a tsunami deposit at the cretaceous tertiary boundary in texas at sites near the brazos river texas an iridium anomaly and the paleontologic cretaceous tertiary boundary directly overlie a sandstone bed in which coarse grained sandstone with large clasts of mudstone and reworked carbonate nodules grades upward to wave ripple laminated very fine grained sandstone this bed is the only sandstone bed in a sequence of uppermost cretaceous to lowermost paleocene mudstone that records about 1 million years of quiet water deposition in midshelf to outer shelf depths conditions for depositing such a sandstone layer at these depths are most consistent with the occurrence of a tsunami about 50 to 100 meters high the most likely source for such a tsunami at the cretaceous tertiary boundary is a bolidewater impact

from orogenic hinterlands to mediterranean style back arc basins a comparative analysis hinterland plateaux and mediterranean style back arc basins both form behind active subduction zones or collisional megathrusts and share many characteristics 1 early crustal thickening to about twice normal continental thickness 2 thin lithospheric mantle 3 mixed magmatism including asthenospheric lithospheric and crustal melts 4 late stage horizontal extension accompanied by vertical shortening horizontal extension and vertical shortening are driven by high gravitational potential energy gpe contrasts between the hinterland and surrounding lithosphere which may reach 7 10 12 n m 1 equivalent to about 2 5 times the ridge push force if extension is rapid relative to the rate of lithospheric cooling gpe may remain positive even as extension continues declining to the mid ocean ridge value as crustal thickness approaches zero this suggests that hinterland plateaux could ultimately evolve into oceanic back arc basins the rate direction and amount of extension and the rate of vertical shortening depend on the plate boundary conditions and the gpe of the surrounding lithosphere vertical shortening in tibet is limited by work required to deform the surrounding asian lithosphere whereas mediterranean back arc basins can extend at the expense of regions of thin continental or oceanic crust

structure and kinematics of the south iberian paleomargin and its relationship with the flysch trough units extensional tectonics within the gibraltar arc fold and thrust belt western betics abstract the superposition of structures observed in a selected area of the external zones of the betic orogen situated in the westernmost segment of the peri mediterranean mountain belt reveals an alternation of compressional and extensional events during the overall convergence of the african and eurasian plates that bound the system an early miocene compressional event produced the formation of the so called gibraltar arc fold and thrust belt formed by the units derived from the south iberian paleomargin and the flysch trough this wedge constitutes the footwall of the gibraltar thrust whose hanging wall corresponds to the alboran domain the outward migration of the compressional front w to nwward in the south iberian segment was followed by the outward migration of the extensional locus related to the middle miocene rifting that led to the alboran basin subsidence the tectonic inversion of the gibraltar thrust was accompanied by normal faulting of the innermost part of the paleomargin and the flysch trough units finally the alboran region underwent n s to nw se compression from late miocene onwards which caused the uplift of the gibraltar arc area

landward fining from multiple sources in a sand sheet deposited by the 1929 grand banks tsunami newfoundland abstract a sandy deposit from the 1929 grand banks tsunami in newfoundland contains sediment from two distinct sources one from an inferred gravel shoreline close to the deposit and one from a sandy dune some 200 m seaward of the deposit the deposit ranges from 0 to 15 cm thick and is composed of a bimodal mix of fine and coarse sand we took approximately 100 core samples of this deposit in an attempt to characterize lateral grain size trends within the sand although the coarse fraction does fine with distance inland the fine fraction does not change size over the study area and the aggregate grain size changes in no systematic way we interpret this deposit to represent the mixture of material picked up at the bar with material picked up at the gravel shoreline the bar material does not fine in part because it is already fairly well sorted but also because it is far from its source the shoreline material on the other hand is poorly sorted so that the tsunami took only those grains it was capable of moving and deposited them near their source we estimated the size of the tsunami by determining the flow depth flow velocity combinations required to advect sand from the bar to the back of the deposit and by estimating the shear velocity required for motion of the largest grain we found during our survey this modeling indicates an average flow depth of about 2 5 2 8 m over the area at a flow velocity of 1 9 2 2 m s this estimate compares well with eyewitness accounts of a maximum flow depth of 7 m at the shoreline if our estimate represents an average over the whole study area

quasi real time fault model estimation for near field tsunami forecasting based on rtk gps analysis application to the 2011 tohoku oki earthquake mw 9 0 1 real time crustal deformation monitoring is extremely important for achieving rapid understanding of actual earthquake scales because the measured permanent displacement directly gives the true earthquake size seismic moment mw information which in turn provides tsunami forecasting we have developed an algorithm to detect estimate static ground displacements due to earthquake faulting from real time kinematic gps rtk gps time series the new algorithm identifies permanent displacements by monitoring the difference of a short term average sta to a long term average lta of the gps time series we assessed the noise property and precision of the rtk gps time series with various baseline length conditions and orbits and discerned that the real time ephemerides based on the international gnss service igs are sufficient for crustal deformation monitoring with long baselines up to 1 000 km we applied the algorithm to data obtained in the 2011 off the pacific coast of tohoku earthquake mw 9 0 to test the possibility of coseismic displacement detections and further we inverted the obtained displacement fields for a fault model the inversion estimated a fault model with mw 8 7 which is close to the actual mw of 9 0 within five minutes from the origin time once the fault model is estimated tsunami waveforms can be immediately synthesized using pre computed tsunami green s functions the calculated waveforms showed good agreement with the actual tsunami observations both in arrival times and wave heights suggesting that the rtk gps data by our algorithm can provide reliable rapid tsunami forecasting that can complement existing tsunami forecasting systems based on seismic observations

reexamination of the a d 869 jogan earthquake size from tsunami deposit distribution simulated flow depth and velocity the rupture parameters and magnitude of the a d 869 jogan earthquake a predecessor of the 2011 tohoku earthquake were previously estimated by matching tsunami deposit distributions with simulated inundation areas the tsunami inundation associated with the 2011 tohoku earthquake however extended farther inland than the sandy tsunami deposits numerical simulation of the 2011 tsunami indicated that flow depths and velocities were approximately 1 m and 0 6 m s respectively at the most inland sand deposit sites on the ishinomaki and sendai plains while these values depend on the assumed bottom roughness we used these values to compare tsunami deposits and inundation simulation of the 869 jogan earthquake from both uniform slip and 2011 type variable slip fault models the results showed that the rupture length of the 869 jogan earthquake was at least 200 km and its minimum moment magnitude was 8 6

superposed and refolded metamorphic isograds and superposed directions of shear during late orogenic extension in the alboran domain southern spain the timing kinematics and mode of exhumation within the alpujarride complex the largest tectonic unit of the alboran domain are controversial alternative tectonic models include synorogenic exhumation during pre miocene crustal thickening intraorogenic exhumation during repeated phases of contraction and extension and late orogenic exhumation during early miocene crustal thinning new structural and petrographic relationships documented in this study support the latter model subhorizontal foliations stretching lineations and recumbent folds are associated with early miocene high temperature decompressional metamorphism and vertical condensation of the metamorphic sequence relict isograds associated with high pressure metamorphism and burial are systematically overprinted by isograds associated with high temperature metamorphism and rapid decompression during the early stages of extensional exhumation and growth of sillimanite ene directed shear d2 overprinted thrusts and foliations associated with crustal thickening d1 during the later stages of extensional exhumation and growth of andalusite from ductile to semibrittle conditions north directed shear d3 produced kilometer scale recumbent folds that refold isograds stretching lineations characterize superposed directions of orogen parallel l2 and later orogen perpendicular l3 shear associated with a rapid temporal transition in the kinematics of extensional exhumation during the final stages of crustal thinning and cooling ductile structures d2 d3 were cut by brittle low angle normal faults d4

eclogites of the ojen nappe a record of subduction in the alpujarride complex betic cordilleras southern spain eclogites interlayered with amphibolites and migmatites occur in an upper unit ojcn nappe of the alpujarride complex betic cor dilleras estimates of p t conditions reveal a retrograde meta morphic path from an edogitic stage at 15 kbar and c 730 c to amphibolite facies conditions at 5 8 kbar or less and c 650 c the ronda peridotites belonging to the uppermost alpujarride nappe los reales nappe structurally overlie the eclogite bearing unit it is suggested that eclogitic metamorphism and overthrusting of the peridotites reflect dfierent stages of the same convergent episode

polyphase tectonic evolution of fore arc basin related to step fault as revealed by seismic reflection data from the alboran sea w mediterranean 25 pages 14 figures 1 table seismic reflection and bathymetric data collected during the marlboro and saras cruises are stored at sismer and seanoe sea scientific open data edition https doi org 10 17600 11480100 https doi org 10 17600 12450090 and https campagnes flotteoceanographique fr campagnes 12000010

lateral interaction between metamorphic core complexes and less extended tilt block domains the alpujarras strike slip transfer fault zone betics se spain abstract the alpujarras area in southeastern spain exhibits one of the scant documented examples of extension related strike slip faults bordering core complexes in the world faults of the alpujarras fault zone define a regional scale complex ene striking transfer zone that marks the boundary among the sierra nevada elongated dome a highly extended constricted core complex and a less extended domain formed by large scale tilt blocks detailed mapping and structural analysis show that the alpujarras fault zone is an integral part of the wsw directed normal fault systems that thinned the betic hinterland during the middle miocene to recent time fault patterns and palaeostress analysis both indicate that dextral movement along the strike slip faults was induced by a local stress field with a sub horizontal e w to ese wnw trending maximum principal stress axis which is synchronous with the regional stress field driving the normal fault systems palaeostress analysis also indicates subsequent variations in the stress field with a sub horizontal nw se to n s trending maximum principal stress axis thus producing both the tectonic inversion of the northern fault of the alpujarras system and shortening of the unloaded extensional detachment footwall a simplified kinematic model for the tectonic evolution of the alpujarras area from the middle miocene to recent emphasizes the kinematic coupling of normal faults and strike slip transfer zones in the extensional process

