich composition however coarse grained phlogopitic mica separated from a minor less evolved porphyritic part of the intrusion yields an excellent 40 ar 39 ar plateau age of 136 1 ma rb sr whole rock samples give a regression line of age 155 11ma and an initial 87 sr 86 sr ratio of 0 7174 0 0017 mswd 280 the scatter may reflect the widespread recrystallization and deformation of the arnea granite the arnea granite is at least late jurassic in age and has undergone regional greenschist metamorphism during the early cretaceous biotite from the sithonia granitoid yields a plateau age of 43 0 6 ma muscovites from crosscutting pegmatites within the granitoid give slightly saddle shaped age spectra with minimum ages of 49 ma and 50 ma suggesting argon 40 excess biotite and muscovite from the ouranopolis granitoid yield plateau ages of 44 1 1 ma and 47 0 7 ma respectively it is suggested that this granitoid is coeval and cogenetic with the sithonia granitoid both intrusions are eocene in age rb sr whole rock samples from the sithonia and ouranopolis granitoids failed to provide any isochrons this is interpreted to be due to inhomogeneities in these young intrusions the age data strongly suggest that the sithonia and ouranopolis granitoids are unrelated to the arnea granite coupled with geochemical and petrographic data these results clarify the relationships between some of the granitic intrusions and have important regional implications

granular flow and viscous fluctuations in low bagnold number granitic magmas recent thermal and fluid dynamical models have shown that density driven ascent of isoviscous granitic melt through the crust in narrow dykes is geologically instantaneous provided the role of suspended crystals is ignored however it is well known that solids in suspension can avect significantly the rheology and hence flow properties of magmas leading to the subjective criticism that granite ascent and emplacement rates based on simple dyke transport models may be unrealistic by estimating the magnitude of shear stresses developed during continuous flow in a 6 m wide granitic dyke we show yield strengths in excess of 10 4 pascals are required to stop flow entirely if the pressure gradient driving the flow is high using granular flow theory we show how fluctuations in particle velocity in the shear field can be used to predict the rheological behaviour of magmas with crystal contents solidosity in the range 0 1 specimen calculations for the solidosity and fluctuation on particle velocity for ascending granitic magmas show that the energy associated with these irregular movements is much greater than that expected on purely brownian grounds we find no clear correlation between viscosity i and the yield strength and while it is possible that magma has curious unexpected bonding properties magmatic suspensions where the grain size is on the scale of centimetres e g some coarsely porphyritic magmas low estimated bagnold numbers c 10 8 render bingham flow models inappropriate self organization of the flow into a crystal poor margin and crystal rich core flow differentiation by diffusion of particles towards the region of minimal shear results in the familiar plug type flow profiles traditionally associated with an inherent yield strength shear enhanced diffusion is an inevitable consequence of granular flow that leads to flow differentiation providing a simple mechanistic explanation for high concentrations of pheoncrysts in the cores of porphyritic dykes bagnold effect deviation from simple newtonian flow is unlikely to be significant until the magma has stopped ascending and emplacement begins

three dimensional shape and emplacement of the cardenchosa deformed pluton variscan orogen southwestern iberian massif the cardenchosa pluton is a lower carboniferous variscan granite located in the southwestern iberian massif it intruded along the contact between the sierra albarrana and azuaga tectonic units to the northwest the pluton connects with the left lateral azuaga fault the pluton appears in the footwall of the low angle normal casa del cafefault which crops out to the west of the granite gravimetric modelling shows the pluton to have a flat bottom at a depth of 2 km strain analysis of post emplacement deformation of the pluton indicates that a the deformation of the pluton accommodates the displacement of the azuaga fault and b the pluton prior to the solid state deformation was a lens shaped laccolith of approximately 10 km diameter and 2 km thickness the cardenchosa pluton was a single pulse of magma trapped in a rheological discontinuity of the upper crust the contact between the sierra albarrana and azuaga units the magma would ascend through dikes since no root has been detected the tectonic scenario during the intrusion was one of regional extension 2000 elsevier science ltd all rights reserved

timing of tectonic emplacement of the ophiolites and terrane paleogeography in the hellenides the timing of tectonic emplacement of the ophiolites is analyzed in the four oceanic terranes of the hellenides h2 h4 h6 h8 the criteria for this analysis are based on a the post emplacement sedimentary cover or intrusive rocks b the syn emplacement tectonostratigraphic formations and c the youngest rocks involved in the structure of the autochthon and the allochthon unit in each case the timing becomes younger towards the more external tectonic units of the hellenides with i late eocene oligocene age in the external ophiolite belt of the pindos cyclades oceanic terrane h2 ii late jurassic early cretaceous age in the internal ophiolite belt of the vardar axios oceanic terrane h4 iii post liassic pre late jurassic age in the ophiolites of lesvos circum rhodope oceanic terrane h6 and iv pre late jurassic age in the ophiolites of volvi eastern rhodope terrane h8 an ophiolite obduction model can be applied with the ophiolitic nappes always emplaced on top of pre alpine continental terranes with mesozoic shallow water carbonate platforms the geometry of the continental terranes drifting during the mesozoic within the tethys ocean controls the number and dimensions of the tethyan oceanic basins where a continental terrane dies out the two adjacent oceanic basins merge into one larger basin this seems to be the case of the pelagonian terrane h3 which is terminated north of skopje where the pindos oceanic basin h2 merges with the vardar axios oceanic basin h4

