a coupled hydrodynamic modeling system for phailin cyclone in the bay of bengal abstract east coast of india is characterized by low to medium topography and an extensive network of major estuaries bays mangrove creeks rivers and tidal inlets that permit inland flooding during tropical cyclones a coupled wave surge hydrodynamic modeling system adcirc swan is implemented to simulate storm surge still water level elevation and wave induced setup associated with phailin a very severe cyclonic storm that made landfall in the odisha state east coast of india during october 2013 the coupled model provides a realistic description on the dynamic interaction of tides wind waves and currents which is critical for operational needs the study assesses the role of wave induced setup on the net water level elevation using time varying wave radiation stress that is dynamically updated in the coupled model run numerical experiments are carried out for both storm surge alone and coupled mode versions dependent upon complex bathymetry and coastal geometry inclusion of wave induced setup in coupled runs results in an additional 23 36 increase of peak surge relative to an uncoupled surge tide simulation the significant wave height from coupled model also shows an excellent match with observed wave heights from a wave rider buoy located off the odisha coast the comparison of surge residuals between model and observation also exhibits a good match the study highlights the importance of having a coupled wave hydrodynamic model for operational needs in the north indian ocean

missing aragonitic biota and the diagenetic evolution of heterozoan carbonates a case study from the oligo miocene of the central mediterranean abstract several previous studies have addressed the diagenetic evolution of heterozoan carbonate assemblages generally it is assumed that early diagenetic processes in heterozoan settings are mainly destructive including abrasion and dissolution on the sea floor constructive diagenesis cementation is delayed to later stages in the burial environment with pressure solution of calcitic grains acting as a cement source this paper presents a study of oligo miocene inner to outer ramp heterozoan carbonates from the central mediterranean maltese islands and sicily indicating that early diagenetic processes are more important than previously assumed four to five different cement types including fibrous two types of epitaxial bladed and blocky cement are distinguished based on transmitted light microscopy cathodoluminescence microscopy allowed a differentiation between primary high mg calcitic fibrous and epitaxial cement i and primary low mg calcitic epitaxial cement ii bladed and blocky cements stable isotope data indicate cement precipitation from marine marine derived and meteoric waters trace element analyses point to cementation in an open system maltese islands and a closed system sicily our investigations show that the majority of constructive diagenetic processes in these rocks occurs rather early in the shallow marine burial environment which is transitional between the marine seafloor and the deep burial diagenetic environment the main cement source in this environment is assumed to be aragonite we suggest careful consideration of the importance of aragonitic components in fossil heterozoan settings which seem to be more abundant than previously assumed and can act as a major early cement source due to the low preservation potential of these components detailed geochemical studies are necessary to detect aragonite as the cement source our findings also have implications when considering the reservoir qualities of these rocks because primary porosity can be occluded early and secondary porosity is not preserved

seismic property characterization of lithotypes cropping out in the siracusa urban area italy the town of siracusa is located in the south eastern coast of sicily southern italy in a wide inlet engraved into a limestone formation this lithotype which is overlaid by soft sediments such as sandy clays and detritus can be considered as the local bedrock present study aims to investigate on the dynamic properties of main lithotypes outcropping in the study area and their relationships with the local seismic response non invasive seismic prospecting techniques using the vertical component of surface waves masw and remi were adopted as well as ambient noise measurements processed through the nakamura technique the best solution for the experimental dispersion curves was selected using the neighbourhood algorithm and information about the deeper part of the estimated shear wave profiles was obtained by considering the ellipticity of the fundamental peak moreover a cluster analysis was performed to subdivide into homogeneous groups the experimental noise spectral ratios results obtained pointed out that the use of combined different methods provides a robust way to characterize the investigated soils and to reduce the problems linked to the non uniqueness of solutions during the interpretation of geophysical data

evolution of the northwestern iblean mountains sicily uplift plicocene pleistocene sea level changes paleoenvironment and volcanism the late miocene to pleistocene evolution of the northwestern iblean plateau sicily is marked by a complex interplay of subaerial and submarine volcanism subsidence and uplift eustatic sea level changes and shallow water carbonate and clay sedimentation volcanic activity occurred in distinct phases differing drastically in volume chemical composition eruptive and depositional sites and eruptive mechanisms six of the newly defined formations in the northwestern iblean plateau are either entirely volcanic or contain significant amounts of volcanics the eastern part of a shallow marine basin was filled completely by late pliocene tholeiitic lava flows militello formation that had advanced subaerially from the south southeast lava deltas advanced southwestward on top of earlier pillow breccia debris flow deposits intertongued with soft trubi marls and chalks true submarine eruptions monte caliella formation simultaneously produced densely packed pillow piles up to 250 m thick inferred water depths based on volcanologic and paleoecologic criteria of interbedded and overlying calcarenites agree well

volcanic edifice weakening via decarbonation a self limiting process 1 the inherent instability of volcanic edifices and their resultant propensity for catastrophic collapse is a constant source of volcanic risk structural instability of volcanic edifices may be amplified by the presence of carbonate rocks in the sub volcanic strata due to the debilitating response of carbonates to thermally induced alteration nonetheless decarbonation reactions the primary weakening mechanism may stall when the system becomes buffered by rising levels of a reaction product carbon dioxide such thermodynamic stalling might be inferred to serve to circumvent the weakness of volcanic structures however the present study shows that even when decarbonation is halted rock physical properties continue to degrade due to thermal microcracking furthermore as a result the pathways for the escape of carbon dioxide are numerous within a volcanic edifice therefore in the case of an edifice with a sub volcanic sedimentary basement the generation of carbon dioxide via decarbonation is unlikely to hinder its impact on instability and thus potentially devastating flank collapse

the distribution and palaeoenvironment of early miocene phosphorites of southeast sicily and their relationships with the maltese phosphorites abstract several phosphatic limestone localites occur within the irminio member ragusa formation of the western hyblean of southeast sicily in areas of maximum development such as around sampieri and modica the phosphatized intraslcast dominated deposits attain a thickness of up to 0 6m and are associated with a phosphatized underlying hardground thin and possibly discontinous spreads of phosphatized intraclast form a broader zone beyond the central semi autochthonous zone microfossil analysis of associated strata demonstrates that all occurences of phosphatized strata within the irminio member are restricted to a single level of probable late burdigalian early miocene age the bed correlates well both biostratigraphically and lithologically with the upper main phosphorite conglomerate bed of the maltese islands which lie c 95 km south of the sicilian province five more distinct phosphorite beds occur in the maltese islands being best developed in the western and northern parts of the islands they range in age from aquitanian to late burdigalian these are principally francolite replaced micrate conglomerates which may be associated with phosphatized underlying hardgrounds in places a major central mediterranean phosphatogenic province of early miocene age is postulated inorder to account for the simultaneous occurrence of phosphorites in sicily and malta

