deep seated gravitational slope deformations related landslides and tectonics abstract deep seated gravitational slope deformations and their relationships with tectonic deformation of rocks is considered to examine the viewpoint of tectonics as a causative factor in slope deformation first a distinction is made between the different types of deep seated gravitational slope deformation then the geomorphological and structural effects of the different macrostructural deformations induced by tectonics on the scale of the whole deforming ridge is briefly discussed finally some case studies that represent either verified or possible cases of gravity deformation in response to tectonic activity are used as illustration

a neolithic yew bow in the polish carpathians evidence of the impact of human activity on mountainous palaeoenvironment from the kamiennik landslide peat bog abstract a unique artefact the fragment of a bow made of yew wood indicating the hunting activity of prehistoric man was found within the sediments of the landslide peat bog at the depth of 330 cm formed on the mt kamiennik polish flysch carpathians the datings of this artefact using 14 c method at ca 3790 3380 cal bc indicate its connection with the activity of the neolithic man related to the funnel beaker culture in the sequence of the peat bog deposits formed since the atlantic phase the palaeoclimatic changes of the middle and late holocene as well as traces of human impact in these and subsequent periods were recorded and analysed using palynological macrofossils lithological methods and dated with radiocarbon palaeoenvironmental changes identified in the peat horizon bearing the artefact were marked by the delivery of minerogenic high energy deposits with charcoal to the peat bog as well as distinct changes of plant communities these phenomena confirm a significant human impact caused by the prehistoric man on landslide areas on the other hand the study confirms significant importance of climatic condition for human activity and proves that landslide peat bog deposits are very sensitive records of palaeoenvironmental changes the archaeological artefact essentially supplements the results of our interdisciplinary palaeoenvironmental study it is one of the rare neolithic bows found in the area of europe till now

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

some forms of mountain peaks in the canadian rockies controlled by their rock structure abstract different mountain shapes in sedimentary sequences in the canadian rockies were enhanced by glacial erosion and have been modified post glacially by gravity driven slope processes slope modification by both glacial erosion and post glaciation landslides is related to slope geometry and rock structure particularly bedding dip five mountain peak shapes in monoclinal sequences each fall into different ranges of bedding dips 1 castellate and 2 matterhorn mountains occur in sub horizontal beds and their slopes are generally 35 65 and oblique to both bedding and joints 3 cuestas develop in gently to moderately dipping beds dip slopes and steeper normal escarpments form their cataclinal and anaclinal sides respectively with the dihedral angle between them about 90 4 hogbacks in moderately to steeply dipping beds have similar slope angles on both cataclinal and anaclinal slopes cataclinal slopes are either dip slopes or underdip slopes but anaclinal slopes are often steepened escarpments the dihedral angle between the slopes is usually slope gradients on a sample of 34 peaks are closely related to landslides particularly rock slides and rock topples these landslide modes are controlled by bedding dips

dynamic crystallization of chondrule melts of porphyritic and radial pyroxene composition abstract dynamic crystallization experiments in which heterogeneous nucleation is an important variable have been completed on four melts of chondrule composition compositions were chosen to best represent chondrules with porphyritic pyroxene and radial pyroxene textures experimental results show that heterogeneous nucleation is essential for the formation of porphyritic textures without preexisting nuclei too much supercooling is established before crystallization is initiated and the textures are more likely to be dendritic or radial in the near total absence of nuclei radial textures can form at cooling rates as slow as 5 c hr in this study by varying the heterogeneous nucleation conditions and having a melt in which the appropriate phases are stable or metastable analogs to most of the recognized chondrule textures can be produced in a single melt composition olivine inclusions in pyroxene can form readily during an experiment from a starting material which did not initially contain olivine crystals thus care must be taken in the assumption that olivine inclusions in pyroxene represent preexisting crystals

programmed cooling experiments in the system mgo sio2 kinetics of a peritectic reaction programmed cooling experiments with compositions in the system mgo sio 2 ranging from 59 wt sio 2 with olivine on the liquidus to 63 wt sio 2 with protoenstatite on the liquidus cooled at rates of from 0 4 to 25 min crystallize forsterite but not pyroxene because pyroxene does not nucleate the forsterite plus melt reaction does not take place allowing forsterite to crystallize metastably at sub solidus temperatures a 65 1 wt sio 2 composition with cristobalite on the liquidus crystallizes a number of different phases depending on cooling rate and initial superheating the ease of forsterite nucleation relative to pyroxene offers an explanation for the occurrence of olivine instead of low ca pyroxene in the groundmass of tholeiitic basalts modified journal abstract

crystal morphologies in pillow basalts implications for mid ocean ridge processes abstract we present the results of a detailed petrological study of a sparsely phyric basalt mapco ch98 dr11 dredged along the mid atlantic ridge 30 41 n the sample contains microphenocrysts of olivine that display four different rapid growth morphologies comparison of these morphologies with those obtained in dynamic crystallization experiments allows us to constrain the thermal history of the sample the dendritic morphology swallowtail chain and lattice olivine is directly related to the final quenching during magma seawater interaction in contrast the three other morphologies namely the complex polyhedral crystal the closed hopper and the complex swallowtail morphology result from several cycles of cooling heating corresponding to a maximum degree of undercooling of 20 25 c during crystal growth these thermal variations occurred before eruption and are interpreted to be the result of turbulent convection in a small magmatic body beneath the ridge the results suggest that the mid atlantic ridge is underlain by a mush zone that releases batches of liquid during tectonic segregation aphyric basalts are emitted during eruptions controlled by the tectonic activity whereas phyric basalts correspond to small fractions of magma from the mush zone mobilized by reinjections of primitive magmas

analysis of massif fracturing during deep seated gravitational slope deformation by physical and numerical modeling abstract both 3 d physical modeling and 2 d numerical modeling were used to analyze the development of deep seated gravitational slope deformations we focused especially on the link between fracturing and morphological features such as sagging sackung physical modeling was performed by using properly scaled analogue materials as well as an original vertical accelerator device this device enables cyclic loading of the model and to advance step by step in the deformation process this technique is thus particularly well suited to analyze rupture initiation and evolution surface deformation is registered with a high resolution digital camera internal model deformation was studied by making cross sections at different experiment stages the failure of one or both mountain sides was observed with a deep seated failure zone that follows an almost circular trajectory it intersects the surface perpendicularly in the upper part other fractures are generated in the moving mass in response to its motion fracture network becomes wider and morphological features such as counterscarps are generated numerical models were performed with a 2 d finite element code named adeli we tried to reproduce physical modeling results by using the same mechanical behaviour and parameters of the analogue material the results reproduced failure initiation well but poorly described moving mass deformation furthermore rupture initiation in the 2 d numerical models occurs more easily e g for a lower acceleration value than in the 3 d physical models confirming the importance of the three dimensional analysis

gravitationally induced caves and other discontinuities detected by 2d electrical resistivity tomography case studies from the polish flysch carpathians abstract widened discontinuities among them crevice type caves are characteristic phenomena of landslides in anisotropic rock massifs forming the flysch carpathians we tested the reliability of 2d electrical resistivity tomography ert in the detection of well mapped cave passages and then tried to explore new subsurface cavities in three sites of crevice type caves in the polish flysch carpathians the jaskinia miecharska jaskinia malinowska and jaskinia diabla dziura caves each comprising a different stage of mass movement development and thus being a representative case study the total of 14 ert profiles was selected while each of them was measured by several electrode arrays dipole dipole wenner and or wenner schlumberger our results show that the selection of an appropriate electrode array and spacing are crucial for the detection of subsurface cavities measurement using the dipole dipole electrode array gave best results in the detection of known structures and its interpretation seems to be most reliable in the extrapolation of non investigated areas the application of ert shows abundant occurrence of air filled voids in gravitationally deformed flysch massifs and in several places its results enable comparison with open spaces detected by speleological exploration ert enables us to identify fractures in deformed slopes before the proper failure of these slopes affected by a landslide as well as in landslides themselves fissure zones connected with trenches less dense segments of colluvial ramparts and some lithological tectonical or gravitationally induced elements of slope structures the reliability of ert detection of potential caves was verified by speleological exploration of a newly discovered cave at the jaskinia miecharska site following the ert campaign