debris flow triggering characterization through a comparative analysis among different mountain catchments abstract the research focuses on the assessment of the conditions for debris flow triggering in three very active mountain catchments the study areas are the following rudan torrent vodo di cadore mount antelao in the dolomites italy chiesa torrent pieve di livinallongo mount col di lana in the dolomites italy and rebaixader torrent border between the regions of catalonia and aragon axial pyrenees area spain due to the differences among these basins and related source areas where debris flows originate the knowledge on the link between geomorphic conditions and driving mechanisms for debris flow activation is outlined the study of debris flow initiation is carried out through a hydrological approach and a slope stability analysis the hydrological analysis is supported by the calibration of intensity duration curves of triggering rainfalls coupled with a distributed rainfall runoff model the analysis is corroborated using literature equations to compute critical discharges for sediment motion at the different levels of terrain deformation the main results highlight the following i a quite narrow range of triggering water discharges 0 03 0 16 m3 s and shear stresses 267 413 n m2 promoting a new insight on the specific hazard mitigation ii the quantification of a second stage of bed breakage in some circumstances capable of amplifying the debris flow magnitude and iii a minimum critical rainfall duration needed to effectively entrain the phenomenon 12 22 min that might help to define more precise alert conditions finally the geomorphologic differences among basins revealed two main typologies in terms of driving the triggering mode flow rate dominant in the rudan type basins and mixed flow rate plus slope stability conditioned in the chiesa rebaixader type basins

application of geophysical measurements for assessing the role of fissures in water infiltration within a clay landslide trieves area french alps rainfall and its consequences are usually considered as the major factor triggering slope instabilities within clay deposits the link between rainfall water infiltration and landslide activity may be complex and comprehensive sets of data are still necessary to understand how water infiltrates in cohesive material on unstable slopes made of fine grained sediments gravitational deformation generates superficial shear ruptures and tension fissures whose continuous opening could be amplified by shrinkage during dry periods this fissure network at the surface can be very dense and strongly controls the water infiltration process however it remains difficult to assess the fissure evolution at depth and its eventual relationship with shallow slip surfaces this work presents the results of a geophysical study which aimed to characterize the fissures that are observed along the unstable clay slopes of the trieves area french alps the site was first investigated combining geomorphological analysis drilling borehole logging geotechnical tests and geophysical experiments this investigation evidenced the presence of at least three rupture surfaces at 5 10 15 and 42 m with a water flow at the second one in a second step permanent instruments were installed piezometers and soil water content probes results indicate high water infiltration velocities down to the water table located at 2 5 m depth that are likely to be linked with sub vertical preferential paths such as fissures geophysical parameters electrical resistivity s wave velocities and rayleigh waves attenuation were monitored geophysical results suggest that fissures are permanently open that they serve as preferential infiltration paths and that they can reach at least a depth of 2 m the methods employed in this research put forward that the system of imbricated fissures drains water from the surface down to the shallow slip surfaces at 5 and 10 15 m this work highlights the role of fissures network in water infiltration in the numerous clay landslides of the trieves area copyright 2011 john wiley sons ltd

scaling properties of rainfall induced landslides predicted by a physically based model abstract natural landslides exhibit scaling properties revealed by power law relationships these relationships include the frequency of the size e g area volume of the landslides and the rainfall conditions responsible for slope failures in a region reasons for the scaling behavior of landslides are poorly known we investigate the possibility of using the transient rainfall infiltration and grid based regional slope stability analysis code trigrs a consolidated physically based numerical model that describes the stability instability conditions of natural slopes forced by rainfall to determine the frequency statistics of the area of the unstable slopes and the rainfall intensity i duration d conditions that result in landslides in a region we apply trigrs in a portion of the upper tiber river basin central italy the spatially distributed model predicts the stability instability conditions of individual grid cells given the local terrain and rainfall conditions we run trigrs using multiple synthetic rainfall histories and we compare the modeling results with empirical evidences of the area of landslides and of the rainfall conditions that have caused landslides in the study area our findings revealed that trigrs is capable of reproducing the frequency of the size of the patches of terrain predicted as unstable by the model which match the frequency size statistics of landslides in the study area and the mean rainfall d i conditions that result in unstable slopes in the study area which match rainfall i d thresholds for possible landslide occurrence our results are a step towards understanding the mechanisms that give rise to landslide scaling properties