impact of carbonate producing biota on platform architecture insights from miocene examples of the mediterranean region abstract different types of carbonate platforms formed in the mediterranean during the miocene low angle homoclinal types of ramp distally steepened ramps flat topped platforms and reef rimmed shelves the critical differences between these platforms result from differences in the capacities of the carbonate systems to accumulate sediments above hydrodynamic base level ecologically controlled accommodation the various depositional profiles and facies belt distributions resulted from the interplay between different sediment production and redistribution processes and the internal architectures resulted from the response of each type of platform to changes in accommodation heterogeneities driven by high frequency sea level cycles are maximized in platforms ruled by shallow water euphotic framework dominated production and minimized in low angle ramps where sediment resulted from aphotic and oligophotic carbonate production in the mediterranean region there is no direct relationship between type of platform and global temperature as shown by the coeval occurrence of different platforms in similar latitudinal settings although temperature is a key limiting factor other paleoceanographic factors such as trophic resources may have also been along with biological evolution important factors influencing different types of carbonate producing biotas

iblean diatremes 2 shallow marine volcanism in the central mediterranean at the onset of the messinian salinity crisis iblean mountains se sicily a multidisciplinary approach a multidisciplinary analysis of intraplate volcanic complexes interbedded with shallow and deeper marine sediments of a late miocene carbonate platform iblean plateau sicily has allowed a detailed paleo environmental reconstruction our approach includes sedimentology physical volcanology stratigraphy geochemistry mineralogy paleontology and 40ar 39ar dating four volcanic complexes are distinguished from each other two comprise an eastern shallow water platform diatreme field and carlentini complex and two a western deeper water environment representing a seamount belt on the carbonate ramp valle guffari seamount and mineo complex the late miocene volcanism was not time equivalent episodic eruptions took place from the late tortonian ca 9 38 ma at mt carrubba to early messinian ca 6 46 ma at valle guffari explosive volcanism of the diatreme field may be related geodynamically to the period of periodic sea level oscillations at the onset of the messinian salinity crisis marine diatomites preserved in the crater areas of two diatremes are the only remnants of early messinian diatomites in the eastern iblean mountains

crustal structure variations and transcurrent faulting at the eastern and western margins of the eastern mediterranean abstract crustal structure variations within the crust of the eastern mediterranean as well as within the continental crust of the land areas east and west of the basin have caused segmentation of the collision zones which extend from sicily through the calabrian arc the hellenic arc and the cyprian arc to the taurus chain on both sides of the eastern mediterranean in southeastern sicily and in the levant similar tectonic features have developed hinge faults exist along both continental margins due to the different modes of collision between the land areas and the adjacent oceanic areas landward of the margins two large transcurrent fault systems the scicli fault zone and the dead sea rift have developed due to the existence of unique crustal units within the continental crust adjacent to the margins on both sides these units are more buoyant than the adjacent crust and resist underthrusting the initial faulting along both transcurrent fault systems probably started at the collision zone in the north and propagated to the south where large extensional areas the pantelleria rift and the red sea exist

integrated micropalaeontological study ostracods and calcareous plankton of the langhian western hyblean successions sicily italy abstract four sections cropping out in the hyblean plateau se sicily were studied biostratigraphically and palaeoecologically the investigated succession was referred to the early late langhian on the basis of both the planktonic foraminifers lowermost part of the praeorbulina glomerosa sicana subzone lowermost part of the orbulina universa subzone and the calcareous nannofossils uppermost part of the mnn4a zone lowermost part of the mnn5b subzone all the biozonal markers were recorded and further significant events were identified the most remarkable ones are two paracmes of paragloborotalia siakensis within the p glomerosa sicana subzone and the distribution of helicosphaera waltrans which characterises the upper part of the mnn5a subzone the ostracod palaeoecological analysis indicated a progressive and gradual trend from thermospheric to psychrospheric conditions and probably a basin deepening from upper to lower epibathyal the flowing of deep atlantic waters into the basin is documented by the entry of the psychrospheric species agrenocythere hazelae within the upper part of the p glomerosa sicana subzone only in the late langhian however were typical psychrospheric conditions probably reached these data provide evidence that oceanic deep water masses reached the central mediterranean passing through both the western connections to the atlantic ocean and the african sicilian threshold during a great part of the langhian

sedimentary and tectonic evolution of the eastern hyblean plateau southeastern sicily during late cretaceous to quaternary time abstract two palaeogeographic domains have been distinguished in the cretaceous quaternary sequences which crop out in the hyblean region of southeastern sicily in the northeast shallow water algal bryozoan calcarenites of oligocene miocene age overlie either cretaceous rudist limestones or volcanics further to the northeast the stratigraphic gap increases as the miocene limestone thins and in the a g i p well catania 10 plio pleistocene sediments and volcanics directly overlie upper jurassic rocks in the southwestern part of the hyblean plateau pelagic sediments occupy the cretaceous miocene interval they were deposited in a shallow basin dipping gently towards the southwest the transition between the two zones is marked by much evidence of synsedimentary tectonic activity such as widespread slumping and the development of megabreccias composed of cretaceous and eocene blocks the palaeogeographic picture is one of carbonate reefs and volcanic seamounts developing in the upper cretaceous they formed platforms fault bounded to the west and southwest from which were derived the detrital sediments found in the basin and occasional spectacular gravity slides in present day terms the structural high probably corresponds to the northeastern margin of the hyblean plateau and in part to the siracusa syracuse malta escarpment the pattern is little changed in the upper miocene with volcanoclastics of phreatomagmatic origin intercalated with coral bioherms overlying algal bryozoan calcarenites upper tortonian lower messinian limestones with a restricted fauna indicate a shallow water environment which grades up into continental conditions in the eastern hyblean plateau the tertiary sequence is capped by pliocene submarine to subaerial mafic lava flows lower pleistocene sediments consist of biocalcarenites and clays which fill deep graben delimited by plio pleistocene faults the inshore continuation of the malta syracuse escarpment system of faults from a tectonic standpoint the hyblean region a gently deformed segment of the african continental margin acted as a foreland during tertiary times a cretaceous eocene tectonic phase was responsible for the palaeogeographic pattern which existed during most of the cenozoic the present pattern is the result of three main tectonic phases following the regional upper miocene uplift of early middle pliocene plio pleistocene and middle pleistocene recent age which influenced the tectonic evolution of the present ionian coast and the malta syracuse escarpment