wellbore cement alteration during decades of abandonment and following co2 attack a geochemical modelling study in the area of potential co2 reservoirs in the pannonian basin abstract in east central europe the sedimentary rocks and saline reservoirs of the pannonian basin provide the greatest potential for geological sequestration of co2 however there is no knowledge about the integrity of cement casing and plugs in abandoned wellbores drilled in the last century which surround the potential co2 geological storage sites thermodynamic and kinetic batch and 1d kinetic reactive transport models have been built up in phreeqc to estimate the present composition of hydrated cement in different depths 106 1478 2136 and 2718 m of these abandoned wellbores and to access cement reactivity for the effect of potentially injected co2 the wellbore cements are all predicted to presently consist of mainly calcium silicate hydrate csh and portlandite but differences occur due to the stability of ettringite connected to the temperature of the geological environment with the depth the amount of potentially dissolved co2 increases which induces the breakdown of portlandite and csh in the cement and the major precipitation of calcite and amorphous silica the transformation affects the whole width of the cement casing after about 2 3 years in most of the depths however the calculated mass transfer among minerals indicate a 2 6 porosity drop which raises the attention to potential pore clogging this process significantly reduces the risks of abandoned wellbores when implementing co2 geological storage

numerical models of tsunami sediment transport current understanding and future directions abstract researchers who study tsunami deposits share common ultimate goals of their work which are to better assess the magnitude information of paleotsunamis and to contribute to the assessment of future tsunami risks numerical modeling of tsunami sediment transport is an important piece of interdisciplinary research that fills the gap between geological studies and practical utilization of tsunami deposits forward and inverse numerical models that address tsunami transport of sand and boulders have been developed over the last two decades forward models are capable of delineating the time evolution of tsunami hydrodynamics sediment transport and the resulting morphological changes associated with erosion and deposition inverse models estimate tsunami characteristics such as flow speed and depth from deposits numerical modeling can be used not only to quantify paleotsunamis but also to enhance our understanding of tsunami sedimentology and hydrodynamics to make progress towards the ultimate goal of improved tsunami risk assessment development of an in depth mutual understanding between modelers and geologists of the advantages limitations and uncertainties in both numerical modeling and geological records is an important challenge

lateral variation of the crust in the iberian peninsula new evidence from the betic cordillera abstract new results from a seismic refraction wide angle reflection survey carried out in the betic cordillera in autumn 1989 contribute to a better picture of its deep structure one nw se profile cuts across the iberian massif the external and internal betics the structure of the crust in the iberian massif shows characteristics similar to those found in previous experiments the lower crust is found as a distinct layer 12 km thick with an average velocity of 6 8 km s 1 the moho is found at about 35 km depth this structure extends southeastward until a 3 4 km upwelling of the moho about 30 km north of the present day surface boundary between the external and internal betic units further southeast the moho deepens to 38 km and the lower crust is no longer seismically detected the absence of differentiated lower crust beneath part of the external betics may be related with the mesozoic rifting of the south iberian passive margin instead this absence under the internal betics may be caused by rifting in conjunction with the collisional evolution of the orogen a wnw ese profile lying in the internal betics shows the presence of a prominent reflector at 10 12 km depth this seems to be a widespread feature in the internal betics and may be interpreted as a detachment surface the moho is found at 38 km depth rising strongly in the easternmost betics seismic data suggest a thin crust in the offshore area southwest of malaga probably containing a massive zone of high velocity rocks which is also supported by available geophysical and geological data

magnetic constraints on the thermal evolution of a collapsing orogen summary the thermal evolution of an orogen undergoing late stage extension was investigated using rock magnetic properties of a suite of mafic dyke rocks affected by greenschist facies metamorphism in the internal zones of the betic cordillera southern spain the natural remanent magnetization nrm in the dykes intruded into the lowest geological unit is made up of up to three components the lowest temperature component lt is in the direction of the present day magnetic field and is believed to be a chemical remanent magnetization crm or viscous remanent magnetization vrm acquired in the recent magnetic field the intermediate temperature it component unblocked between 200 c and 450 c is thought to be largely a thermoviscous overprint acquired during metamorphism this component is carried by either primary or authogenic sulfides and low unblocking temperature magnetite the component of magnetization with the highest blocking temperature ht is isolated above 450 c and is interpreted as the primary component of remanent magnetization it is most likely that this component is carried by magnetite that resides in the plagioclase and has been shielded from the metamorphism which transformed most of the original magnetite to metamorphic amphibole chlorite and biotite thermal demagnetization of these dykes separates the it overprint from the ht primary remanence at a sharp junction occurring at 450 c for single domain grains this translates to a peak palaeotemperature in the natural sample of approximately 370 c which is close to the estimated temperature experienced by the greenschist facies country rocks 400 c in contrast results obtained from a dyke that is intruded into an overlying weakly metamorphosed geological unit indicates that temperatures only reached about 175 c in this unit these results are consistent with temperatures deduced from geological constraints and they imply that between 4 and 6 km of section has been removed between the two units during late orogenic extension these new data are then combined with previously published ar ar wholerock geochronology and information on vertical axis rotations to put constraints on the thermotectonic evolution of this collapsing orogen

tsunami heights along the pacific coast of northern honshu recorded from the 2011 tohoku and previous great earthquakes the 2011 tohoku earthquake generated a huge destructive tsunami with coastal heights of up to 40 m recorded along northern honshu the sanriku coast experienced similar tsunamis and damage from the 1896 and 1933 sanriku earthquakes whereas the only damaging tsunamis on both the ibaraki and chiba coasts in the previous century were from the 1960 and 2010 chile earthquakes we summarized 12 field surveys in which the height of the 2011 tsunami was recorded at 296 points along with descriptions of the survey method reliability and accuracy we then compared them with the above mentioned tsunamis at locations for which specific measurements were given in previous reports on the sanriku coast the 2011 tsunami heights are positively correlated with the previous sanriku tsunamis indicating that local variations resulting from the irregular coastline were more dominant factors than the earthquake location type or magnitude for near field tsunamis the correlations with the chilean tsunami heights are less significant due to the differences between the local and trans pacific tsunamis on the ibaraki and chiba coasts the 2011 tohoku and the two chilean tsunami heights are positively correlated showing the general decrease toward the south with small local variations such as large heights near peninsulas

historical tsunami and storm deposits during the last five centuries on the sanriku coast japan abstract nine event deposits in a small alluvial valley along the sanriku coast japan were correlated with historical tsunamis and storms that have been recorded in this region since the 15th century we identified nine sandy layers in 15 geo slices collected at distances ranging from 140 to 260 m from the coast in a lowland back marsh protected from the sea by a high sandy ridge based on their sedimentary characteristics grain size distribution and marine microfossil assemblages namely coccoliths these event layers which were well preserved in their order of deposition were probably either tsunami or storm deposits diatom analysis revealed four stages of paleo environmental change from tidal marsh to wetland the uppermost event layer covering the ground surface is probably the deposit from the 2011 tohoku oki tsunami ages for other event deposits were radiometrically dated using 14 c 137 cs and 210 pb with bayesian estimation the second event layers can be correlated with the 1960 chilean or 1968 aomori oki earthquake tsunamis the candidates for the third event layer are the 1947 catherine and 1948 ione typhoons as well as the candidates for the second event layer the fourth and fifth event layers are likely associated with the 1933 and 1896 sanriku oki earthquake tsunamis four lower event layers can be correlated with historical tsunamis and storms that occurred during the 15th to 18th centuries such as the 1611 sanriku oki earthquake tsunami

lithospheric structure beneath the alboran basin results from 3d gravity modeling and tectonic relevance a three dimensional gravity modeling combined with integrated heat flow and elevation modeling is conducted to map out the crustal and lithospheric mantle thickness in the alboran basin in the westernmost mediterranean a sediment corrected bouguer anomaly has been derived using a depth to the basement map and densities determined from well logs and seismic data the gravity effect of the base of the lithosphere has been removed from the sediment corrected bouguer anomaly to obtain a crustal bouguer anomaly which has been inverted for crustal thickness the resulting lithospheric structure is further constrained by elevation data under the assumption of local isostasy the low residual elevation anomalies obtained 100 m in average suggest that the area is in local isostasy particularly the medium and long wavelength topography features variations in crustal thickness range from 36 km underneath the betic and rif chains to 12 km beneath the easternmost part of the alboran sea basin in the transition to the south balearic basin in western alboran the moho lies at a rather constant depth of 18 km deepening sharply toward the gibraltar strait down to 30 32 km the base of the lithosphere shallows from 140 km depth in the gibraltar strait to 45 km depth in the easternmost alboran sea lithospheric thinning penetrates to the southeastern side of the iberian margin crosscutting topographic highs of the central and eastern betic chain our results favor mantle delamination produced by detachment and subsequent peeling away of the lithospheric mantle rather than convective removal of the lithospheric mantle either by orogenic collapse or detachment and sinking of a lithospheric slab

geochemical modeling of carbonation of hydrated oil well cement exposed to co 2 saturated brine solution storage of co2 into geological formations such as deep saline aquifers and depleted oil gas reservoirs is being investigated to help reduce releases to the atmosphere a critical issue is the long term efficacy of engineered man made hydrated cement seals that surround or plug boreholes in order to investigate the impact of co2 interactions with hydrated cement the present study focuses on the alteration processes that were observed in a hydrated cement core based on type g portland cement after laboratory experimental reaction with a co2 saturated brine for 6 months the carbonated cement block consisted of an orange outer zone an alteration rim and the intact cement core the phreeqc geochemical code was used to simulate the experimental conditions and data using 1d reactive transport modeling the first phases to dissolve were portlandite cs and ettringite providing calcium to solution three caco3 polymorphs were predicted to precipitate but the less stable of these aragonite vaterite were transformed to calcite over time according to simulations the final product after 1000 years of reaction will be 68 calcite 18 friedel s salt and 14 al fe si hydro oxides as the reaction front moved within the sample porosity decreased due to the formation of amorphous phases and carbonates the proposed model is a useful tool in describing longer term hydrated cement alteration behavior during co2 geological storage and to compare their results with in situ observations from field experiments