development of concepts concerning the genesis and emplacement of tethyan ophiolites in the eastern mediterranean and oman regions this article uses evidence mainly from the eastern mediterranean and oman to help understand the origin and emplacement of ophiolites field studies in these regions emphasize the diversity of ophiolite related sedimentary and tectonic processes topics to be discussed here include the sedimentary covers of ophiolites their metamorphic soles related melanges and emplaced continental margin slope rise units modes of ophiolite emplacement will also be considered and tectonic reconstructions that have a direct bearing on the origin and emplacement of ophiolites the writer argues that there is compelling evidence that many ophiolites formed by spreading above intraoceanic subduction zones evidence from their intact sedimentary covers however indicates that such subduction was only incipient in most cases as directly associated volcanic arcs or back arc basins are rare metamorphic soles record fragments of oceanic lithosphere derived from settings ranging from open ocean to continental slope rise settings underlying melanges record the subduction of most of the ocean lithosphere formed at spreading ridges continental margin units beneath ophiolites demonstrate that these ophiolites were formed in ocean basins that were mainly initiated by continental rifting in the eastern mediterranean and oman regions ophiolite emplacement was commonly achieved by trench margin collision although strike slip transpression and large scale accretion along subducting margins played a role in some cases taking account of the mesozoic palaeotectonic setting of the eastern mediterranean region it is widely believed that ophiolites of two main ages mid jurassic and late cretaceous were formed in several small oceanic basins separated by rifted microcontinents the history of tethys in pre mesozoic time remains more open to question lastly giant subduction related ophiolites as in oman cyprus or the balkans may not be forming anywhere in the world ocean today but may instead relate to rare events in earth history when regional to global plate boundaries were drastically reorganised

neotethys closure history of anatolia insights from 40ar 39ar geochronology and p t estimation in high pressure metasedimentary rocks the multiple high pressure hp low temperature lt metamorphic units of western and central anatolia offer a great opportunity to investigate the subduction and continental accretion related evolution of the eastern limb of the long lived aegean subduction system recent reports of the hp lt index mineral fe mg carpholite in three metasedimentary units of the gondwana derived anatolide tauride continental block namely the afyon zone the oren unit and the southern menderes massif suggest a more complicated scenario than the single continental accretion model generally put forward in previous studies this study presents the first isotopic dates white mica 40ar 39ar geochronology and where possible are combined with p t estimates chlorite thermometry phengite barometry multi equilibrium thermobarometry on carpholite bearing rocks from these three hp lt metasedimentary units it is shown that in the afyon zone carpholite bearing assemblages were retrogressed through greenschist facies conditions at c 67 62 ma early retrograde stages in the oren unit are dated to 63 59 ma in the kurudere nebiler unit hp mesozoic cover of the southern menderes massif hp retrograde stages are dated to c 45 ma and post collisional cooling to c 26 ma these new results support that the oren unit represents the westernmost continuation of the afyon zone whereas the kurudere nebiler unit correlates with the cycladic blueschist unit of the aegean domain in western anatolia three successive hp lt metamorphic belts thus formed the northernmost tavsanli zone c 88 82 ma the oren afyon zone between 70 and 65 ma and the kurudere nebiler unit c 52 45 ma the southward younging trend of the hp lt metamorphism from the upper and internal to the deeper and more external structural units as in the aegean domain points to the persistence of subduction in western anatolia between 93 90 and c 35 ma after the accretion of the menderes tauride terrane in eocene times subduction stopped leading to continental collision and associated barrovian type metamorphism because by contrast the aegean subduction did remain active due to slab roll back and trench migration the eastern limb below southwestern anatolia of the hellenic slab was dramatically curved and consequently teared it therefore is suggested that the possibility for subduction to continue after the accretion of buoyant e g continental terranes probably depends much on palaeogeography

metamorphic evolution and geochemistry of kyanite eclogites in central rhodope northern greece in central rhodope of northern greece kyanite eclogites were discovered in the area of thermes they are strongly overprinted and exhibit a multi stage development of minerals and mineral assemblages formed during successive stages of the exhumation the initial high pressure assemblage was garnet omphacite kyanite zoisite phengite rutile quartz corundum fe mg spinel sapphirine and hogbomite occur as products of a first high temperature overprint still at high pressures whereas various symplectites corundum plagioclase pl spinel pl sapphirine pl clinopyroxene pl biotite pl amphibole pl grew during subsequent stages of the exhumation diablastic amphibole plagioclase formed as end products of the amphibolitization according to geochemical data the protoliths of the kyanite eclogites were basalts to basaltic andesites with volcanic arc affinities for the high pressure stage of metamorphism minimum pt conditions were around 19 kbar 700 c while for the initial stages of the overprint high pressure granulite facies conditions prevailed t 800 c at p 15 kbar the pt conditions of the amphibolite facies were 8 11 kbar 580 690 c the kyanite eclogites of thermes record the highest temperatures of metamorphism within the whole of rhodope