large boulder deposits by tsunami waves along the ionian coast of south eastern sicily italy abstract the ionian coast of south eastern sicily between the towns of augusta and siracusa is characterized by the occurrence of anomalous calcareous boulders they are mostly scattered along large terraces located 2 5 m above sea level gently sloping towards the sea boulders are up to 182 t in weight and are arranged either in isolated elements or small groups composed of a few stacked elements several boulders show biogenic encrustations serpulids balanids lithophaga all over their surface which suggest that they were dragged from the mid sublittoral zone other boulders are partially covered by biogenic encrustations and show morphological features karstic pools exposed fracture surfaces suggesting that they were detached and scattered from the mid supralittoral zone direct observations on each boulder distance from the shoreline size and weight together with statistical analysis of the storm regime of the area allowed to operate hydrodynamic estimations useful to verify if tsunami or storm waves were responsible for their detachment and transport while radiocarbon age determinations on marine organisms constrained the timing collected data compared to historical catalogues suggest that in the last 1000 years three seismic events with local sources could have triggered tsunami waves associated with the boulder deposits occurring in the area the first two were probably triggered by the earthquakes of february 4 1169 and january 11 1693 which destroyed south eastern sicily according to geological data and numerical modelling the seismogenic source could be located in the ionian offshore between catania and siracusa the third tsunami was generated by the strong earthquake which took place in the strait of messina on december 28 1908

regional deformation and offshore crustal local faulting as combined processes to explain uplift through time constrained by investigating differentially uplifted late quaternary palaeoshorelines the foreland hyblean plateau se sicily

integrated planktonic foraminifera bolboforma and carbon isotope stratigraphy in a mid early late miocene carbonate ramp setting from the acreide area sicily taxa of bolboforma a marine calcareous microfossil group of uncertain origin with affinities to protophytic algae are generally used for biostratigraphy of lower eocene to lower pleistocene marine sediments from high latitudes biostratigraphy based on bolboforma has been applied only rarely to european outcrop sections and very rarely to mediterranean sections three bolboforma and two planktonic foraminifera events are identified and used to interpret the sedimentation rate of the 90 m of slope sediments from the palazzolo section palazzolo acreide area sicily and spanning the interval from 11 9 to approximately 10 5 ma carbon isotope stratigraphy supports the age assigment based on bolboforma and planktonic foraminifera in particular the sediments of the palazzolo section seem to record the latest pulse of the monterey event a major perturbation in the global carbon cycle related to global intensification of upwelling expanded use of the bolboforma may thus improve stratigraphy in outcropping miocene sequences in temperate regions particularly in shallower water facies with poorly resolved planktonic foraminifera and nannofossil stratigraphy

palaeoenvironmental paleontologic and stratigraphic significance of vertebrate remains in pleistocene limnic and alluvial deposits from southeastern sicily abstract in southeastern sicily on the hyblean plateau limnic deposits overlie early pleistocene marine sediments and are covered by early middle pleistocene marine sands in the limnic deposits fossil remains of large mammals have been collected and these represent the oldest found in a well established pleistocene stratigraphic succession in sicily the faunal association includes elephas falconeri busk the smallest sicilian elephant an elephant less reduced in size than e falconeri a canid vulpes sp rodents leithia melitensis adams chiroptera insectivora fishes birds amphibians bufo sp discoglossus sp and reptiles lacerta sp testudo sp emys orbicularis linnaeus alluvial fan deposits overlying the limnic deposits contain elephas mnaidriensis adams hippopotamus pentlandi meyer cervus siciliae pohlig and bovidae these new findings provide the stratigraphic evidence to definitively discredit previous chronological schemes for the pleistocene dwarf elephants which assumed a progressive decrease of the size with time a hypothesis recently questioned by isoleucine epimerization age determination which however were object of discussion these findings also represent a new step toward a better knowledge of the taphonomic conditions of the pleistocene mammal bearing deposits in mediterranean islands traditionally linked to karstic environment distribution of mammal faunas in the hyblean plateau proves fundamental in recognizing and dating pleistocene mammal faunas in sicily the new findings fully confirm the assumption that sicily experienced two elephant immigrations in pleistocene times

late tortonian lower messinian miocene palaeogeography of se sicily information from two new formations of the sorting group abstract a thick volcanoclastic biohermal and lagoonal sequence of strata succeeds the siracusa limestone member monti climiti formation of se sicily this overlying sequence may be divided into two new formations on the basis of lithostratigraphy petrology and palaeontology the older formation here named the carlentini formation is predominantly a thick volcanoclastic sequence but with two intervening carbonate horizons faunas are rare within the volcanic strata but may be abundant and associated with corals and patch reefs within the two carbonate levels the younger formation here named the monte carrubba formation is almost exclusively composed of oolitic grainstones and lagoonal wackestones peritidal carbonates are developed in the northeast of the area faunas are frequently of low diversity euryhaline mollusc associations are dominant although pecten vigolenesis occurs in the lower beds collectively the new formations span the late tortonian lower messinian time interval and may be correlated with the calcare di base of the main sicilian basin to the west the palaeoenvironmental reconstruction suggests that both formations were deposited around the sw margins to a low island or landmass lying to the north of the hyblean region

stress strain and mass changes at mt etna during the period between the 1991 93 and 2001 flank eruptions abstract during the 8 year period between the 1991 93 and 2001 flank eruptions the eruptive activity of mt etna was confined to the summit craters deformation and tomography studies indicate that this activity was fed by a magma accumulation zone centered ne of the summit at a depth of 5 to 9 km below sea level the most significant gravity changes measured during the same period were induced by mass redistributions at shallower depth below the southeastern flank of the volcano where minor ground deformation was observed i e vertical displacements within 2 cm the mismatch between the position of pressure and mass sources is difficult to explain under the assumption that both are directly related to magma dynamics past studies have suggested that the gravity changes observed during 1994 2001 may primarily reflect changes in the rate of microfracturing along the nnw sse fracture weakness zone fwz that crosses the se slope of etna we use the finite element method to shed new light on the complex relations between stress strain and mass changes that occurred at etna during the studied period in particular following previous results on the degradation of the mechanical properties of rocks we perform a set of simulations assuming that the part of the medium containing the fwz is characterized by a lower young s modulus than would be expected from interpolation of tomographic data we find that the presence of the fwz creates a distortion of the displacement field induced by the deeper pressure source locally resulting in a weak extensional regime this finding supports the hypothesis of a cause effect relationship between pressurization beneath the nw flank and tensile extension beneath the se slope of the volcano we propose that this extensional regime enhanced the propagation of pressurized gas that in turn amplified the tensile strain across the fwz we also find that decreasing the value of young s modulus in the fwz allows for a larger amount of extension at depth with no change in the magnitude of surface displacements this result provides an indication of how the changes in the rate of microfracturing at depth which are needed to induce the observed gravity changes might have occurred without large ground deformation

