present day kinematics of the mediterranean a comprehensive overview of gps results i combine recently published gps results to derive a geodetic horizontal velocity field consistent at the scale of the mediterranean and the surrounding alpine belts the velocity field is then used to discuss the boundary conditions around each major deforming area in the mediterranean to describe the main patterns of motion and deformation to critically review the existing kinematics models and to finally point out the main unresolved kinematics questions strain rate in europe north of the alpines belt is dominated by the signature of the glacial isostatic adjustment and tectonic strain remains below the current accuracy of gps results in the western mediterranean deformation is restricted to the betics the alboran and the morrocan rif with west to southwestward motion with respect to iberia which is part of stable europe shortening consistent with the relative nubia eurasia plate motion is found throughout the maghrebides but the distribution of deformation in northern africa remains largely unknown the central mediterranean is dominated by the counter clockwise rotation of the adriatic the junction between the southern adriatic domain and nubia has yet to be firmly established the deformation over a wide area east of the maghrebides in tunisia and the gulf of sirte in libya still remains to be quantified in the eastern mediterranean the velocity field is dominated by a general anti clockwise rotation and a general trend towards the hellenic trench with velocity magnitude increasing with decreasing distances from the trench this trend is observed not only in the aegean and anatolia but also in the southern balkans geodetic results emphasize that the convergence of the nubia and arabia plates towards eurasia directly controls the deformation across only very few segments along the plate boundary zone additional processes are therefore required to explain the observed velocity field and deformation pattern

spectrally based remote sensing of river bathymetry this paper evaluates the potential for remote mapping of river bathymetry by 1 examining the theoretical basis of a simple ratio based technique for retrieving depth information from passive optical image data 2 performing radiative transfer simulations to quantify the effects of suspended sediment concentration bottom reflectance and water surface state 3 assessing the accuracy of spectrally based depth retrieval under field conditions via ground based reflectance measurements and 4 producing bathymetric maps for a pair of gravel bed rivers from hyperspectral image data consideration of the relative magnitudes of various radiance components allowed us to define the range of conditions under which spectrally based depth retrieval is appropriate the remotely sensed signal must be dominated by bottom reflected radiance we developed a simple algorithm called optimal band ratio analysis obra for identifying pairs of wavelengths for which this critical assumption is valid and which yield strong linear relationships between an image derived quantity x and flow depth d obra of simulated spectra indicated that water column optical properties were accounted for by a shorter wavelength numerator band sensitive to scattering by suspended sediment while depth information was provided by a longer wavelength denominator band subject to strong absorption by pure water field spectra suggested that bottom reflectance was fairly homogeneous isolating the effect of depth and that radiance measured above the water surface was primarily reflected from the bottom not the water column obra of these data 28 of which were collected during a period of high turbidity yielded strong x versus d relations r2 from 0 792 to 0 976 demonstrating that accurate depth retrieval is feasible under field conditions moreover application of obra to hyperspectral image data resulted in spatially coherent hydraulically reasonable bathymetric maps though negative depth estimates occurred along channel margins where pixels were mixed this study indicates that passive optical remote sensing could become a viable tool for measuring river bathymetry copyright 2009 john wiley sons ltd

selection of earthquake scaling relationships for seismic hazard analysis a fundamentally important but typically abbreviated component of seismic hazard analysis is the selection of earthquake scaling relationships these are typically regressions of historical earthquake datasets in which magnitude is estimated from parameters such as fault rupture length and area the mix of historical data from different tectonic environments and the different forms of the regression equations can result in large differences in magnitude estimates for a given fault rupture length or area we compile a worldwide set of regressions and make a first order shortlisting of regressions according to their relevance to a range of tectonic regimes plate tectonic setting and fault slip type in existence around the world regression relevance is based largely on the geographical distribution age and quantity quality of earthquake data used to develop them our compilation is limited to regressions of magnitude or seismic moment on fault rupture area or length and our shortlisted regressions show a large magnitude range up to a full magnitude unit for a given rupture length or area across the various tectonic regimes these large differences in magnitude estimates underline the importance of choosing regressions carefully for seismic hazard application in different tectonic environments

controls on fan development evidence from fan morphometry and sedimentology sierra nevada se spain abstract we have studied the morphology and the morphometric relations between alluvial fans and drainage basins in a bajada system including more than 20 coalescent fans developed since the late pleistocene as a result of the recent uplift of the sierra nevada betic cordillera spain three allocycles of tectonic origin were recognised across which there is a clear evolution from debris flow to sheet flow dominated fans in connection with a decrease in the volume of fines available in the source areas the larger volume of accommodation space created by higher tectonic subsidence in the northern sector favoured vertical accumulation of sediment with the appearance of less elongated fans in the rest of the system where subsidence is less more elongated fans appear with the development of incised channels and irregular distribution of sediment in depositional lobes this involves the appearance of markedly asymmetric transverse profiles as well as lengthy recurrence between the sedimentation events on particular sectors of the fans where headward eroding gullies develop the lithology of the source area where intensely fractured rocks are found is responsible for an important sediment supply and a significant degree of clast sorting from the source area consequently a weak longitudinal trend in particle size can be recognised which influences the predominance of longitudinal constant slope profiles and anomalous relations between both fan area and fan slope and their drainage areas recent intense tectonic activity has caused the appearance of abnormally low slopes in upper sectors of some catchments where mass flows are trapped and the fans present a subsequently higher proportion of sheet flows recent piracy phenomena can be recognised in some of the drainage basins which indicate rejuvenation of the source area in which case the fan presents a rapid increase in the proportion of mass flows with the development of a segmented longitudinal profile due to the recent nature of the processes the morphometric relations in the fan fed by the basin affected by capture do not coincide with the other fans in the area

limestone and the problem of radiocarbon dating of land snail shell carbonate in order to test the role of limestone in producing anomalously old radiocarbon ages in land snail shells 14 c analyses were performed on shell carbonate of modern land snails from limestone and nonlimestone areas of jamaica no anomaly was found in snails from the nonlimestone area implying that such material is suitable for radiocarbon dating snails from limestone areas produced variable anomalies of as much as 3 120 yr due to incorporation of 14 c free limestone into shell carbonate all rock scraping snails and most leaf litter feeding snails from limestone areas showed anomalous 14 c contents because of the variability in 14 c content even within species no standard correction factor for limestone anomaly can be applied however dating error can be minimized by selecting ecologically appropriate species or by comparison of analyses of several fossil species within a stratum to their modern counterparts

eastern alpine tectono metamorphic evolution constraints from two dimensional p t t modeling we use two dimensional 2 d p t t modeling to constrain the thermal and rheological aspects of different scenarios for the late mesozoic and cenozoic tectonic evolution of the eastern alps inferred from excellent data sets from the tauern window tw models invoking subduction of the south penninic sp oceanic lithosphere during thrusting and subsequent erosion of the austro alpine aa upper plate nappe stack are inconsistent with the observed thermal evolution within the aa and penninic units in these models predictions for the aa peak thermal conditions are lower than observed after exhumation and cooling to midcrustal levels and subduction of the continental middle penninic mp block the aa undergoes a phase of renewed heating to almost the previous peak temperatures simultaneously the penninic units experience a phase of heating upon subduction followed by cooling after onset of subduction of the north penninic np basin the model predictions are inconsistent with the observed nearly isothermal uplift path of the sp after subduction and cannot explain observed inverted metamorphic peak conditions in the deeper aa amphibolite facies down to the higher penninic unit greenschist facies a model with the beginning of subduction of the sp occurring after crustal thickening of the aa and subsequent return to normal crustal thicknesses is compatible with the p t t data in this model peak temperature conditions are higher in the aa followed by a phase of strong cooling in the aa upper plate with the onset of underthrusting this model also explains successfully nearly isothermal exhumation of the mp and inverted metamorphic peak conditions in the deeper aa material accreted to the hanging wall from the oceanic crust sp experiences a phase of cooling during ongoing subduction of oceanic lithosphere and begins to heat up to its thermal climax after the subduction of trailing continental lithosphere the subsequent pt path of the penninic units strongly depends on the timing and rates of underthrusting by the foreland observed pt paths in the mp within the tw require continuous subduction of the np and the trailing european foreland under the exhuming mp block documented rapid cooling in the final uplift phase of the penninic units in the tw requires exhumation rates up to approximately 4 mm yr predictions of slightly elevated present day geothermal gradients in the tw area are consistent with available heat flow data as a result of mesozoic rifting followed by late mesozoic crustal thickening of the aa paleorheological reconstructions are characterized by a contrast between relatively strong oceanic lithosphere and adjacent weak continental lithosphere predicted decoupling of weak continental and oceanic lithosphere during subsequent subduction of the penninic units can explain observed late cretaceous crustal extension in the aa units in terms of gravitational spreading ongoing subduction leads to an overall strength increase due to underthrusting of cool oceanic lithosphere whereas subduction of continental lithosphere causes a strength decrease in the upper levels of the lithosphere continuous crustal thickening and relaxation of the depressed isotherms reduce the strength of the lower lithospheric mantle beneath the central orogen further enhanced by rapid late stage uplift predictions for the present day rheological structure of the eastern alps support the existence of a strong upper crustal layer two wedge shaped strong upper mantle layers to the north and the south of the orogen and a weak upper mantle underlying the central orogen

terex toolbox for semi automated selection of fluvial terrace and floodplain features from lidar terraces and floodplains are important indicators of near channel sediment dynamics serving as potential sediment sources and sinks increasing availability of high resolution topography data over large areas calls for development of semi automated techniques for identification and measurement of these features in this study we introduce a novel tool that accommodates user defined parameters including a local relief threshold selected by a variable size moving window minimum area threshold and maximum distance from the channel to identify and map discrete terrace and floodplain surfaces each of the parameters can easily be calibrated for a given watershed or reach subsequently the tool automatically measures planform area absolute elevation and height relative to the local river channel for each terrace polygon we validate the tool in two locations where terrace maps were previously developed via manual digitization from lidar and extensive field mapping campaigns the tool is also tested on six different types of rivers to provide examples of starting selection parameters and to test effectiveness of the tool across a wide range of landscapes generally the tool provides a high quality draft map of terrace and floodplain surfaces across the wide range of environmental conditions for which it has been tested we find that the tool functions best in catchments where the terraces are spatially extensive with distinct differences between the terrace and floodplain the most challenging environments for semi automated terrace and floodplain mapping include steep catchments with dense riparian vegetation and very small terraces 10 m2 in areal extent we then apply the tool to map terraces and floodplains in the root river watershed southeastern minnesota and generate exceedance plots for terrace heights these plots provide a first pass analysis to indicate the tributaries and reaches of the river where terraces constitute a significant source of sediment copyright 2013 john wiley sons ltd

