a large scale lateral spreading its genesis and quaternary evolution in the coastal sector between cogoleto and varazze liguria italy abstract the results of a study carried out on a coastal area of central western liguria northern italy where metamorphosed basic and ultrabasic rocks outcrop are presented the study indicates that a wide area 16 km 2 was involved in a large scale deep seated gravitational slope deformation dsgsd this movement has special features related to the lithology and structure of the involved rock mass to the plio quaternary uplifting and brittle tectonics affecting an area where a paleosurface was recognised and to the continental shelf dynamics the particular geometry of the dsgsd was recognised on the basis of detailed analyses of the above mentioned aspects due to its characteristics the deep seated deformation can be classified as a lateral spreading the current altitude of the pliocene marine clay outcrops and their deposition bathymetry allowed estimation of the uplift rate of the coastal area the altitudinal variations of an ancient marine terrace which was displaced by the dsgsd were used to reconstruct the chronology of the gravitational movement a final issue concerns the very large scale and the particular kind of phenomenon both of which are certainly new in liguria

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

effective electrode array in mapping karst hazards in electrical resistivity tomography when conducting environmental and engineering investigations in karst terranes engineers and geologists often supplement exploratory borehole results with data gathered from surface geophysics to reduce the site characterization cost and establish the most useful locations for borings or samples when conducting resistivity investigations a frequently occurring problem is the need to determine which of the many existing electrode configurations will respond best to the material changes in karst features each array has its advantages and disadvantages in terms of depth of investigation sensitivity to horizontal or vertical variations and signal strength in the application presented in this paper numerical forward modeling was conducted of dipole dipole schlumberger and wenner arrays and they produced markedly different anomaly shapes for a conceptual model of the development of a cover collapse sinkhole the resolution of the three above mentioned arrays was further evaluated along a section of i 70 near frederick maryland where a sinkhole had occurred in the median of the highway the image from the dipole dipole array appeared to be better than those from the wenner and schlumerger arrays in displaying the sinkhole collapse area however they are all less effective than a mixed array in which apparent resistivities from all the three arrays are combined and processed together in the model because the mixed array requires a significant increase in data collection the dipole dipole array appears to be the most effective and less costly configuration in mapping karst hazards areas this conclusion was then confirmed by two case studies

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

application of field geophysics in geomorphology advances and limitations exemplified by case studies abstract during the last decade the use of geophysical techniques has become popular in many geomorphological studies however the correct handling of geophysical instruments and the subsequent processing of the data they yield are difficult tasks furthermore the description and interpretation of geomorphological settings to which they apply can significantly influence the data gathering and subsequent modelling procedure e g achieving a maximum depth of 30 m requires a certain profile length and geophone spacing or a particular frequency of antenna for more than three decades geophysical techniques have been successfully applied for example in permafrost studies however in many cases complex or more heterogeneous subsurface structures could not be adequately interpreted due to limited computer facilities and time consuming calculations as a result of recent technical improvements geophysical techniques have been applied to a wider spectrum of geomorphological and geological settings this paper aims to present some examples of geomorphological studies that demonstrate the powerful integration of geophysical techniques and highlight some of the limitations of these techniques a focus has been given to the three most frequently used techniques in geomorphology to date namely ground penetrating radar seismic refraction and dc resistivity promising applications are reported for a broad range of landforms and environments such as talus slopes block fields landslides complex valley fill deposits karst and loess covered landforms a qualitative assessment highlights suitable landforms and environments the techniques can help to answer yet unsolved questions in geomorphological research regarding for example sediment thickness and internal structures however based on case studies it can be shown that the use of a single geophysical technique or a single interpretation tool is not recommended for many geomorphological surface and subsurface conditions as this may lead to significant errors in interpretation because of changing physical properties of the subsurface material e g sediment water content in many cases only a combination of two or sometimes even three geophysical methods gives sufficient insight to avoid serious misinterpretation a good practice guide has been framed that provides recommendations to enable the successful application of three important geophysical methods in geomorphology and to help users avoid making serious mistakes