challenges of anticipating the 2011 tohoku earthquake and tsunami using coastal geology 1 can the magnitude of a giant earthquake be estimated from paleoseismological data alone attempts to estimate the size of the jogan earthquake of ad 869 whose tsunami affected much of the same coast as the 2011 tohoku tsunami offers an excellent opportunity to address this question which is fundamental to assessing earthquake and tsunami hazards at subduction zones between 2004 and 2010 examining stratigraphy at 399 locations beneath paddy fields along 180 km of coast mainly south of sendai we learned that a tsunami deposit associated with the ad 869 jogan earthquake had run inland at least 1 5 km across multiple coastal lowlands and that one of the lowlands had subsided during the jogan earthquake and an earlier earthquake as well radiocarbon ages just below above sand deposits left by the pre jogan tsunamis suggested recurrence intervals in the range of 500 to 800 years modeling inundation and subsidence we estimated size of the jogan earthquake as moment magnitude 8 4 or larger and a fault rupture area 200 km long we did not consider a longer rupture like the one in 2011 because coastal landform and absence of a volcanic ash layer make any jogan layer difficult to identify along the sanriku coast still sendai tsunami geology might have reduced casualties by improving evacuation maps and informing public awareness campaigns

late orogenic doming in the eastern betic cordilleras final exhumation of the nevado filabride complex and its relation to basin genesis the geometry timing and kinematics of late orogenic extension in the betic cordilleras pose the problem of a decoupling of upper crustal and lower crustal deformation regimes perpendicular directions of extension in metamorphic domes and nearby sedimentary basins remain unexplained this paper puts kinematic constraints on the final exhumation of the nevado filabride complex focusing on the formation of metamorphic domes and their relations with the adjacent basins structural fabrics and kinematic indicators below the main shear zones as well as their relations with both published changing metamorphic p t conditions and geochronological data were studied our approach describes 1 a consistent top to the west shear parallel to dome axes of during d2 i e during decompression with distributed ductile flow and the onset of strain localization along major shear zones 2 further strain localization along the major shear zones under greenschist facies conditions during d3 leading to s c mylonites formation accompanied with a rock strong thickness reduction 3 the divergence of shear direction on either limbs of domes during d3 showing the appearance of the dome geometry and 4 a local evolution toward n s brittle extension d4 in the upper plate and formation of sedimentary basins continuous ductile to brittle top to the west shear is compatible with the slab retreat hypothesis from the miocene the formation of domes which adds gravitational forces responsible for the final stages of exhumation is thus characterized by important kinematics changes necessary to explain coeval n s opened basins later from the upper tortonian a contractional event d5 amplified the earlier domal structures forming the present north vergent folds

exhumation of high pressure metapelites and coeval crustal extension in the alpujarride complex betic cordillera abstract the current configuration of the alpujarride complex betic orogen comprises a stack of thinned tectonic units made up mainly of continental crust p t path modelling in different levels of an alpujarride unit the salobrena tectonic unit reveals a high pressure metamorphic stage followed by subsequent decompression at nearly isothermal conditions nevertheless the p t conditions differ from one level to another while the top of the permo triassic metapelites includes carpholite kyanite bearing assemblages 10 kbar 425 c intermediate levels are characterized by mg rich chloritoid zn rich staurolite kyanite bearing assemblages minimum 10 5 kbar 450 c and the bottom of the palaeozoic metapelite sequence presents garnet kyanite plagioclase bearing assemblages average conditions of 13 kbar 625 c thus the salobrena tectonic unit represents an entire upper continental segment containing several crustal layers which underwent high pressure metamorphism during alpine continental subduction the decompression associated with an important mineral growth stage and the development of flat lying regional foliation reflects the thinning of this crustal segment which resulted in parallel disposition of the bedding and metamorphic zones at low pressure conditions large scale folds affect the regional foliation producing stratigraphic duplication metamorphic inversions and the general reorganization of previous alpujarride sheets finally brittle miocene extensional tectonics coeval with the generation of the alboran basin contributed to the definitive exhumation of the alpujarride complex

extensional tectonics in the northeastern betics se spain case study of extension in a multilayered upper crust with contrasting rheologies extension in the northeastern betics took place along two main directions corresponding to a minimum of two successive orthogonal extensional systems with n nw and w sw sense of shear respectively strain was strongly localised within weaker metapelites and gypsum leading to the development of several extensional detachments which accommodated the thinning produced by extensional ramps and listric faults within the stronger carbonate rocks extension along several detachments led to the preservation in a single thinned section of layers representative of different crustal depths of a previously thickened upper crust the n to nw directed extensional system was formed by brittle to brittle ductile detachments which were active during the upper oligocene and lower miocene coeval to vertical ductile thinning of underlying greenschist facies metamorphic rocks the w to sw directed extensional system active during the middle and upper miocene shows multiple slip surfaces which transferred displacement to a brittle detachment with a ramp flat geometry that stepped down into the footwall of the previous nw directed system the geometry of both extensional systems was determined by the rheological heterogeneity of the studied crustal section further upper miocene extension was accommodated by radial extension with a dominant set of sw directed listric faults which tilted the aforementioned detachments and exhumed them in the core of km scale elongated extensional domes

a new structural and kinematic framework for the alboran domain betic rif arc western mediterranean orogenic system the processes that drastically thinned and rapidly exhumed the alboran domain in southern spain are poorly understood geological maps cross sections and a synthesis of previous work in the alpujarride complex provide a new structural framework for the alboran domain with major revision of the previously defined lithotectonic units alboran continental lithosphere was buried and thickened in the paleogene d 1 and subsequently thinned during late orogenic extension in the early miocene regional patterns of stretching lineations and late recumbent folds record important spatiotemporal changes in the kinematics of extension east directed shear d 2 is preserved in deep orogenic levels and thinned the crustal sequence during rapid exhumation and high temperature metamorphism north directed shear d 3 d 4 is preserved in upper orogenic levels and reworked earlier structures during the later stages of exhumation and cooling this large scale switch in the direction of finite stretching resulted from the interaction between components of orogen parallel d 2 and orogen perpendicular d 3 d 4 extension and associated vertical and lateral gradients in strain we provide a novel kinematic model for gravity driven extensional collapse of the alboran domain compatible with both westward motion of the alboran domain relative to the iberian margin and subsequent northward extensional flow and emplacement of alboran lithosphere onto the iberian margin supplementary material a list of sample names coordinates and descriptions plus a google earth kmz file of sample locations is available at https doi org 10 6084 m9 figshare 5508643 a geological sketch map of the sierra de las estancias indicating the trend of stretching lineations in the alpujarride complex and location of major geological boundaries is available at https doi org 10 6084 m9 figshare 5513398

extension versus compression during the miocene tectonic evolution of the betic chain late folding of normal fault systems the westernmost part of the mediterranean alpine belt is represented by the betic rif orogenic belt around the gibraltar arc which in turn surrounds the alboran basin in the betic chain early and middle miocene crustal thinning of the alboran basement is well established as extensional low angle normal faults and detachment faults developed in both ductile and brittle conditions thinned a previously thickened crust in the alboran domain of the central betics two main extensional episodes are evidenced a langhian one with a north northwestward transport direction followed by a west southwestward extension serravallian in age therefore all the units heretofore considered to be thrust nappes are in reality extensional units bounded by low angle normal faults the cortical segment studied formed the basement of the miocene alboran basin in which progressively deeper basement units were covered by younger marine sediments as a result of extensional denudation processes the age of these sediments clearly dates the faulting the extensional evolution during the miocene is much more complex than the past models suggest during the upper miocene these extensional systems were folded as the result of a compressive regime which allowed them to be well exposed compression in the gibraltar arc is nearly contemporaneous with extension and the westward migration of the compression through its footwall is related with the extensional spreading

a model for tsunami flow inversion from deposits tsuflind abstract modern tsunami deposits are employed to estimate the overland flow characteristics of tsunamis with the help of the overland flow characteristics the characteristics of the causative tsunami wave can be estimated the understanding of tsunami deposits has tremendously improved over the last decades there are three prominent inversion models a moore s advection model moore et al 2007 b soulsby s model soulsby et al 2007 and c tsusedmod jaffe gelfenbuam 2007 tsuflind incorporates all three models and adds new modules to better simulate tsunami deposit formation and calculate flow condition tsuflind takes grain size distribution thickness water depth and topography information as inputs tsuflind computes sediment concentration grain size distribution of sediment source and initial flow condition to match the sediment thickness and grain size distribution from field observation furthermore tsuflind estimates the flow speed froude number and representative wave amplitude the model is tested by using field data collected at ranganathapuram india after the 2004 india ocean tsunami tsuflind reproduces the field measurement grain size distribution with less than 5 error tsunami speed in this test case is about 4 7 ms 1 at 150 m inland and decreases to 3 3 ms 1 350 m inland from the shoreline the estimated wave amplitude of the largest wave for this test case is about 5 to 7 m

rates of mineral dissolution under co2 storage conditions abstract evaluating the potential of a sedimentary basin reservoir to securely store co 2 benefits from a comprehensive understanding of the geochemical reactions that take place once co 2 is injected into a formation in particular models that predict the transport and reaction of co 2 within a reservoir require a definition of the types of reactions affected by enhanced levels of co 2 and how the kinetics of these reactions will affect a heterogeneous mineralogy and formation waters within a reservoir over time in this review we evaluate rate models used to describe mineral dissolution kinetics and compare the range in values reported for the kinetic parameters used to describe the reactivity of various minerals relevant to mainly siliciclastic reservoirs parameters that have a significant impact on model results include the reactive surface area of a mineral the apparent activation energies used to extrapolate reaction rates to the temperatures of potential storage reservoirs c 50 125 c and the in situ ph of formation waters with elevated concentrations of dissolved co 2 the variation in reported values for these parameters can lead to predicted rates that span many orders of magnitude for a given mineral despite these uncertainties recent success with geochemical models has been made by applying a monte carlo approach to optimise the kinetic parameters for minerals where robust thermodynamic and kinetic data do not exist