cretaceous palaeogene flysch zone of the east alps and carpathians identification and plate tectonic significance of dormant and active deep sea trenches in the alpine carpathian arc

plio pleistocene lacustrine evaporites of the baza basin betic chain se spain abstract the baza basin the eastern part of the guadix baza basin in se spain underwent a significant evaporitic sedimentation in non marine settings during the plio pleistocene the largest of these settings developed in the central part of the basin as a shallow saline lake system where abundant gypsum deposits occur benamaurel and galera gypsum units this paper studies these deposits from the cartographic stratigraphic sedimentologic petrographic and isotopic points of view all the gypsum has been preserved as primary enabling a good characterization of the environmental conditions of the original precipitates three interconnected subenvironments or zones inner intermediate and marginal are differentiated in this saline lake system in the inner zone shallow to relatively deeper central lake a regular alternation of gypsum and carbonate laminae accumulated suggesting a seasonal regime many of the gypsum laminae display size gradation both reverse and symmetrical indicating free precipitation in a stable brine body in the intermediate zone mosaic of shallow lakes carbonate dolomitic beds formed in association with dark lutite levels gypsum beds and gypsum nodules and micronodules moreover anoxic conditions developed in this zone which resulted in the formation of native sulphur occurrences of economic value in the marginal zone the evaporitic deposits are developed only locally the galera gypsum unit in particular the various gypsum lithofacies in these marginal deposits suggest the presence of a number of shallow to exposed settings saline mudflat saline marsh and gypsiferous pond the isotopic composition 34 s 18 o of the gypsum samples is consistent with a triassic origin of the sulphate as a result of chemical recycling these data also suggest that a similar recycling mechanism operated in the saline lake system where the gypsum sediments from the margins were coevally recycled towards the inner part both the evaporitic mineralogy and the gypsum and carbonate lithofacies suggest that semiarid conditions prevailed in this basin during the accumulation of the evaporite units

new empirical relationships among magnitude rupture length rupture width rupture area and surface displacement source parameters for historical earthquakes worldwide are compiled to develop a series of empirical relationships among moment magnitude m surface rupture length subsurface rupture length downdip rupture width rupture area and maximum and average displacement per event the resulting data base is a significant update of previous compilations and includes the additional source parameters of seismic moment moment magnitude subsurface rupture length downdip rupture width and average surface displacement each source parameter is classified as reliable or unreliable based on our evaluation of the accuracy of individual values only the reliable source parameters are used in the final analyses in comparing source parameters we note the following trends 1 generally the length of rupture at the surface is equal to 75 of the subsurface rupture length however the ratio of surface rupture length to subsurface rupture length increases with magnitude 2 the average surface displacement per event is about one half the maximum surface displacement per event and 3 the average subsurface displacement on the fault plane is less than the maximum surface displacement but more than the average surface displacement thus for most earthquakes in this data base slip on the fault plane at seismogenic depths is manifested by similar displacements at the surface log linear regressions between earthquake magnitude and surface rupture length subsurface rupture length and rupture area are especially well correlated showing standard deviations of 0 25 to 0 35 magnitude units most relationships are not statistically different at a 95 significance level as a function of the style of faulting thus we consider the regressions for all slip types to be appropriate for most applications regressions between magnitude and displacement magnitude and rupture width and between displacement and rupture length are less well correlated and have larger standard deviation than regressions between magnitude and length or area the large number of data points in most of these regressions and their statistical stability suggest that they are unlikely to change significantly in response to additional data separating the data according to extensional and compressional tectonic environments neither provides statistically different results nor improves the statistical significance of the regressions regressions for cases in which earthquake magnitude is either the independent or the dependent parameter can be used to estimate maximum earthquake magnitudes both for surface faults and for subsurface seismic sources such as blind faults and to estimate the expected surface displacement along a fault for a given size earthquake

integration of paleoseismic data from multiple sites to develop an objective earthquake chronology application to the weber segment of the wasatch fault zone utah we present a method to evaluate and integrate paleoseismic data from multiple sites into a single objective measure of earthquake timing and recurrence on discrete segments of active faults we apply this method to the weber segment ws of the wasatch fault zone using data from four fault trench studies completed between 1981 and 2009 after systematically reevaluating the stratigraphic and chro nologic data from each trench site we constructed time stratigraphic oxcal models that yield site probability density functions pdfs of the times of individual earth quakes we next qualitatively correlated the site pdfs into a segment wide earthquake chronology which is supported by overlapping site pdfs large per event displace ments and prominent segment boundaries for each segment wide earthquake we computed the product of the site pdf probabilities in common time bins which emphasizes the overlap in the site earthquake times and gives more weight to the narrowest best defined pdfs the product method yields smaller earthquake timing uncertainties compared to taking the mean of the site pdfs but is best suited to earth quakes constrained by broad overlapping site pdfs we calculated segment wide earthquake recurrence intervals and uncertainties using a monte carlo model five surface faulting earthquakes occurred on the ws at about 5 9 4 5 3 1 1 1 and 0 6 ka with the exception of the 1 1 ka event we used the product method to define the earthquake times the revised ws chronology yields a mean recurrence interval of 1 3 kyr 0 7 1 9 kyr estimated two sigma 2 range based on interevent recurrence these data help clarify the paleoearthquake history of the ws including the important question of the timing and rupture extent of the most recent earthquake and are essential to the improvement of earthquake probability assessments for the wasatch front region

manganiferous cherts of the franciscan assemblage i general geology ancient and modern analogues and implications for hydrothermal convection at oceanic spreading centers there are several hundred ophiolitic manganiferous chert deposits primarily of late jurassic to early cretaceous age known within the franciscan assemblage of california the sequences typically consist of one to three massive manganiferous chert lenses containing 30 to 50 percent mn and averaging 1 m in thickness by 15 m subcircular diameter these are separated by an average 2 to 10 m of thin bedded radiolarian cherts and overlie basalts or greenstones both their geology and chemistry indicate that the ore lenses are hydrothermal and may have formed on the flanks of a mid ocean ridge or within a back arc basin it is proposed that the sequences developed as a result of sea floor spreading over a series of deep hydrothermal seawater convection cells paralleling a spreading center and spaced roughly 5 to 10 km apart chemical profiles of mn fe si al cu ni zn co ba ti the rare earth elements and 87 sr 86 sr have been determined through two complete sections these profiles indicate hydrothermal input of mn si cu ni zn and ba and detrital or hydrogenous input of al and co they illustrate the use of ti as a measure of relative detrital sedimentation rates fe is strongly fractionated from mn within the ores fe mn 0 1 and fe mn ratios decrease upward throughout each section suggesting preferential deposition of fe within the sediment and of mn at the seawater interface rare earth element distributions reflect the interaction of sea water and underlying basalts sr isotopic ratios of the ores and basalts demonstrate both strong and moderate seawater influences respectively fluid inclusion analyses on veins of undetermined age show seawater salinity temperatures of roughly 200 degrees c and tentative entrapment pressures corresponding to 1 700 m water depth early and intermediate veins were injected into unconsolidated siliceous sediment producing a characteristic bleached and pseudobrecciated texture an analogy is drawn with the present day field of hydrothermal mounds near the galapagos rift and with ophiolitic complexes of the northern apennines and other localities

the anthropogenic nature of present day low energy rivers in western france and implications for current restoration projects abstract as in other european countries western france has seen an increase in river restoration projects in this paper we examine the restoration goals methods and objectives with respect to the long term trajectory and understanding of the contemporary dynamics of the small low energy rivers typical of the lowlands of western europe the exhaustive geomorphological paleoenvironmental and historical research conducted in the seulles river basin normandy provides very accurate documentation of the nature and place of the different legacies in the fluvial systems we have inherited the sedimentation rate in the seulles valley bottom has multiplied by a factor of 20 since the end of the bronze age and has generated dramatic changes in fluvial forms hydraulic control of the rivers and valley bottoms drainage throughout the last millennium has channelized rivers within these deposits the single meandering channel which characterizes this river today is the legacy of the delayed and complex effects of long term exploitation of the river basin and the fluvial system bring to light that the naturalness of the restored rivers might be questioned our research emphasizes the gap between the poor knowledge of the functioning of these rivers and the concrete objectives of the restoration works undertaken including dam and weir removal account of the long term history of fluvial systems is required not only to produce a pedagogic history of the river degradation but more fundamentally i to situate the current functioning of the fluvial system in a trajectory to try to identify thresholds and anticipate the potential turning points in a context of climate and land use change ii to understand the role of morphosedimentary legacies on the current dynamics iii to open the discussion on reference functioning or expected states and iv to open discussion on the sustainability of ecological restoration to conclude we point out the necessity to take into account the hybrid nature of low energy rivers in rural environments and to develop specific evaluation protocols which would include both biophysical processes and usual human activities which could be a way to share the evaluation and overcome conflicts between socioeconomic needs and environmental issues

inversion of moment tensor focal mechanisms for active stresses around the microcontinent iberia tectonic implications the iberian microcontinent and its connected oceanic crust are affected by deformations related to the eurasian african plate boundary active stress inversions from populations of moment tensor focal mechanisms have been performed around and inside the iberian peninsula using a total of 213 moment tensor estimates main results are 1 the tensorial solutions show better consistency and lower misfits compared to those obtained previously from first p arrival focal mechanisms 2 along the eurasia africa western boundary the type of active stresses progressively changes easternwards from triaxial extension to uniaxial compression along the terceira ridge the gloria fault zone and the gulf of cadiz 3 in the betics alboran rif zone uniaxial extension predominates with shmax n155oe trending 4 in n algeria uniaxial compression reappears 5 the iberian foreland is currently under strike slip to uniaxial extension tensorial conditions