a numerical comparison of 2d resistivity imaging with 10 electrode arrays numerical simulations are used to compare the resolution and efficiency of 2d resistivity imaging surveys for 10 electrode arrays the arrays analysed include polepole pp pole dipole pd half wenner hw wenner wn schlumberger sc dipole dipole dd wenner wb array gm multiple or moving gradient array gd and midpoint potential referred measurement mpr arrays five synthetic geological models simulating a buried channel a narrow conductive dike a narrow resistive dike dipping blocks and covered waste ponds were used to examine the surveying efficiency anomaly effects signal to noise ratios and the imaging capabilities of these arrays the responses to variations in the data density and noise sensitivities of these electrode configurations were also investigated using robust l1 norm inversion and smoothness constrained least squares l2 norm inversion for the five synthetic models the results show the following i gm and wn are less contaminated by noise than the other electrode arrays ii the relative anomaly effects for the different arrays vary with the geological models however the relatively high anomaly effects of pp gm and wb surveys do not always give a high resolution image pd dd and gd can yield better resolution images than gm pp wn and wb although they are more susceptible to noise contamination sc is also a strong candidate but is expected to give more edge effects iii the imaging quality of these arrays is relatively robust with respect to reductions in the data density of a multi electrode layout within the tested ranges iv the robust inversion generally gives better imaging results than the l2 norm inversion especially with noisy data except for the dipping block structure presented here v gd and mpr are well suited to multichannel surveying and gd may produce images that are comparable to those obtained with dd and pd accordingly the gd pd dd and sc arrays are strongly recommended for 2d resistivity imaging where the final choice will be determined by the expected geology the purpose of the survey and logistical considerations

mechanics of the scouring and sinking of submerged structures in a mobile bed a physical model study abstract wave induced flow velocity and turbulence may cause scouring in the seabed around coastal structures depending on the wave climate and tidal water depth a 3 d physical modelling study was conducted to investigate the possible causes of the sinking of two submerged coastal structures on the santa maria del mar smm beach spain the experimental investigation was conducted by employing a froude similarity law with a geometric scale of 1 20 and the submerged modular structure was subjected to different wave climates and tidal water levels the combinations of the significant wave height and peak period were chosen from in situ real wave conditions that were monitored during the sinking of the prototype structures linking and unlinking conditions for the modules in the structure were investigated in this study the results show that the modules sank to approximately 48 of their height at the end of the tests with storm waves and semi linking conditions of low water depth most of the experimental results were compatible with the prototype monitoring results tests with proper linking among the modules and tests with an appropriate gravel foundation resulted in a sustainable solution because they presented much less or almost no scouring and sinking

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

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

geophysical investigation of a large landslide in glaciolacustrine clays in the trieves area french alps abstract slope movements in clay deposits are spread all over the world and result from complex deformation processes including internal strains in the landslide body and slipping along rupture surfaces such mass movements are likely to generate changes in the geophysical parameters characterizing the ground which can be used to map the landslide body in the last decade geophysical techniques have been increasingly used for landslide investigation purposes however the success of any geophysical technique is overall controlled by the existence of a geophysical contrast differentiating the body to be mapped for landslides affecting thick clay materials from soft clay to shale or marl electrical and seismic techniques have been mainly applied in the past in this study we attempt to physically characterize the deformation within a large slide avignonet affecting laminated clays which were deposited in a glacially dammed lake during the wurm period clay deposits which cover an area of 300 km2 south of grenoble french alps and have a maximum thickness of 200 m overlay compact alluvial layers and marly limestone of mesozoic age piezometric data at avignonet show that the water table is very shallow implying that the slide developed in saturated clay several seismic and electrical profiles were performed in order to tentatively correlate the variations of p wave vp velocity s wave velocity vs and electrical resistivity with geotechnical data and morphological observations in such saturated and fine material it turned out that only the s wave velocity exhibits significant variations with the displacement rates and the morphological features vs values at shallow depth were found to be inversely correlated with displacement rates measured by gps with a division by at least a factor of 2 between the zones unaffected and strongly deformed by the landslide these results suggest that vs mapping could provide valuable information on the deformation state of the clay material and that the evolution of vs with time could be used as an indicator for characterizing the landslide activity in the subsurface including the evolution into a flow