comparison of earthquake source models for the 2011 tohoku event using tsunami simulations and near field observations selection of the earthquake source used in tsunami models of the 2011 tohoku event affects the simulated tsunami waveform across the near field different earthquake sources based on inversions of seismic waveforms tsunami waveforms and global positioning system gps data give distinguishable patterns of simulated tsunami heights in many locations in tohoku and at near field deep ocean assessment and reporting of tsunamis dart buoys we compared 10 sources proposed by different research groups using the geoclaw code to simulate the resulting tsunami several simulations accurately reproduced observations at simulation sites with high grid resolution many earthquake sources produced results within 20 difference from the observations between 38 and 39 n including realistic inundation on the sendai plain reflecting a common reliance on large initial seafloor uplift around 38 n 0 5 143 25 e 0 75 as might be expected dart data was better reproduced by sources created by inversion techniques that incorporated dart data in the inversion most of the earthquake sources tested at sites with high grid resolution were unable to reproduce the magnitude of runup north of 39 n indicating that an additional source of tsunamigenic energy not present in most source models is needed to explain these observations online material figures of buoy inundation and run up simulations and observations associated data sets and simulation code

sediment transport modeling of multiple grain sizes for the 2011 tohoku tsunami on a steep coastal valley of numanohama northeast japan abstract the grain size distribution of a tsunami deposit may have a correlation with the tsunami inundation process and further with the tsunami source characteristics we test this hypothesis using thickness and grain size distribution data of the 2011 tohoku tsunami deposit in numanohama coast iwate prefecture japan here we build and validate a tsunami sediment transport model that can simulate deposit thickness and grain size distribution our numerical model has three layers parent bed deposit bed and suspended load layers the two bed layers contain information about the grain size distribution this numerical model can handle a wide range of grain sizes from 0 063 4 to 5 657 mm 2 5 the grain size distributions at 12 sample points along a 900 m transect from the beach through a marsh and up to the inundation limit are used to validate the tsunami sediment transport model we adopt a reference tsunami source model that can well reproduce the observed tsunami run up heights ranging from 16 to 35 m along the steep valley during the 2011 tsunami the simulated sand thickness distribution along the transect is consistent with the observed thickness ranging from 3 to 23 cm the computed net erosion and deposition suggest that most of the sand deposit was originated from the near shore the shapes of the simulated grain size distributions represented by their sorting skewness kurtosis and mean at most of the sample sites are similar to the observations the differences between the observed and simulated peak of grain size distributions are less than 1 to evaluate the sensitivity to the tsunami source model we test five tsunami scenarios which are modified from the reference source model while the tsunami scenario with 120 of the reference amplitude can also reproduce the thickness and grain size distribution the scenarios with amplitudes smaller than 80 of the reference or with wave periods shorter than 50 of the reference source model underestimate the thickness and cannot reproduce the grain size distributions our simulation results suggest that it is possible to estimate tsunami wave amplitude and wave period from sediment deposit thickness and grain size distribution data

a numerical model for tsunami induced morphology change we describe the development of a time resolved model for tsunami induced morphology change based on an existing boussinesq model for weakly dispersive free surface waves coupled to a depth integrated model for sediment concentration and an equation for bed level change the model allows for spatial variability in bottom friction coefficients and accounts for the presence of non erodible beds or finite depths of available sediment the model is verified using one laboratory data set and against field observations of morphology change in the crescent city ca harbor during the 2011 tohoku tsunami event the model is then applied to a hypothetical example illustrating the impact of tsunami inundation on an undeveloped barrier island

re estimated fault model of the 17th century great earthquake off hokkaido using tsunami deposit data abstract paleotsunami researches revealed that a great earthquake occurred off eastern hokkaido japan and generated a large tsunami in the 17th century tsunami deposits from this event have been found at far inland from the pacific coast in eastern hokkaido previous study estimated the fault model of the 17th century great earthquake by comparing locations of lowland tsunami deposits and computed tsunami inundation areas tsunami deposits were also traced at high cliff near the coast as high as 18 m above the sea level recent paleotsunami study also traced tsunami deposits at other high cliffs along the pacific coast the fault model estimated from previous study cannot explain the tsunami deposit data at high cliffs near the coast in this study we estimated the fault model of the 17th century great earthquake to explain both lowland widespread tsunami deposit areas and tsunami deposit data at high cliffs near the coast we found that distributions of lowland tsunami deposits were mainly explained by wide rupture area at the plate interface in tokachi oki segment and nemuro oki segment tsunami deposits at high cliff near the coast were mainly explained by very large slip of 25 m at the shallow part of the plate interface near the trench in those segments the total seismic moment of the 17th century great earthquake was calculated to be 1 7 10 22 n m m w 8 8 the 2011 great tohoku earthquake ruptured large area off tohoku and very large slip amount was found at the shallow part of the plate interface near the trench the 17th century great earthquake had the same characteristics as the 2011 great tohoku earthquake

flow speed estimated by inverse modeling of sandy sediment deposited by the 29 september 2009 tsunami near satitoa east upolu samoa abstract sandy deposits from the 29 september 2009 tsunami on the east coast of upolu samoa were investigated to document their characteristics and used to apply an inverse sediment transport model to estimate tsunami flow speed sandy deposits 6 to 15 cm thick formed from 25 to 250 m inland sedimentary layers in the deposits that are defined by vertical grain size variation and contacts are interpreted to have formed during onshore runup of two waves deposits at 3 locations 100 170 and 240 m inland contained two layers that are predominately normally graded 80 but contained massive sections 15 and inversely graded sections 5 at their bases about 75 of the total thickness of normally graded intervals exhibits a signature of sediment falling out of suspension at their top this type of grading termed suspension grading here was first recognized in turbidity current deposits and is characterized by the entire distribution shifting finer upwards in a layer as high settling velocity coarser material deposits first and low settling velocity finer material deposits last the jaffe and gelfenbaum 2007 inverse sediment transport model was applied to intervals within layers that exhibited suspension grading to estimate tsunami flow speed and was able to reproduce the general trends of the observed suspension grading a key unknown input in the modeling is the bottom roughness for a bottom roughness parameterization using a manning s n of 0 03 equivalent to a z0 0 006 m for the observed flow depths of 2 3 m flow speeds calculated for the 2 layers at the 3 locations were 3 8 3 6 and 3 7 m s bottom layer earlier wave and 4 4 4 4 and 4 1 m s top layer later wave at 100 170 and 240 m inland respectively these estimates are consistent with the 3 8 m s tsunami flow speed from boulder transport calculations and result in froude numbers of 0 7 1 0 when maximum measured flow depths are used because the inverse model assumes the deposit was formed by sediment falling out of suspension care must be taken to model only intervals of the deposit exhibiting suspension grading including intervals deposited by either bedload or suspended load transport convergences result in higher and sometimes unrealistic tsunami flow speed estimates

neogene tectonic evolution of the southwestern alboran basin as inferred from seismic data off morocco the southwestern part of the western mediterranean alboran basin including part of the alboran ridge xaouen bank was investigated through the analysis of 28 intersecting multichannel seismic lines the seismic stratigraphy is tied to the amoco well el jebha 1 five seismic units or subunits are described from the quaternary to the middle and lower miocene the acoustic basement is interpreted to be mainly paleozoic and triassic metamorphic rocks of the alboran domain nappes and in places middle miocene messinian calc alkalic volcanics in the depocenters the thickness of the sedimentary infill mostly clays and turbidites exceeds 9 km normal faults of middle miocene tortonian age are broadly parallel to the coast and dip either seaward or landward they were mostly inverted during pre and post messinian episodes of compression which formed a set of en echelon north verging faulted folds in the alboran ridge area in relation with sinistral movement along the offshore projection of the jebha fault after pliocene subsidence a final episode of compression reactivated the earlier folds and pushed the alboran ridge onto the moroccan slope the complex structural history suggests many structural and stratigraphic potential hydrocarbon traps a high resolution seismic survey could lead to the definition of new exploration plays

effects of topography on particle composition of 2011 tsunami deposits on the ria type sanriku coast japan abstract a geological survey was conducted in a small valley along the sanriku coast and the grain compositions of both autochthonous gravels and the 2011 tsunami deposit from the tohoku oki earthquake were investigated to reveal the depositional form of the tsunami deposits on the ria type coast the features of autochthonous gravels in the beach riverbed and slope areas are characterized by a combination of their rock type and roundness the roundness values of the beach and slope gravels are large 0 8 0 9 and small 0 1 0 2 respectively regardless of rock type and the riverbed gravels are typically granite rocks with an intermediate roundness 0 4 0 5 the 2011 tsunami deposits along the survey transect include the above autochthonous gravels and show several characteristic features such as a sharp erosional contact with the underlying peaty soil normal and or inverse grading structures mud sheets and richness in gravels in the lower unit while the thickness shows no systematic changes with the distance from the coast the presence of slope gravels suggests high tsunami inundation and flux which eroded bare rock and talus and transported them to the valley plain by backwash current the mixture of beach and riverbed deposits implies the formation of both an upstream current from the beach which transported beach pebbles inland and a backwash current along the channel which accumulated sub angular riverbed gravels around the river mouth the characteristics of the 2011 tsunami deposit on the sanriku coast where narrow valleys are surrounded by high cliffs with steep slopes are significantly different from those of sandy tsunami deposits in sendai plain where a flat plain develops within several kilometers of the coastline the differences among sedimentary facies are affected by the topography and autochthonous deposits

formation of chocolate tablet boudins results from scaled analogue models abstract we used power law viscous plasticine as a rock analogue to simulate chocolate tablet boudinage of rocks undergoing dislocation creep a competent plasticine layer oriented perpendicular to the main shortening direction z underwent two phases of plane strain in a weaker plasticine matrix with the principal stretching axis x and the axis of no change y replacing each other from the first to the second phase in each phase of plane strain boudinage was controlled by an initial phase of viscous necking followed by extension fracture along the neck domain increase in the magnitude of finite strain e and decrease in layer thickness h i result in a decrease in the boudin width w a and an increase in the number of boudins n given the viscosity ratio between layer and matrix m is higher than ca 5 the number of boudins decreases and the boudin width increases with increasing values of m an unexpected result of the present study is that in each experiment the number of boudins was significantly higher during the second phase of plane strain this difference should be related to additional drag of the matrix plasticine on the stiff layer in the neck domains formed during the first phase of boudinage the aspect ratio of the second generation of boudins w d w a h i is compatible with aspect ratios of natural boudins and with aspect ratios calculated using analytical solutions