stress and palaeostress in the betic rif cordilleras miocene to the present palaeostress orientation in the betic rif cordilleras can be determined for the miocene to the quaternary by analysis of brittle microstructures faults joints striated pebbles and stylolites in the central and northern south iberian domain 1 was subhorizontal and trended nw se from the early miocene to the present in the northern alboran domain from the burdigalian to the serravallian palaeostress ellipsoids were oblate with 3 subhorizontal and trending ene wsw in the southern part of the south iberian domain and in the northern part of the alboran domain betic cordillera from the tortonian to the quaternary palaeostress ellipsoids were variable in the granada region they were prolate with 1 subvertical but in the almeria region they were triaxial with 2 subvertical and 3 subhorizontal and trending ne sw to e w in the rif the alboran and african maghrebian domains were affected by palaeostresses with 1 subhorizontal varying from ne sw in tortonian times to n s in the plio quaternary a study of earthquake focal mechanisms by the right dihedra method indicates that the present day general stress field around the betic rif cordilleras is compressional with 1 subhorizontal and trending nw se in the betic rif cordilleras this general stress field is modified and the present day orientations of 1 2 and 3 are nearly the same as those of the palaeostresses in the pliocene and quaternary the distribution and evolution of stresses in the betic rif cordilleras from the miocene to the present can be correlated with the main neogene deformations extensional structures in the central and northern alboran domain and the southern part of the south iberian domain and compressional structures in the south iberian and african maghrebian domains and in the southern part of the alboran domain

spatial disaggregation and aggregation procedures for characterizing fluvial features at the network scale application to the rhone basin france network scale heterogeneity in fluvial forms and processes has been analyzed for decades through the field based characterization of a reduced number of sites spatially continuous data sets are increasingly available at a national scale e g digital elevation models or aerial orthophotographs and open up new possibilities to investigate spatial structures in stream networks the paper introduces a gis methodological framework to support and automate the large scale characterization of the fluvial system based on spatial disaggregation and aggregation procedures the spatial disaggregation consists in the longitudinal discretisation of geographical objects into relatively high resolution spatial units to characterize fluvial features continuously along stream networks because rivers are heterogeneous and hierarchically organized the spatial aggregation aims to delineate statistically pattern or process based spatial units to answer questions at appropriate scales the paper develops the gis implementation of the disaggregation and aggregation procedures for characterizing stream networks in a geomorphic perspective we illustrate the approach on the rhone network focusing on the characterization of three geographical objects commonly used in classification schemes the streamline the valley bottom and the active channel the latter on a limited area the spatial aggregation is automated using the threshold test of pettitt 1979 to detect change points in univariate data series and delineate homogeneous spatial units throughout the stream network we provide three simple application examples to illustrate the potentialities of the spatial aggregation to investigate spatial heterogeneity in stream networks finally insights limitations and future challenging issues emerging from the application of the methodological framework are discussed

sedimentary fabrics in alpine ophicalcites south pennine arosa zone switzerland many ultramafic complexes in the south pennine nappes of eastern switzerland are covered by serpentinite breccias known as ophicalcites the breccias are overlain by radiolarites or younger oceanic sediments their fabric and their components document a combined tectonic sedimentary origin of the breccias in the davos area the breccias occur along distinct zones in the ultramafic host rock typically nonfragmented peridotite serpentinite grades rapidly through a narrow zone of host rock cut by different generations of dikes into complex breccias dominated by a carbonate matrix the breccias are of polyphase origin as shown by the different phases of fragmentation and generations of cementation and sediment infill these are distinguished by color differences and by a bimodal grain size distribution that also exhibits geopetal structures comparison with breccias from present day oceanic fracture zones suggests that the tethyan serpentinite breccias may have formed in a transform setting a sinistral transform margin along the northern edge of the apulian microplate or promontory is in line with current plate kinematic reconstructions

reach scale morphological adjustments and stages of channel evolution the case of the trebbia river northern italy abstract a multitemporal series of aerial photos and cross section topographic surveys have been used to analyze reach scale channel evolution along a segment length of about 22 km of the lower trebbia river northern italy with the aims to investigate the relations between channel width vs bed level adjustments and to identify spatio temporal patterns of stages of channel evolution dendrochronology was used to determine the age of tree establishment of riparian and island forests during channel evolution we identified a first phase of major adjustments 1954 1992 following a series of disturbances dominated by channel narrowing and bed incision during the final stage of narrowing woody vegetation establishment contributed to stabilize new floodplain or island surfaces a period of partial morphological recovery occurred from 1992 to 2010 dominated by an inversion of trend of channel width during the phase of partial recovery a stage of widening combined with a continuation of bed incision was identified and a last stage characterized by widening and initial aggradation was observed on the central portion of the study reaches suitability and differences of existing channel evolution models cems derived in other geographical contexts were discussed and a specific conceptual model comprising four stages of channel evolution was developed for the lower trebbia river

geological constraints on the alpine evolution of the mediterranean tethys abstract the geological data on the mediterranean chains and basins are used to point out the constraints that they put on the location through time of oceanic versus continental lithosphere and on the successive relations between them emphasis is put on the rules and conventions which enable us to interpret the geological data in terms of plate tectonics and on the major disputed points for which a solution must be chosen in the first part the location of oceanic versus continental lithosphere is dealt with using the data on the present day basins the ophiolites and the subduction processes a neogene age is retained for the western mediterranean and the surrounding continental blocks are considered to have been previously a part of iberia a cretaceous age is retained for the eastern mediterranean apulia is considered as a part of the african plate except for this period the black sea is considered as a back arc basin formed mostly during the upper cretaceous the ophiolites are used to locate the mesozoic oceans for the double ophiolitic belts of the dinaro hellenides and the taurides the tectonic interpretations which minimise the number of oceanic basins have been retained for the kirsehir block of turkey the chosen solution locates a jurassic ocean to the north and makes it disappear when a cretaceous ocean opens to the south data on the subduction processes added to the information on these basins and led us to consider as oceanic the unknown basements of the carpathian flysch and the maghrebian flysch basins the second part deals with the organisation of basins and platforms emphasising the chronology of their formation and subsequent crushing it furnished step by step constraints on the tectonic history of the system which is related to plate displacement the general pattern derived from these data shows a wedge shaped tethyan ocean which disappeared mostly through repeated subduction below the eastern part of its northern margin the jurassic stage shows westward extension of the ocean between the eurasian and african plates and ends with the dinaro hellenic obduction the cretaceous stage shows a complete reorganisation including individual displacement of the iberian apulian and kirsehir sub plates the tertiary stage shows the general collision between the renewed eurasian and african plates and neogene subduction of the basins which avoided collision

continuity and episodicity in the early alpine tectonic evolution of the western carpathians how large scale processes are expressed by the orogenic architecture and rock record data

the significance of giant seismites in the plio pleistocene baza palaeo lake s spain terra nova 22 172 179 2010 abstract giant load type seismites uncommon in the geological record are described in plio pleistocene lacustrine deposits of the baza basin betic cordillera s iberia deformed beds of the marginal lacustrine and distal alluvial facies of the baza palaeo lake can be traced continuously for several kilometres soft sediment deformation is represented by load type structures of large dimensions pillows around 4 m in width and 2 m in height three dimensional exposures show ellipsoidal pillows separated by fluidized channels without any preferred orientation the final size of these load type seismites is strongly influenced by sedimentary factors such as the presence of a reverse density gradient in sediments and the bed thickness the giant seismites of the baza basin are located in a region which is unlikely to have been subjected to high magnitude earthquakes maximum around 7 0 therefore magnitude is not the main factor that controls the size of these load type structures

paleomagnetism and paleogeography of jurassic radiolarian cherts from the northern apennines of italy oriented samples of jurassic radiolarian chert were collected from the tuscan domain continental margin and the ligurid domain oceanic of the northern apennines for paleomagnetic study to determine the paleogeographic origins of these rocks the oceanic rocks are all thermochemically overprinted by a mostly reversed polarity component of magnetization b that was likely acquired during late miocene regional uplift of the northern apennines this component also dominates the lower brittle chert of the tuscan cherts but disappears upsection in the more clay rich and ductile siliceous marlstones in addition the tuscan cherts retain an inferred primary magnetization c isolated at temperatures between 560 and 660 c which passes a fold test and shows a polarity stratigraphy this component indicates a paleolatitude of 11 4 n and a counterclockwise vertical axis rotation of 29 9 with respect to the southern alps of italy of 49 8 with respect to africa and of 91 8 with respect to eurasia our results suggest that the tuscan domain was farther south than other deep water continental margin sections of adria and that transcurrent faulting might have played a significant role in the orogenic evolution of the northern apennines

plate boundary kinematics in the alps motion in the arosa suture zone the arosa zone forms a melange complex along the penninic austroalpine boundary and belongs to the main alpine suture zone accretion and plate collision occurred during cretaceous and lower tertiary time a mixture of ophiolitic rocks and pelagic sediments is imbricated with flysch and blocks of austroalpine continental derivation we present a description of deformation structures an analysis of strain and a kinematic interpretation based on structural work deformation histories of imbricates show a translation path that was west directed between ca 110 and 50 ma and north directed thereafter the kinematics of the arosa zone agrees with the recently deduced displacement history of the austroalpine units in the eastern alps during the cretaceous orogeny this calls for a predominantly top to the west imbrication of austroalpine and penninic units and is in contradiction to what is inferred in most models of the eastern alps a direct relation between the deformation along the austroalpine margin and relative plate motion existed

geochronological position of badlands and geomorphological patterns in the guadix baza basin se spain abstract the guadix baza basin is one of a number of intramontane depressions located within the betic cordillera se spain where the geological and geomorphological evolution is controlled by tectonic activity the basin ceased to be closed after capture by the atlantic network when five main land systems developed late pleistocene geological evolution basically consisted of erosional modelling when badlands were deeply incised in highly erodible materials marls and silts three travertine platforms and several palaeolithic sites were used to determine that this main incision period fell within a 115 000 48 000 yr range there are few signs of geomorphological evolution of this basin in the last 48 000 yr based on these geomorphological data and soil development tectonic uplift of the basin probably played a secondary role in its evolution and climatic conditions in southern iberia in the 144 000 48 000 yr period were more humid and variable than later