a comparative analysis of terrain stability models for predicting shallow landslides in colluvial soils abstract most of the slopes of the hilly areas of the apennines are composed of colluvial soils originating from the weathering of the bedrock and down slope transportation shallow slides affect this superficial cover depend largely on the surface topography and are a recurrent problem sinmap and shalstab are terrain stability models that combine steady state hydrology assumptions with the infinite slope stability model to quantify shallow slope stability they have a similar physical basis but they use different indices to quantify instability the purposes of this study are to test and compare the approaches of sinmap and shalstab models for slope stability analysis and to compare the results of these analyses with the locations of the shallow landslides that occurred on november 2002 in an area of the oltrepo pavese northern apennines the territory of s giuletta characterized by clayey silty colluvial soils represents the test site the digital elevation model was constructed from a 1 5000 scale contour map and was used to estimate the slope of the terrain as well as the potential soil moisture conditions in situ and laboratory tests provided the basis for measuring values for soil hydraulic and geotechnical parameters moisture content soil suction atterberg limits methylene blue dye adsorption hydraulic conductivity soil thickness was extracted from a soil database an inventory of landslide from interpretation of aerial photographs and field surveys was used to document sites of instability mostly soil slips and to provide a test of model performance by comparing observed landslide locations with model predictions the study discusses the practical advantages and limitations of the two models in connection with the geological characteristics of the studied area which could be representative of similar geological contexts in the apennines

regolith structure analysis a contribution to understanding the local occurrence of shallow landslides austrian tyrol abstract this study focuses on shallow landslides on alpine slopes usually triggered by extreme rainfall events or rapid snowmelt shallow landslides cause soil loss of agricultural land and can even induce larger mass movements to estimate shallow landslide susceptibility it is crucial to understand the interactions of the conditioning factors the structure of the shallow subsurface regolith represents the least well known variable hydrological characteristics of the slope and its resulting stability depend very much on the structure and thickness of the regolith however conditions of the shallow subsurface have hitherto not been investigated in detail due to difficulties in area wide data collection by adapting a common method from engineering sciences our research provides new insights into the small scale structure of a regolith body on an alpine slope in the inner schmirn valley tyrol austria we carried out field measurements by applying densely spaced lightweight dynamic cone penetrometer tests dcpt on a test site of 30 m by 30 m to cope with the three dimensional 3d characteristics of the regolith body we suggest the application of a 3d volumetric lattice voxel model for the analysis of patterns and variations in the penetration resistance we propose a spatial interpolation by the regularized spline with tension rst method we approximated three different geotechnical parameters i the thickness of the local regolith ii the penetration resistance within the regolith and iii the surface of the solid bedrock an exploratory analysis allowed us to describe surface and bedrock morphology and to detect discontinuities in the regolith in the immediate vicinity of the landslide in addition we were able to establish a distinct spatial relation of the derived geotechnical parameters and slope failure the proposed method was developed tested and verified in an individual case study but the results indicate a great potential for future applications in shallow landslide susceptibility analysis the findings of this study improve knowledge on the relation between shallow subsurface structure and the occurrence of shallow landslides they also allow predictions about the potential evolvement of existing shallow landslides through secondary gliding processes

regional hydrological thresholds for landslides and floods in the tiber river basin central italy the definition of landslide warning thresholds based on the analysis of hydrological data is proposed in the tiber river basin of central italy historical information on landslides and floods for the period 1918 1990 was available from a nationwide bibliographical and archive inventory on geohydrological catastrophes hydrological data were obtained from mean daily discharge records at various gauging stations within the basin several hundred hydrological events broadly defined as a series of consecutive days having mean daily discharge exceeding a predefined value were identified hydrological parameters obtained from the discharge records were used to rank the events according to their probability to trigger mass movements or inundations and to define regional thresholds for the occurrence of landslides and floods the proposed approach not lacking limitations has conceptual and operational advantages among which is the possibility of using historical information on geohydrological catastrophes