tsunami history over the past 2000 years on the sanriku coast japan determined using gravel deposits to estimate tsunami inundation behavior abstract at numanohama marsh on the rocky sanriku coast in northeast japan we identified 17 sand layers with sedimentary structures characteristic of event deposits i e a sharp erosional contact with the underlying unit a normal and or inverse grading structure parallel cross lamination mud clasts and or a thin mud layer abundant marine nannofossils coccoliths and the small catchment area in the narrow valley suggest that these event layers were likely formed by inundations during tsunamis or storms among the 17 sand layers nine contained gravels derived from the beach riverbed or slope areas six event layers contained all three of these gravels suggesting a strong inflow current that transported round pebbles from the beach erosion of wall rock in the valley during the inflow and outflow phases and a backwash current that caused sub angular riverbed gravel to accumulate in lowland areas these six layers were traced up to 490 m inland from the coastline present elevation 7 m above mean sea level and were several cm thick at almost every survey point we concluded that these six event layers are tsunami deposits and dating results revealed that they correlate with the 2011 tohoku oki earthquake the 1933 and 1896 sanriku oki earthquakes any of the 1763 aomori oki 1793 miyagi oki and 1856 aomori oki earthquakes the 1611 tohoku oki earthquake and the 869 tohoku oki jogan earthquake in addition changes in the sedimentary environment inferred from diatom assemblages were well correlated with the deposition of three of the event layers two historical earthquakes the 1454 and 1611 tohoku oki earthquakes have been previously suggested as being the immediate predecessors of the 2011 tohoku oki earthquake and our dating results favor the 1611 earthquake although the source region of the 869 tohoku oki jogan earthquake has been estimated to have been off the fukushima and miyagi prefectures our results suggest that the source region extended further north along the japan trench

a unified source model for the 2011 tohoku earthquake abstract the devastating 2011 tohoku earthquake was observed by dense networks of geophysical instruments a unified source model was constructed through joint inversion of teleseismic strong motion and geodetic datasets the result indicates that the earthquake consists of three main ruptures after small rupture in the initial 50 s the first rupture expanded at a slow speed of 1 8 km s to the northeast and east the second rupture began 20 s later at the slowest speed of 1 5 km s and became dominant with the largest slip of 36 m the third rupture then played the leading role propagating southward at a speed of 2 5 km s only the tsunami inversion requires an extension of the source fault to a shallow part between the first rupture area and the japan trench recovering tsunamigenic slips larger than 40 m the slow rupture speed and tsunamigenic slips can explain the features of the disaster by the earthquake

carbonation of borehole seals comparing evidence from short term laboratory experiments and long term natural analogues abstract it is crucial that the engineered seals of boreholes in the vicinity of a deep storage facility remain effective for considerable timescales if the long term geological containment of stored co2 is to be effective these timescales extend beyond those achievable by laboratory experiments or industrial experience study of the carbonation of natural ca silicate hydrate csh phases provides a useful insight into the alteration processes and evolution of cement phases over long timescales more comparable with those considered in performance assessments samples from two such natural analogues in northern ireland have been compared with samples from laboratory experiments on the carbonation of portland cement samples showed similar carbonation reaction processes even though the natural and experimental samples underwent carbonation under very different conditions and timescales these included conversion of the csh phases to caco3 and sio2 and the formation of a well defined reaction front in laboratory experiments the reaction front is associated with localised ca migration localised matrix porosity increase and localised shrinkage of the cement matrix with concomitant cracking behind the reaction front is a zone of caco3 precipitation that partly seals porosity a broader and more porous permeable reaction zone was created in the laboratory experiments compared to the natural samples and it is possible that short term experiments might not fully replicate slower longer term processes that the natural samples had only undergone limited carbonation even though they had been exposed to atmospheric co2 or dissolved hco 3 in groundwater for several thousands of years may indicate that the limited amounts of carbonate mineral formation may have protected the csh phases from further reaction

orthogonal folding of extensional detachments structure and origin of the sierra nevada elongated dome betics se spain 1 a close relationship of the kinematics and timing between low angle extensional faulting and upright folding is established for the miocene detachment systems in the hinterland of the betics in southeastern spain folding accompanied tectonic denudation developing elongated domes with fold axes both parallel and perpendicular to the direction of extension the geometry kinematics and tectonic evolution of two major sequentially developed extensional fault systems have been characterized in several e w elongated mountain ranges of the central betics on the basis of new cartographic and structural data and a comprehensive revision of other available geological and geophysical observations the extensional systems have an average wsw direction of extension and led to exhumation of the two lower metamorphic complexes of the betics the nevado filabride and the alpujarride during the middle and upper miocene serravallian to tortonian the extended domain contains a core complex with distal and proximal antiformal hinges separated by around 60 km and with a fold amplitude of 6 km measured parallel to the direction of extension the total amount of extension across the core complex is about 109 116 km corresponding to a stretching factor of 3 5 3 9 estimated using the distance between fold axial surfaces and a geometrical model accomplishing footwall deformation during tectonic denudation via subvertical simple shear the elongated domal and basinal geometry of the detachments and their respective footwalls is due to the interference between two sets of orthogonal large scale open folds trending n s and e w longitudinal n s trending folds are interpreted as isostatic folds i e folds that developed in response to differential unloading of the extensional detachment footwalls inducing ductile flow in the middle crust these folds formed in a rolling hinge anticline in which rotation migrates westward through the footwall as it is progressively unroofed in contrast e w trending folds being subparallel to the direction of extension have a contractional origin and progressively affect to the west the isostatically readjusted segments of the detachments once they are inactive orthogonal folding occurred since the serravallian to lower pliocene extension is still active from the rolling hinge anticline in sierra nevada to the west the middle miocene to pliocene tectonic evolution of the sierra nevada elongated dome at the core of the betic hinterland is another example of the coexistence of extension and contraction during continued overall convergence and mountain building

development of large north facing folds and their relation to crustal extension in the alboran domain alpujarras region betic cordilleras spain detailed research in the eastern part of the alpujarras region betic cordilleras has revealed the existence of large recumbent fold structures involving lithological sequences previously considered to belong to different tectonic units we have reconstructed a large complex fold structure which can be followed axially for over 50 km based on a careful revision of the boundaries between lithological formations a structural analysis of the carbonate and metapelite sequences and the use of mineralogical techniques such as measurements of d001 basal spacing of phengite paragonite and chlorite determinations of the illite crystallinity index ic and b0 parameters of mica and chlorite structural field data described in this paper include gently dipping axial plane cleavage surfaces common occurrence of gently dipping boudinage and pinch and swell structures and associated sub orthogonal stretching lineation similarity in orientation of this stretching lineation with the slip direction of the low angle normal faults and close association between north facing recumbent folds and top to the north low angle normal faults the slip direction of the faults being broadly perpendicular to the fold axes these features clearly indicate that extensional processes played a decisive role in the generation of the alpujarras large recumbent folds the development of these recumbent folds probably occurred during the early to middle miocene extensional tectonics that affected the betic cordilleras the formation of large scale folds in association with normal faulting is consistent with the p t paths and geochronological data established for the alpujarride region

mantle core complexes and neogene extensional detachment tectonics in the western betic cordilleras spain an alternative model for the emplacement of the ronda peridotite abstract an alternative model for the emplacement of the ronda peridotite betic alpine orogenic belt southern spain is proposed involving mantle uprising during a major neogene extensional event the development of a detachment system and its further evolution by isostatic rebound and upward arching would have triggered the tectonic denudation of these ultramafic bodies forming what may be termed mantle core complexes mantle core complexes would represent a final step in the core complex forming processes once a complete separation of the upper and lower blocks has been achieved in a detachment system marking probably the transition from an intracontinental to a proto oceanic rift environment

active transfer fault zone linking a segmented extensional system betics southern spain insight into heterogeneous extension driven by edge delamination pliocene and quaternary tectonic structures mainly consisting of segmented northwest southeast normal faults and associated seismicity in the central betics do not agree with the transpressive tectonic nature of the africa eurasia plate boundary in the ibero maghrebian region active extensional deformation here is heterogeneous individual segmented normal faults being linked by relay ramps and transfer faults including oblique slip and both dextral and sinistral strike slip faults normal faults extend the hanging wall of an extensional detachment that is the active segment of a complex system of successive wsw directed extensional detachments which have thinned the betic upper crust since middle miocene two areas which are connected by an active 40 km long dextral strike slip transfer fault zone concentrate present day extension both the seismicity distribution and focal mechanisms agree with the position and regime of the observed faults the activity of the transfer zone during middle miocene to present implies a mode of extension which must have remained substantially the same over the entire period thus the mechanisms driving extension should still be operating both the westward migration of the extensional loci and the high asymmetry of the extensional systems can be related to edge delamination below the south iberian margin coupled with roll back under the alboran sea involving the asymmetric westward inflow of asthenospheric material under the margins

slip distribution of the 2007 bengkulu earthquake inferred from tsunami waveforms and insar data 1 joint inversion study using tsunami waveforms and insar data provides a new way to understand the magnitude and spatial extent of subduction zone earthquakes a great earthquake mw 8 5 occurred on 12 september 2007 off the west coast of bengkulu indonesia the tsunami generated by the event was recorded by tide gauge stations around the indian ocean and by two bottom pressure sensors in the deep sea the ground surface displacements produced by the earthquake on pagai islands and on sumatra island were observed by interferometric synthetic aperture radar insar we estimated the slip distribution of the earthquake by joint inversion incorporating a spatial smoothness constraint using tsunami waveforms and insar data the total released seismic moment calculated from the slip distribution is 6 7 1021 n m mw 8 5 consistent with the seismic moment of the global cmt solution 6 71 1021 n m the maximum observed tsunami heights along the coast of bengkulu agree with those computed from the slip distribution the slip amount of the 2007 earthquake is smaller than the amount of potential slip that has been accumulated since after the 1797 and 1833 events the premise is that averaged over long periods of time the entire fault must slip equal amounts therefore the 2007 great earthquake could be followed by several great earthquakes that will rupture the plate interface until the potential slip that has been accumulated is completely released