hydrothermal chert and associated siliceous rocks from the northern pacific their geological significance as indication od ocean ridge activity adachi m yamamoto k and sugisaki r 1986 hydrothermal chert and associated siliceous rocks from the northern pacific their geological significance as indication of ocean ridge activity sediment geol 47 i25 148 analyses of 42 cretaceous rock samples from deep sea drilling project dsdp leg 32 in tile northern pacific show that chert and porcellanite are enriched in fe mn p cu ba mo ni and pb relative to both triassic biogenic cherts of central japan and cretaceous dsdp cherts of leg 62 the iron enrichment up to 6 68ve fe20 as total iron is most prominent in chert immediately overlying basal basah which is the only chert free of radiolarians and veined by megaquartz containing many fluid inclusions chemical features characterized by a low ratio for a1 ai fe mn and ai z tio 2 and a high ratio for total fe2oj tio 2 mno tio 2 and mo tio 2 as well as petrological evidence indicatc that the cherts formed in an intense submarine hydrothermal environment on or near the cretaceous japanese spreading center which separated the kula plate from the pacific plate the spreading rate of the cretaceous japanese spreading center estimated from the chemical composition of the cherts was about 3 7 cm r i the rate is comparable to that inferred from the geomagnetic data

least action principle equilibrium states iterative adjustment and the stability of alluvial channels the energy based least action principle lap has proven to be very successful for explaining natural phenomena in both classical and modern physics this paper briefly reviews its historical development and details how in three ways it governs the behaviour and stability of alluvial rivers first the lap embodies the special stationary equilibrium state of motion and so its incorporation with the principle of energy conservation explains why so many optimizing hypotheses have been proposed in fluvial geomorphology second the variational approach underlying the lap provides a more straightforward and simpler fuzzy object orientated method for solving river regime problems than do the various complex newtonian formulations third it is shown that in fluvial systems with surplus energy the surplus can be expended with slope and or channel geometry adjustments with the degree of channel geometry adjustment quantified by the dimensionless numbers f for depth dominated adjustment and h for width depth dominated adjustment different planforms are preferred at different energy levels with h providing a quantitative measure of the flow s efficiency for moving sediment in rivers with insufficient energy the interactions of endogenous and exogenous factors are shown to be capable in certain circumstances of achieving a stationary equilibrium condition which acts as the attractor state importantly this study describes how iterative changes enable systems to achieve such a stable equilibrium copyright 2007 john wiley sons ltd

active faulting in the central betic cordillera spain palaeoseismological constraint of the surface rupturing history of the baza fault central betic cordillera iberian peninsula abstract this paper on the baza fault provides the first palaeoseismic data from trenches in the central sector of the betic cordillera s spain one of the most tectonically active areas of the iberian peninsula with the palaeoseismological data we constructed time stratigraphic oxcal models that yield probability density functions pdfs of individual palaeoseismic event timing we analysed pdf overlap to quantitatively correlate the walls and site events into a single earthquake chronology we assembled a surface rupturing history of the baza fault for the last ca 45 000 years we postulated six alternative surface rupturing histories including 8 9 fault wide earthquakes we calculated fault wide earthquake recurrence intervals using monte carlo this analysis yielded a 4750 5150 yr recurrence interval finally compared our results with the results from empirical relationships our results will provide a basis for future analyses of more of other active normal faults in this region moreover our results will be essential for improving earthquake probability assessments in spain where palaeoseismic data are scarce

sediment supply and channel morphology in mountain river systems 1 relative importance of lithology topography and climate 1 quantifying landscape scale variations in sediment supply to streams and rivers is fundamental to our understanding of both denudational processes and stream channel morpho dynamics previous studies have linked a variety of sediment supply proxies to climatic topographic or geologic factors but few have connected these directly to the characteristics of fluvial systems draining these landscapes here we correlate landscape controls on sediment supply to observed sedimentology and channel patterns through direct measurements of water and sediment fluxes in over 80 drainage basins ranging in area from 1 4 to 35 000 km2 in the northern rocky mountains usa these data show that the relative sediment supply defined by the bankfull sediment concentration is dominated by basin lithology while exhibiting little correlation to factors such as relief mean basin slope and drainage density bankfull sediment concentrations bed load and suspended load increase as much as 100 fold as basin lithology becomes dominated by softer sedimentary and volcanic rocks relative to basins with more resistant lithologies as bed load concentrations increase stream beds become less armored and bed load grain size coarsens at very high sediment concentrations bed surface subsurface and bed load grain sizes converge and a transition from single thread to to braided channel patterns is commonly observed

cretaceous tertiary rhenodanubian flysch wedge eastern alps clues to sediment supply and basin configuration from zircon fission track data the provenance of cenomanian to eocene flysch deposits accreted along the northern margin of the eastern alps has been investigated by means of zircon fission track ft geochronology and zircon morphology the rhenodanubian flysch and ybbsitz klippen zone comprise several nappes representing the main flysch and laab basins the laab basin received sediments of stable european provenance indicated by pre variscan variscan and permian triassic zircon ft ages and was thus located in the immediate south of the european margin the main flysch basin was supplied mainly from the evolving eastern alps and was therefore situated south of the laab basin zircon populations with permian to jurassic cooling ages in the main flysch basin are related to increased heat fluxes during the break up of pangaea and are probably derived from the northwestern part of the eastern alps the dominant cretaceous zircon ft cooling ages reflect eoalpine metamorphism in the austroalpine realm

fault slip analysis along the northern margin of the eastern alps molasse helvetic nappes north and south penninic flysch and the northern calcareous alps fault slip data are analyzed and paleostress tensors computed from 84 stations along the northern margin of the eastern alps between liechtenstein and vienna most fault sets resulted from more than one deformation heterogenous sets are divided into homogenous subsets by cross cutting relationships observed in the field and stress tensors are calculated separately for each subset the deviatoric stress tensors fall into six distinct groups that are regionally consistent in orientation stress ratio and relative age throughout the northern margin of the eastern alps from oldest to youngest the tensor groups are as follows 1 1 subhorizontal e w 3 subvertical thrusting related e w compression this group is only encountered in the south penninic flysch and the northern calcareous alps 2 1 subhorizontal n s 3 subvertical thrusting related n s directed compression 3 1 subhorizontal n s 3 subhorizonal e w strike slip faulting conjugate to n s compression 4 1 subvertical 3 subhorizontal e w e w directed subhorizontal extension 5 1 subhorizontal e w 3 subhorizontal n s strike slip faulting during e w compression and 6 1 subvertical 3 subhorizontal about n s 3 trajectories are oriented perpendicular to the general strike of the eastern alps and parallel topographic gradients the six trensor groups correlate with distinct steps in the cretaceous and the post eocene tectonic evolution of the northern units of the eastern alps 1 1 thrusting related e w compressional structures in the south penninic flysch and the northern calcareous alps are correlated to cretaceous top to w directed thrusting in the south penninic and austroalpine domains 2 2 thrusting related n s compressional structures encompass large scale folds with e w trending axes rare e w oriented thrust branch lines and cut off lines and s dipping ramps in the rhenodanubian flysch tensors reflect the stresses during northward thrusting in the late eocene early miocene 3 3 4 strike slip faults and extensional structures depicting n s compression and e w extension formed during the eastward lateral extrusion of the eastern alps prominent reactivations of strike slip faults during subhorizontal extension in the east and permutation between 1 and 2 reflecting periodic superposition of strike slip and normal faulting in the western eastern alps during overall e w extension suggest a close relationship of both tensor groups deformation resulted in the eastward lateral motion of the northern units of the eastern alps that started during the miocene 4 5 the significance of late miocene e w directed compression reactivating pre existing fractures and faults is presently not well understood we tentatively relate this event to a major change of boundary conditions within the miocene 5 6 the youngest deformation recorded is caused by surface uplift and gravitational collapse of the eastern alps

a method for the assessment and analysis of the hydromorphological condition of italian streams the morphological quality index mqi article i nfo a new index has been developed for the hydromorphological assessment of italian rivers the method was designed to comply with the eu water framework directive requirements but its use can be extended to other applications in river management the evaluation of stream morphological quality is preceded by a phase of river segmentation consisting ofan initial division of the network intoriver reaches with homogeneous morphological characteristics the evaluation procedure consists of a set of 28 indicators which were defined to assess longitudinal and lateral continuity channel pattern cross section configuration bed structure and substrate and vegetation in the riparian corridor these characteristics are analyzed in terms of geomorpholog ical functionality artificiality and channel adjustments indicators classes and the scoring system were defined based on expert judgement the scoringsystemleads tothe definition of the morphologicalquality index mqi application of the method to 102 river reaches covering a wide range of physical conditions and human pres sures of italian streams enabled the testing of the overall methodology and the refinement of the indicators and scores limitations strengths and the applicability of the method are also discussed in the paper

river channel adjustments in southern italy over the past 150 years and implications for channel recovery abstract multi temporal gis analysis of topographic maps and aerial photographs along with topographic and geomorphological surveys are used to assess evolutionary trends and key control factors of channel adjustments for five major rivers in southern italy the trigno biferno volturno sinni and crati rivers to support assessment of channel recovery and river restoration three distinct phases of channel adjustment are identified over the past 150 years primarily driven by human disturbances firstly slight channel widening dominated from the last decades of the nineteenth century to the 1950s secondly from the 1950s to the end of the 1990s altered sediment fluxes induced by in channel mining and channel works brought about moderate to very intense incision up to 6 7 m accompanied by strong channel narrowing up to 96 and changes in channel configuration from multi threaded to single threaded patterns thirdly the period from around 2000 to 2015 has been characterized by channel stabilization and local widening evolutionary trajectories of the rivers studied are quite similar to those reconstructed for other italian rivers particularly regarding the second phase of channel adjustments and ongoing transitions towards channel recovery in some reaches analyses of river dynamics recovery potential and connectivity with sediment sources of the study reaches framed in their catchment context can be used as part of a wider interdisciplinary approach that views effective river restoration alongside sustainable and risk reduced river management