landslide triggering scenarios in homogeneous geological contexts the area surrounding acri calabria italy abstract the paper describes a methodology to detect landslide triggering scenarios in geological homogeneous areas and for some specific landslide categories in these scenarios the rainfall landslide relationship as well as the pluviometric load conditions influencing slope instability have to be investigated the methodology is applied to an area located in northern calabria italy and affected by widespread and different slope instability phenomena outcropped fractured and deeply weathered crystalline rock masses determining geologic homogeneous conditions are present in the same area suitable and homogeneous climatic features have also been found according to the methodology adopted the hydrologic analysis of rainfall time series is initially carried out notwithstanding historical data concerning landslide mobilization but using simple models to determine critical pluviometric scenarios for the three landslide categories shallow medium deep and deep landslide triggering scenarios individualized according to this procedure are less significant as compared to the landslide mobilization detected in the study area by means of historical research and ascribed to the three landslide categories according to geomorphologic analysis subsequently the possible landslide triggering scenarios are outlined by carefully investigating the hydrologic analysis limited to the periods identified according to the historical data in the study area and approximately for all the areas characterized by the outcrop of fractured and deeply weathered crystalline rocks significant triggering scenarios can be outlined in particular shallow landslide triggers could be activated by rainfall events with intensities exceeding 90 mm day and or with amounts exceeding 160 mm as for medium deep and deep landslides triggering mechanisms are more complicated and effective rainfall contribution must be taken into account compared to groundwater storage moreover a more complex link between deep landslides and precipitation is confirmed the results obtained to date highlight the potential of this methodology which enables us to define and progressively improve the knowledge framework by means of a work sequence integrating different disciplinary tools and results

the three metamorphic belts of the hellenides a review and a kinematic interpretation summary new results obtained in the three metamorphic belts of the hellenides suggest that each belt has a different structure geotectonic setting and evolution the external metamorphic belt of peloponnesus crete has probably resulted from nappe movement in the vicinity of an evolving island arc system the blueschists occurring within this external belt are allochthonous and have been transported with other nappes over the external carbonate platform of the pre apulian plattenkalk ionian tripolitza almyropotamos units this implies that there was only one true blueschist domain initiated in the cycladic area during early eocene the kinematic interpretation is based on the distinction of a and b structures and on the nature of the shear zones between the different domains especially that between the metamorphic hellenides below and the non metamorphic hellenides above the existence of the probably lower palaeozoic meta sedimentary sequence of kastoria in the northern pelagonian zone indicates that the overlying ophiolite bearing almopias unit has been derived from within the hercynian domain the kastoria sedimentary sequence the ophiolites of vertiskos and the carbonate platform of pangeon are considered to be most likely elements of a probable hercynian orogeny

susceptibility and triggering scenarios at a regional scale for shallow landslides abstract the work aims at identifying susceptible areas and pluviometric triggering scenarios at a regional scale in calabria italy with reference to shallow landsliding events the proposed methodology follows a statistical approach and uses a database linked to a gis that has been created to support the various steps of spatial data management and manipulation the shallow landslide predisposing factors taken into account are derived from i the 40 m digital terrain model of the region an 15 075 km2 extension ii outcropping lithology iii soils and iv land use more precisely a map of the slopes has been drawn from the digital terrain model two kinds of covers prevalently coarse grained cg cover or fine grained fg cover were identified referring to the geotechnical characteristics of geomaterial covers and to the lithology map soilscapes were drawn from soil maps and finally the land use map was employed without any prior processing subsequently the inventory maps of some shallow landsliding events totaling more than 30 000 instabilities of the past and detected by field surveys and photo aerial restitution were employed to calibrate the relative importance of these predisposing factors the use of single factors first level analysis therefore provides three different susceptibility maps second level analysis however enables better location of areas susceptible to shallow landsliding events by crossing the single susceptibility maps on the basis of the susceptibility map obtained by the second level analysis five different classes of susceptibility to shallow landsliding events have been outlined over the regional territory 8 9 of the regional territory shows very high susceptibility 14 3 high susceptibility 15 moderate susceptibility 3 6 low susceptibility and finally about 58 very low susceptibility finally the maps of two significant shallow landsliding events of the past and their related rainfalls have been utilized to identify the relevant pluviometric triggering scenarios by using 205 daily rainfall series different triggering pluviometric scenarios have been identified with reference to cg and fg covers a value of 365 mm of the total rainfall of the event and or 170 mm d of the rainfall maximum intensity and a value of 325 mm of the total rainfall of the event and or 158 mm d of the rainfall maximum intensity are able to trigger shallow landsliding events for cg and fg covers respectively the results obtained from this study can help administrative authorities to plan future development activities and mitigation measures in shallow landslide prone areas in addition the proposed methodology can be useful in managing emergency situations at a regional scale for shallow landsliding events triggered by intense rainfalls through this approach the susceptibility and the pluviometric triggering scenario maps will be improved by means of finer calibration of the involved factors