magma serpentinite interaction as the origin of diatremes a case study from the hyblean plateau southeastern sicily some diatremes formed in the hyblean plateau in a time span from 6 5 to 9 4 ma producing volcaniclastic deposits which host deep seated xenoliths the origin of the explosive activity that has brecciated the magma and the country rocks is controversial two are the prevalent models phreatomagmatic and magmatic brecciation we propose an alternative explanation based on the thermal and mechanical interaction of a rising basaltic magma with serpentinized mantle rocks representing the main lithologies in the permo triassic hyblean basement we suggest that magma serpentinite interaction could have remobilized fluids from serpentinites that reached the overpressure necessary for the brecciation of country rocks the possible depth of this interaction has been estimated considering variations of porosity and permeability at different depths in the hyblean lithosphere these properties have been taken into account in the dimensionless parameter v e jamtveit et al in physical geology of high level magmatic systems vol 234 geological society london special publications london pp 233 241 2004 which reflects the relative rates of heat and fluid transport since a high fluid flux is enhanced by a high boiling temperature of pore water raised by magma rock heat exchange v e remains less than 1 up to a depth of 7 km corresponding to the average thickness of the sedimentary volcanic sequence characterized by a high permeability k 10 12 10 14 m2 that inhibits fluid overpressure built up in contrast to both phreatomagmatic and magmatic models at deeper levels k 10 19 m2 from 8 km downward the value of v e is greater than 1 therefore we propose that the dehydration of serpentinites upon heating by hot basaltic magma would have liberated huge amounts of fluids whose accumulation at an average depth of 8 km beneath the impermeable serpentinized level induced supercritical fluid overpressure strong enough to exceed the lithospheric pressure fluid overpressure caused the opening of fractures in the overlying permeable upper crust triggering the energetic fluid expansion and hence the brecciation of country rocks finally we suppose that aforementioned conditions for supercritical fluid overpressure could have been gained in other areas of the hyblean region in coincidence with various mesozoic volcanic events even though older diatremes may have been obliterated by subsequent sedimentary cycles and volcanic events as well as in serpentinite diatremes in the navajo volcanic field colorado plateau sw usa

an ams structural and paleomagnetic study of quaternary deformation in eastern sicily abstract an integrated structural anisotropy of magnetic susceptibility ams and paleomagnetic study was carried out on plio pleistocene sedimentary basins in eastern sicily these basins belong to three main tectonic domains the tyrrhenian hinterland domain the catania foredeep domain and the hyblean foreland domain we sampled 329 oriented samples from 25 sites in selected areas from the different tectonic domains the ams is typical for weakly deformed sediments with a magnetic foliation sub parallel to the bedding plane and a well defined magnetic lineation the orientation of the magnetic lineation is strongly controlled by the main tectonic deformation recorded in the basins structural and ams data define a transition from nw se extension in the tyrrhenian hinterland domain to e w compression in the catania foredeep domain to e w extension in the hyblean foreland domain respectively reliable paleomagnetic results have been obtained in 12 out of 25 sampled sites data show that no significant rotations occurred in any of the studied basins at least since the middle pleistocene these results allow us to define an upper limit to the large rotations about vertical axes that have been previously found in the calabria and sicily regions

gravity slide and resedimentation processes in a miocene carbonate ramp hyblean platcau southeastern sicily abstract more than twenty sharp based channel form structures occur in the miocene palazzolo formation carbonates within a distally steepened se sicilian miocene carbonate ramp contemporaneous biota indicate deposition in water depths of 70 150 m fully exposed structures commonly exceed one kilometre along palacostrike their bases are concordant with the host strata but these steepen to 15 in proximity of their margins internal bedding planes generally are concordant with the basal truncation surface the lithologies of the channel fills are similar to the host sediment there is little evidence that these structures are erosional since they contain neither breccias nor turbidites rather they are interpreted as the product of gravitational sliding involving thin detached sheets of consolidated ramp carbonates the resulting irregular topography was draped by redeposited fine grained carbonate sediments once healed and further oversteepened renewed gravity sliding occurred this resulted in a 250 m thick slide dominated succession in a zone 4 km wide located between the outer ramp apron comprised of coralline algal and foraminifera rich sediments and basin margin pelagic marls this phenomenon although unusual in shallow water settings is well known from modern continental slope environments sliding was probably triggered by seismicity in the region associated with two known mesozoic basement faults an alternative hypothesis involving pressure gradient build up along distally steepened ramp zones during storm surges is dismissed as a cause although this mechanism may have facilitated resedimentation of seafloor sediments over the slide zone

tectonic analysis of a flexed foreland the ragusa platform abstract detailed field studies of fracture patterns and paleostress reconstructions based on analyses of fault slip data sets allow the identification of the late cenozoic stress pattern evolution of the ragusa platform during the late miocene to early pleistocene period a complex extensional pattern developed it was dominated in almost the entire hyblean plateau by nw se to nnw sse extensions related to the flexure of the foreland under the load of the allochthonous units of the sicilian fold and thrust belt these extensional tectonics were characterized by ne sw to ene wsw trending normal faults and grabens in eastern hyblea ne sw to ene wsw extension have prevailed at least since the late cretaceous they are linked to the effects of the malta escarpment in the western ragusa platform a third minor wnw ese extension associated with sets of nne ssw trending normal faults may be correlated with the development of the gela basin in addition these major extensions induced complex patterns of perpendicular normal fault systems through permutations between the principal stress axes 2 and 3 the pliocene pleistocene extensional paleostress field evolution is marked in almost the entire platform by the alternation of two or three main extensional stress patterns ne sw to nnw sse wnw ese and ne sw to ene wsw extensions each of them controlled by particular boundary conditions three minor compressional paleostress orientations have been identified they correspond to three minor compressional events dominated by 020 030 070 080 and 100 110 compressional directions these events occurred in within the general pliocene pleistocene extensive context the 100 110 event is of early middle pliocene age its large regional distribution suggests that this event may have resulted from interactions between the major blocks constituting the africa eurasian boundary the relative chronology shows that the 020 030 compression predates the 070 080 one the origins of these compressional events are still uncertain due to poor regional control