is history of rivers important in restoration projects the example of human impact on a lowland river valley the obra river poland abstract palaeoenvironmental and palaeohydrological reconstructions can provide important guidance for river restoration projects this paper reconstructs the trajectory of river pattern changes of a lowland river the obra river western poland as a basis to inform realistic restoration activities the history of river changes is reconstructed for the last 12 700 radiocarbon years bp the sequence and timing of change differ from widely recognized conventional assessments of transitions from braided to meandering planforms in the polish lowlands traces of a laterally migrating anabranching system were found in the middle obra valley in its lower course a transition from a braided to meandering planform took place later than in other rivers of the polish lowlands sediment delivery from parts of the catchment situated downstream of lakes in the river course could have been the main reason for maintenance of the braided pattern restoration scenarios that take into account the trajectory of river planform changes are hypothesized in relation to variations of sediment supply and degree of anthropogenic impact

effects of geomorphology and groundwater level on the spatio temporal variability of riverine cold water patches assessed using thermal infrared tir remote sensing temperature is a key factor for river ecosystems in summer patches of cold water are formed in the river by groundwater seepage these patches have strong ecological significance and extend to the surface water in a well mixed riverine system these patches can serve as thermal refuges for some fish species during summer in this study the temporal variability and spatial distribution of cold water patches were explored along a 50 km river reach the lower ain river france using thermal infrared airborne remote sensing this study examines a new range of processes acting on cold water patches at different scales that have not previously been touched upon in the literature three airborne campaigns were conducted during the summers of 2010 2011 and 2014 based on these images a large number of cold water patches were identified using an automated method four types of patches were observed tributary plumes cold side channels former channels or point bar backwater channels side seeps located directly in the river channel and gravel bar seeps occurring at the downstream end of gravel bars logistic regression was used to analyze the longitudinal distribution of cold water patches according to geomorphologic indicators reflecting current or past fluvial process side seeps were found to be related to the local geology cold side channels were correlated to contemporary and past lateral river mobility gravel bar seeps were related to the current development of bars and are more prevalent in wandering reaches than in single bed incised and paved reaches the logistic model was subsequently used to evaluate gravel bar seep variability in the past the model suggests larger numbers of seeps in the mid 20th century when bar surface area was higher interannual variability in the occurrence and spatial extent of side seeps and gravel bar seeps appear to be related to groundwater level fluctuations cold side channels exhibited greater interannual stability nonetheless among all patch types some are quite stable over time while others are transient these results can be used to target areas with high densities of stable and spatially extensive cold water patches that are considered ecological refuges in the context of pronounced low flow and a rise in water temperature

making riverscapes real abstract the structure and function of rivers have long been characterized either by 1 qualitative models such as the river continuum concept or serial discontinuity concept which paint broad descriptive portraits of how river habitats and communities vary or 2 quantitative models such as downstream hydraulic geometry which rely on a limited number of measurements spread widely throughout a river basin in contrast authors such as fausch et al 2002 and wiens 2002 proposed applying existing quantitative spatially comprehensive ecology and landscape ecology methods to rivers this new framework for river sciences which preserves variability and spatial relationships is called a riverine landscape or a riverscape application of this riverscape concept requires information on the spatial distribution of organism scale habitats throughout entire river systems this article examines the ways in which recent technical and methodological developments can allow us to quantitatively implement and realize the riverscape concept using 3 cm true color aerial photos and 5 m resolution elevation data from the river tromie scotland we apply the newly developed fluvial information system which integrates a suite of cutting edge high resolution remote sensing methods in a spatially explicit framework this new integrated approach allows for the extraction of primary fluvial variables such as width depth particle size and elevation from these first order variables we derive second order geomorphic and hydraulic variables including velocity stream power froude number and shear stress channel slope can be approximated from available topographic data based on these first and second order variables we produce riverscape metrics that begin to explore how geomorphic structures may influence river habitats including connectivity patchiness of habitat and habitat distributions the results show a complex interplay of geomorphic variable and habitat patchiness that is not predicted by existing fluvial theory riverscapes thus challenge the existing understanding of how rivers structure themselves and will force development of new paradigms

assessment of channel changes due to long term bedload supply decrease roubion river france this paper presents the observations made in the watershed of the upper roubion river which drains a submediterranean mountainous environment and in two of its main tributaries the soubrion and bine creeks our aim was to analyze contemporary morphological and sedimentary changes in response to a progressive decrease in bedload supply this decrease is linked to an increase of forest cover in the watershed during the 20th century following rural depopulation and to a correlated decrease in peak flows several variables were systematically measured width slope bed level change sediment size along 23 km of river whereas dendrochronological data floodplain cross sections and estimated recurrence intervals of sediment entrainment based on critical shear stress calculations were also produced for specific sites to complete our analysis evidence of three major phenomena was obtained on both the roubion and its tributaries i bed degradation ii development of stable pavement in incised reaches and iii channel narrowing associated with the development of alluvial forest on recently abandoned portions of the pre existing active channel forest development began in the 1950s these three phenomena show positively covariant relationships that lead us to propose a descriptive model of mountain fluvial system adjustments to progressive decrease of bedload

subsidence and sedimentation on jurassic passive continental margin southern alps italy the southern alps of italy preserve a tectonically intact array of jurassic facies that record the evolution of a part of the margin of the apulian plate from its ancestral beginnings in a complex of permian and triassic rifted continental basins through the initial stages of breakup and stepwise foundering of a carbonate platform breakup was accompanied first by the rapid accumulation of thick prisms of carbonate turbidites in newly formed fault troughs then as the new ligurian oceanic basin began to open farther west and as subsidence gradually slowed accumulation of a succession of slowly deposited biogenous pelagic sediments recorded not only the increasing depths of the seafloor but also fluctuations in oceanographic conditions of fertility carbonate dissolutio levels and the strength of bottom currents estimates of the history of seafloor depths based on a simple subsidence law of the form subsidence k age 12 provide a basis for the construction of a set of curves showing the changing depths of significant carbonate dissolution surfaces during the jurassic in this region the rapid 1 km deepening of the compensation depth for calcite during the late jurassic may be due to a change in regional oceanic vertical circulation patterns from upwelling fertile silica rich carbonate dissolving to downwelling less fertile silica poor carbonate preserving

repeated palaeoseismic activity of the ventas de zafarraya fault s spain and its relation with the 1884 andalusian earthquake one of the most destructive historical earthquakes m 6 7 in spain occurred in 1884 along the normal ventas de zafarraya fault located in the central betic cordilleras palaeoseismic and radiocarbon data presented in this study are the first to constrain the timing of the pre 1884 fault history in the last 10 ka these data yield a recurrence interval of between 2 and 3 ka for major earthquakes under the assumption of uniform return periods along the normal fault the holocene slip rate is estimated to be in the order of 0 35 0 05 mm year which is significantly higher than the mean slip rate of 0 17 0 03 mm year since the tortonian several of the most important deformations and secondary features such as landslides and liquefaction are related to strong ground motion and document the holocene activity of the ventas de zafarraya fault

architecture and tectono stratigraphic evolution of the intramontane baza basin betics se spain constraints from seismic imaging abstract the baza basin is a large neogene intramontane basin in the betic cordillera of southern spain that formed during the tortonian late miocene the betic cordillera was produced by nw se oblique convergence between the eurasian and african plates three seismic reflection lines each 18 km long vibroseis method were acquired across the baza basin to reveal the architecture of the sedimentary infill and faulting during basin formation we applied rather conventional cdp data processing followed by first arrival p wave tomography to provide complementary structural information and establish velocity models for the post stack migration these images show a highly asymmetric structure for the basin with sediments thickening westward reaching a maximum observed thickness of 2200 m near the governing baza fault zone bfz three major seismic units including several subunits on top of the acoustic basement could be identified we use stratigraphic information from the uplifted block of the bfz and other outcrops at the basin edges together with available information from neighboring betic basins to tentatively correlate the seismic units to the known stratigraphy in the area until new drilling or surface outcrop data is not available this interpretation is preliminary the seismic units could be associated to tortonian marine deposits and latest miocene to pleistocene continental fluvio lacustrine sediments individual strands of the bfz truncate the basin sediments strong fault reflections imaged in two lines are the product of the large impedance contrast between sedimentary fill and basement in the central part of the basin several basement faults document strong deformation related to the early stages of basin formation some of these faults can be traced up to the shallowest imaged depth levels indicating activity until recent times

lidar based fluvial remote sensing to assess 50 100 year human driven channel changes at a regional level the case of the piedmont region italy

a catchment scale assessment of patterns and controls of historic 2d river planform adjustment abstract the supply transfer and deposition of sediment from channel headwaters to lowland sinks is a fundamental process governing upland catchment geomorphology and can begin to be understood by quantifying 2d river planform adjustments over time this paper presents a catchment scale methodology to quantify historic patterns of 2d channel planform adjustment and considers geomorphic controls on 2d river stability the methodology is applied to 18 rivers total length 24 km in the upland headwaters of the previously glaciated wasdale catchment 45 km2 lake district northwest england planform adjustments were mapped from historic maps and air photographs over six contiguous time windows covering the last 150 yr a total of 1048 adjustment and stable reaches were mapped over the full period of analysis 1860 2010 32 8 km of the channels studied were adjusting contrasts were identified between the geomorphic characteristics slope catchment area unit specific stream power channel width and valley bottom width of adjusting and stable reaches the majority of adjustments mapped were observed in third and fourth order channels in the floodplain valley transfer zone where the channels were laterally unconfined mean valley bottom widths of 230 180 m with low sediment continuity in contrast lower order channels were typically confined mean valley bottom widths of 31 43 m and showed relative 2d lateral stability hence valley bottom width was found to be important in determining the available space for rivers to adjust over the full period of analysis 38 of planform adjustments involved combined processes for example as bar and bend adjustments the study demonstrates the importance of stream network hierarchy in determining spatial patterns of historic planform adjustments at the catchment scale the methodology developed provides a quantitative assessment of planform adjustment patterns and geomorphic controls which is needed to support the prioritisation of future river management and restoration