a multidisciplinary geophysical study in the betic chain southern iberia peninsula abstract the combined analysis of magnetotelluric measurements tomographic velocity models and deep seismic reflection images confirms that the betics orogen consists of the juxtaposition of two crustal domains characterized by distinctive physical properties at depth these data sets show evidence for a non coincidence of the petrological and the seismic moho beneath the betics chain the data sets reveal the geophysical properties of the alboran domain internal betics and the iberian massif external betics according to this the iberian crust features a relatively high seismic velocity is seismically transparent in the seismic reflection images and is electrically resistive the alboran domain crust is characterized by a low average velocity displays high reflectivity in the seismic reflection images and is electrically conductive the outcrops of the metamorphic complexes alpujarride and nevado filabride showing relatively high velocities coupled with low v p v s values 1 67 derived from the wadati slopes suggest the existence of rocks rich in silica beneath the alboran domain crust an interpreted detachment at 12 km depth imaged by deep seismic reflection suggests that these rocks could be related to the iberian upper crust partial melts and fluids are proposed to explain the high conductivity observed at deep crustal levels these would account also for the reflectivity and the low v p v s ratios mapped beneath the alboran domain

paleomagnetic rotations and the kinematics of the gibraltar arc paleomagnetic investigations of a mesozoic limestone sequence around the gibraltar arc show that there have been large systematic rotations about a vertical axis and imply that there must have been a significant component of westward motion within the betic rif orogenic belt rotations of the late jurassic and late cretaceous limestones in the betic cordillera of southern spain are clockwise with the exception of the unrotated sierra gorda whereas the jurassic sites in the rif mountains of morocco are rotated counterclockwise except in the area around tetuan these data are generally consistent with formation of the arc either by a westward moving alboran microplate or by extensional collapse of a collisional mountain chain the former model however fails to recognize the nonrigid nonplate like character of the alboran domain and lacks a definable driving mechanism a model of a collapsing east west elongated ridge that takes into account the obliquity of the convergence along the active margin may provide mechanisms both for the observed rotations and for the large westward component of motion and therefore can explain the geometry of the gibraltar are

continental collision crustal thinning and nappe forming during the pre miocene evolution of the alpujarride complex alboran domain betics the tectono metamorphic evolution of the alpujarride complex within the internal zones of the gibraltar arc indicates that the alboran crustal domain underwent several contractional and extensional events the superposition of structures and the metamorphic evolution observed in the alpujarride complex and in particular in the adra unit suggest that these events are as follows a the first thickening event d1 results from continental subduction and is evidenced by the presence of pre s2 high pressure mineral relicts b the thinning and associated vertical shortening event d2 is indicated by an almost isothermal decompression during which the s2 main foliation developed c kilometric scale n vergent recumbent folds of the condensed metamorphic sequences and thrust and nappe forming in the alpujarride complex suggest that a second thickening event d3 took place d the second thinning event d4 which affects the whole alboran domain is evidenced by extensional fault systems resulting in the opening of the alboran sea the oldest synrift deposits are of the late oligocene and early miocene suggesting that d1 to d3 events are pre miocene and e from the late tortonian to the pliocene the extensional systems were folded due to a continuous n s to nw se compression

tectonic evolution of the betic rif arc new constraints from 40ar 39ar dating on white micas in the temsamane units external rif northern morocco article i nfo the betic rif orogen at the western end of the mediterranean is a key region to improve our knowledge on the africa eurasia convergence the temsamane units in spite of their external position in the rif northern morocco underwent medium pressure low temperature mp lt conditions ca 7 9 kbar 330 430 c we propose a new tectonic and metamorphic evolution scenario for the rif southern branch of the orogen on the basis of first 40 ar 39 ar dating on petrologically and structurally characterized white micas three groups of 40 ar 39 ar ages are observed 1 chattian or older si rich highest pressure mica relics 2 15 12 5 ma corresponding to the micas defining the foliation and 3 messinian or younger late micas and alteration we propose that the mp lt metamorphic event in the external rif is oligocene in age highlighting a subduction event during this period which could be almost contemporaneous with the burial of hp lt units from the internal rif alboran domain the exhumation of these units characterized by an intense e w stretching and by top to the west shear senses is middle to late miocene in age we propose a correlation of tectonic and metamorphic events at the betic rif arc scale we argue that the exhumation of the external units of the rif 1 is younger than that of the alboran domain internal unit of the rif and mirrors a different tectonic setting but 2 strongly resembles to that documented in the lower alboran domain units of the betics we show that a regional e w extension is recorded on both sides of the betic rif arc during the middle miocene this extension probably reflects back arc deformation of an eastward dipping subduction that retreated westward during the middle to late miocene in the western mediterranean

geochemical effects of co2 sequestration on fractured wellbore cement at the cement caprock interface abstract the potential impact to the integrity of wellbore cements as a result of exposure to supercritical carbon dioxide scco2 has been raised as an area of some concern with respect to long term effectiveness of co2 storage in geological formations in flow through experiments we simulated diffusion of brine and scco2 from the interface between wellbore cement and caprock into a fracture bearing portland cement the experiments were performed at in situ reservoir pressure pore pressure 19 9 mpa and temperature 54 c conditions for 113 days for this purpose we saturated illite rich shale and the portland cement core 2 02 cm 5 35 cm with 1 65 m brine for 14 days after this period of time we injected scco2 into the system for 99 days and simulated a diffusion process by using a pressure gradient of 0 7 mpa calcite precipitation occurred within the fracture and the induced pressure of crystal growth may explain an increase in the relative permeability along the fracture with time scco2 induced reactions extended 5 mm into the portland cement core from the fracture and formed an orange colored zone the orange colored zone is nearly completely carbonated with crystalline phases consisting mainly of calcite aragonite and vaterite the only crystalline cement component that persisted in the orange colored zone was brownmillerite interior portions of the hydrated cement were partially carbonated modified in texture and contained newly formed calcite hydrogarnet and hydrocalumite friedel s salt cement porosity decreased from 37 8 to 23 8 during carbonation and was associated with a 19 6 increase in mass

survey of 2011 tohoku earthquake tsunami inundation and run up 1 at 14 46 local time on march 11 2011 a magnitude 9 0 earthquake occurred off the coast of northeast japan this earthquake generated a tsunami that struck japan as well as various locations around the pacific ocean with the participation of researchers from throughout japan joint research groups conducted a tsunami survey along a 2000 km stretch of the japanese coast more than 5300 locations have been surveyed to date generating the largest tsunami survey dataset in the world on the sendai plain the maximum inundation height was 19 5 m and the tsunami bore propagated more than 5 km inland along the ria coast from about 50 to 200 km north of sendai the narrow bays focused the tsunami waves generating the largest inundation heights and run ups the survey data clearly show a regional dependence of tsunami characteristics

process based modeling of tsunami inundation and sediment transport 1 the infrequent and unpredictable nature of tsunamis precludes the use of field experiments to measure the hydrodynamic and sediment transport processes that occur instead these processes are often approximated from laboratory numerical and theoretical studies or inferred from observations of the resultant sediment deposits here delft3d a three dimensional numerical model is used to simulate the inundation and sediment transport of a tsunami similar in magnitude to the 26 december 2004 indian ocean tsunami over one measured and three idealized morphologies the model is first shown to match well the observations taken at kuala meurisi sumatra and then used to examine in detail the processes that occur during the tsunami the model predicts that at a given cross shore location the onshore flow accelerates rapidly to a maximum as the wavefront passes and then gradually decelerates before reversing direction and flowing offshore the onshore flow does not tend to zero everywhere at maximum inundation but instead flow reversal occurs near the shoreline even as the wavefront continues to inundate landward while some sediment is eroded by the passing wavefront the suspension of sandy sediment is dominated by the long duration high velocity backwash that occurs along the beach face and offshore of the shoreline some of the sediment suspended during backwash is advected shoreward by the subsequent wave creating large spatial gradients in the suspended sediment concentrations which may not be in equilibrium with the local hydrodynamics the inundation and transport of sediment during a tsunami can be affected by complexities in the morphological profile and interactions between multiple waves and many of the hydrodynamic and sediment transport processes predicted here are similar to analogous processes previously observed in the swash zone

linked fault families in basin formation abstract recent models of faulting tectonics in basins and passive margins have emphasized the linked nature of faults in a way that is analogous to that developed for thrust regimes a linked fault system requires three components ramps flats and sidewalls or transfers basins that are the result of other processes are not considered in this contribution and the examples used are drawn from the midland valley and northumberland basins of the u k where existing mapping by the british geological survey as well as field work undertaken by the author indicate that such models are appropriate this paper summarizes the geometric features and constraints of such models and emphasizes the role of each of the three critical components of a linked system for large deformations that result in the formation of major extensional and strike slip basins the principal geometries can be understood by reference to regionally and locally balanced fault models that involve detachment ramp and sidewall or transfer elements tip strains and both lateral and vertical accommodation zones are included in the general model but these probably account for less than 10 of the total upper crustal strain the basic analysis of a linked basin system requires the transfer of displacement on and between the fault and shear zone components the geometry of the stratigraphic units is used to deduce the active linkage on the fault system in oblique slip systems and where the dominant extensional ramp is connected to oblique transfer and detachment systems lateral and sidewall sub basins and intra basin uplifts occur as part of continuing slip on the fault system these control facies distribution and depocentre evolution the existence of a basin forming linked system frequently controls later deformation of basins and margins and an appreciation of basin growth faults and stratigraphic geometry is essential in the interpretation of inverted basins and orogenic belts involving supracrustal formations