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

geochemical constraints on the modes of carbonate precipitation in peridotites from the logatchev hydrothermal vent field and gakkel ridge the ultramafic hosted logatchev hydrothermal field lhf at 15 n on the mid atlantic ridge and the arctic gakkel ridge gr feature carbonate precipitates aragonite calcite and dolomite in voids and fractures within different types of host rocks we present chemical and sr isotopic compositions of these different carbonates to examine the conditions that led to their formation our data reveal that different processes have led to the precipitation of carbonates in the various settings seawater like 87sr 86sr ratios for aragonite in serpentinites 0 70909 to 0 70917 from the lhf are similar to those of aragonite from the gr 0 70912 to 0 70917 and indicate aragonite precipitation from seawater at ambient conditions at both sites aragonite veins in sulfide breccias from lhf also have seawater like sr isotope compositions 0 70909 to 0 70915 however their rare earth element ree patterns show a clear positive europium eu anomaly indicative of a small 1 hydrothermal contribution in contrast to aragonite dolomite from the lhf has precipitated at much higher temperatures 100 c and yet its 87sr 86sr ratios 0 70896 to 0 70907 are only slightly lower than those of aragonite even higher temperatures are calculated for the precipitation of deformed calcite veins in serpentine talc fault schists form north of the lhf these calcites show unradiogenic 87sr 86sr ratios 0 70460 to 0 70499 indicative of precipitation from evolved hydrothermal fluids a simple mixing model based on sr mass balance and enthalpy conservation indicates strongly variable conditions of fluid mixing and heat transfers involved in carbonate formation dolomite precipitated from a mixture of 97 seawater and 3 hydrothermal fluid that should have had a temperature of approximately 14 c assuming that no heat was transferred the much higher apparent precipitation temperatures based on oxygen isotopes 100 c may be indicative of conductive heating probably of seawater prior to mixing the hydrothermal calcite in the fault schist has precipitated from a mixture of 67 hydrothermal fluid and 33 seawater which should have had an isenthalpic mixing temperature of 250 c the significantly lower temperatures calculated from oxygen isotopes are likely due to conductive cooling of hydrothermal fluid discharging along faults rare earth element patterns corroborate the results of the mixing model since the hydrothermal calcite which formed from waters with the greatest hydrothermal contribution has ree patterns that closely resemble those of vent fluids from the lhf our results demonstrate for the first time that 1 precipitation from pure seawater 2 conductive heating of seawater and 3 conductive cooling of hydrothermal fluids in the sub seafloor all can lead to carbonate precipitation within a single ultramafic hosted hydrothermal system

petrogenesis of a vitrophyre in the martian meteorite breccia nwa 7034 abstract northwest africa nwa 7034 and its paired meteorites nwa 7533 and nwa 7475 are the first recognized martian polymict breccia samples an unusual large subrounded clast in nwa 7034 shows a vitrophyric texture consisting of skeletal pyroxene and olivine with mesostasis this lithology has not been observed in the paired meteorites it crystallized under disequilibrium conditions as indicated by its olivine and pyroxene kdfe mg partitioning values as well as reversed order of crystallization and mineral compositions relative to those predicted by melts we report the highest bulk ni value 1020 ppm measured in any known martian meteorite or martian igneous rock suggesting an impact melt origin for the vitrophyre addition of 5 3 7 7 chondritic material to the target rock would account for the ni enrichment the bulk major and trace element abundances of the vitrophyre indicate that the protolith was not the host breccia nor any other martian meteorites however the clast is compositionally similar to humphrey rock in gusev crater analyzed by the spirit rover and to a texturally distinct group of clasts in the paired meteorite nwa 7533 thus we propose that the target rock was an igneous lithology similar to gusev basalts which was subsequently contaminated by a chondritic impactor

gravitationally induced non karst caves tectonic and morphological constrains classification and dating polish flysch carpathians case study abstract analysis of non karst caves in the flysch carpathians confirms the connection between the tectonic evolution of this orogen and the initial phase of cave formation the compressional extensional regime during the tectonic stages of the evolution of the carpathians is the foundation of subsequent gravitational stresses within the slopes which brought about various deformations of rock massifs producing diverse types of subsurface cavities caves therefore most caves that occur in the carpathians represent forms of the opening and widening of joints and stress zones originated much earlier classification based on the chronology and mechanisms of these caves is proposed a chronological approach requires understanding the relationship of cave development to the stages of slope evolution and enables the construction of the morphogenetic classification whereas consideration of the processes affecting the rock massif structure allows geomechanic classification using the morphogenetic criterion three categories of caves can be distinguished initial caves developed during slope deformations preceding the principal slope failures landslides subsequent caves formed during the main slope failure and intermediate caves related to the main scarp formation on the basis of the geomechanic criterion the following types of caves can be distinguished dilational caves formed due to tensional fractures widening dilatancy caves formed due to the fissure macrodilatancy and boulder caves which represent chaotic cavities in order to illustrate this classification type localities of the various cave types are presented the radiocarbon dating of secondary formations speleothems occurring in the caves indicate that they initially formed in the weichselian upper plenivistulian late glacial and early holocene and underwent various transformations

olivine growth rates in a tholeiitic basalt an experimental study of melt inclusions in plagioclase abstract basaltic glass inclusions trapped in plagioclase phenocrysts an 84 are remnant of their parent magmatic liquid they can be used as natural reactors for the experimental investigation of olivine growth rate as a function of temperature the growth of one olivine nucleus can be observed at constant temperature supercooling from 15 to 150 c have been investigated growth habits vary from equant to feather in qualitative agreement with previous studies growth rates vary from 10 m s 1 to 6 10 7 m s 1 they vary with the direction the growth process planar or dendritic and the degree of supercooling chemical analysis of crystal overgrowth and the remaining liquid composition enables a mass balance calculation which confirms the rates determined optically the small number of results obtained so far does not permit to draw inferences on the growth mechanisms

application of a textural geospeedometer to the late stage magmatic history of mil 03346 dynamic crystallization experiments performed on fe rich al poor basalt are employed as a textural calibration set to quantify the late stage igneous history of nakhlite miller range mil 03346 the ratio of crystal melt surface area to volume typifying morphologically distinct populations of ca pyroxene has been shown to vary as a strong function of cooling rate hammer 2006 furthermore a texture of phenocrysts surrounded by finer grained groundmass crystals arises by sequential nucleation events during constant rate cooling but multiple populations nucleate only if the cooling rate is 72 c h 1 textural analysis of meteorite mil 03346 reveals at least two distinct populations the ca pyroxene phenocryst and microphenocryst three dimensional 3d aspect ratios are 112 8 3 and 1530 160 mm 1 respectively by comparison with the calibration set the range of cooling rates consistent with 3d aspect ratios of both populations in mil 03346 is 20 c h 1 an additional experiment was performed approximating a conductive heat transfer profile in order to interpret and apply results of constant rate cooling experiments to the natural cooling of magma results suggest that the textures of constant rate experiments parallel the initial period of rapid cooling in natural magma initial cooling rates of 20 c h 1 in the lava hosting mil 03346 occur in conductively solidifying lava at depths of 0 4 m constraining the minimum total thickness to 0 8 m crystal accumulation beginning in a subsurface reservoir and continuing after lava emplacement as an inflated pahoehoe sheet satisfies all textural constraints on the late stage igneous history of mil 03346