fault reactivation by stress pattern reorganization in the hyblean foreland domain of se sicily italy and seismotectonic implications abstract between the october 2011 and the july 2012 several seismic swarms occurred in the hyblean foreland domain of se sicily italy along the cavagrande canyon one of the most impressive fluvial incisions of sicily despite the low magnitude of the events main shock with m 3 7 they represent the biggest strain release of the hyblean area over the last 10 years a careful waveform analysis of the earthquakes revealed that most of them form a family of multiplets these findings allow us to reconstruct the attitude of the accountable fault plane by interpolating their high precision 3d location parameters into a gis platform a detailed morpho structural analysis performed at the ideal updip projection of the modeled plane showed that during the middle late pleistocene the epicentral area has been deformed by a belt of extensional faults a segment of which matches well with the computer generated surface despite the field evidence computed focal solutions support contrasting strike slip kinematics on the same fault plane clearly indicating a dextral shearing on this pre existing normal fault the seismic swarms nucleated on a small rupture area along a 10 km long nw se trending fault segment that could be able to generate m 6 earthquakes following our analysis and looking at seismicity distribution in the se portion of hyblean area we assess that a stress pattern reorganization occurred all over the hyblean foreland between the late pleistocene and present day change in the trajectory of the max stress axes from vertical to horizontal seems to have involved a pre existing large scale fault configuration with considerable seismotectonic implications

sedimentology and palaeoenvironment of the southeast sicilian tertiary platform carbonates abstract a thick succession of shelf and shelf slope carbonates is developed in southeastern sicily sedimentological aspects of the oligocene to tortonian sequence including distribution and palaeoenvironmental factors are considered a new formation and four new members are proposed in the upper part of the succession the region comprises a western half typically exhibiting the principal deeper water planktonic facies including marls and an eastern area displaying typically inner shelf carbonates and an attenuated succession coralline algal limestones and calcarenites are more typical of this latter region but there are also some volcanic intercalations an attempt is made to relate the hyblean succession to that of the maltese islands which lie at the southern end of this tertiary carbonate platform

the contribution of tectonics to relative sea level change during the holocene in coastal south eastern sicily new data from boreholes abstract in order to detect ongoing vertical crustal movement and assess both tectonic instability and marine invasion risk in the south eastern sicily coastal area holocene sea level indicators have been compared to the sea level curve for the same period a stratigraphical and sedimentological study accompanied by 14 c ams dating has been carried out using seven boreholes in the most depressed coastal sectors the catania plain the lagoonal environments between augusta and siracusa and the vendicari lagoon south of siracusa the distinct boreholes showed irregular transitional successions represented by infralittoral beach sands lagoon and brackish marsh deposits moreover 14 c ams dating on gastropod and bivalves collected at various depths indicated a holocene age for these deposits that lie directly on the lower middle pleistocene substratum taking into account that the infralittoral and lagoon sediments occurring in the analysed coastal areas were deposited during the holocene sea level rise and that the gastropod and bivalve fragments sampled in the boreholes are with good approximation sea level indicators the short term vertical motion undergone by this region during the holocene can be estimated comparing the sampling depth below the present sea level of the dated shells to the sea level rising curve for the central eastern sicily coast the coastal plains between catania and siracusa resulted involved during the holocene in tectonic uplifting with rates varying from about 1 mm y in the catania area to 0 5 mm y in the siracusa area conversely in the same period the south eastern most coastal sector of sicily can be considered tectonically stable these results are comparable to uplift rates obtained from geomorphologic and archaeological sea level markers and are consistent with a remote effect of the active normal fault system located in the ionian offshore between catania and siracusa

mesozoic and cenozoic rocks from malta escarpment central mediterranean sedimentary rocks of triassic neogene age are present on the malta escarpment of the eastern mediterranean upper triassic dolomitic limestones of shallow water origin at depths between 2 5 and 3 5 km are similar in lithofacies to coeval platform carbonates of the siracusa syracuse belt of southern sicily jurassic rocks include lower middle liassic shallow water limestones followed by condensed hemipelagic lime deposits indicative of sinking and starving of the former platform cretaceous materials are represented by both red marls rich in planktonic faunas and reworked volcaniclastic breccias including shallow water skeletal material paleogene rocks are both shallow water limestones with corals algae and bivalves and redeposited calcarenites of lithofacies similar to those from surface and subsurface of the ragusa zone oligocene lower miocene rocks from the escarpment are also similar in lithology to the coeval ragusa deposits tortonian is represented by hemipelagic marls indicating open marine environment pervasive dolomitization on lime crusts and on initial stage fissure fillings with strongly positive isotopic oxygen ratio is thought to be a product of messinian evaporitic drawdown pliocene sediments belong to the trubi facies and consist of pelagic foraminiferal chalk an impressive vertical relief existed by miocene times as attested by messinian crusts and veins on or in rocks as old as late triassic our data do not provide evidence that this morphologic feature necessarily coincides with a continent ocean transition the present escarpment was produced by faulting erosion and defacement

influence of pore system characteristics on limestone vulnerability a laboratory study hyblean limestone of oligo miocene age was widely used as a construction material in the architectural heritage of eastern sicily italy among them the so called pietra bianca di melilli melilli limestone and calcare di siracusa syracuse limestone were prized for their attractive appearance ease of quarrying and workability syracuse limestone shows general weathering whereas melilli limestone is better preserved and only differential erosion or superficial exfoliation can be detected in monuments the cause of the different behavior of these two limestones was investigated from the petrographic and petrophysical points of view the saturation coefficient is higher in melilli limestone and ultrasound measurements indicate that it is less compact than syracuse limestone so that melilli limestone could deteriorate more easily than syracuse limestone however pore interconnections and the size of very small pores play the main role in the durability of both materials the irregularity of the syracuse pore system and its greater number of micropores hinder water flow through the exterior promote stress in pore structure and favor the development of scaling as confirmed by salt crystallization tests in melilli limestone the low concentration of micropores and fast water evaporation allow solutions to reach the surface more easily resulting in less damaging efflorescence