a simple model for calculating tsunami flow speed from tsunami deposits abstract this paper presents a simple model for tsunami sedimentation that can be applied to calculate tsunami flow speed from the thickness and grain size of a tsunami deposit the inverse problem for sandy tsunami deposits where grain size and thickness vary gradually in the direction of transport tsunami sediment transport is modeled as a steady spatially uniform process the amount of sediment in suspension is assumed to be in equilibrium with the steady portion of the long period slowing varying uprush portion of the tsunami spatial flow deceleration is assumed to be small and not to contribute significantly to the tsunami deposit tsunami deposits are formed from sediment settling from the water column when flow speeds on land go to zero everywhere at the time of maximum tsunami inundation there is little erosion of the deposit by return flow because it is a slow flow and is concentrated in topographic lows variations in grain size of the deposit are found to have more effect on calculated tsunami flow speed than deposit thickness the model is tested using field data collected at arop papua new guinea soon after the 1998 tsunami speed estimates of 14 m s at 200 m inland from the shoreline compare favorably with those from a 1 d inundation model and from application of bernoulli s principle to water levels on buildings left standing after the tsunami as evidence that the model is applicable to some sandy tsunami deposits the model reproduces the observed normal grading and vertical variation in sorting and skewness of a deposit formed by the 1998 tsunami

evolution of near surface ramp flat ramp normal faults and implication during intramontane basin formation in the eastern betic cordillera the huercal overa basin se spain 1 the nucleation propagation and associated folding of ramp flat ramp normal faults were analyzed from field examples developed in a brittle ductile multilayer sequence of the huercal overa basin se spain gently dipping sandy silt layers which display a low cohesive strength c0 7 kpa 34 favor the development of extensional detachments a tectonic origin instead of a possible gravitational origin is supported by the perpendicularity between the paleoslope direction of the fluvial deltaic environment inferred from imbricated pebbles and the senses of movement deduced from fault slicken lines the link between high angle normal faults hanfs formed at different levels in the layered sequence with horizontal fault segments comes to develop ramp flat ramp normal faults with associated roll over in the hanging wall observed extensional duplexes are formed by parallel detachments connected through synthetic riedel faults these riedel faults would produce the back rotation of the individual blocks horses i e extensional folding of the originally subhorizontal layers there is no correlation between the analyzed ramp flat ramp normal faults accommodating south southeastward extension during serravallian lower tortonian and either the regional alpujarride nevado filabride west directed extensional shear zone or the top to the north detachments within alpujarride units which are clearly sealed by serravallian lower tortonian sediments therefore the studied normal faults are restricted to the brittle ductile multilayer fluvio deltaic sequence and accommodate moderate late extension instead of belonging to a large crustal extensional system connected with a regional detachment at depth therefore the basin formed in a moderate crustal thickness context where small and medium scale extensional systems were subordinate structures these natural examples support the development of low angle normal faults at very shallow crustal levels in multilayer sequences with suitable rheological conditions

palaeomagnetic rotations and fault kinematics in the rif arc of morocco palaeomagnetic and structural investigations in the rif arc of morocco indicate that there have been large rotations associated with a pattern of outwardly directed thrusting rock magnetic experiments in conjunction with thermal and alternating field demagnetization demonstrate that eight sites in jurassic and cretaceous limestones along the internal external boundary have a stable remanent magnetization this is in most cases rotated anticlockwise by as much as 100 from the expected mesozoic declination but in the tetuan area there are large clockwise rotations kinematic indicators from fault surfaces indicate the following 1 in the eastern rif there has been predominantly south directed thrusting partly overprinted by extensional and sinistral strike slip faults 2 at the eastern end of the n 70 e striking jebha fault zone there is a pattern of dominant sinistral ne trending and subsidiary dextral se trending strike slip faults overprinted by normal faults while at the western end deformation consists largely of south directed thrusting 3 in the northern section of the chain where the structural trends are dominantly n s thrusting is directed w to nw it is suggested that the data are best explained by differential motion and rotation of thrust sheets during outwardly directed thrusting around the arc

tectonic inversion of an asymmetric graben insights from a combined field and gravity survey in the sorbas basin the formation of sedimentary basins in the alboran domain is associated with the exhumation of metamorphic core complexes over a ca 15 ma period through a transition from regional late orogenic extension to compression an integrated study coupling field analysis and gravity data acquisition was performed in the sorbas basin in the southeastern betic cordillera detailed field observations revealed for the first time that extensional tectonics occurred before shortening in this basin two extensional events were recorded with nw se to n s and ne sw kinematics respectively the first of which being likely responsible for the basin initiation tectonic inversion of the basin then occurred around 8 ma in an overall ca n s shortening context 2d gravity sections reveal that the basin acted as an active depocenter as the basin floor locally exceeding 2 km depth is characterized by a marked asymmetric architecture based on this integrated study we explore a new evolutionary scenario which can be used as a basis for interpretations of the neogene tectonic history of the southeastern betics

flow speed estimated by inverse modeling of sandy tsunami deposits results from the 11 march 2011 tsunami on the coastal plain near the sendai airport honshu japan abstract tsunami deposits contain information about the flow that created them which can be interpreted to estimate tsunami magnitude sandy deposits near sendai airport are modeled using an inverse sediment transport model to explore the spatial and temporal variation of tsunami flow speed in the 11 march 2011 tohoku oki tsunami the 2011 deposits contain grain size signatures of both sediment transport convergences and sediment settling out of suspension sediment transport convergences form massive or inversely graded intervals sediment falling out of suspension forms a specific type of normal grading termed suspension grading the jaffe and gelfenbaum 2007 inverse sediment transport model which relates the thickness and bulk grain size of suspension graded intervals to tsunami flow speed was applied to 24 suspension graded intervals ranging in thickness from 2 to 4 cm at 7 trenches located from about 250 to 1350 m inland from the shoreline modeled tsunami flow speeds range from 2 2 to 9 0 m s and were strongly dependent on the choice of manning s n roughness parameterization flow speeds were highest from about 75 300 m landward of the forested sand dunes where the tsunami encountered lower roughness in a low lying area as it traveled downslope and decreased by 16 as the tsunami moved inland over the subsequent 596 m as many as 5 suspension graded intervals interpreted as forming during the onshore flow of up to 5 waves were identified at each location with a tendency for an inland decrease in the number of suspension graded intervals suggesting fewer waves inland tsunami flows tended to be fastest in the lower two intervals earlier waves and slowest in the uppermost interval last wave of the deposits modeled reconstructions of the suspension graded intervals at a vertical resolution of 1 cm reproduced observed upward fining of the distributions reasonably well supporting the use of the inverse model estimates of the time required to form 99 of the thickness of the suspension graded intervals ranged 2 to 5 min allowing that sediment falling from suspension could have formed these portions of the deposits in the time between waves application of the inverse model to determine paleotsunami flow speeds from deposits although now possible is complicated by uncertainty in roughness as inverse approaches to estimating roughness and tsunami flow speed improve the magnitude of paleotsunamis will be better understood and the ability to assess tsunami hazard from paleotsunami deposits will improve

numerical simulation of sedimentation and erosion caused by the 2011 tohoku tsunami in oarai port japan abstract the 2011 tohoku tsunami induced sediment deposition of 334 000 m3 mainly in the basin and 9 m erosion at the tips of a breakwater and a groin in oarai port japan the tsunami induced bathymetry change was simulated using a numerical model and the simulated bathymetry change was compared with the measured one the comparison showed that the simulated bathymetry change quantitatively agreed with the measured one including the sediment deposition and the erosion mentioned above although the erosion measured along the breakwater was not well reproduced by the model the time series of simulated bathymetry change water level current and suspended sediment concentration showed that the sediment deposition in the center of the basin was mostly induced by the sediments that moved into the basin through its entrance between the breakwater and the groin and were redistributed by counterclockwise vortices the severe erosion at the tip of the breakwater was mainly induced by the strong southward currents

reduction effect of tsunami sediment transport by a coastal forest numerical simulation of the 2011 tohoku tsunami on the sendai plain japan abstract we examined the effect of the coastal forest on tsunami sediment movement on the sendai plain japan during the 2011 tohoku tsunami using a numerical simulation of sediment transport to account for the variable roughness coefficient in the coastal forest a composite equivalent roughness coefficient was adopted the simulated mean concentration of suspended sediment wave height flow velocity and inundation limit were significantly reduced by the coastal forest for fine to medium sand the volumes of maximum deposition and erosion were reduced to 57 83 of those in the simulation without the coastal forest these reductions were particularly notable for fine sand the maximum extent and thickness of the sand layer were also reduced the simulated sediment thickness and extent with the coastal forest for finer grain sizes roughly agreed with the observations while the simulated results for coarser sand underestimated the observations the reduction of sediment transport due to the coastal forest suggests that land use conditions and the vegetation environment at the time of a tsunami should be considered when studying historical and paleo tsunamis using the geological evidence

time and space distribution of coseismic slip of the 2011 tohoku earthquake as inferred from tsunami waveform data a multiple time window inversion of 53 high sampling tsunami waveforms on ocean bottom pressure global positioning system coastal wave and tide gauges shows a temporal and spatial slip distribution during the 2011 tohoku earthquake the fault rupture started near the hypocenter and propagated into both deep and shallow parts of the plate interface a very large slip approximately 25 m in the deep part off miyagi at a location similar to the previous 869 jogan earthquake model was responsible for the initial rise of tsunami waveforms and the recorded tsunami inundation in the sendai and ishinomaki plains a huge slip up to 69 m occurred in the shallow part near the trench axis 3 min after the rupture initiation this delayed shallow rupture extended for 400 km with more than a 10 m slip at a location similar to the 1896 sanriku tsunami earthquake and was responsible for the peak amplitudes of the tsunami waveforms and the maximum tsunami heights measured on the northern sanriku coast 100 km north of the largest slip the average slip on the entire fault was 9 5 m and the total seismic moment was 4 2 1022 n m m w 9 0 the large horizontal displacement of seafloor slope was responsible for 20 40 of tsunami amplitudes the 2011 deep slip alone could reproduce the distribution of the 869 tsunami deposits indicating that the 869 jogan earthquake source could be similar to the 2011 earthquake at least in the deep plate interface the large tsunami at the fukushima nuclear power station is due to either the combination of a deep and shallow slip or a triggering of a shallow slip by a deep slip which was not accounted for in the previous tsunami hazard assessments online material table of estimated slip for all subfaults at 0 5 min invervals