timescales of convection in magma chambers below the mid atlantic ridge from melt inclusions investigations closed hopper and complex swallowtail morphologies of olivine microcrysts have been described in the past in both mid oceanic ridge basalts and subaerial tholeitic volcanoes and indicate fluctuations in magma undercooling we describe similar morphologies in a mid atlantic ridge pillow basalt sample rd87dr10 and in addition we estimate the duration of temperature fluctuations required to produce these textures as follows 1 pairs of melt inclusions are arranged symmetrically around the centre of hopper crystals and each pair represents a heating cooling cycle using the literature olivine growth rates relevant to the observed morphologies and measuring the distance between two successive inclusions we estimate the minimum time elapsed during one convection cycle 2 the major element composition of melt inclusions analysed by electron microprobe was found to be in the range of the boundary layer measured in the glass surrounding the olivines irrespective of their size several major elements demonstrate that this boundary layer results from rapid quenching on the seafloor and not from crystal growth at depth implying the inclusions had the same composition as the surrounding magma when they were sealed using diffusivity of slow diffusing elements such as al2o3 we estimate the minimum time required for inclusion formation these two independent approaches give concordant results each cooling heating cycle lasted between a few minutes and 1 h minimum thus these crystals probably recorded thermal convection in small magmatic bodies a dyke or shallow magma chamber during the last hour or hours before eruption

a 3 d geological and structural synthesis of the leinster area of the agnew wiluna belt yilgarn craton western australia with special reference to the volcanological setting of komatiite associated nickel sulfide deposits the leinster area is situated toward the southern end of the agnew wiluna belt in the yilgarn craton of western australia and hosts the giant perseverance komatiite associated nickel sulfide deposit at in excess of 1 2 mt contained ni this is the biggest type 1 basal sulfide rich accumulation deposit in the world and it is associated with a number of smaller deposits that extend over a strike length of 20 km adjacent to the perseverance fault on the eastern margin of the belt in broad terms the greenstone sequence comprises an eastern rift proximal komatiite dacite sequence and a western and more marginal basalt dominated sequence with minor komatiite the komatiites display a wide range of compositions and textures from highly magnesian olivine meso to adcumulate rocks composed of olivine with forsterite contents of up to 94 5 to sequences of thin spinifex textured komatiite flow units this compositional range indicates considerable variation in volcanic facies from rift proximal to distal loci of focused flow termed pathways indicated by thickened cord like bodies of more olivine rich rock occur at all scales and are intimately associated with the ni sulfide mineralization the pathways are linked by thinner sequences of lower mgo rocks either layered olivine orthocumulate rocks or sequences of thin spinifex textured flow units some of the lower mgo komatiite sequences appear to emanate from the tops of pathways in the manner of breakout flows in tube fed basaltic terrains variably sulfidic black shales and cherts and barren exhalative iron sulfide horizons are intimately interlayered with the komatiitic rocks the overprinting effects of regional deformation and metamorphism spanning at least 80 m y are considerable at least eight local deformation events have been recognized by previous workers these have been used to constrain the 3 d model and can be linked to craton wide structural schemes some of the major faults are clearly accretionary and reflect reactivation of underlying basin forming structures early north over south thrusting was followed by e w directed basin closure and the development of nnw trending open regional folds extension accompanied batholithic granitoid intrusion and reactivated rift parallel nnw trending faults producing the major strike slip fault systems that divide the greenstone succession into a series of structural and stratigraphic domains the ensuing orogenic collapse resulted in overturning of the stratigraphy to the east subsequent brittle deformation events have produced fault sets in a variety of orientations that can be related to ongoing shortening with a variable principal stress orientation there is a complex interplay of structural and volcanological controls on the formation and subsequent deformation of the ni sulfide deposits in this ancient terrane three dimensional modeling has furthered a detailed understanding of the geologic and structural evolution of the belt allowed the identification of komatiite pathway positions and their plunges and provided quantitative data on the magnitude and direction of fault offsets of different generations the modeling exercise has shown that it is possible to strip away the effects of overprinting metamorphism and deformation to reveal some of the primary controls on komatiite volcanism and the location of ni sulfide deposits even in those portions of greenstone belts that are highly deformed and have undergone amphibolite facies metamorphism this is illustrated with case studies of the perseverance venus rocky s reward harmony and sir lancelot deposits three dimensional modeling has the capacity to integrate geologic geochemical and geophysical datasets in a way that fully utilizes the results of past exploration programs and produces a premium geologic product that can be used to guide further exploration the recent discovery of the venus deposit is in part a tribute to the power of this approach

late holocene episodic displacement on fault scarps related to interstratal dissolution of evaporites teruel neogene graben ne spain abstract the mio pliocene formations of the turolian type section teruel graben spain have sagged due to dissolution of the underlying triassic evaporites generating a 1 7 km long monocline and accompanying synform with 130 m of structural relief the crest of the monocline is affected by a graben that counterbalances the shortening caused by passive bending in the adjacent syncline this graben is controlled by a master synthetic fault and a swarm of antithetic and synthetic faults with a conspicuous geomorphic expression after acquiring ground penetrating radar gpr profiles three trenches were excavated in depressions associated with uphill facing fault scarps to our knowledge these are the first trenches excavated across faults caused by deep seated dissolution of evaporites the geometrical relationships observed in two trenches indicate late holocene episodic displacement as many as 3 events some of the parameters estimated for the investigated faults are clearly different from those expectable for tectonic faults in this intraplate area they include high apparent vertical slip rates 0 6 1 mm yr low average recurrence of faulting events 1 2 2 ka and very high displacement per event values 65 cm for surface ruptures less then 200 m long our findings suggest that considering evaporite collapse faults as creeping structures is not a reliable criterion to differentiate between tectonic faults seismogenic and dissolution induced gravitational faults nonseismogenic

a mid miocene to early pleistocene multi level cave as a gauge for tectonic uplift of the swabian alb southwest germany a recently discovered deep cave laierhohle within a plateau of upper jurassic limestone is the deepest 126 m of the southwest german swabian alb providing a unique gauge for crustal tilting and isostatic uplift of the southwest german crust from late mid miocene to earliest pleistocene horizontal levels are considered a product of a stationary palaeo water table vertical shafts are related to base level fall which in turn may be the result of uplift and or incision we correlate speleogenetic with dated geomorphic features and thus come to a chronology of events the laierhohle records five episodes of long term stability of the karst water table covering the time span from late middle miocene until the pliocene pleistocene transition the first two stable episodes can be dated to the late middle miocene and late miocene horizontal levels 1 and 2a an episode responsible for the formation of level 2b falls within early pliocene time levels 3a and 3b are spatially well separated but must have formed within a relatively short time span towards the end of the pliocene in the working area total depth of penetrative karstification was in the order of 120 m this penetration has been accomplished over a period of approximately 12 ma resulting in an average uplift rate of 0 01 mm a