graben formation the maltese islands a case history abstract the structural setting of the maltese islands is governed by two rift systems of different ages and trends and the interference of both accompanying faults are exposed at many places along cliffs and belong to the most spectacular phenomena of rift faulting of the world malta is part of a wide shelf bridge that connects the ragusa platform of southern sicily and the tripolitanian platform of northern libya the archipelago is underlain by a continental crust of african provenance the older rift generation traversing the islands strikes about 50 to 70 to create a basin and range structure on western malta comino and eastern gozo this micro province is framed by two master faults at an average distance of 14 km crustal extension started during the early miocene as observed by growth faulting and sedimentary dikes parallel to the future rift a syndepositional uparching of about 200 m has preceded the physiographical rifting in post middle miocene times discrete dip slip faulting created an external wedge block split by internal tilt blocks of antithetic character both compensating an average 15 crustal spreading normal to the rift axis shoulder upwarping of approximately 120 m has evolved synchronously with the rifting structures of the first generation are crosscut by still active second generation rift faults which on malta strike about 120 but on gozo between 80 and 90 these faults are associated with the pantelleria rift whose deep trough sets immediately south of the islands rifting was mainly originated during late miocene early pliocene time to continue in parts up to the present a set of transform faults runs through the straits on both sides of comino to form a complicated en echelon or riedel shear structure on easternmost gozo and westernmost malta shoulder upwarping related to the pantelleria rift has considerably tilted the block of malta nne ward and caused the inundated river valleys of the natural harbour of valletta the superimposition of two rift structures of different trends has been caused principally by a rotation of the controlling stress regime about 10 m y ago the active afro eurasian collision front is located about 200 km north and northwest of the islands a contemporary change of plate tectonic stresses is discussed to explain the intraplate rift pattern on malta as foreland specific reactions to plate tectonic processes

a geological and paleomagnetic study of the hyblean volcanic rocks sicily abstract the geological and paleomagnetic study of the hyblean volcanic rocks in southeastern sicily permits the following conclusions 1 1 the upper cretaceous volcanics are considerably more extensive than earlier studies indicated they stretch from north of augusta to the vicinity of siracusa their magnetization is identical to that of the better known outcrops around capo passero of the two new age dates reported here one is younger than any so far reported 2 2 the upper tortonian flows are normally magnetized suggesting a correlation of the carlentini formation with magnetic interval 7 the flows at the top of the tellaro formation are also normally magnetized and are tentatively correlated with the carlentini formation flows shorter reversed intervals within interval 7 may be represented by two less well dated flows 3 3 the lowest pliocene flows have an adequate stratigraphie control and their magnetization is consistent with the extrusion of the pillow lavas during the mammoth event the militello flow sequence together with the francofonte flows appear by indirect argument to lie within the oldest reversed interval i e pre kaena of the matuyama epoch the individual flows in which both normal and reversed directions have been found cannot be assigned positions in magneto stratigraphie scale 4 4 the geomagnetic pole positions are consistent with that of the african plate during the cretaceous and a european plate location during both pliocene and miocene time the pole positions are upper cretaceous 212 3 e 69 3 n upper miocene 200 9 e 82 1 n pliocene 339 3 e 85 9 n

correlation between earthquake damage and seismic site effects the study case of lentini and carlentini italy abstract on december 13th 1990 a magnitude 5 6 seismic event felt throughout sicily and having maximum seismic intensity vii viii occurred although it is classified as moderate magnitude it caused causalities and the collapse of a few buildings two of the most struck cities were carlentini and lentini located in south eastern sicily at about 20 km from the instrumental epicenter in order to evaluate the influence of ground features on the damage distribution both vulnerability and damage maps were drawn using information collected in about 6000 forms coming from official ascertainments significant damage observed in some portions of the investigated areas appears related to the modest quality of the buildings that were classified as medium to high vulnerability to evaluate the role played by the geologic setting two sites were instrumented to measure shear wave velocity of the main lithotypes sixty three ambient vibrations measurements were also performed both in free field and inside some buildings moreover using information coming from geological and geophysical surveys 1d numerical modelling were done to achieve information about the main ground motion parameters the results highlight the occurrence of significant site effects and the potential presence of resonance phenomena between site and structure during the occurrence of a seismic event seismic site amplifications together with the buildings vulnerability observed through damage surveys contributed to enhance the inherent seismic risk of the investigated area

quaternary normal faulting in southeastern sicily italy a seismic source for the 1693 large earthquake summary we present geological and morphological data combined with an analysis of seismic reflection lines across the ionian ovshore zone and information on historical earthquakes in order to yield new constraints on active faulting in southeastern sicily this region one of the most seismically active of the mediterranean is avected by wnw ese regional extension producing normal faulting of the southern edge of the siculo calabrian rift zone our data describe two systems of quaternary normal faults characterized by diverent ages and related to distinct tectonic processes the older nw se trending normal fault segments developed up to 400 kyr ago and striking perpendicular to the main front of the maghrebian thrust belt bound the small basins occurring along the eastern coast of the hyblean plateau the younger fault system is represented by prominent nnw sse trending normal fault segments and extends along the ionian ovshore zone following the ne sw trending avola and rosolini ispica normal faults these faults are characterized by vertical slip rates of 0 7 3 3 mm yr 1 and might be associated with the large seismic events of january 1693 we suggest that the main shock of the january 1693 earthquakes m 7 could be related to a 45 km long normal fault with a right lateral component of motion a long term net slip rate of about 3 7 mm yr 1 is calculated and a recurrence interval of about 550 50 yr is proposed for large events similar to that of january 1693

