the dead sea transform fault system abstract a new map showing the major features of the dead sea transform fault system based on seismicity satellite imagery geological maps and bathymetric charts is presented special attention is given to the possible northward continuation of the transform system beneath the mediterranean sea near ed damur south of beirut the map shows the dead sea transform system to be a series of offset overlapping left lateral transform faults with a rhombochasm between each pair the system has similarities with the equatorial fracture zones in the atlantic ocean throughout the dead sea transform system is considered in its regional setting i e as extending from the red sea spreading centre in the south to the eurasian collision zone in the north it is suggested that it may intersect the latter somewhere east of cyprus making that area the northernmost termination of the dead sea transform system

block models of crustal motion in southern california constrained by gps measurements 1 we estimate slip rates on major active faults in southern california using a block model constrained by global positioning system measurements of interseismic deformation the block model includes the effects of block rotation and elastic strain accumulation consistent with a simple model of the earthquake cycle our estimates of the right lateral strike slip rate on the san andreas fault vary by at least a factor of 5 from a high of 35 9 0 5 mm yr in the carrizo plain to a low of 5 1 1 5 mm yr through the san bernadino segment shortening across the puente hills thrust and left lateral slip on the raymond hill fault are consistent with both thickening and escape tectonics in the los angeles basin discrepancies between geodetic and geologic slip rate estimates along the san andreas and san jacinto faults as well as in the eastern california shear zone may be explained by a temporal change in fault system behavior we find no substantial evidence for long term postseismic relaxation and infer that the viscosity of the lower crust upper mantle may be relatively high 1019 pa s

crustal shortening in the palmyride fold belt syria and implications for movement along the dead sea fault system an edited version of this paper was published in tectonics by the american geophysical union agu copyright 1990 agu see also http www agu org journals tc http atlas geo cornell edu syria chaimov tectonics 1990 html

block modeling with connected fault network geometries and a linear elastic coupling estimator in spherical coordinates geodetic observations of interseismic deformation provide constraints on the partitioning of fault slip across plate boundary zones the spatial distribution of both elastic and inelastic strain accumulation and the nature of the fault system evolution here we describe linear block theory which decomposes surface velocity fields into four components 1 plate rotations 2 elastic deformation from faults with kinematically consistent slip rates 3 elastic deformation from faults with spatially variable coupling and 4 homogeneous intrablock strain elastic deformation rates are computed for each fault segment in a homogeneous elastic half space using multiple optimal planar cartesian coordinate systems to minimize areal distortion and triangular dislocation elements to accurately represent complex fault system geometry block motions fault slip rates elastic coupling and internal block strain rates are determined simultaneously using a linear estimator with constraints from both geodetically determined velocity fields and geologic fault slip rate estimates we also introduce algorithms for efficiently implementing alternative fault network geometries to quantify parameter sensitivity to nonlinear perturbations in model geometry

the seismicity along the dead sea fault during the last 60 000 years abstract evidence for unchanging slip rate and a gutenberg richter relation for earthquake distribution along the dead sea fault during the past 60 000 yr are presented the evidence comes from three different segments approximately 100 km apart and from three different timescales prehistoric paleoseismic historical and modern instrumental records the paleoseismic data are based on two different methods in the southern arava valley and the northern jordan valley segments the amount of normal displacement along several faults is used while in the dead sea basin the appearance of brecciated beds which are considered as seismites is used we found that for the southern arava valley segment a constant dip slip rate of 0 5 mm yr can explain the cumulative normal slip during the past 45 000 yr this suggests that normal faulting is only 10 of the total left lateral strike slip motion we also found that for all three segments the paleoseismic and historical records of strong earthquakes lie on the linear extrapolation of the frequency magnitude relation of the instrumental record the calculated b values for all three segments are between 0 85 and 1 similar to other major strike slip faults in the world it is concluded that the gutenberg richter distribution is a stable mode in the tectonic setting of the dead sea fault during the past 60 000 yr