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

crevice type caves as initial forms of rock landslide development in the flysch carpathians crevice type caves formed along joints are very common in the polish flysch carpathians more than 600 have been recorded the caves represent accessible parts of the widened cracks which are basic initial forms of development of deep seated rock landslides structural features of four selected caves situated in different parts of the carpathians were studied in order to determine relations between joint systems and landslide formation the studies prove that the main rock scarps often represent effects of earlier propagation of the cracks cutting surfaces due to loading and unloading shearing stress the cracks are structural forms developed along joints or faults the cutting surfaces represented by cracks caves develop a long time before the main gravitational mass movements whereas the sliding surfaces shearing zones are formed or significantly modified ad hoc during the gravitational transport of rock masses occurrence of the deep initial cracks causes modification of shape of the sliding surfaces which are noncircular the mountain slopes cut by many cracks are permanently developed thus the periodic increase of activity of external factors floods downpours earthquakes etc leads to common formation of the landslides earlier prepared by crack development this model of slope evolution enables us to interpret the occurrence of the landslide phases in the holocene during which increasing of frequency of the landslides is observed

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

correlations of cave levels stream terraces and planation surfaces along the river mur timing of landscape evolution along the eastern margin of the alps the transition zone of the eastern alps to the pannonian basin provides one of the best sources of information on landscape evolution of the eastern alpine mountain range the region was non glaciated during the entire pleistocene thus direct influence of glacial carving as a landscape forming process can be excluded and relics of landforms are preserved that date back to at least the late neogene in this study we provide a correlation between various planation surfaces across the orogen basin transition in particular we use stream terraces planation surfaces and cave levels that cover a vertical spread of some 700 m our correlation is used to show that both sides of the transition zone uplifted together starting at least about 5 ma ago for our correlation we use recently published terrestrial cosmogenic nuclide tcn burial ages from cave sediments new optically stimulated luminescence osl ages of a stream terrace and u th ages from speleothems minimum age constraints of cave levels from burial ages of cave sediments covering the last 4 ma are used to place age constraints on surface features by parallelizing cave levels with planation surfaces the osl results for the top section of the type locality of the helfbrunn terrace suggest an early wurm development 80 5 3 7 to 68 7 4 0 ka the terrace origin as a penultimate gravel deposit in classical alpine terminology riss is therefore questioned u series speleothem ages from caves nearby indicate formation during marine isotope stages mis 5c and 5a which are both interstadial warm periods as osl ages from the terrace also show a time of deposition during mis 5a ending at the mis 5 4 transition this supports the idea of temperate climatic conditions at the time of deposition in general tectonic activity is interpreted to be the main driving force for the formation and evolution of these landforms whilst climate change is suggested to be of minor importance obvious hiatuses in miocene to pleistocene sediments are related to ongoing erosion and re excavation of an uplifting and rejuvenating landscape

dynamic cyrstallization of chondrule melts of porphyritic olivine composition textures experimental and natural abstract melts of the same composition as has been defined for porphyritic olivine chondrules have been crystallized under controlled cooling conditions dynamic crystallization the full range of textures observed in such chondrules has been duplicated in the experimentally produced analogs the primary controlling factor in producing this range of textuures is the heterogeneous nucleation behavior in general if nuclei are present when cooling begins growth starts immediately at low degrees of supercooling and porphyritic textures result the shapes of the phenocyrsts depend on the growth rate which in turn depends on the cooling rate with high nucleation densities and modest to low cooling rates the textures are microporphyritic with generally equant euhedral phenocrysts as the nucleatio density decreases the phenocrysts become larger and as the cooling rate increases they become increasingly skeletal if nuclei are not present when cooling begins growth is delayed until subcritical sized embryos graduate to supercritical nuclei growth usually begins at some significant degree of supercooling depending on the cooling rate and how long it takes the embryos to become nuclei the shapes of the crystals depend on the degree of supercooling when growth is initiated and on the subsequent cooling rate the resulting textures vary from plate dendrites barred olivine chondrules to randomly oriented elongated skeletal crystals as the degree of supercooling and cooling rates decreases the results of a matrix of experiments set limits on the maximum melting temperatures of chondrule forming materials and the subsequent cooling rates based primarily on crystal shape the porphyritic textures develop best for this composition at melting temperatures less than 1590 c and cooling rates near 100 c hr and definitely less than 1000 c hr at cooling rates significantly less than 100 c hr the phenocrysts are generally larger than observed in chondrules and as cooling rates approach 1000 c hr they become more skeletal barred olivine chondrule textures form best from materials melted at higher temperatures and cooling rates in the range 1000 to 3000 c hr

a multi methodological re evaluation of the volcanic events during the 1580 ce and 1808 eruptions at sao jorge island azores archipelago portugal abstract among all eruptions that took place on the azores archipelago since the portuguese settlement in the xvi century those of 1580 and 1808 in the island of sao jorge were unusual the magma erupted in 1580 ascended from at least 23 km and ponded at a minimum depth of 16 km here residual magma fractionated mafic phases and plagioclase during 228 years before erupted again in 1808 magma emission occurred from numerous fissures active at the same time and opening for several kilometres following a local tectonic trend hydro volcanic outbursts and hot rock fall over steep slopes caused casualties and injuries and lava flows and heavy tephra fallout affected the local economy despite of all these dramatic consequences the memory of these eruptions is almost vanished representative geosites and morphological landforms if not hindered by lush vegetation have been reshaped by diffuse quarries and reworked to recover croplands and pastures aiming at a better comprehension of the multiple hazards associated with volcanic eruptions at sao jorge island we retraced the volcanic events of these two eruptions by matching our re interpretation of historic reports with field data and photogrammetry and with fluid inclusions petrography and geochemical data of erupted products

crystal growth in incongruently melting compositions programmed cooling experiments with diopside programmed cooling experiments using a synthetic diopside glass and constant cooling rates of from l0o to 300oc hr first crystallize forsterite and then with decreasing temperature clinopyroxene wollastonite the forsterite grows as hopper shaped crystals which then develop dendrites from external corners the morphological development can be qualitatively explained by a model involving di ffusion in the melt and interface attachment kinetics microprobe traverses across forsterite glass interfaces show that the magnitude of the mgo depletion in the melt near flat interface segments varies from 1 72 to 4 28 percent and increases with increasing run time for a given cooling rate and with increasing value of the product of the cooling rate times the run time for all cooling rates the results are in qualitative agreement with theoretical predictions near a particular crystal mgo depletion is least at corners and greatest in reentrants the clinopyroxene is more magnesian than diopside solid solution towards enstatite and grows as dendrites the wollastonite occurs between the clinopyroxene dendrite arms the clinopyroxene first appears at nominal undercoolings 1391 iou n of from l82o to 240 c depending on the cooling rate unlike other sets of programmed cooling experiments which show a continual increase in nominal undercooling with increasing cooling rate these experiments show a maximum in clinopyroxene undercooling at 50 c hr the undercooling is actually least for the 300oc hr runs introduction when crystals grow from a melt with a different composition at least two processes must be involved in the growth process the molecular attachment process occurring at the crystal melt interface and redistribution of chemical components in the melt in response to the selective removal of some of them by the crystal removal of the latent heat of crystallization from the crystal melt interface may be important if the growth rate is high traditional descriptions of the interaction of diffusion and crystal growth assume that the liquid and crystal compositions at the interface are the equilibrium compositions for the temperature at which growth is occuring e 9 elbaum 1959 such descriptions may not be satisfactory for silicates and other materials which grow by a layer spreading mechanism because these 0003 004x 8 l 0304 0223 02 00 materials require a finite supersaturation or undercooling really the same thing at the interface for growth to occur o hara et al 1968 hopper and uhlmann 1974 kirkpatrick 1975 this layerspreading growth mechanism also greatly affects the development of skeletal and dendritic crystal morphologies allowing fully faceted crystals to grow to a larger size than would be possible if interface kinetics were not important recent theoretical developments have shown how the effect of interface kinetics can be taken into account for both interface stability and the overall growth process this paper briefly reviews the recent theory presents the results of programmsd sssling experiments in which forsterite clinopyroxene and wollastonite grow from a synthetic stoichiometric diopside melt and uses the theory to interpret these results 223 kirkpatrick et al growth in incongruently melting compositions theory recent advances in crystal growth theory can help in the understanding of three major aspects of the experiments to be discussed here l the origin of the skeletal morphologies of the forsterite and clinopyroxene crystals 2 the time temperature position and cooling rate dependences of the liquid composition at the forsterite melt interface and 3 the variation in liquid composition away from the forsteriteliquid interface this section will briefly review these theoretical developments