from deep seated slope deformation to rock avalanche destabilization and transportation models of the sierre landslide switzerland abstract sackung is a widespread post glacial morphological feature affecting alpine mountains and creating characteristic geomorphological expression that can be detected from topography over long time evolution internal deformation can lead to the formation of rapidly moving phenomena such as a rock slide or rock avalanche in this study a detailed description of the sierre rock avalanche sw switzerland is presented this convex shaped postglacial instability is one of the larger rock avalanche in the alps involving more than 1 5 billion m3 with a run out distance of about 14 km and extremely low fahrboschung angle this study presents comprehensive analyses of the structural and geological characteristics leading to the development of the sierre rock avalanche in particular by combining field observations digital elevation model analyses and numerical modelling the strong influence of both ductile and brittle tectonic structures on the failure mechanism and on the failure surface geometry is highlighted the detection of pre failure deformation indicates that the development of the rock avalanche corresponds to the last evolutionary stage of a pre existing deep seated gravitational slope instability these analyses accompanied by the dating and the characterization of rock avalanche deposits allow the proposal of a destabilization model that clarifies the different phases leading to the development of the sierre rock avalanche

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

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

deep geophysical investigation of the large sechilienne landslide western alps france and calibration with geological data a geophysical imaging campaign including four 950 m electrical profiles and four 470 m long seismic profiles was performed on the large sechilienne landslide with the objective of constraining the depth and the volume of the affected zone compared to the undisturbed ground the moving area exhibits lower velocity and higher resistivity values comparison with existing geodetic geomorphic and geological data investigation gallery and borehole allowed showing that these geophysical parameter variations result from intense fracturing and the progressive development of air filled voids within the moving mass a maximum thickness of 150 m to 200 m was found in the most deconsolidated zones locally near vertical very low resistivity anomalies were evidenced related to cataclasis zones filled with clayey material applying the wyllie s experimental law rock mass porosity images were derived from seismic tomography profiles porosity between 30 and 4 was found from the top to the bottom of the deconsolidated zone explaining the deep water table considering a porosity threshold of 3 7 for the sound bedrock the total volume of the sechilienne landslide was estimated to about 60 10 106 m3 a more precise bracket than the previous estimations 20 106 to 100 106 m3

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

regional mapping and characterisation of old landslides in hilly regions using lidar based imagery in southern flanders abstract analysis of lidar derived imagery led to the discovery of more than 330 pre holocene to recent landslides in southern flanders 4850 km 2 the morphology of three landslides including the 266 5 ha deep seated gravitational slope deformation in alden biesen was investigated in more detail the analysis of the morphological and topographical characteristics width length relation frequency area distribution and topographical threshold of the landslides revealed important differences compared to the characteristics reported in other landslide studies and helped understanding possible landslide triggering mechanisms especially the possibility of a seismic origin of the landslides was investigated finally a heuristic model for region wide landslide susceptibility mapping was successfully tested the susceptibility model and map allow prediction of future landslide locations and contribute to better understanding the role of individual causal factors on landslide location and spatial density the results suggest that landslides on low gradient soil mantled hills are a more important contributor to landscape evolution of hilly areas than was hitherto thought the morphology of all hilly regions of flanders is clearly marked by landslide processes and higher landslide densities often coincide with the presence of quaternary active faults this study further shows that high resolution topographical data such as lidar significantly contributes to a better detection of old previously unknown landslides

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

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

preliminary phanerozoic polar wander paths for the north and south china blocks polar wander paths for the north and south china blocks suggest that 1 both were parts of gondwana in the palaeozoic 2 the north china block accreted to siberia in the late permian and 3 the south china block accreted to the north china block in the middle triassic to the early jurassic comparison of the polar wander path for the south china block with that for northern eurasia suggests that relative motion of over 4 000 km has occurred between them

large sackung along major tectonic features in the central italian alps deep seated gravitational slope deformation sackung is common in alpine mountain belts it is controlled by lithological geomorphological and structural features we describe and discuss five examples of dsgsd along the insubric line periadriatic fault in the central italian alps the five examples are different in morphology size state of activity and distribution and are located along both primary and secondary valleys we demonstrate relations between structural and gravitational features and discuss the possibility that structural has both passive and active roles in sackung development analysis of ps sar data shows that the studied examples are not active today numerical modelling demonstrates the importance of lithological and structural constraints postglacial debuttressing groundwater fluctuations and weathering on sackung triggering and development