geomorphic process rates of landslides along a humidity gradient in the tropical andes areas with high landslide activity and diversity were encountered in the tropical andes of southern ecuador under contrasting semi arid to perhumid climatic conditions the objective of this study was to determine and compare geomorphic process rates of shallow landslides along this remarkable humidity gradient and subject to different types of human made and natural environmental changes geomorphic work geomorphic power and landslide mobilization rate lmr were therefore calculated for shallow landslides in two study areas with two separate geological or land use related subareas each while landslide ages were known in the perhumid reserva biologica san francisco rbsf area only an approximation of the frequency of critical landslide triggering rainfall events was available for the semi arid masamanaca area landslide volumes were estimated by volume area scaling generalized additive models gams were used as landslide susceptibility models in order to analyze the relative importance of topography and to downscale lmr values to a fine spatial resolution lmr in the perhumid rbsf area ranged from 2 mm yr 1 in the natural part of this area with tropical mountain rainforests to 5 mm yr 1 in the human influenced part the semi arid masamanaca area though subject to greater estimation uncertainties displayed lmr on the order of 0 4 to 4 mm yr 1 for shallow landslides the results provide a basis for the spatially differentiated assessment of landscape evolution and degradation in an area with a close relation between landslide activity natural vegetation succession and human land use

map view restoration of aegean west anatolian accretion and extension since the eocene 1 the aegean region greece western turkey is one of the best studied continental extensional provinces here we provide the first detailed kinematic restoration of the aegean region since 35 ma the region consists of stacked upper crustal slices nappes that reflect a complex paleogeography these were decoupled from the subducting african adriatic lithospheric slab especially since 25 ma extensional detachments cut the nappe stack and exhumed its metamorphosed portions in metamorphic core complexes we reconstruct up to 400 km of trench perpendicular ne sw extension in two stages from 25 to 15 ma the aegean forearc rotated clockwise relative to the moesian platform around euler poles in northern greece accommodated by extensional detachments in the north and an inferred transfer fault se of the menderes massif the majority of extension occurred after 15 ma up to 290 km by opposite rotations of the western and eastern parts of the region simultaneously the aegean region underwent up to 650 km of post 25 ma trench parallel extension leading to dramatic crustal thinning on crete we restore a detachment configuration with the mid cycladic lineament representing a detachment that accommodated trench parallel extension in the central aegean region finally we demonstrate that the sakarya zone and cretaceous ophiolites of turkey cannot be traced far into the aegean region and are likely bounded by a pre 35 ma n s fault zone this fault became reactivated since 25 ma as an extensional detachment located west of lesbos island the paleogeographic units south of the izmir ankara sava suture however can be correlated from greece to turkey

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

a multi annual landslide inventory for the assessment of shallow landslide susceptibility two test cases in vorarlberg austria abstract geomorphological landslide inventories provide crucial input data for any study on the assessment of landslide susceptibility hazard or risk several approaches for assessing landslide susceptibility have been proposed to identify areas particularly vulnerable to this natural hazard what they have in common is the need for data of observed landslides therefore the first step of any study on landslide susceptibility is usually the compilation of a geomorphological landslide inventory using a geographical information system recent research has proved the feasibility of orthophoto interpretation for the preparation of an inventory aimed at the delineation of landslides with the use of distinctive signs in the imagery data in this study a multi annual landslide inventory focusing on shallow landslides i e translational soil slides of 0 2 m in depth was compiled for two study areas in vorarlberg austria from the interpretation of nine orthophoto series in addition derivatives of two generations of airborne laser scanning data aided the mapping procedure landslide scar areas were delineated on the basis of a high resolution differential digital terrain model the derivation of landslide volumes depths and depth to length ratios are discussed results show that most mapped landslides meet the definition of a shallow landslide the inventory therefore provides the data basis for the assessment of shallow landslide susceptibility and allows for the application of various modelling techniques

a warning system for rainfall induced shallow failures abstract it is widely recognised that soil slips and debris flows are triggered by short intense storms owing its geologic geomorphologic and climatic settings the piedmont region nw italy is highly prone to the occurrence of this kind of landslides in the last two centuries in fact a total of 105 severe meteoric events which triggered shallow failures occurred and of these 18 events took place from 1990 to 2002 a fair number of rainfall thresholds have been proposed in the literature defined both on empirical or on physical bases empirical thresholds are defined collecting rainfall data for landslide meteoric events and for events without landslides while physical thresholds are based on numerical models that consider the relation between rainfall pore pressure and slope stability the main objective of this paper is the identification of the empirical triggering thresholds for the piedmont region four meteoric events were selected and analysed november 4 5 1994 july 7 8 1996 april 27 30 2000 october 13 16 2000 because they supply a wide range of variation for both rainfall parameters duration intensity cumulative rainfalls and the number of induced landslides in the intensity duration plot the critical limit is described by the equation i 19d 0 50 where i rainfall intensity expressed in mm h and d rainfall duration expressed in hours such a limit is traced to envelop 90 of the points on the graph in the ni d diagram the triggering thresholds are given by the equations ni 0 76d 0 33 and ni 4 62d 0 79 where ni normalised intensity with respect to the annual precipitation map expressed in mm h pma 100 in the article the different meaning of these thresholds is discussed finally the diagram ni ncr is proposed the triggering threshold is given by the expression ni 0 09ln ncr 0 54 where ncr is the normalised cumulative critical rainfall mm pma 100 the application of the triggering thresholds as a fundamental element in a warning system dedicated to the safeguarding of population in landslide prone areas is discussed in detail an operating procedure which is presently being verified and tested in the studied area is described