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

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

genesis and geomorphic evolution of the velke pinky stopes in the zlatohorska highlands eastern sudetes montanogenic landforms are commonly viewed as hazards by society but they are also holders of specific and uncommon morphology with unique dynamics that act as remarks on landscape history the velke pinky stopes in the zlatohorska highlands eastern sudetes are naturally revitalized post mining landforms with long term geoecological succession their genetic origin is diverse but recent processes such as deep seated slope deformations rockfalls and ground subsidence have resulted in a distinct morphology dominated by rock walls and the accumulation of blocks and debris wedges this morphology predisposes the stopes to become the core area of the most recent dynamic geomorphic activity within the wider relatively homogenous area by dendrogeomorphic techniques we identified more than 20 rockfall events within three of the stopes with increased activity since the 1980s only the 1991 and 2006 events were identical for all three stopes we obtained the years of exposures from 10 roots revealing the ground subsidence and opening of tension cracks or even the lateral retreat of the flanks of minor depressions the schmidt hammer test revealed the most recent and fresh gravitational activity in one of the stopes a relationship between the superficial morphology and underground structure was proven by electrical resistivity profiling compared to the previous studies engaged with the abandoned mines we presented how complex their evolution can be our study brings new information about the historical development of anthropogenic relief forms moreover our results suggest that standard research approaches can be successfully applied for development analysis of these specific forms

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

evidence for dendritic crystallization of forsterite olivine during contact metamorphism of siliceous dolostones alta stock aureole utah forsterite crystals produced during metamorphism of siliceous dolomites in the alta utah contact aureole were investigated in situ and with crystal separates to constrain their aureole scale textural and morphological variability as the contact is approached forsterite crystals increase in abundance but decrease in average size suggesting greater kinetic influence on forsterite nucleation and growth in the inner aureole crystal morphologies vary widely from dendritic to skeletal to euhedral shapes across both periclase and forsterite zones highly skeletal forms of forsterite preserve crystallographically controlled internal scaffolding reentrants and internal void boundaries scanning electron microscope imaging of texturally more mature forsterite crystals reveals the common occurrence of surface features such as hopper structures ridges and terraces features that have been linked to dendritic crystallization of olivine in igneous rocks near end member forsterite crystals fo99 from the middle to outer forsterite zone exhibit complex cathodoluminescence cl patterns which can be linked to grain scale heterogeneities in the trace elements li b p and ti these grain scale cl zoning patterns can be correlated to crystallographic forms typical of forsterite the textural trends morphological characteristics surface features and cl patterns suggest that euhedral forsterite crystals grew by a process of early dendritic crystallization hopper development and infilling of hopper reentrants these results caution against interpreting all grain scale zoning profiles preserved in metamorphic forsterites as simple core to rim time sequences consideration of the possible role of dendritic crystallization in the development of forsterite morphologies is required to interpret 2 d element or isotope zoning profiles preserved in individual forsterite grains

dendritic crystallization a single process for all the textures of olivine in basalts the olivine macrocrysts found in oceanites picrites and magnesian basalts erupted at hotspot volcanoes are generally interpreted either as phenocrysts crystallized from the magma or as xenocrysts extracted from a deforming cumulate to constrain the origin of these crystals we studied their texture and composition at piton de la fournaise volcano la reunion we show that macrocrysts are organized and subdivided into parallel units this suggests a crystallization by dendritic growth and ripening rather than by a complex combination of paired nucleation crystal aggregation or synneusis dendritic growth is also evidenced by the occurrence of hollow faces p rich zones melt and cr spinel inclusions formed from the accumulation of slow diffusing impurities p cr al in the liquid at the contact with rapid growing olivine we suggest that early dendritic crystallization may even cause branch misorientations and lattice mismatches yielding subgrain boundaries dislocation lamellae and to a certain extent undulose extinction which have all been formerly interpreted in terms of plastic intracrystalline deformation we interpret olivine macrocrysts as phenocrysts crystallized under a strong degree of undercooling t 60 c and derived from a harrisitic mush formed on the cold walls of the magma reservoir given the growth shapes indicated by p zoning patterns and external faces the olivine macrocrysts which consist of groups of several subcrystals have grown in suspension within the liquid and were neither aggregated into a dense cumulate nor corroded shocked or deformed before or during their transport to the surface the major consequence of our study is that most olivine macrocrysts are not xenocrysts and very few of them if any have experienced intracrystalline deformation the importance of deforming creeping cumulate bodies thought to accommodate the spreading of basaltic volcanoes in la reunion and hawaii may hence have been overestimated

rapid least squares inversion of apparent resistivity pseudosections by a quasi newton method1 a fast inversion technique for the interpretation of data from resistivity tomography surveys has been developed for operation on a microcomputer this technique is based on the smoothness constrained least squares method and it produces a two dimensional subsurface model from the apparent resistivity pseudosection in the first iteration a homogeneous earth model is used as the starting model for which the apparent resistivity partial derivative values can be calculated analytically for subsequent iterations a quasi newton method is used to estimate the partial derivatives which reduces the computer time and memory space required by about eight and twelve times respectively compared to the conventional least squares method tests with a variety of computer models and data from field surveys show that this technique is insensitive to random noise and converges rapidly this technique takes about one minute to invert a single data set on an 80486dx microcomputer

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

eruption dynamics inferred from microlite crystallization experiments application to plinian and dome forming eruptions of mt pelee martinique lesser antilles decompression experiments have been conducted to simulate syn eruptive crystallization in volcanic conduits to infer magma ascent rates and conditions during dome forming and plinian eruptions of silicic arc volcanoes the experiments were carried out on starting material with the composition of mt pele e rhyolitic interstitial melt 76 wt sio2 and consisted of three consecutive steps hydration decompression and annealing hydration saturated and undersaturated was performed at 8508c and 200mpa and was followed by isothermal decompression either linearly or stepwise to a final pressure pf of 30 or 5 10mpa decompression rates range from 0 003 to 25mpamin 1 decompression durations of 15 min to 40 days two samples were cooled by 258c and 508c during a 3 day step at pf subsequent to decompression the samples were held for up to 15 days at pf the experiments generated three types of crystals as products of pre syn and post decompression crystallization the experiments basically differ from previous studies in that they are specifically designed to discriminate crystal nucleation from growth and to evaluate the influence of pre decompression crystals on the decompression induced crystallization the effects of pre decompression crystals decompression rate undercooling pf and terminal cooling have been determined on plagioclase nucleation growth morphology and composition the main results suggest a positive correlation between decompression rate and the number density of plagioclase crystals nucleated at pf and highlight the effect of pre decompression crystals in further decompression induced crystallization the relations between the decompression conditions and the plagioclase characteristics have been used to infer mt pele e eruption dynamics suggesting that 1 plinian magmas ascend from the reservoir within less than 1h 1 10 m s 2 dome and block and ash flow magmas ascend within more than 2 5 days giving time for syn decompression crystallization around pre existent microlites 3 dome magmas provide evidence for long stagnation and cooling at low pressure and 4 surge magmas ascend without significant crystallization within less than 4 days and massively nucleate plagioclase at very low pressure the extent and violence of dome destruction may depend on the size or age of the dome with large or old domes favouring mildly explosive block and ash flows whereas small or young protodomes may generate highly explosive surges