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

evolution stages of large deep seated landslides at the front of a subalpine meridional chain maritime alps france abstract studying long term evolution of gravitational slope evolution is a key to understanding deep seated landslide processes this paper deals with three large deep seated landslides dsls at a front of a subalpine meridional chain on the la marbriere slope near the town of grasse alpes maritimes france the geological framework controlling the stability and morphology of the dsls is associated with thick and tamped triassic layers of mudstone with gypsum overlain by highly faulted jurassic limestone gravitational deformation affects the entire slope involving a movement of about 1 1 10 8 m 3 of rock material it creates large disturbances in landscape morphology such as scarps counter slope scarps trenches and other typical gravitational morpho structures geomorphological mapping coupled with deep electrical resistivity tomography ert reveals a strong correlation between these morpho structures and inherited brittle tectonic features this observation relies on spatial and geometrical relations on the surface and at the depth of more than 150 m checked by ert between the most persistent fault and the gravitational morpho structures the specific distribution of the morpho structures on the basis of their morphological typologies and variations in the stage of evolution of three dsls provides an interpretation of their kinematics during the last 400 ka it appears that soft substratums combined with inherited persistent anisotropies are key factors in the development of the dsls indeed outflow of mudstone due to the lithostatic pressure imposed by individual limestone compartments has led to general slope subsidence then a progressive toppling of a rock mass may have led to the catastrophic rock collapse along bedding planes the evolution of the dsls can be divided into three distinct stages represented by three zones a young collapse stage zone 1 a pre collapse stage zone 2 and an old mature stage 400 ka zone 3 as the dsls occur on the same slope and in the same geological context this area offers interesting perspectives for understanding factors controlling the long term gravitational evolution of slopes

tectonic vs gravitational morphostructures in the central eastern alps italy constraints on the recent evolution of the mountain range abstract deep seated gravitational slope deformations dsgsds influence landscape development in tectonically active mountain ranges nevertheless the relationships among tectonics dsgsds and topography are poorly known in this paper the distribution of dsgsds and their relationships with tectonic structures and active processes surface processes and topography were investigated at different scales over 100 dsgsds were mapped in a 5000 km2 sector of the central eastern alps between the valtellina engadine and venosta valleys detailed lineament mapping was carried out by photo interpretation in a smaller area about 750 km2 including the upper valtellina and val venosta fault populations were also analysed in the field and their mechanisms unravelled allowing to identify different structural stages the youngest being consistent with the regional pattern of the ongoing crustal deformation finally four dsgsd examples have been investigated in detail by geological and 2d geomechanical modelling dsgsds affect more than 10 of the study area and mainly cluster in areas where anisotropic fractured rock mass and high local relief occur their onset and development is subjected to a strong passive control by mesoscopic and major tectonic features including regional nappe boundaries as well as nw se n s and ne sw trending recent brittle structures the kinematic consistency between these structures and the pattern of seismicity suggests that active tectonics may force dsgsds although field evidence and numerical models indicate slope debuttressing related to deglaciation as a primary triggering mechanism

quaternary gravitational morpho genesis of central apennines italy insights from the mt genzana case history abstract this paper focuses on a study aimed at defining the role of geological structural setting and quaternary morpho structural evolution on the onset and development of a deep seated gravitational slope deformation which affects the western slope of mt genzana ridge central apennines italy this case history is particularly significant as it comprises several aspects of such gravitational processes both in general terms and with particular reference to the apennines in fact i the morpho structural setting is representative of widespread conditions in central apennines ii the deforming slope partially evolved in a large rockslide avalanche iii the deformational process provides evidence of an ongoing state of activity iv the rockslide avalanche debris formed a stable natural dam thus implying significant variations in the morphologic hydraulic and hydrogeological setting v the gravitational deformation as well as the rockslide avalanche reveal a strong structural control the main study activities were addressed to define a detailed geological model of the gravity driven process by means of geological structural geomorphological and geomechanical surveys as a result a robust hypothesis about the kinematics of the process was possible with particular reference to the identification of geological structural constraints the process in fact involves a specific section of the slope exactly where a dextral transtensional structure is present thus implying local structural conditions that favor sliding processes the rock mass is intensively jointed by high angle discontinuity sets and the bedding attitude is quite parallel to the slope angle within this frame the gravitational process can be classified as a structurally constrained translational slide locally evolved into a rockslide avalanche the activation of such a deformation can be in its turn related to the quaternary morphological evolution of the area which was affected by a significant topographic stress increase testified by stratigraphic and morphologic evidence