the baza fault a major active extensional fault in the central betic cordillera south spain in the guadix baza basin betic cordillera lies the baza fault a structure that will be described for the first time in this paper eight gravity profiles and a seismic reflection profile coupled with surface studies indicate the existence of a ne dipping normal fault with a variable strike with n s and nw se segments this 37 km long fault divides the basin into two sectors guadix to the west and baza to the east since the late miocene the activity of this fault has created a half graben in its hanging wall the seismic reflection profile shows that the fill of this 2 000 3 000 m thick asymmetric basin is syntectonic the fault has associated seismicity the most important of which is the 1531 baza earthquake since the late tortonian to the present i e over approximately the last 8 million years extension rates obtained vary between 0 12 and 0 33 mm year for the baza fault being one of the major active normal faults to accommodate the current ene wsw extension produced in the central betic cordillera the existence of this fault and other normal faults in the central betic cordillera enhanced the extension in the upper crust from the late miocene to the present in this regional compressive setting

an approach for measuring confinement and assessing the influence of valley setting on river forms and processes valley setting and confinement or lack thereof are primary controls on river character and behaviour although there are various proxies for valley confinement direct measures that quantify the nature and extent of confinement are generally lacking and or inconsistently described as such they do not lend themselves to consistent analysis over large spatial scales here we clearly define forms of confinement to aid in quantification of degrees of confinement types of margin that can induce confinement are differentiated as a valley margin valley bottom margin and or anthropogenic margin such margins sometimes overlap and share the same location and in other situations are separated giving immediate clues as to the valley setting we apply this framework to examples from australia united states and new zealand showing how this framework can be applied across the spectrum of river diversity this method can help to inform interpretations of reach scale river behaviour highlighting the role of antecedent controls on contemporary forms and processes clear definitions of confinement are shown to support catchment scale analysis of river patterns along longitudinal profiles and appraisals of the geomorphic effectiveness of floods and sediment flux in catchments e g process zone distribution lateral sediment inputs and dis connectivity copyright 2015 john wiley sons ltd

glacis geometry as a geomorphic marker of recent tectonics the guadix baza basin south spain abstract the guadix baza basin occupies 4000 km 2 and constitutes the largest intramontane basin of the betic cordillera southern spain it has a well preserved geomorphic surface a glacis which started to be eroded when the basin conditions changed from endorheic to exorheic taking into account its large preserved surface area more than 1200 km 2 and its pre deformational geometry this geomorphic surface is a useful marker of recent deformation combining geological and geomorphological data and high resolution dem topographic profiles of the glacis have been produced to estimate vertical displacements caused by active compression and extension structures these structures have produced relative vertical displacements of up to 100 m from the late middle pleistocene to the present assuming an age for the glacis of between 205 and 600 ka it has been possible to estimate long term minimum and maximum vertical rates of the activity of normal faults and folds using this geomorphic surface as a marker vertical slip rates range from 0 07 to 0 49 mm year for the main active normal faults and vertical folding rates range from 0 05 to 0 17 mm year for several active folds these long term vertical slip and folding rates are in accordance with other values previously estimated in other sectors of the betic cordillera when present detailed geomorphic study of recent glacis is an excellent tool for evaluating active tectonics over large regions

normal faulting driven by denudational isostatic rebound fluvial piracy in the guadix baza basin southeast spain promoted erosion of a high volume of sediments during the late quaternary after the former internal drainage of this basin changed to external due to headward erosion by the guadalquivir river as a response to load release this basin underwent uplift which in turn enhanced fluvial incision and erosional processes differential erosion within the guadix baza basin resulted in dissimilar isostatic rebound we numerically model the lithospheric response to sediment unloading and show a total rising of 15 m in the guadix subbasin compared to 2 m in the baza subbasin this differential uplift is likely to have been accommodated along the baza normal fault which has been active throughout the quaternary modeling results suggest that 13 of the total quaternary fault throw directly arises from the differential isostatic readjustment between subbasins this example is one of the first estimates of fault slip partitioning between tectonic and isostatic effects due to unloading driven by river incision

bathymetric structure from motion extracting shallow stream bathymetry from multi view stereo photogrammetry stream bathymetry is a critical variable in a number of river science applications in larger rivers bathymetry can be measured with instruments such as sonar single or multi beam bathymetric airborne lidar light detection and ranging or acoustic doppler current profilers however in smaller streams with depths less than 2 m bathymetry is one of the more difficult variables to map at high resolution optical remote sensing techniques offer several potential solutions for collecting high resolution bathymetry in this research i focus on direct photogrammetric measurements of bathymetry using multi view stereo photogrammetry specifically structure from motion sfm the main barrier to accurate bathymetric mapping with any photogrammetric technique is correcting for the refraction of light as it passes between the two different media air and water which causes water depths to appear shallower than they are i propose and test an iterative approach that calculates a series of refraction correction equations for every point camera combination in a sfm point cloud this new method is meant to address shortcomings of other correction techniques and works within the current preferred method for sfm data collection oblique and highly convergent photographs the multi camera refraction correction presented here produces bathymetric datasets with accuracies of 0 02 of the flying height and precisions of 0 1 of the flying height this methodology like many fluvial remote sensing methods will only work under ideal conditions e g clear water but it provides an additional tool for collecting high resolution bathymetric datasets for a variety of river coastal and estuary systems copyright 2016 john wiley sons ltd

kinematics of the iberia maghreb plate contact from seismic moment tensors and gps observations the iberian peninsula and the maghreb experience moderate earthquake activity and oblique nw se convergence between africa and eurasia at a rate of 5 mm yr coeval extension in the alboran basin and a n35 e trending band of active left lateral shear deformation in the alboran betic region are not straightforward to understand in the context of regional shortening and evidence complexity of deformation at the plate contact we estimate 86 seismic moment tensors mw 3 3 to 6 9 from time domain inversion of near regional waveforms in an intermediate period band those and previous moment tensors are used to describe regional faulting style and calculate average stress tensors the solutions associated to the trans alboran shear zone show predominantly strike slip faulting and indicate a clockwise rotation of the largest principal stress orientation compared to the regional convergence direction 1 at n350 e at the n algerian and sw iberian margins reverse faulting solutions dominate corresponding to n350 e and n310 e compression respectively over most of the betic range and intraplate iberia we observe predominately normal faulting and wsw ene extension 3 at n240 e from gps observations we estimate that more than 3 mm yr of african nubian eurasian plate convergence are currently accommodated at the n algerian margin 2 mm yr in the moroccan atlas and 2 mm yr at the sw iberian margin 2 mm yr is a reasonable estimate for convergence within the alboran region while alboran extension can be quantified as 2 5 mm yr along the stretching direction n240 e superposition of both motions explains the observed left lateral transtensional regime in the trans alboran shear zone two potential driving mechanisms of differential motion of the alboran betic gibraltar domain may coexist in the region a secondary stress source other than plate convergence related to regional scale dynamic processes in the upper mantle of the alboran region as well as drag from the continental scale motion of the nubian plate along the southern limit of the region in the atlantic ocean the 3 5 mm yr westward motion of the gibraltar arc relative to intraplate iberia can be accommodated at the transpressive sw iberian margin while available gps observations do not support an active subduction process in this area

the origin of hydrothermal metalliferous sediments associated with the early mesozoic othris and pindos ophiolites mainland greece abstract metalliferous sediments and sulphides are associated with the jurassic othris and pindos ophiolites central and northern greece these ophiolites formed at an early mesozoic spreading ridge within a small pindos ocean basin created by rifting of the northern margin of gondwanaland ubiquitous terrigenous silt was derived from adjacent continental margins mainly the pelagonian microcontinent to the east in the othris area disseminated massive and vein sulphides occur within and above morb type pillow lavas and volcaniclastic sediments sulphide was precipitated in quartz veins within fault controlled stockworks episode with local epidosite is locally very abundant in extrusives immediately underlying thick si fe rich hydrothermal sediments massive sulphides were precipitated as small fault controlled bodies that are directly overlain by fe rich mudstones and fe rich cherts strongly depleted in mn mudstones relatively enriched in hydrothermal fe mn cu zn pb ree and ba were ponded into small fault controlled hollows around the fringes of the sulphide precipitating field elsewhere e g northern othris manganese rich layers in ribbon radiolarites are strongly enriched in mn and trace elements metal enriched deposits are also found within slices of mid ocean ridge type lavas associated with melange avdella melange structurally underlying the pindos ophiolite nw greece sulphides there are restricted to tiny massive deposits overlying pillow lava and sulphide veins within ophiolitic extrusives pillow lavas are overlain by volcanic talus breccias shed from submarine fault scarps overlying metalliferous mudstones are enriched in fe and other hydrothermal constituents probably derived from nearby sulphide precipitating zones and mixed with lithogenous sediments the metalliferous deposits preserve a variety of hydrothermal deposits within an early mesozoic small ocean basin the pindos sediments reflect mixing of ferruginous hydrothermal constituents with terrigenous sediment possibly during the earlier stages of basin opening the othris sulphide and ferruginous oxide sediments record evidence of a small high temperature hydrothermal field formed near the spreading axis when the ocean neared its maximum width manganese rich cherts in the northern othris area reflect widespread accumulation of hydrothermal constituents on the abyssal plain derived from axial high temperature hydrothermal fields and or related to low temperature off axis discharge