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

deep seated gravitational slope deformations controlled by the structure of flysch nappe outliers insights from large scale electrical resistivity tomography survey and lidar mapping abstract the flysch nappe outliers represent a structural setting prone to the development of deep seated gravitational slope deformations dsgsds the study area of the palkovicke h rky hills represents an isolated outlier of the carpathians flysch nappes czech republic geomorphological mapping based on field surveys and interpretation of lidar data reveals the occurrence of various types of slope deformations including two dsgsds with the aim of detecting the main controlling factors of the dsgsds a multiapproach investigation combining surface and underground studies has been performed structural measurement points to a brachysynclinal structure composed of jointed and lithologically diverse strata with step like topography high resolution lidar data suggest strong tectonic disruption caused by conjugated transtensional and en echelon tectonic faults controlling the course of slope segments river valleys and landslide scarps four specific localities have been subjected to geophysical surveying kilometre scale electrical resistivity tomography ert profiles that have depths of penetration reaching the limits of the method 150 m were acquired across the gravitationally deformed nappe outlier the data show the overall structural conditions of the nappe outlier consisting of alternating lithological units affected by folds and fault zones a local subordinate anticline within the central part of the brachysynclinal structure has controlled the origin of the most morphologically pronounced dsgsds other large scale dsgsds related to the inherited fault system potentially affect the entire n nw segment of the studied elevation data integration indicate that structural conditions including lithological boundaries tectonic disruption and local folding to be the main controlling factors of the dsgsds evolution

tectonic strain changes affecting the development of deep seated gravitational slope deformations in the bohemian massif and outer western carpathians abstract this paper describes a pair of intensively studied deep seated gravitational slope deformations from the czech republic structural geological mapping and the interrogation of high resolution lidar dems have been used to reassess the extent of each slope deformation and to obtain new information about their surface morphologies electrical resistivity tomography has been used to image the subsurface structures while rod dilatometers and permanently installed mechanical extensometers have been used to define their kinematic behaviour dilatometric measurements from across a fissure the edge of the mu sk hill dsgsd show that the progressive trend has been interspersed by five periods of movement acceleration since monitoring began in 1990 while extensometric measurements from across a second fissure about 50 m from the edge of the plateau show that this discontinuity was affected by an significant period of extension from 2004 to 2006 and a significant period of compression from 2006 to 2008 these data demonstrate that the mu sk hill dsgsd is characterised by the lateral spreading of rigid sandstone blocks across a plastic marl formation at the edge of p ihrazy plateau extensometric measurements from the kn hyn mountain dsgsd show that a fault located at a depth of about 25 m below the surface is characterised by progressive dilation whereas a fault located at a depth of about 57 5 m below the surface is characterised by episodic vertical dip slip displacements both faults are affected by horizontal dextral strike slip displacements these data demonstrate that the kn hyn mountain dsgsd is characterised by translational rocksliding associated with the neotectonic uplift of the outer western carpathians the presented kinematic data have been compared to records of precipitation groundwater level earthquakes and strain changes measured by the fault displacement monitoring network eu tecnet strain changes induced by the widespread redistribution of stress through the crustal appear to represent an important and hitherto underappreciated geomorphological process affecting the development of the slope deformations at mu sk hill and kn hyn mountain future research will focus discovering whether this finding holds true for other deep seated gravitational slope deformations in different geomorphological and geological settings

an origin for harrisitic and granular olivine in the rum layered suite nw scotland a crystal size distribution study dendritic crystal morphologies occur in a number of igneous rocks and are thought to originate from the rapid growth of crystals yet many examples of dendritic morphologies are found in plutonic igneous rocks where cooling rates should be low results from crystal size distribution csd measurements on harrisitic olivines from rum scotland combined with estimated olivine growth rates suggest that the characteristic skeletal hopper and branching olivines of harrisitic cumulates that are up to centimetres long may have exceptionally short crystal growth times several hours to several hundreds of days this together with very low calculated nucleation densities for harrisitic olivine supports the interpretation of harrisite being a disequilibrium texture developed in response to supersaturation of the magma in olivine we propose that this supersaturation arose through undercooling of thin picrite sheets emplaced along the rum magma chamber floor beneath cooler resident magma it is envisaged that the picrite sheets were largely free of suspended olivine crystals coupled with the olivine enriched composition of the melt and the increasing cooling rate this allowed homogeneous nucleation of olivine to set in at deeper undercooling and greater olivine supersaturation than if there had been plentiful suspended olivines to act as heterogeneous nuclei the enhanced supersaturation caused rapid growth of olivine once nucleation began with skeletal and dendritic shapes it is suggested that the observed interlayered sequences of harrisite and cumulus peridotite found throughout the rum layered suite are a result of multiple episodes of harrisite crystallization resulting from picrite emplacement that alternated with periods of crystal growth and accumulation in the main body of magma at lesser degrees of undercooling

formation of apollo 17 orange and black glass beads size frequency distributions of the cross sections of orange and black glass beads in the 125 250 m fraction of soil 74220 have been determined cross section medians of black vitrophyric and orange glassy beads in the 125 250 m fraction are 0 16 mm and 0 14 mm respectively the vitrophyric beads contain skeletal olivine crystals mantled by ilmenite some beads contain fragments and euhedral crystals of endogeneous olivine free flight cooling rates and the critical cooling rate for crystallization have been determined with a synthetic melt of orange glass composition the critical cooling rate is approximately 100 c s the free flight cooling rate of droplets 0 16 mm in diameter is approximately 1080 c s it is inferred that apollo 17 orange melt droplets were erupted together with a large mass of hot gas and or formed a dense cloud of heat radiating droplets

origin of glass inclusions hosted in magnesian porphyritic olivines chondrules deciphering planetesimal compositions abstract glass inclusions occur in the most primitive magnesian porphyritic olivines of chondrules formed very early in the solar system and understanding their formation and preservation is crucial for explaining early solar system evolution several different and frequently opposed models have been proposed to explain the origin of these glass inclusions and their host olivines ranging from condensation processes in the nebula to crystallization products of chondrule melts however none of these models fully satisfy all the petrographic chemical and isotopic observations in this experimental work we show that the peculiar compositions of these inclusions that exhibit significant chemical disequilibrium between glass and host olivine result from the slow crystallization of metastable olivines from a magma the inhibition of plagioclase nucleation resulting in metastable olivine crystallization instead of the equilibrium assemblage anorthite clinopyroxene is a natural consequence of the high liquidus temperature of the magma this result implies a restricted compositional range for the parental magmas of these melt inclusions olivine phenocrysts inside type ia chondrules are thus interpreted as fragments of magmatic cumulates formed in magma ocean like environments on fully or partially molten planetesimals in a similar manner as for terrestrial rocks studies of melt inclusions giving information about the earliest magma oceans could open a new way of assessing the evolution of the earliest bodies of the solar system