geodetic imaging of plate motions slip rates and partitioning of deformation in japan 1 interseismic deformation in japan results from the combined effects of tectonic processes including rotation of crustal blocks and the earthquake cycle process of elastic strain accumulation about upper plate faults and subduction zone interfaces we use spherical linear block theory constrained by geodetic observations from densely spaced global positioning system gps stations to estimate plate motions fault slip rates and spatially variable interplate coupling on the japan kuril sagami and nankai subduction zones the reference model developed in this paper consists of 20 blocks produces a mean residual velocity magnitude of 1 84 mm yr at 950 stations and accounts for 96 of the observed interseismic deformation signal we estimate fault slip rates in excess of 15 mm yr along the niigata kobe tectonic zone and itoigawa shizuoka tectonic line through central japan confirming their hypothesized roles as major tectonic boundaries oblique convergence across the nankai trough is partitioned with 3 4 of the 30 mm yr of trench parallel motion accommodated by strike slip motion on the subduction interface and the remaining 1 4 accommodated by right lateral slip on the median tectonic line in contrast our models suggest negligible slip partitioning in eastern hokkaido where oblique slip on the japan kuril subduction interface accommodates all of the trench parallel component of relative plate motion inferred spatial variations in the rake and magnitude of slip deficit on subduction zone interfaces reflect the influences of megathrust geometry and earthquake cycle processes such as enhanced elastic strain accumulation about seismic asperities and coseismic sense fault motion indicative of silent slip events or afterslip following large earthquakes

chemical characterization of obsidians from different mediterranean sources by non destructive sem eds analytical method the aim of our research is to check the sem eds non destructive analytical method for discriminating and locating the possible sources of obsidian artefacts moreover in order to obtain a significant discrimination of mediterranean obsidians we analysed samples collected from outcrops of the major sources monte arci sardinia and palmarola lipari pantelleria gyali and melos islands all samples were analysed by both xrf whole rock and sem eds glass and microliths microphenocrysts the xrf analysis reveals that major elements discriminate obsidian the discrimination using major elements is very useful because the amount of trace elements is lower than the detection limit of a si li ed detector the major elements particularly sio2 al2o3 cao na2o and k2o of obsidian glass discriminate the six main mediterranean sources our work demonstrates therefore the possibility of discriminating different provenance of obsidian artefacts using sem eds by means of a relatively rapid effective and above all non destructive method

global positioning system measurements of strain accumulation and slip transfer through the restraining bend along the dead sea fault system in lebanon an edited version of this paper was published in geophysical journal international by blackwell publishing blackwell publishing retains the copyright to this paper copyright 2007 see also http www blackwell synergy com doi abs 10 1111 j 1365 246x 2006 03328 x http atlas geo cornell edu deadsea publications gomez2007 gji htm

compiling an earthquake catalogue for the arabian plate western asia abstract the arabian plate is surrounded by regions of relatively high seismicity accounting for this seismicity is of great importance for seismic hazard and risk assessments seismic zoning and land use in this study a homogenous earthquake catalogue of moment magnitude mw for the arabian plate is provided the comprehensive and homogenous earthquake catalogue provided in the current study spatially involves the entire arabian peninsula and neighboring areas covering all earthquake sources that can generate substantial hazard for the arabian plate mainland the catalogue extends in time from 19 to 2015 with a total number of 13 156 events of which 497 are historical events four polygons covering the entire arabian plate were delineated and different data sources including special studies local regional and international catalogues were used to prepare the earthquake catalogue moment magnitudes mw that provided by original sources were given the highest magnitude type priority and introduced to the catalogues with their references earthquakes with magnitude differ from mw were converted into this scale applying empirical relationships derived in the current or in previous studies the four polygons catalogues were included in two comprehensive earthquake catalogues constituting the historical and instrumental periods duplicate events were identified and discarded from the current catalogue the present earthquake catalogue was declustered in order to contain only independent events and investigated for the completeness with time of different magnitude spans