tectonic sedimentary evolution of the western margin of the mesozoic vardar ocean evidence from the pelagonian and almopias zones northern greece

global positioning system constraints on plate kinematics and dynamics in the eastern mediterranean and caucasus we present and interpret global positioning system gps measurements of crustal motions for the period 1988 1997 at 189 sites extending east west from the caucasus mountains to the adriatic sea and north south from the southern edge of the eurasian plate to the northern edge of the african plate sites on the northern arabian platform move 18 2 mm yr at n25 5 w relative to eurasia less than the nuvel 1a circuit closure rate 25 1 mm yr at n21 7 w preliminary motion estimates 1994 1997 for stations located in egypt on the northeastern part of africa show northward motion at 5 6 2 mm yr also slower than nuvel ia estimates 10 1 mm yr at n2 4 e eastern turkey is characterized by distributed deformation while central turkey is characterized by coherent plate motion internal deformation of 2 mm yr involving westward displacement and counterclockwise rotation of the anatolian plate the anatolian plate is de coupled from eurasia along the right lateral strike slip north anatolian fault naf we derive a best fitting euler vector for anatolia eurasia motion of 30 7 0 8 n 32 6 0 4 e 1 2 0 1 myr the euler vector gives an upper bound for naf slip rate of 24 1 mm yr we determine a preliminary gps arabia anatolia euler vector of 32 9 1 2 n 40 3 1 1 e 0 8 0 2 myr and an upper bound on left lateral slip on the east anatolian fault eaf of 9 1 mm yr the central and southern aegean is characterized by coherent motion internal deformation of 2 mm yr toward the sw at 30 1 mm yr relative to eurasia stations in the se aegean deviate significantly from the overall motion of the southern aegean showing increasing velocities toward the trench and reaching 10 1 mm yr relative to the southern aegean as a whole

the geodynamic evolution of the alpine orogen in the cyclades aegean sea greece insights from diverse origins and modes of emplacement of ultramafic rocks

evidence for significant granite space creation by the ballooning mechanism the example of the ardara pluton ireland the emplacement mechanism of the ardara granite a caledonian pluton located on the northwestern seaboard of ireland has been a widely cited and a key point of reference in the debate about the granite space problem for nearly half a century early models related its subcircular tailed shape concentric foliation pattern and concentrically deformed envelope to diapirism it was subsequently reinterpreted using strain data as a ballooning pluton that was created by 70 in situ expansion at the emplacement site and was later cut by a regional shear zone recently it was the leading example in a wide ranging review of forcefully emplaced plutons of this type and was reinterpreted as a series of nested diapirs associated with only modest amounts 30 of forceful space creation but a large component of inferred early block stoping we report the results of the complete remapping and extensive collection of new structural data from this 8 km diameter normally zoned three phase calc alkaline pluton we confirm the existence of the steeply inclined internal foliation pattern and that it was formed in the magmatic state although this and the outline of the pluton are modified by late stage high temperature solid state regional transcurrent shear zones along two of the pluton contacts structural mapping has failed to identify a macroscopic lineation in the magmatic foliation planes and this is confirmed by strain determinations using mafic enclave populations and magmatic crystal separations for the magmatic state deformation that show nearly pure flattening type strains k 0 strains measured by these techniques show an apparently smooth gradient increasing outward toward the pluton contacts from an inner low strain zone we argue that these features together with the simple normal petrographic zonation a lack of small scale structures that would indicate the pluton had moved up relative to the wall rocks and an exposure level that is not in the roof zone are inconsistent with diapirism either singly or multiply but are most easily explained by a ballooning emplacement mechanism synmagmatic shear sense data from both the pluton and the adjacent country rocks indicate however that within the overall context of radial ballooning there was a limited amount of late stage nonradial northward injection of magma an inversion of the deformed enclave and crystal spacing strain determinations and strain determinations within the country rocks suggest that more than 80 of the volume of the pluton was accommodated by the ballooning mechanism

heterogeneous mantle complex crustal processes and obduction kinematics in a unified pindos vourinos ophiolitic slab northern greece