clues for a tortonian reconstruction of the gibraltar arc structural pattern deformation diachronism and block rotations abstract we proposed a reconstruction of one of the tightest orogenic arcs on earth the gibraltar arc system this reconstruction which includes onshore and offshore data is completed for approximately 9 ma the clues that lead us to draw it are based on a review in terms of structures and age of the superposed deformational events that took place during miocene with special attention to the external zones this review and new structural data presented in this paper permit us to constrain the timing of vertical axis rotations evidenced by previously published paleomagnetic data and to identify homogeneous domains in terms of relationships between timing of deformation events re magnetization and rotations in particular remagnetization in the betics took place after the main shortening which produced the external fold and thrust belts pre upper miocene but was mostly previous to a contractive reorganization that affected the whole area it should have occurred during lower tortonian between 9 9 and 11 ma from tortonian to present block rotations as high as 53 took place together with plate convergence they accommodated a tightening and lengthening of the gibraltar arc system and drastically altered its geometry as the orientation and position of any pre 9 ma kinematic indicator or structural element is also modified our reconstruction should be used as starting point for any pre tortonian model of the westernmost orogenic segment of the alpine mediterranean system

mode of extensional tectonics in the southeastern betics se spain implications for the tectonic evolution of the peri alboran orogenic system the gibraltar arc which closes the westernmost part of the mediterranean basin is a miocene a type subduction arc formed by the continental collision of various pre miocene terranes in the major zone of collision between the iberian and african cratons the hanging wall block known as the alboran domain has undergone more than 300 km migration from a more easterly position where it was the continuation of the alpine cretaceous paleogene orogen contemporaneous with thin skinned thrusting in the footwall the alboran domain underwent two episodes of nearly orthogonal extension in which extensional systems developed with directions of extension varying from a nnw sse system orthogonal to the belt axis in the late burdigalian langhian to a wsw directed orogen parallel one in the serravallian the superposition of these two systems resulted in a chocolate tablet megastructure this extensional pattern is not satisfactorily explained in previously proposed models for the evolution of the arc orthogonal extension is plausible in a process of the gravitational collapse of an overthickened crust nevertheless orogen parallel extension is more difficult to explain in this context we advocate that the wsw directed low angle normal faults formed during large scale extension in connection with important westward arc migration the driving force of extension in a general context of convergence is controversial and varies between a convective removal model and a delamination model constraints on both the timing and the kinematics of extension as presented in this paper seem to support the contribution of both mechanisms convective removal may have started the process but continued n s convergence could have resulted in westward tectonic escape and asymmetric lateral inflow of asthenospheric material accompanying lithospheric delamination

a reappraisal of the alpine structure of the alpujarride complex in the betic cordillera interplay of shortening and extension in the westernmost mediterranean abstract the alpujarride complex has concentrated discussion on the extent and role of orogenic extension in the betic rif orogen westernmost mediterranean structural analysis on permo triassic rocks of the alpujarride complex is a firm basis to assess extension and to integrate it in the plate tectonic scenario the main alpine deformation was dominated by top to the ne shearing with rare map scale folds as a whole this deformation attests ductile extension during exhumation of previously subducted rocks some authors have suggested that the alpujarride complex continued evolving extensionally since this early exhumation but in this paper a stage of regional shortening is documented thus km scale overturned nw vergent folds are interpreted as witnessing shortening subsequently post metamorphic low angle faults of burdigalian langhian age cut the train of folds in two ways firstly top to the n thrusts generated stratigraphic and metamorphic superpositions then top to the n low angle normal faults kinematically congruent with the thrusts formed due to accretion at deep levels of the orogenic wedge when the nevado filabride complex underthrust the alpujarride complex the shortening stage occurred at latest oligocene early middle miocene and can be related to fast convergence rates between africa and iberia later a drop in the convergent rates prompted lithospheric rollback and top to the sw crustal extension since serravallian time coexisting with moderate orthogonal shortening that gave way to e w trending upright folds

source model of the great 2011 tohoku earthquake estimated from tsunami waveforms and crustal deformation data the slip distribution of the 11 march 2011 tohoku earthquake is inferred from tsunami waveforms gps data and seafloor crustal deformation data the major slip region extends all the way to the trench and the large slip area extends 300 km long and 160 km wide the largest slip of 44 m is located up dip of the hypocenter the large slip amount about 41 m ruptured the plate interface near the trench the seismic moment calculated from the estimated slip distribution is 5 5 10 22 n m mw 9 1 the large tsunami due to the 2011 tohoku earthquake is generated from those large slip areas near the trench the additional uplift at the sedimentary wedge as suggested for the 1896 sanriku earthquake may have occurred during the 2011 tohoku earthquake too

tsunami inundation sediment transport and deposition process of tsunami deposits on coastal lowland inferred from the tsunami sand transport laboratory experiment tstle abstract the processes of tsunami inundation sediment transport and deposition on coastal lowlands are investigated experimentally we conducted large scale experiments with land slopes of 0 00 and 0 01 and compared them with experiments conducted previously with a slope of 0 02 the ratio of marine originated sediment in the inland deposits decreased as the land slope decreased reflecting the strong inundation flow and weak return flow the sediment concentration near the bed increased remarkably and supplied a greater quantity of coarse sand inland when the land slope decreased indicating the strong influence of land slope on bed load the extent of sandy deposits and the inundation limit nearly corresponded with the sloping topographies however the inundation flow reached much farther inland than the sandy deposits on the flat i e level topography this was because the extent of sandy deposits was determined by the flow speed which depended in turn on the wave speed whereas the inundation limit was determined by the inland water mass which depended in turn on the waveform the floating load reached the inundation limit and formed very thin and sparse muddy deposits considering the uncertainty of the waveform and the difficulty of detecting muddy deposits it is more feasible to estimate the wave speed from the extent of sandy deposits the spatial distributions of sandy deposits for various waves land slopes and topographies were characterized by the nondimensional area density and inundation distance this result suggested the possibility of quantitative comparison among field investigations of tsunami deposits under various conditions the formation of an inverse grading layer experimentally observed in a wide range of inland deposits was attributed to kinetic sieving the bed load under slow deposition was speculated to thicken the inverse grading layer by reworking the coarse sand additionally the sediment behind dunes became liquefied and showed shear deformation during the erosion the shear deformation of liquefied sediment below the erosional surface might leave sedimentary characteristics specific to earthquake tsunamis

formation of chocolate tablet boudins in a foreland fold and thrust belt a case study from the external variscides almograve portugal abstract chocolate tablet boudins of quartzite are restricted to steep limbs of d 1 folds along the sw coast of portugal the chocolate tablet geometry results from older vertical and younger horizontal quartz veins both sets of veins developed during similar conditions by extension fracture in pre existing necked domains 1 both veins show stretched crystal fibers 2 the boudin aspect ratio is the same in vertical 3 0 1 4 and in horizontal sections 2 9 1 2 3 temperatures obtained from fluid inclusions are similar 200 20 for vertical and 230 22 c for horizontal veins and are compatible with temperatures obtained from illite crystallinity ca 200 ca 250 c given thermal equilibrium between the host rock and the precipitating fluid the chocolate tablet boudins formed close to the metamorphic peak we interpret that the vertical veins developed after the limbs of the d 1 folds had attained their steep attitude and the orientation of the greatest and intermediate principal strain axes had interchanged subsequently the initial strain field was restored and opening of horizontal veins led to the chocolate tablet geometry the direction of the main shortening direction was constant from the initial buckling stage via isoclinal folding and during all boudinage stages

sedimentary deposits from the 17 july 2006 western java tsunami indonesia use of grain size analyses to assess tsunami flow depth speed and traction carpet characteristics the 2006 western java tsunami deposited a discontinuous sheet of sand up to 20 cm thick flooded coastal southern java to a depth of at least 8 m and inundated up to 1 km inland in most places the primarily heavy mineral sand sheet is normally graded and in some it contains complex internal stratigraphy structures within the sand sheet probably record the passage of up to two individual waves a point noted in eyewitness accounts we studied the 2006 tsunami deposits in detail along a flow parallel transect about 750 m long 15 km east of cilacap the tsunami deposit first becomes discernable from the underlying sediment 70 m from the shoreline from 75 to 300 m inland the deposit has been laid down in rice paddies and maintains a thickness of 10 20 cm landward of 300 m the deposit thins dramatically reaching 1 mm by 450 m inland from 450 m to the edge of deposition around 700 m inland the deposit remains 1 mm thick deposition generally attended inundation along the transect the tsunami deposited sand to within about 40 m of the inundation limit the thicker part of the deposit contains primarily sand indistinguishable from that found on the beach 3 weeks after the event but after about 450 m and roughly coinciding with the decrease in thickness the tsunami sediment shifts to become more like the underlying paddy soil than the beach sand grain sizes within the deposit tend to fine upward and landward although overall upward fining takes place in two discrete pulses with an initial section of inverse grading followed by a section of normal grading the two inversely graded sections are also density graded with denser grains at the base and less dense grains at the top the two normally graded sections show no trends in density the inversely graded sections show high density sediment to the base and become less dense upward and represents traction carpet flows at the base of the tsunami these are suggestive of high shear rates in the flow because of the grain sorting in the traction carpet the landward fining trends usually seen in tsunami deposits are masked although lateral changes of mean sediment grain size along the transect do show overall landward fining with more variation as the deposit tapers off the deposit is also thicker in the more seaward portions than would be produced by tsunamis lacking traction carpets

interference pattern of extensional fault systems a case study of the miocene rifting of the alboran basement north of sierra nevada betic chain abstract in the betic rif orogenic belt in the westernmost part of the mediterranean early and middle miocene crustal thinning of the upper part of the alboran basement is well established by previous studies in the alboran domain of the central betics the present distribution of the alpujarride units results from the extensional dismembering of a pre miocene nappe stack under brittle conditions the interference of two subperpendicular and successive extensional fault systems can explain the current geometric pattern of the alpujarride units upper burdigalian langhian north south extension was followed by west to southwestward extension of serravallian age northeast of sierra nevada these two extensional systems have resulted in a spectacular chocolate tablet megastructure and the cropping out at any one vertical sequence of a varying number of extensional units belonging to the alpujarride complex this pattern can be considered representative of the middle miocene tectonics of the entire alboran domain in the betics and illustrates the development of rifting processes in the upper crust