quaternary landscape development alluvial fan chronology and erosion of the mecca hills at the southern end of the san andreas fault zone abstract quantitative geomorphic analysis combined with cosmogenic nuclide 10 be based geochronology and denudation rates have been used to further the understanding of the quaternary landscape development of the mecca hills a zone of transpressional uplift along the southern end of the san andreas fault in southern california the similar timing of convergent uplifts along the san andreas fault with the initiation of the sub parallel san jacinto fault suggest a possible link between the two tectonic events the ages of alluvial fans and the rates of catchment wide denudation have been integrated to assess the relative influence of climate and tectonic uplift on the development of catchments within the mecca hills ages for major geomorphic surfaces based on 10 be surface exposure dating of boulders and 10 be depth profiles define the timing of surface stabilization to 2 6 5 6 1 3 ka qyf1 surface 67 2 5 3 ka qvof2 surface and 280 24 ka qvof1 surface comparison of 10 be measurements from active channel deposits qac and fluvial terraces qt illustrate a complex history of erosion sediment storage and sediment transport in this environment beryllium 10 catchment wide denudation rates range from 19 9 3 2 to 149 22 5 m ma and demonstrate strong correlations with mean catchment slope and with total active fault length normalized by catchment area the lack of strong correlation with other geomorphic variables suggests that tectonic uplift and rock weakening have the greatest control the currently measured topography and denudation rates across the mecca hills may be most consistent with a model of radial topographic growth in contrast to a model based on the rapid uplift and advection of crust

strain partitioning of active transpression within the lebanese restraining bend of the dead sea fault lebanon and sw syria this material has been published in the journal of the geological society of london the only definitive repository of the content that has been certified and accepted after peer review copyright and all rights therein are retained by the geological society of london copyright 2001 the geological society of london see also http atlas geo cornell edu deadsea publications gomez2007 gsl htm

magnetic vs structural fabrics whipple detachment structure whipple wash california abstract orientations of ellipsoids of anisotropy of magnetic susceptibility ams are compared with those of mesoscopic structural features for the breccia and upper mylonite zones for the whipple detachment zone in whipple wash whipple mountains eastern california the anisotropy of the breccia which ranges up to 5 is much less than that of the mylonitic gneiss which can exceed 100 slight differences in trend are evident between the ams ellipsoid elongations and those of mineral lineations maximum axes 1 of the ams ellipsoids for both breccia and mylonite trend generally ssw nne with shallow plunge whereas mineral stretching lineations in the mylonite gneiss have trends near ne sw with shallow plunge measured fold axes are close to the 1 axes ssw nne 1 axes in the breccia show more variation e w and ssw nne at different structural levels mesoscopic mineral lineations in the breccia were not discernible for the planar elements ams ellipsoid flattening is generally more closely parallel to foliation surfaces in the mylonite than in the breccia this is evident from overlapping minimum susceptibility axes 3 and foliation pole clusters 3 axes are more scattered than are poles of foliation the scatter in 3 is possibly the superimposed susceptibility effect of several structural surfaces of different ages joints small faults transposed metamorphic foliations and mylonitic foliation especially interesting are the discovery of good 1 definitions in the breccia the apparent lack of correlation of 1 axes with the very prominent stretching lineations in the mylonite and the similarity of the 1 axial trends with those of the fold fracture pole patterns

obsidian characterization by laser ablation icp ms and its application to prehistoric trade in the mediterranean and the near east sources and distribution of obsidian within the aegean and anatolia for geological studies interest in mass spectrometry with an inductively coupled plasma as an ion source and its association with laser ablation as a sample introduction technique la icp ms has steadily increased during the past few years and is now being developed in other fields such as archaeology after a description of the analytical procedure and the calculation method we show the potential of this technique to characterize almost non destructively archaeological artefacts among the 70 elements that could be routinely analysed by la icp ms with detection limits below the ppm level we choose to determine the more critical ones in order to evaluate the geochemical models of the magmatic process major elements rare earths and some transition elements a detailed survey of cappadocian obsidian flows is given and includes the characterization of nine different sources evidence of complex trade activities is clearly shown by the obsidian tools found at different prehistoric sites from neolithic to bronze age levels in the mediterranean and the near east new results obtained on some archaeological sites located in turkey syria and cyprus are presented they show the importance of cappadocian sources in obsidian trade our results show that la icp ms allows a non destructive analysis of archaeological objects and that it combines the advantage of the different classical methods used to characterize obsidian sources mainly xrf and inaa with high sensitivity and rapidity thus la icp ms appears to be a very powerful analytical tool and at this time this technique is the only one which can non destructively determine such an important number of elements with such low detection limits