pendant bioconstructions cemented by microbial carbonate in submerged marine caves holocene se sicily abstract unusual pendant bioconstructions occur within two submerged caves in the plemmirio marine protected area south of syracuse se sicily these cm to dm sized bioconstructions project downward from the cave roofs the main framework builders are serpulids belonging to the genera protula semivermilia and josephella encrusting bryozoans corals hydrozoans and sponges are subordinately present whereas bivalves and brachiopods are overall rare these faunal associations are characteristic of the studied caves but only in some places they form small bioconstructions that are cemented by microbial carbonates made up by autochthonous peloidal to clotted peloidal and aphanitic micrite the autochthonous micrite stabilizes the pendant bioconstructions herein referred to as biostalactites the microbial carbonate reveals high contents of bacterial lipid biomarkers among the most abundant compounds are mono o alkyl glycerol ethers mages and branched fatty acids 10 me c16 0 iso and anteiso c15 0 and c17 0 interpreted as biomarkers of sulfate reducing bacteria other compounds preserved in the autochthonous carbonates include lipids derived from marine zoo and phytoplankton brassicasterol dinosterol and monounsaturated short chain fatty acids unspecified marine bacteria saturated and monounsaturated short chain fatty acids and land plants long chain fatty acids long chain alcohols stigmasterol sitosterol and campesterol the observed lipid biomarker signatures are remarkably similar to those of post glacial reefal microbialites where microbialite formation in cavities of the coral framework was also mediated by sulfate reducing bacteria in the submerged caves of plemmirio marine protected area serpulid colonies apparently occur preferentially where freshwater is seeping through crevices in the limestone the consequent nutrification is believed to favor serpulid aggregation and the growth of other skeletal i e bryozoans and corals and soft bodied organisms i e sponges and ascidiae the resultant accumulation of biomass and its taphonomy provide niches for sulfate reducing bacteria which induce carbonate precipitation cementing and stabilizing the biostalactites the finding of pendant cemented bioconstructions in the mazzere and granchi caves of the plemmirio marine protected area reveals that sulfate reducing bacteria are involved in microbialite formation in various cryptic environments the formation of such peloidal to clotted peloidal microcrystalline carbonates in cryptic ecosystems is a significant factor for the stabilization of different kinds of bioconstructions spanning from small biostalactites to large reefs

deep origin of the dome shaped hyblean plateau southeastern sicily a new tectono magmatic model southeastern sicily is characterized by a prominent topography known as the hyblean plateau it is commonly considered as a flexural bulge formed by the northwest plunging of the hyblean malta platform beneath the sicilian fold and thrust belt however its noncylindrical shape and multiphase uplift history correlated to the late miocene and plio pleistocene volcanism outline a possible magmatic control on the hyblean plateau topographic expression we argue using 2 d flexural models that the flexural bending alone is unlikely to explain the high anomalous elevation of the hyblean plateau moreover topographic analysis show that the hyblean plateau has a dome shape composed of radially tilted preserved surfaces defining individual blocks the block edges seem to be related to deep seated inherited faults using an analogue modeling approach we show that magmatic intrusions beneath the thick meso cenozoic sedimentary cover can reproduce the first order morphology of the hyblean plateau when a structural inheritance is imposed accordingly we propose a tectono magmatic model that favors mafic sill intrusions as the major uplift source for the topographic anomaly however to explain the strong positive bouguer anomaly a deeper high density intracrustal body is needed moho uprising related to mesozoic rifting or mafic lower crust underplating intraplating since the late cretaceous can be evoked the small wavelength of the topography and the deep intracrustal mass anomaly makes the lithospheric elastic stresses sufficiently high to maintain a nonisostatic state over the geological time scales

palaeoenvironment and palaeogeography of miocene marls from southeast sicily and the maltese islands abstract tortonian marls and clays are extensively developed in southeast sicily macrofaunas are sparsely distributed in these strata except for a new section at musenna hill in the vittoria scoglitti area this section together with two other coastal sequences of about the same age are described for the first time their abundant faunas are recorded ecological requirements for these faunas are considered and some attempt is made to place them into the known sicilian miocene stratigraphy the musenna hill section shows a particularly close relationship to the upper part of the miocene blue clay formation of the maltese islands both from the viewpoint of sediment and macrofauna the maltese faunas are recorded in detail for the first time and ecological and palaeogeographical information is considered an attempt at an overall regional palaeoenvironmental reconstruction is made for the maltese and southeast sicilian parts of the central mediterranean for tortonian times

late pliocene volcanic island growth and flood basalt like lava emplacement in the hyblean mountains se sicily 1 since 200 ma the hyblean mountains southeastern sicily have been the site of recurrent mainly submarine mafic volcanism in the upper pliocene large volumes of tholeiitic products were erupted in a shallow marine environment leading to the growth of volcanic islands the deposits of this tholeiitic episode can be grouped into two main facies associations 1 pillow lavas and hyaloclastite tuffs erupted and deposited entirely under water and 2 submarine pillow breccias fed from subaerial lava flows entering the ocean and subaerial lavas which are distinguished into a coastal lava platform facies and an inland facies lava flows into the ocean led to the growth of lava deltas consisting of a basal flow foot breccia and an overlying sequence of p hoehoe flow units the latter rarely exceeding 0 5 m in thickness in outcrop this facies association shows evidence for significant instability of the lava deltas during growth indicating very similar processes to those observed during the current eruption of k lauea volcano hawaii away from the coast of the growing island the inland facies is characterized by thicker up to several meters p hoehoe flow units showing evidence for sheet flow inflation and limited outcrops of scoria and or bomb deposits evidence for lava transport through tubes exists in the form of tumuli and multiple vesicle layers drained tubes are absent all tholeiitic products were emitted in a single instantaneous voluminous event 120 km3 consistent with very high effusion rates similar to those of flood basalts or the 1783 skaftar fires iceland eruption

accidental contamination during hydrocarbon exploitation and the rapid transfer of heavy mineral fines through an overlying highly karstified aquifer paradiso spring se sicily abstract the area around ragusa in sicily is well known for the exploration of petroleum deposits hosted in mesozoic carbonate rocks these reservoirs are overlain by less permeable rocks whereas the surface geology is characterized by outcrops of oligo miocene carbonate units hosting important aquifers some of the karst springs of the area are used as drinking water supplies and therefore these vulnerable aquifers should be monitored and protected adequately in the early afternoon 14 00 of 27 may until the late evening 19 30 of 28 may 2011 during the construction of an exploitation borehole tresauro 2 more than 1000 m3 of drilling fluids were lost in an unknown karst void two days later from 06 30 on 30 may water flowing from paradiso spring lying some 13 7 km sw of the borehole and 378 m lower normally used as a domestic water supply was so intensely coloured that it was unfit for drinking bulk chemical analyses carried out on the water have shown a composition that is very similar to that of the drilling fluids lost at the tresauro borehole confirming a hydrological connection estimations indicate that the first signs of the drilling fluids took about 59 h to flow from their injection point to the spring corresponding to a mean velocity of 230 m h that paradiso spring is recharged by a well developed underground drainage system is also confirmed by the marked flow rate changes measured at the spring ranging from a base flow of around 10 15 l s to flood peaks of 2 3 m3 s reflecting the source and nature of the initial contamination the pollution lasted for just a few days and the water returned to acceptable drinking water standards relatively quickly however pollution related to heavy mineral fines continues to be registered during flooding of the spring when the aqueducts are normally shut down because of the high turbidity values this pollution event offers an instructive example of how hydrocarbon exploitation in intensely karstified areas where natural springs provide domestic water supplies should be controlled effectively to prevent such disasters occurring this pollution incident is also a useful example of how such accidental tracer tests can identify rapid karstic flowpaths over long distances