stratigraphy and sedimentology of jurassic bedded chert overlying ophiolites in the north apennines italy in the north apennines of italy upper jurassic bedded chert stratigraphically overlies ophiolitic rocks and is overlain by lower to middle cretaceous pelagic limestone and shale and upper cretaceous flysch the bedded chert best exposed in east liguria and on elba is typically 30 80 m thick but occasionally reaches 150 200 m thickness it consists of two main alternating lithologies siliceous mudstone sm and radiolarite r chert sections commonly show characteristic stratigraphic changes lower cherts display a striking rhythmic alternation of r and ferruginous sm beds in middle cherts sm beds are much less ferruginous and shalier intercalations are locally present in upper cherts r beds are less frequent and sm beds are essentially non ferruginous r beds are generally 1 4 cm thick and consist of 80 90 quartz 5 15 clays and usually 1 hematite they are commonly parallel laminated and rarely size graded in size graded beds large radiolaria are more abundant near the bed base commonly together with ophiolitic or sm clasts and small radiolaria more abundant near the bed top sorting is poor throughout most r beds r beds are interpreted as turbidites cf nisbet price 1974 model calculations suggest that typical settling velocities of radiolaria during redeposition are 1 cm sec 1 which is low and of restricted range relative to the 1 10 cm sec 1 settling velocities of clastic grains of comparable size range radiolaria therefore should have only a limited tendency to grade and sort during deposition from a turbulent current sm beds are commonly 1 7 cm thick although much thicker ones occur near the base of sections and consist mainly of 50 70 quartz 15 35 clays and 0 15 hematite microscopic clay silica aggregates and highly corroded remnants of radiolaria are common sm beds are interpreted as mainly ambient pelagic sediment which accumulated slowly in topographic lows and which was modified by near surface dissolution of biogenic silica in sm beds which contain two texturally different layers the lower one is interpreted as the top of the underlying radiolarian turbidite north apennine cherts represent the first sediment deposited on oceanic crust formed during the opening of the north apennine part of the tethys the ophiolitic basement had a rugged topography which favoured the redeposition of siliceous sediment hematite and local mn enrichments in sm beds in the lower chert sections represent hydrothermal precipitates inferred to have originated at a spreading axis during seafloor spreading accumulation of siliceous sediments progressively reduced the topography deposition of ophiolitic detritus within the sediments phased out during early chert sedimentation and the hydrothermal contribution during early middle chert sedimentation as local basins filled during late chert sedimentation radiolarian turbidites became less frequent the first limestones at the top of chert sections are calcareous ooze turbidites derived from above the ccd and deposited slightly below it gradual descent of the ccd to ocean floor depths at the end of the jurassic bosellini winterer 1975 led to the replacement of siliceous by carbonate sedimentation

geomorphologic evidence of the active baza fault betic cordillera south spain abstract the present work investigates a mountain front within the plio quaternary deposits belonging to the sedimentary fill of the guadix baza basin betic cordillera southern spain this 30 km long front developed in soft sediments and within a context of high erosion is generated by the recent activity of the baza normal fault the mountain front is the natural limit between the western and eastern sectors corresponding to the two sub basins of guadix and baza the two main glacis described in previous works in the area of the baza fault the old glacis in the guadix sub basin and the recent glacis in the baza sub basin are interpreted here as a single one displaced by the fault using this glacis as a marker we deduced that its age and the transition of the basin from endorheic to exorheic must be much older than previous estimations the baza fault may be considered as one of the most active faults of the central part of the betic cordillera according to the results of the general quantitative analysis of the mountain front relief using the smf vf ratio and the sl index

balancing lateral orogenic float of the eastern alps abstract oligocene to miocene post collisional shortening between the adriatic and european plates was compensated by frontal thrusting onto the molasse foreland basin and by contemporaneous lateral wedging of the austroalpine upper plate balancing of the upper plate shortening by horizontal retrodeformation of lateral escaping and extruding wedges of the austroalpine lid enables an evaluation of the total post collisional deformation of the hangingwall plate quantification of the north south shortening and east west extension of the upper plate is derived from displacement data of major faults that dissect the austroalpine wedges indentation of the south alpine unit corresponds to 64 km north south shortening and a minimum of 120 km of east west extension lateral wedging affected the eastern alps east of the giudicarie fault west of the giudicarie fault north south shortening was compensated by 50 to 80 km of backthrusting in the lombardian thrust system of the southern alps the main structures that bound the escaping wedges to the north are the inntal fault system ca 50 km sinistral offset the konigsee lammertal traunsee klt fault 10 km and the salzach ennstal mariazell puchberg semp fault system 60 km these faults as well as a number of minor faults with displacements less than 10 km root in the basal detachment of the alps the thin skinned nature of lateral escape related structures north of the semp line is documented by industry reflection seismic lines crossing the northern calcareous alps nca and the frontal thrust of the eastern alps complex triangle zones with passive roof backthrusts of middle miocene molasse sediments formed in front of the laterally escaping wedges of the northern eastern alps the aim of this paper is a semiquantitative reconstruction of the upper plate of the eastern alps most of the data is published elsewhere

disturbance stream incision and channel evolution the roles of excess transport capacity and boundary materials in controlling channel response abstract channel incision is part of denudation drainage network development and landscape evolution rejuvenation of fluvial networks by channel incision often leads to further network development and an increase in drainage density as gullies migrate into previously non incised surfaces large anthropogenic disturbances similar to large or catastrophic natural events greatly compress time scales for incision and related processes by creating enormous imbalances between upstream sediment delivery and available transporting power field examples of channel responses to antrhopogenic and natural disturbances are presented for fluvial systems in the mid continent and pacific northwest usa and central italy responses to different types of disturbances are shown to result in similar spatial and temporal trends of incision for vastly different fluvial systems similar disturbances are shown to result in varying relative magnitudes of vertical and lateral widening processes and different channel morphologies as a function of the type of boundary sediments comprising the bed and banks this apparent contradiction is explained through an analysis of temporal adjustments to flow energy shear stress and stream power with time numerical simulations of sand bed channels of varying bank resistance and disturbed by reducing the upstream sediment supply by half show identical adjustments in flow energy and the rate of energy dissipation the processes that dominate adjustment and the ultimate stable geometries however are vastly different depending on the cohesion of the channel banks and the supply of hydraulically controlled sediment sand provided by bank erosion the non linear asymptotic nature of fluvial adjustment to incision caused by channelization or other causes is borne out in similar temporal trends of sediment loads from disturbed systems the sediments emanating from incised channels can represent a large proportion of the total sediment yield from a landscape with erosion from the channel banks generally the dominant source disturbances that effect available force stream power or flow energy or change erosional resistance such that an excess of flow energy occurs can result in incision channel incision therefore can be considered a quintessential feature of dis equilibrated fluvial systems

the recent upper miocene to quaternary and present tectonic stress distributions in the iberian peninsula a general synthesis of the recent and present stress situation and evolution in the iberian peninsula was obtained from microstructural and seismological analysis the stress evolution was deduced from 1 fault population analysis fpa from 409 sites distributed throughout the iberian peninsula 2 paleostress indicators given by 324 stations taken from the bibliography and 3 seismic data corresponding to 161 focal mechanisms evenly spread in the studied region the application of fpa together with the determination of stress tensors and focal mechanisms for the whole iberian microplate has provided two main results 1 the iberian peninsula is undergoing a nw se oriented compression except for the northeastern part pyrenees ebro basin and iberian chain where it is n s to ne sw and the gulf of cadiz where it seems to be e w and 2 the main trends of the stress field have remained almost constant since the upper miocene the analysis performed by zones suggests the presence of local heterogeneities in the stress field

moment tensor solutions for the iberian maghreb region during the iberarray deployment 2009 2013 abstract we perform regional moment tensor inversion for 84 earthquakes that occurred in the iberian maghreb region during the second and third leg of iberarray deployment 2009 2013 during this period around 300 seismic broadband stations were operating in the area reducing the interstation spacing to 50 km over extended areas we use the established processing sequence of the iag moment tensor catalogue increasing to 309 solutions with this update new moment tensor solutions present magnitudes ranging from mw 3 2 to 6 3 and source depths from 2 to 620 km most solutions correspond to northern algeria where a compressive deformation pattern is consolidated the betic rif sector shows a progression of faulting styles from mainly shear faulting in the east via predominantly extension in the central sector to reverse and strike slip faulting in the west at the sw iberia margin the predominance of strike slip and reverse faulting agrees with the expected transpressive character of the eurasian nubia plate boundary new strike slip and oblique reverse solutions in the trans alboran shear zone reflect its left lateral regime the most significant improvement corresponds to the atlas mountains and the surroundings of the gibraltar arc with scarce previous solutions reverse and strike slip faulting solutions in the atlas system display the accommodation of plate convergence by shortening in the belt at the gibraltar arc several new solutions were obtained at lower crustal and subcrustal depths these mechanisms show substantial heterogeneity covering the full range of faulting styles with highly variable orientations of principal stress axes including opposite strike slip faulting solutions at short distance the observations are not straightforward to explain by a simple geodynamic scenario and suggest the interplay of different processes among them plate convergence in old oceanic lithospheric with large brittle thickness at the sw iberia margin as well as delamination of thickened continental lithosphere beneath the betic rif arc

long plio pleistocene terrestrial record of climate change and mammal turnover in southern spain abstract cyclostratigraphic analysis of the pliocene zujar section guadix baza basin southeastern spain has enabled the recognition of a number of climatically forced cycles reflecting alternating dry and wet periods peaks of aridity are recorded at ca 3 95 3 55 3 2 2 8 and 1 8 myr b p the first dry period at about 4 0 myr b p corresponds to the early ruscinian mammal age while the second arid interval at about 3 6 myr b p corresponds to the establishment of the mediterranean double seasonality the significant mammal turnover between the late ruscinian and early villanyian stages is placed between chron 2an 2n and the very base of chron 2an 1n coincident with the dry phase recognized at about 3 2 myr b p the fourth aridity maximum at 2 8 myr b p roughly coincides with the equus event in western europe and is probably related to the beginning of the glacial interglacial dynamics in the northern hemisphere finally the last dry peak at about 1 8 myr b p is probably related to the set of mammalian events characterizing the transition from the late pliocene faunas to those of the early pleistocene

structural analysis of recent and active faults and regional state of stress in the epicentral area of the 1978 thessaloniki earthquakes northern greece during spring and summer 1978 macedonia greece suffered damaging seismic activity during the two main shocks which occurred on may 23 mb 5 7 and june 20 mb 6 1 seismic open cracks and faults were formed in the epicentral area 25 km nne from thessaloniki they have been mapped and their kinematics analyzed these studies have shown that they result from the reactivation of existing faults of pleistocene recent and historical age and that the crust is stretching along a n s to nne ssw direction in that part of the north aegean principal stress directions have been computed from the slip vectors measured on recent neotectonic faults and seismic cracks and faults this computation utilizing a simple mechanical model homogeneous deformation through the addition of small and independent displacements of rigid blocks in a highly fractured body a striking feature of this analysis is that the tensional directions 3 deduced from seismic faulting and from recent neotectonic faulting are nearly the same they are compatible with the regional tension axis deduced from focal mechanisms of north aegean and with the focal mechanisms of the 1978 thessaloniki main shocks they are also compatible with in situ stress measurements in this region studies of superficial seismic faulting strongly support previous assumptions proposed from aftershock distribution the 1978 thessaloniki earthquakes resulted from reactivation of several different faults situated within the same ne dipping fault zone of upper eocene lower oligocene age and older separating the serbo macedonian massif from the peonias east vardar zone