gps measurements of current crustal movements along the dead sea fault 1 a network of 11 continuous gps stations was constructed in israel between 1996 and 2001 to monitor current crustal movements across the dead sea fault dsf analysis of the gps measurements with respect to the itrf2000 reference frame yields time series of daily site positions containing both secular and seasonal variations horizontal secular variations station velocities are evaluated with respect to the main tectonic element in the region the dsf we use six velocity vectors west of the dsf to define the itrf2000 pole of the sinai sub plate and rotate the velocity field for all stations into the sinai reference frame srf the velocity vectors reveal that 1 relative station movements are less than 4 mm yr 2 the nine stations located west of the dsf show no statistically significant motion with respect to the srf and 3 the two stations located in the golan heights katz and elro and a station in damascus syria udmc show 1 7 2 8 mm yr northward motion with respect to sinai indicating a left lateral motion along the dsf using locked fault models we estimate the current slip rate across the dsf as 3 3 0 4 mm yr if we exclude the northern sites elro and udmc which are located adjacent to the compressional jog of mount hermon our estimate increases to 3 7 0 4 mm yr the calculated itrf2000 sinai eurasia and nubia poles and a published pole for arabia allow us to calculate the current relative plate motion of sinai arabia and sinai nubia

holocene faulting and earthquake recurrence along the serghaya branch of the dead sea fault system in syria and lebanon an edited version of this paper was published in geophysical journal international by blackwell publishing blackwell publishing retains the copyright copyright 2003 blackwell publishing see also http www blackwell synergy com doi abs 10 1046 j 1365 246x 2003 01933 x http atlas geo cornell edu deadsea publications gomez2003 gji htm

structural framework and deformation history of the western cyprus arc abstract an extensive grid of high resolution multichannel seismic reflection profiles complemented with wider spaced deep penetrating industry seismic profiles revealed that the pre messinian miocene structural architecture of the antalya basin and its southwestern extension into the florence rise is characterized by a very prominent broadly northwest southeast striking and largely southwest verging fold thrust belt with occasional northeast verging backthrusts during the messinian a number of prominent thrusts remained active however numerous thrusts which were active during the pre messinian miocene became inactive during the uppermost messinian quaternary the stain was partitioned into five broadly northwest southeast trending morphotectonic domains each delineated by a distinctive seafloor morphology a a domain across the inner and western antalya basin is dominated by extensional faults b a domain immediately south of the extensional faults is characterized by contractional structures c a halokinetic zone in southwestern antalya basin north of the foothills of the anaxagoras mountain is characterized by numerous positive flower structures beneath a corrugated seafloor d a domain characterized by fluid escape structures immediately southeast of the halokinetic zone and e a domain across the crestal portion of the florence rise is dominated by prominent inversion structures detailed mapping documented that several of these tectonic domains can be readily correlated with previously mapped tectonic elements in the eastern mediterranean as well as structures mapped across the adjacent landmass the change from ubiquitous pre messinian miocene contraction to partitioned strain of the latest messinian quaternary is likely related to the collision of the eratosthenes with cyprus and the resultant jostling of the tectonic blocks

mantle dynamics in the mediterranean the mediterranean offers a unique opportunity to study the driving forces of tectonic deformation within a complex mobile belt lithospheric dynamics are affected by slab rollback and collision of two large slowly moving plates forcing fragments of continental and oceanic lithosphere to interact this paper reviews the rich and growing set of constraints from geological reconstructions geodetic data and crustal and upper mantle heterogeneity imaged by structural seismology we proceed to discuss a conceptual and quantitative framework for the causes of surface deformation exploring existing and newly developed tectonic and numerical geodynamic models we illustrate the role of mantle convection on surface geology a coherent picture emerges which can be outlined by two almost symmetric upper mantle convection cells the downwellings are found in the center of the mediterranean and are associated with the descent of the tyrrhenian and the hellenic slabs during plate convergence these slabs migrated backward with respect to the eurasian upper plate inducing a return flow of the asthenosphere from the backarc regions towards the subduction zones this flow can be found at large distance from the subduction zones and is at present expressed in two upwellings beneath anatolia and eastern iberia this convection system provides an explanation for the general pattern of seismic anisotropy in the mediterranean first order anatolia and adria microplate kinematics and may contribute to the high elevation of scarcely deformed areas such as anatolia and eastern iberia more generally the mediterranean is an illustration of how upper mantle small scale convection leads to intraplate deformation and complex plate boundary reconfiguration at the westernmost terminus of the tethyan collision