european cretaceous shorelines stage by stage abstract inferred shorelines are presented for the twelve cretaceous stages for the area of europe and adjacent seas contained between approximately 35 and 65 n and between 15 w and 25 e there is a brief stage by stage commentary and a bibliography of source materials

fast deformation processes and eruptive activity at mount etna italy the seismic and deformation patterns observed on mount etna before and during the 1991 1993 eruption the third largest since the seventeenth century in terms of lava volume are consistent with the regional tectonic framework of eastern sicily the pattern of the stress field acting on the intermediate and lower crust was defined at the local scale by focal mechanisms of microearthquakes occurring at depths between 10 and 25 km beneath the volcano they provide evidence for a strike slip compressional stress regime with the maximum compressive component acting approximately n s the fault plane solutions and the spatial and temporal distribution of seismicity indicate that usually sinistral shear ruptures occur along approximately ne sw trending fault zones while dip slip ruptures affect approximately nnw sse trending fault zones the latter include the avenues along which magma ascended during the 1991 1993 eruption seismic observations indicate a local inversion of the stress field acting on the upper crust depth 10 km underlying mount etna which was initiated less than 2 months before the eruptive event and disappeared with its end this is consistent with a local tensile regime that favored the magma ascent through the shallow crust the events preceding the eruption and accompanying its onset tilt anomalies and seismic swarms and those occurring shortly after its beginning a mainshock aftershock seismic sequence and associated coseismic tilts provide important evidence for understanding the dynamics of the two main volcano tectonic structures ne sw and nnw sse trending fault zones and associated intrusive mechanisms on etna the shape and location of the eruption feeding dike have been modeled from ground deformation data this approximately nnw sse modeled dike the seismicity and the position of the fractures are consistent with the regional stress field characterized by 1 oriented approximately n s the geophysical data presented and analyzed in the present paper strongly suggest an overall regional tectonic control as well as an active role for the intruding magma in the dynamics of the volcano

submerged archaeological sites along the ionian coast of southeastern sicily italy and implications for the holocene relative sea level change abstract precise measurements of submerged archaeological markers in the siracusa coast southeastern sicily italy provide new data on relative sea level change during the late holocene four submerged archaeological sites have been studied and investigated through direct observations two of them are greek archaic in age 2 5 2 7 ka and are now 0 98 1 48 m below sea level the other two developed during the bronze age 3 2 3 8 ka and are now 1 03 1 97 m below sea level these archaeological data have been integrated with information derived from a submerged speleothem collected in a cave located along the siracusa coast at 20 m depth the positions of the archaeological markers have been measured with respect to present sea level corrected for tide and pressure at the time of surveys these data were compared with predicted sea level rise curves for the holocene using a glacio hydro isostatic model the comparison with the curve for the southeastern sicily coast yields a tectonic component of relative sea level change related to regional uplift uplift rates between 0 3 and 0 8 mm yr have been estimated

geological and geodetic constraints on the active deformation along the northern margin of the hyblean plateau se sicily abstract a geologic and geodetic integrated analysis of the northern margin of the hyblean plateau se sicily has been carried out in order to test the relationship between the active deformation recorded by gps data and the long term tectonic evolution reconstructed by the interpretation of structural and morphological data our study revealed the active growth of a large antiform as a consequence of the positive tectonic inversion of the previous flexure bordering the hyblean foreland the deformation of middle late pleistocene marine terraces and the evolution of the drainage system are consistent with a progressive regional tilting of the entire eastern sector of the hyblean plateau siracusa domain representing the southern limb of the active antiform the geometry of the late quaternary marine strandlines compared with the results of analogue models is compatible with the effects of the nw ward propagation of a detachment fault at depth the active deformation of the hyblean region coherent with the nubia eurasia plate convergence suggests to candidate the inverted tectonics at the northern border of the hyblean plateau as potential seismogenic sources of the area

thermal weakening of the carbonate basement under mt etna volcano italy implications for volcano instability abstract the physical integrity of a sub volcanic basement is crucial in controlling the stability of a volcanic edifice for many volcanoes this basement can comprise thick sequences of carbonates that are prone to significant thermally induced alteration these debilitating thermal reactions facilitated by heat from proximal magma storage volumes promote the weakening of the rock mass and likely therefore encourage edifice instability such instability can result in slow gravitational spreading and episodic to continuous slippage of unstable flanks and may also facilitate catastrophic flank collapse understanding the propensity of a particular sub volcanic basement to such instability requires a detailed understanding of the influence of high temperatures on the chemical physical and mechanical properties of the rocks involved the juxtaposition of a thick carbonate substratum and magmatic heat sources makes mt etna volcano an ideal candidate for our study we investigated experimentally the effect of temperature on two carbonate rocks that have been chosen to represent the deep heterogeneous sedimentary substratum under mt etna volcano this study has demonstrated that thermal stressing resulted in a progressive and significant change in the physical properties of the two rocks porosity wet i e water saturated dynamic poisson s ratio and wet vp vs ratio all increased whilst p and s wave velocities bulk sample density dynamic and static young s modulus dry vp vs ratio and dry dynamic poisson s ratio all decreased at temperatures of 800 c the carbonate in these rocks completely dissociated resulting in a total mass loss of about 45 and the release of about 44 wt of co 2 uniaxial deformation experiments showed that high in situ temperatures 500 c significantly reduced the strength of the carbonates and altered their deformation behaviour above 500 c the rocks deformed in a ductile manner and the output of acoustic emissions was greatly reduced we speculate that thermally induced weakening and the ductile behaviour of the carbonate substratum could be a key factor in explaining the large scale deformation observed at mt etna volcano our findings are consistent with several field observations at mt etna volcano and can quantitatively support the interpretation of 1 the irregularly low seismic velocity zones present within the sub volcanic sedimentary basement 2 the anomalously high co 2 degassing observed 3 the anomalously high vp vs ratios and the rapid migration of fluids and 4 the increasing instability of volcanic edifices in the lifespan of a magmatic system we speculate that carbonate sub volcanic basement may emerge as one of the decisive fundamentals in controlling volcanic stability