origin of sackung uphill facing scarps in the saint elias orogen alaska lidar data visualization and stress modeling quaternary fault scarps occur in mountain blocks throughout the saint elias orogen of southern alaska mechanisms proposed for formation of these scarps include deformation caused by active folding downhill creep and landsliding on steep previously glaciated slopes and superficial faulting caused by strong ground motion during earthquakes field observations and interpretation of high resolution topographic models constructed from a light detection and ranging lidar survey indicate that failure by flexural toppling creates the uphill facing scarps in the mountain that we selected for detailed analysis toppling failure occurs by shearing and outward rotation of sedimentary bedding that dips steeply into the mountainside the scarps are therefore created primarily by gravitational stresses and are not tectonic faults a three dimensional finite element model of the mountain is used to investigate variations in stress field and kinematics of bedding plane failure by flexural toppling the results demonstrate the strong influence of mountain morphology on stress orientations and kinematics of shearing along bedding planes addition of horizontal compressive tectonic stress may reorient principal stresses caused by gravitational loading and either enhance or restrict flexural toppling depending upon the angle between bedding surfaces and mountainside however modulation of gravity loading by tectonic stress requires the basal sliding surfaces beneath the toppled strata to be either locked or only partly developed horizontal acceleration caused by earthquake ground motion and lateral relaxation of mountain flanks following retreat of glaciers also enhance the probability of failure by flexural toppling especially in the upper parts of mountain slopes where earthquake ground motion is amplified the finite element model does not incorporate these latter two processes although we discuss their influence in qualitative terms

tourmaline nodules from capo bianco aplite elba island italy an example of diffusion limited aggregation growth in a magmatic system the morphology of tourmaline nodules occurring in the capo bianco aplite elba island italy is studied outcrop features indicate that tourmaline nodules are the product of magmatic crystallization as they are aligned along flow fields developed within the magmatic hosting mass mesoscopic observations indicate that nodule morphologies are very variable from rounded to dendritic morphometric analyses show that tourmaline nodules are fractals and that fractal dimension quantifies their degree of irregularity numerical simulations of nodule growth are performed by using a diffusion limited aggregation process the presence in natural samples of nodules with different morphologies is explained by considering a chaotic magmatic system characterized by a complex interplay between growth rate in different dynamical regions latent heat of crystallization and local convection dynamics it is suggested that higher growth rates correspond to growth of tourmaline nodules in dynamical regions where the transfer of nutrients is very efficient in such conditions the latent heat released by the growing nodule is high inducing strong local convection dynamics destabilizing the nodule interface and promoting the formation of dendritic morphologies on the contrary the growth of nodules in dynamical regions characterized by weak transfer of nutrients is inhibited leading to weak local convection dynamics and consequently to the formation of rounded morphologies

dynamic crystallization studies on the grande ronde pillow basalts central washington dynamic crystallization experiments were performed to reproduce textural and mineralogic features of some grande ronde columbia river pillow basalts and thereby estimate cooling rates of the various pillow textural zones the essential petrographic features of these pillows can be experimentally duplicated by melting at the liquidus temperature 1140 c followed by isothermal drop crystallization at 1125 c and then linear cooling to subsolidus temperatures at rates between 2400 c hr to reproduce vitrophyric rims and 10o hr to reproduce the holocrystalline interiors in both cooling experiments and the pillows the al content of pyroxenes and the fe content of plagioclase display a systematic variation with respect to cooling rate or position within the pillow pyroxene grain size data derived from the cooling experiments display a linear relationship with cooling rate but are strongly influenced by the original melting temperature pyroxenes crystallized during experiments originally melted at liq

karst geomorphology of carbonatic conglomerates in the folded molasse zone of the northern alps austria germany abstract the folded molasse zone of the northern alps consists of clastic sedimentary rocks that are usually not considered to be karstifiable however large areas within this zone are composed of carbonatic conglomerates numerous karst landforms have recently been discovered but are not recorded on official maps and in the literature therefore a research programme was initiated at the hochgrat site austria germany that included geomorphological mapping and characterisation of the karst phenomena both fracture controlled and hydrodynamically controlled karren were observed on conglomerate outcrops the predominant karst landforms dolines are typically circular funnel shaped most often 2 to 9 m in diameter 1 to 6 m deep and frequently act as swallow holes poljes that are atypically small 1 ha occur in either glacial cirques or syncline depressions are flat floored and lined with sediment and soil and drain underground via swallow holes short caves springs with marked discharge variations and estavelles are further evidence for karst development karstic landforms are widespread in carbonatic conglomerate terrains but their dimensions are smaller than in typical limestone karst the practical implications of these findings are also briefly mentioned in this paper

a magmatic origin for silica rich glass inclusions hosted in porphyritic magnesian olivines in chondrules an experimental study rare silica rich glass inclusions 69 sio2 82 wt are described within magnesian olivines of porphyritic type ia chondrules these glass inclusion compositions are clearly out of equilibrium with their host mg olivines and their presence within the olivines is generally attributed to an unclear secondary process such as a late interaction with nebular gases we performed dynamic crystallisation experiments that demonstrate that these si rich glass inclusions are actually magmatic in origin and were trapped inside olivines that crystallized slowly from a magma with a ci i e solar composition their silica rich compositions are the consequence of the small volumes of inclusions which inhibit the nucleation of secondary crystalline phase ca poor pyroxene but allow olivine to continue to crystallize metastably on the walls of the inclusions we suggest that si rich glass inclusions could be the only reliable relicts of what were the first magmas of the solar system exhibiting a ci i e non fractionated composition

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

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

petrology and shock metamorphism of the olivine phyric shergottite yamato 980459 evidence for a two stage cooling and a single stage ejection history abstract the basaltic martian meteorite yamato 980459 consists of large olivine phenocrysts and often prismatic pyroxenes set into a fine grained groundmass of smaller more fe rich olivine chromite and an interstitial residual material displaying quenching textures of dendritic olivine chain like augite and sulfide droplets in a glassy matrix yamato 980459 is thus the only martian meteorite without plagioclase maskelynite olivine is compositionally zoned from a mg rich core to a fe rich rim with the outer few micrometers being especially rich in iron with fo84 the cores are the most magnesian olivines found in martian meteorites so far pyroxenes are also mostly composite crystals of large orthopyroxene cores and thin ca rich overgrowths separate pigeonite and augites are rare on basis of the mineral compositions the cooling rates determined from crystal morphologies and crystal grain size distributions it is deduced that the parent magma of yamato 980459 initially cooled under near equilibrium conditions e g in a magma chamber allowing chromite and the mg rich silicates to form as cumulus phases fractional crystallization at higher cooling rates and a low degree of undercooling let to the formation of the ca al and fe rich overgrowths on olivine and orthopyroxene while the magma was ascending towards the martian surface finally and before plagioclase and also phosphates could precipitate the magma was very quickly erupted quenching the remaining melt to glass dendritic silicates and sulfide droplets the shape preferred orientation of olivine and pyroxene suggests a quick thin outflow of lava according to the shock effects found in the minerals of yamato 980459 the meteorite experienced an equilibration shock pressure of about 20 25 gpa its near surface position allowed the ejection from the planet s surface already by a single impact event and at relatively low shock pressures

iron iia slag tempered pottery in the negev highlands israel the article presents results of a petrographic investigation of pottery from iron iia settlements in the negev highlands in southern israel it focuses on a group of almost exclusively handmade wares that are tempered with crushed slag the polarizing and electron microscopes explicitly identify these inclusions as copper smelting slag based on the slag as well as certain rock inclusions the slag tempered wares can be sourced to the copper districts in the wadi arabah and hence for the first time provide a link between the negev highlands and the arabah copper production centers in the period under review more specifically they demonstrate direct involvement of at least part of the pastoral nomadic negev highlands population in the copper extraction system