a 3 d viscoelastoplastic model for simulating long term slip on non planar faults summary the geometrical complexity of non planar faults is known to affect not only fault slip rates but also crustal deformation and seismicity in the surrounding region but implementing non planar faults in numerical models has been challenging we have developed a 3 d viscoelastoplastic finite element model to simulate long term steady state fault slip along conceptual restraining bends and crustal deformation around them by incorporating plastic yielding in both fault zones and the surrounding crust this model can predict the quasi steady state stress field and strain partitioning while avoiding pathological stress build up encountered in traditional viscoelastic models here we detail the formulation of this model and explore major model parameters the model results show that restraining bends tend to impede fault slip increase shear stress in the surrounding crust and localize strain in a pair of belts off the fault zone these effects are enhanced by high viscosity in the lower crust and upper mantle high aspect ratio of bend width over fault length fast relative motion of fault blocks and high fault friction these model results may help explain the diffuse deformation surrounding the big bend of the san andreas fault and the more confined deformation around the lebanon bend of the dead sea fault

what can a sessile mollusk tell about neotectonics article i nfo dendropoma petraeum are fixed vermitids mollusk that colonize and construct abrasion platform rims along rocky shorelines these endemic mollusks are considered good relative sea level indicators in the eastern and the southern mediterranean due to their narrow habitat below the sea surface about 10 cm the observed relative sea level values recorded submerged uplifted or at present mean sea level reflect a superposition of eustatic isostatic tectonic and possibly local sedimentary instabilities the present study examines fossil dendropoma samples gathered along the levant coast from northern israel to eastern turkey conventional radiocarbon dates from turkey syria and partly in lebanon and 14 c accelerator mass spectrometer ams from lebanon and israel yields dendropoma ages ranging through late holocene a numerical model is used for calculating the change in sea level through the holocene as a function of glacio hydrology and isostasy of the eastern mediterranean space time dependent subtractions of the model values are used to eliminate the eustatic component of the relative sea level in order to obtain the tectonic component results show a general northward increase in tectonic uplift of the levantine coast with different rates in different tectonic segments this differential uplift corresponds well to the major tectonic segments comprising the levantine continental margin since the pleistocene from the carmel fault to the east anatolian fault hence these segments were still active during the last thousands years and even during the last hundreds years the general trend of northward increase in vertical displacement is predominantly dictated by the convergence between the sinai and arabian plates with anatolia and eurasia across the cyprus arc and zagros belt and the secondarily dictated by the northward increase in convergence component across the sinistral dead sea fault plate boundary

intrabasin paleoearthquake and quiescence correlation of the late holocene dead sea 1 a comprehensive multisite paleoseismic archive of the late holocene dead sea basin past 2500 years is established by constructing two age depth chronological models of two sedimentary sections exposed at the retreating shores of the modern dead sea two new paleoseismic study sites studied are the ein feshkha nature reserve outcrop located at the northern part of the basin and close to an active underwater transverse fault and the east ze elim gully outcrop at the southern part of the basin age depth regression models are calculated for these sections based on atmospheric radiocarbon ages of short lived organic debris calibrated with a bayesian model the uncertainties on individual model ages are smaller than 100 years the new chronological records are compared to a laminae counting study of the ein gedi core migowski et al 2004 located at the central dead sea basin the ein feshkha outcrop yielded the largest number of seismites in the studied time interval n 52 while lower numbers of seismites are recovered from the ze elim outcrop and ein gedi core n 15 and 36 respectively the seismites show no strong dependence on the limnological sedimentological conditions in the particular sampling sites they coappear in both shallow and deep water environments and in different sedimentary facies during time intervals when the chronologies are comparable it appears that the number of seismites is significantly larger in the northern part of the basin ein gedi and ein feshkha seismic quiescence intervals are apparent at all three sites from 2nd 4th century a d and at 500 150 b c at ze elim and ein gedi several synchronous seismites appear in all sections termed here the intrabasin seismites ibs among them 1927 1293 1202 1212 749 551 419 and 33 a d and 31 and mid 2nd century b c the recurrence time of the ibs from the 2nd century b c to the 14th century a d is 200 years compared with 100 years for all earthquakes on a diagram of epicentral distance versus magnitude historic earthquakes that are correlated with ibs plot in a field of high local intensity the farther and stronger ibs earthquakes require lower local intensities to be recorded this study demonstrates that a painstaking effort is still needed for unraveling the seismic history of the dead sea basin the results also indicate that such a study will likely be highly rewarding