comparison of earthquake scaling relations derived from data of the instrumental and preinstrumental era estimates of surface rupture displacement and magnitude for crustal earthquakes from the preinstrumental era pre 1900 tend to be greater than the corresponding estimates derived from modern scaling relations we investigate this tendency using an expanded and updated version of the earthquake dataset of wells and coppersmith 1994 to fit regression relations of moment magnitude on surface rupture length and rupture area and average surface displacement on surface rupture length separate relations are fitted to preinstrumental and instrumental data and the results compared to the equivalent relations of wells and coppersmith we find that our relations for instrumental data remove some but not all of the differences between the preinstrumental data and the relations of wells and coppersmith we attribute the remaining differences largely to natural censoring of surface displacements less than about 1 m and surface rupture lengths less than about 5 km from the dataset for the preinstrumental era because regressions constructed from similarly censored instrumental data are indistinguishable from the preinstrumental regressions since the regressions for our censored instrumental data i e restricted to moderate to large earthquakes are different from regressions for our complete dataset of instrumental earthquakes and from the regressions of wells and coppersmith both with a larger proportion of small to moderate earthquakes the results may indicate that large earthquakes have different scaling relationships from those of smaller earthquakes

european hydraulic geometries for continental scale environmental modelling summary this paper presents a geo exploratory analysis carried out using publicly accessible data to estimate river channel width and mean lake depth these two parameters combined with other more readily available information are key in many environmental assessment applications such as sedimentological and ecological studies and the prediction of surface water residence times for river width runoff estimates have been used to produce a european map of mean annual discharge based on the flow accumulation computed for the gtopo30 digital elevation model dem a regression equation is fitted to predict river width as a function of river discharge for lake depth a landscape roughness index has been calculated on the gtopo30 dem based on this index a regression equation predicts lake depth allowing to populate the existing geographic databases with information on estimated depth using these models for river width and lake depth it is possible to compute representative values of velocity and depth in rivers as well as residence time in lakes at a pan european level these parameters define the hydraulic geometry of european inland waters for typical conditions with errors on the predictions generally within a factor of 2 errors are generally unbiased and geographic patterns such as macroscopic differentiation of catchments and physiographic environments are reproduced in a qualitatively correct way so that overall representativeness of the values for continental scale modelling is further corroborated

strain variations in a seismogenic normal fault baza sub basin betic chain insights from magnetic fabrics ams abstract ams and structural analysis are here applied to study the deformed zone associated with a large scale active normal fault in the central betic cordillera spain namely the baza fault system to determine i the kinematics of structures and their relation with fault zone architecture and segmentation degree ii the correlation between deformational structures and the different types of magnetic fabrics and iii the evolution of magnetic fabrics patterns from sedimentary to shear related associated with normal faults five outcrops 969 samples were analysed along the fault trace which shows different degrees of segmentation along strike and strong localization of deformation along narrow fault zones a first main set of magnetic fabric data corroborates the normal kinematics of the baza fault showing magnetic lineations parallel to the dip slip transport direction a second secondary set of magnetic lineations is parallel to the intersection lineation and can be related to less intense deformation in the fault rocks furthermore a detailed study 523 samples of a trench excavated across the fault zone where two fault splays tend to coalesce in a linkage relay zone indicates that i lithology and distance to fault planes are two factors that control the development of extension related magnetic fabrics in weakly deformed sediments ii the development of shear related fabrics in fault zones entails the mechanical rotation of minerals iii different orientation of magnetic lineations are related to different intensity of bulk deformation and iv magnetic lineation is useful to define local deviations of deformation axes produced by changes in the local extension direction from fault perpendicular to fault parallel extension in the linkage zone between adjacent fault splays

san andreas fault rupture scenarios from multiple paleoseismic records stringing pearls we present a new method to objectively combine paleoseismic event data from multiple sites into rupture scenarios and apply it to the southern san andreas fault ssaf of california first a pool is constructed of all ruptures between sites allowed by fault geometry and available event age probability distribution functions pdfs scenarios constructed by drawing from this pool are evaluated by the average quality of agreement event dating evidence by the degree of misfit of cumulative displacement over all ruptures compared to a prediction from the fault slip rate and elapsed time and by the number of events in the scenario three slip rate models from the 2008 working group on california earthquake probabilities wgcep were considered scenarios with full fault length ruptures tend to be inconsistent with low slip rates through the san bernardino and san gorgonio sections of the ssaf favorable scenarios tend to include 1857 like ruptures for three of the most recent five prehistoric ruptures in the northern half of the ssaf from carrizo to approximately wrightwood they also include one to two ruptures that involve the southern half of the ssaf but most earthquakes there appear shorter and exhibit less consistency from event to event by combining paleoseismic data into ensembles of scenarios and selecting viable scenarios using external constraints our method provides rupture histories useful for seismic hazard assessment without having to first settle which event at a site correlates with those at adjoining sites this opens a way for paleoseismic data to be used with greater power to understand the seismic hazard posed by faults like the southern san andreas

mechanism of sedimentation of rhythmically bedded chert abstract the biogenic chert shale sequences in the upper paleozoic and lower mesozoic inner chichibu terrain and in the tertiary setogawa terrain formed on a bank or in the central part of a marginal sea adjacent to a nearby land the rhythmic layering results from periodic turbidity currents in spicule radiolarian bedded cherts of the inner chichibu terrain most chert beds are of symmetrical triple layered type composed of a middle siliceous layer and upper and lower argillaceous layers the amounts of hydrogenous base metals such as fe mn cu ni v and zn are higher in chert than in shale partings the mno al 2 o 3 ratio and sedimentation rate diagram in fig 4 shows that the average sedimentation rate is 7 1 m m y 1 for chert and 45 m m y 1 for shale partings these lines of evidence suggest that the shale partings formed from distal turbidity currents and are interbedded with hemipelagic biogenic chert on the other hand in the tertiary diatomaceous bedded cherts of the setogawa terrain most sets of chert beds and overlying shale partings were deposited as siliceous turbidites like in many bedded cherts in other orogenic belts of the world the frequency of occurrence of such periodic turbidity currents is calculated as one per 11 200 17 700 yrs in the inner chichibu terrain and one per 2600 10 000 yrs in the setogawa terrain

subduction tectonic erosion and late cretaceous subsidence along the northern austroalpine margin eastern alps austria abstract the late cretaceous to early tertiary subsidence history of the northern calcareous alps nca records the effect of two independent basin formation mechanisms at the northern leading margin of the austroalpine unit the terrestrial to shallow marine sediments of the lower gosau subgroup were deposited mainly within small fault bound basins during a phase of strike slip faulting from the late turonian onwards after a short period of uplift deformation and erosion of 1 to 3 ma renewed rapid subsidence followed during this period the whole nca subsided into bathyal to abyssal depths the characteristics of this second evolutionary phase are 1 a short period of uplift and erosion followed by strong subsidence of the whole nca with tectonic subsidence rates up to 700 m ma 2 sedimentation of turbidites and hemipelagites upper gosau subgroup 3 northward tilting of the depositional area 4 elimination of an accretionary wedge north of the nca as the main source for the sediments and 5 a pronounced migration of the subsidence event from the northwest to the southeast from late turonian santonian to the maastrichtian these features can be explained by a model of subduction tectonic erosion along the northern margin of the austroalpine unit a part of the adriatic microplate tectonic erosion as compared to recent analogues and fore arc modelling may be due to the collision and oblique subduction of an oceanic swell or ridge of the penninic plate beneath the overriding austroalpine unit with the nca on its leading northern margin

plate tectonics and pelagic facies late jurassic to early cretaceous deep sea sediments of the ybbsitz ophiolite unit eastern alps austria abstract pelagic sediments of the ybbsitz unit are part of an ophiolite sequence within the penninic unit in the eastern alps cherts and calpionellid limestones of late jurassic to early cretaceous age were deposited on oceanic basement sedimentation near an oceanic spreading center below the calcium compensation depth ccd is represented by chert clay rhythmites cherts display hydrothermal fe and mn mineralizations that are characterized by low contents of co ni and cu as well as by high fe2o3 tio2 and mno tio2 ratios as the site of deposition migrated away from the spreading center hydrothermal influence ceased due to the late jurassic drop of the ccd calcareous radiolarian ooze was deposited on intrabasinal topographic heighs downslope transport of this ooze to sites below the ccd by turbidity currents resulted in intercalations of calcareous and carbonate free sediments apparently the drop of the ccd was greater than the rate of cooling induced basement subsidence as calcareous radiolarites overly this sequence carbonate contents gradually increase upsection and micritic limestones terminate purely pelagic sedimentation at the jurassic cretaceous boundary plate drift moved the site of deposition towards an active continental margin producing a coarsening upward clastic sequence this sequence starts with turbidite and breccia intercalations in pelagic limestones followed by the deposition of early cretaceous flysch it marks the onset of subduction of the ybbsitz unit under the austroalpine continental margin

fluvialcorridor a new arcgis toolbox package for multiscale riverscape exploration abstract both for scientists and river basin managers development of automated geographic information system gis tools is essential today to characterize riverscapes and explore biogeomorphologic processes over large channel networks since the 1990s gis toolboxes and add in programs have been used to characterize catchments however there is currently no equivalent to a planimetric and longitudinal characterization of fluvial corridor networks at multiple scales this paper describes fluvialcorridor a new gis toolbox this package allows the user i to extract a large set of riverscape features such as the main components of fluvial corridors from dem and vector layers e g stream network or valley bottom and ii to aggregate spatial features into homogeneous segments and metrics characterizing each of them the methodological frameworks involved have been previously described by alber and piegay 2011 leviandier et al 2012 and bertrand et al 2013 and this contribution focuses on the gis tools allowing the user to automatically operate them a case study on the drome river france is provided to illustrate the potential of the package both for geomorphologic understanding and target management actions fluvialcorridor has been developed for arcgis with the related native python library named arcpy and tested on arcgis 10 0 and 10 1 obviously each component of the package can be used separately however it also provides a complete workflow for fluvial corridor characterization even as the toolbox is continually under development and revision case study database fluvialcorridor package and guidelines are available online at http umrevs isig fr