speleogenesis in highly geodynamic contexts the quaternary evolution of monte corchia multi level karst system alpi apuane italy abstract the mt corchia karst system is one of the most important and famous caves in the world different from many other large caves here the geological structure has had only a minor role on the vertical multi level pattern of the cave a detailed geomorphic and morphometric analysis of the cave and a preliminary study of cave sediments along with new datings of speleothems allow us now to depict the multistage evolution of this cave which produced at least three major paleo phreatic levels related to different base level stages the analysis of the directions of cave passages shows that the three main phases have different orientations which can be attributed to the different surface morphology during speleogenesis in former times chronological constraints and geomorphic features suggest that the upper part of mt corchia cave developed during the end of pliocene in a stage of favourable climatic conditions and with a moderate tectonic uplift rate the morphological features and the nature of sediments in the upper paleo phreatic level at 1350 1450 m above present sea level apsl imply the occurrence of a wide allogenic catchment area this drainage pattern persisted also in the following stage during a significant but slow lowering of the base level which allowed the formation and the intense vadose rearrangement of the epi phreatic network around 1100 1250 m apsl an uplift stage in the early pleistocene caused the capture of the basins and the loss of allogenic feeding a third epi phreatic level was formed at around 900 m apsl when the catchment area was reduced to the present extent of carbonate rock more than 1 ma ago the recent evolution is due to rapid uplift and to the progressive incision of surrounding basins which led to the lowering of the local base level and to a readjustment of the cave system in order to adapt to a new equilibrium with the present elevation of the springs

glass forming ability and crystallisation behaviour of sub alkaline silicate melts abstract the intrinsic solidification behaviour and glass forming ability gfa of natural sub alkaline silicate melts have been experimentally quantified via cooling induced solidification approach gfa is measured by the critical cooling rate rc the rate at which a melt solidifies 2 area of crystals cooling rates of 9000 1800 180 60 7 and 1 c h have been run between 1300 c super liquidus region and 800 c quenching temperature at air f o 2 and ambient p for six silicate melts with compositions ranging from basalt b to rhyolite r i e b 100 b 80 r 20 b 60 r 40 b 40 r 60 b 20 r 80 and r 100 and water contents comprised between 53 b 100 and 384 b 20 r 80 ppm the ranges of cooling rates and chemical compositions used in this study are the broadest ever investigated in the earth sciences the phase proportions area were determined by image analysis on about 500 back scattered electron images collected over different magnifications phases are glass clinopyroxene cpx spinel sp and plagioclase plg sp is ubiquitous with abundance of few area and nucleates earlier than silicate crystals cpx solidifies in all runs except in r 100 and its abundance follows asymmetric broad gaussian like trends with tails towards low rates as a function of cooling rate moving from b 100 to b 40 r 60 these trends conserve their shape but shift progressively to lower cooling rates and mineral abundances plg crystallises only at low cooling rates and in sio 2 poor compositions run products with low amounts of crystals 5 area clearly show that cpx preferentially nucleates on surfaces of sp whereas a significant crystallisation of cpx 5 area is observed with decreasing cooling rate and with changing composition from b 100 to b 20 r 80 the crystallisation of silicate crystals is related to the chemical diffusivity of components in the melt also the initial crystallisation of plg occurs preferentially on cpx in general the amount of crystals decreases as the cooling rate increases however in some cases the amount of crystals remains constant or even decreases for b 80 r 20 with decreasing cooling rate rc values change over 5 orders of magnitude being 100 b 20 r 80 b 40 r 60 b 60 r 40 and b 80 r 20 and b 100 respectively the variation of rc can be modelled through nbo t nonbridging oxygen per tetrahedron parameter by the following equation rc a 1 e nbo t b c where a b and c are fitting parameters equal to 9214 0 297 and 0 040 respectively similarly to other glass forming liquids network metallic and molecular systems rc for natural sub alkaline silicate melts is inversely related to the reduced glass transition parameter trg trg tg tm and can be quantified with the equation rc a trg b where a and b are 1 19 10 4 and 28 7 respectively these results may be used to retrieve the solidification conditions of aphyric degassed and oxidised lavas in addition our data provide general constrains on the crystallisation kinetics of natural crystal bearing silicate melts erupted on earth e g lavas with phenocrysts the relationship between crystal content and cooling rate suggests that the solidification path induced by degassing can be also complex and nonlinear the growth of crystals with size up to 1 mm from a nearly anhydrous superheated silicate melt indicates that variable cooling conditions of lavas have to be accounted to discriminate among minerals formed before during and after eruptions moreover our results can be used to design glass ceramics from naturally available easy to find low cost starting materials

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

fossil and recent debris flows in medium high mountains moravskoslezske beskydy mts czech republic abstract the significance of debris flows for the morphogenesis of the medium high mountains of central europe has long been neglected herein we provide evidence from the moravskoslezske beskydy mountains flysch western carpathians czech republic where fossil pleistocene debris flow events in spite of their low recent activity were important erosion and accumulation agents in shaping the mountainous terrain geomorphological and sedimentological analyses helped to differentiate between two classes of debris flow deposits deposits of the 1st class are relatively voluminous contemporary terraced landforms which originated in the pleistocene transport limited conditions recent activity of debris flows presented by the 2nd class accumulations is characterized by the presence of low magnitude events mostly originated during the reworking of older diamictons the inheritance of large volumes of old debris flow diamictons in steep mountainous terrain is the evidence of slow erosional transformation of the last glacial landforms pointing to the fact that recent topography of the mountains is not in full equilibrium with contemporary climatic and environmental conditions

a developmental model of olivine morphology as a function of the cooling rate and the degree of undercooling we performed dynamic crystallization experiments in the cmas system at 1 atm to investigate the evolution of the morphology of forsterite crystals as a function of cooling rate and degree of undercooling in sections parallel to the 010 plane we observed the evolution of the forsterite morphology from tablets to hopper skeletal crystals and then to swallowtail shapes dendritic morphology for increased degree of undercooling the other shapes described in the literature can be interpreted as particular sections of those three shapes the onset of dendritic growth is due to a competition between the growth of the faces of the initial hopper crystal and dendrite overgrowths the forsterite dendrites are formed by a succession of units which look like hopper shapes this result has been tested by an additional set of experiments

coastal cliffs rock slope failures and late quaternary transgressions of the black sea along southern crimea abstract rock slope failures represent a significant hazard along global coastlines but their chronology remains poorly documented here we focus on the geomorphology and chronology of giant rockslides affecting the crimean mountains along the black sea coast geomorphic evidence suggests that high 100 m limestone cliffs flanking the southern slopes of the crimean mountains are scarps of rockslides nested within larger deep seated gravitational slope deformations dsgsds such pervasive slope failures originated due to lateral spreading of intensively faulted late jurassic carbonate blocks moving atop weak plastic late triassic flysch and tuff layers by introducing a dating strategy relying on the combination of the uranium thorium dating u th of exposed calcareous speleothems covering the landslide scarps with the 36cl exposure dating of rock walls we are able to approximate the time interval between the origin of incipient crevices and the final collapse of limestone blocks that exposed the cliff faces for the three representative large scale rockslides between the towns of foros and yalta the initiation of the dsgsds as evidenced by the widening of crevices and the onset of speleothem accumulation was 300 ka bp but the recent cliff morphology along the coast is the result of late pleistocene holocene failures spanning 20 0 5 ka bp the exposures of rockslide scarps occurred mostly at 20 15 8 5 4 and 2 0 5 ka which substantially coincide with the last major black sea transgressions and or more humid holocene intervals our study suggests that before ultimate fast and or catastrophic slope failures the relaxation of rock massifs correlative with karstification cracks opening and incipient sliding lasted on the order of 104 105 years rapid late glacial holocene transgressions of the black sea likely represented the last impulse for the collapse of limestone blocks and the origin of giant rockslides simultaneously affecting the majority of the sw coast of the crimean peninsula