assessing the contribution of roots to the strength of undisturbed slip prone soils summary field observations indicate that slippage of entire portions of the soil mantle on hillsides increases when natural vegetation is altered it has often been hypothesized that reductions in soil reinforcement by roots result from disturbance of vegetation thereby causing the volume of soil slippage on mountains to increase direct methods for assessing the effects of roots on the resistance of soil to slipping require comparison of strengths of root permeated to otherwise identical root free soils various tests under controlled conditions show that the maximum soil reinforcement by root systems of many plant species can be considerable nonetheless direct assessments of the influence of roots on soil strength throughout unstable natural hillsides have been elusive owing to the difficulty of obtaining suitably comparable root permeated and root free samples in heterogeneous soils we describe a method for assessing the magnitude of the contribution of roots to the strength of soil by direct shear tests on otherwise identical root permeated and root free undisturbed soil samples of disparate volumes the effect of sample size on strength estimations of undisturbed soil is discussed

mid ocean ridge and supra subduction affinities in the pindos ophiolites greece implications for magma genesis in a forearc setting abstract the pindos ophiolitic massif is considered an important key area within the albanide hellenide ophiolitic belt and is represented by two tectonically distinct ophiolitic units 1 a lower unit including an intrusive and a volcanic section and 2 an upper ophiolitic unit mainly including mantle harzburgites both units share similar metamorphic soles and tectono sedimentary melanges at their bases the intrusive section of the lower unit is composed by an alternation of troctolites with various ultramafic rock types including dunites lherzolites olivine websterites olivine gabbros anorthositic gabbros gabbros and rare gabbronorites the volcanic and subvolcanic sequence of the lower unit can geochemically be subdivided into three groups of rocks 1 basalts and basaltic andesites of the lower pillow section showing a clear high ti affinity 2 basaltic andesites of the upper pillow section with high ti affinity but showing many geochemical differences with respect to the first group 3 very low ti boninitic basaltic and basaltic andesitic lava flows separating the lower and upper pillow sections and dykes widespread throughout the pindos ophiolites these different magmatic groups originated from fractional crystallization from different primary magmas which were generated in turn from partial melting of mantle sources progressively depleted by previous melt extractions group 1 volcanics may have derived from partial melting ca 20 of an undepleted lherzolitic source while group 2 basaltic rocks may have derived from partial melting ca 10 of a mantle that had previously experienced mid ocean ridge basalt morb extraction finally the group 3 boninites may have derived from partial melting ca 12 17 of a mantle peridotite previously depleted by primary melt extraction of groups 1 and 2 primary melts in order to explain the coexistence of these geochemically different magma groups two petrogenetic models formerly proposed for the albanian ophiolites are discussed

geotechnical aspects of soil slips in alpine regions abstract slope movements are due to many different causes numerous investigations carried out during the last ten years have led to the supposition that almost all slope movements and particularly those occurring in soils are conditioned by a significant combination of factors for the alpine regions quantity duration and kind of precipitation have to be considered as direct mechanical causes combined with such contributing factors as geological and soil mechanical properties aspect vegetation slope inclination and slope morphology they will determine the type dimensions and process of slope movements the detailed investigation of 140 slope movements in slightly cohesive soils show that the process of movement is represented by sliding and flow events in particular it was found out that shallow scars with planar slides predominate so that the supposition of an infinite slope model for slope stability appears to be justified in many cases debris flows and debris avalanches continued downslope of the source area of the scars

regionalization of rainfall thresholds an aid to landslide hazard evaluation rainfall soil properties and morphology are major factors controlling shallow landsliding a series of meteorological events that triggered soil slips in northern italy were studied to define rainfall thresholds and to evaluate a possible regionalization soil properties triggering rainfall and local lithological and morphometrical settings of different sites were used as input to an infiltration model the approach allows the recognition of several triggering conditions in the piedmont pre alpine and alpine regions this suggests the need for different rainfall thresholds with respect to those derived with other methods intensity versus rainfall duration relationships become particularly important when related to soil permeability and thickness and demonstrate the role of antecedent precipitation events with exceptional water discharge from obstructed road culverts reveal the role played by anthropic structures in triggering such phenomena different approaches to slope stability analysis are shown taking into account bedrock lithology topography seepage and local saturation conditions

pore pressure generation and fluidization in a loess landslide triggered by the 1920 haiyuan earthquake china a case study abstract during the 1920 haiyuan earthquake numerous catastrophic landslides were triggered in the loess area in northwest china we investigated in detail a large example of these landslides referred to as dangjiacha landslide in this paper this landslide originated from a slope of about 20 and the displaced soil mass traveled about 3200 m damming a valley we performed a field survey and found that standing water existed in the landslide area and the loess had high porosity we infer that it was the liquefaction of the water saturated loess layer rather than the suspension of silt in the pore air in the loess that caused the great mobility of this landslide to test this inference we performed undrained triaxial compression and ring shear tests on loess samples to examine the shear behavior of loess saturated by either air or water the test results showed that the water saturated loess soil was highly susceptible to flow liquefaction failure fast shear tests on naturally air dried loess samples revealed that the generated pore air pressure was small under the undrained condition and no significant reduction in the shear resistance was observed implying that air entrapped in the loess was unlikely to be the main contributor to the high mobility of this large scale landslide