internal structure of the dead sea leaky transform rift in relation to plate kinematics abstract the structures along the dead sea transform rift are related to the motions of the sinai and arabia plates which border it and to the irregularities of their boundaries the total slip was 105 km left lateral but the present structures were formed mainly during the last 40 km of slip which probably occurred in the plio pleistocene along the southern half of the transform the strike slip motion takes place on en echelon faults this produces rhomb shaped grabens or pull aparts which are sometimes composite and in which there is local crustal separation thus much of the transform is leaky these structures occur in a morpho tectonic rift valley delimited by normal faults which express a small component of transverse extension along a few segments the shape of the transform is such that lateral motion produces local transverse compression the geometric relations of the structures along the transform define an eulerian pole of relative plate motions at 32 8 n 22 6 e 0 5 the older motion was somewhat different and is described by a pole located about 5 west of the above then the component of transverse extension and crustal separation was much smaller than now while local transverse compression was more important the northern half of the dead sea transform has an irregular shape and the bordering plates did not remain rigid as lateral motion continued here transverse compression is often important

late cenozoic uplift along the northern dead sea transform in lebanon and syria an edited version of this paper was published in earth and planetary science letters by elsevier science elsevier science retains the copyright to this paper copyright 2006 elsevier science see also http dx doi org 10 1016 j epsl 2005 10 029 http atlas geo cornell edu deadsea publications gomez2006 epsl htm

seismicity of the eastern mediterranean region perspective from the sinai subplate we conducted a comprehensive study of the seismicity of the eastern mediterranean and examined its relation to the regional plate tectonics based on various published catalogs we have constructed a new list of ml 4 earthquakes which were recorded during the years 1900 1991 and represents most of the seismic moment released in the area over this period b values are 1 02 1 0 and 1 07 for the whole sinai subplate the dead sea transform and the cypriot arc respectively seismic efficiency of the dead sea transform is very low about 7 stressing the role of aseismic deformation in that plate border most of the major and moderate events ml 5 occur in belts associated with the geologically documented borders of the sinai subplate the cypriot convergent arc in the north the dead sea transform in the east and the rift of suez in the southwest the latter like the gulf of eilat aqaba was considered aseismic during the first half of the century the northwestern border however could not be delineated low level activity appears within the subplate especially north of latitude 32 n reflecting the breakdown of this part of sinai as it approaches the cypriot convergence zone though most of the seismic moments tend to concentrate along the subplate borders some moderate activity spreads out in wide belts which reflect the complexity of deformation accompanying motion along the subplate borders

evidence of coseismic ruptures along the roum fault lebanon a possible source for the ad 1837 earthquake abstract the roum fault is the westernmost branch within the lebanese restraining bend of the dead sea transform fault this strike slip fault extends for about 35 km from north of the hula basin to the awali river and shows left lateral strike slip displacements manifested as offset streams and vertical movements recent seismic records indicate its seismogenic potential as the source of the double shock of 16 march 1956 ms 4 8 5 1 earthquake we studied the roum fault using combined field investigations in geomorphology structural geology and palaeoseismology fresh fault scarps and pressure ridges visible along the fault trace attest to recent coseismic ruptures a palaeoseismic trench investigation exposed a complex fault zone with several rupture strands and a minimum of four faulting episodes in the last 10 000 years the most recent event being post 84 239 ad according to historical records the 1 january 1837 ms 7 1 earthquake which induced severe damage in the region is the most likely candidate our results assign a slip rate of 0 86 1 05 mm year along the roum fault which shows that it accommodates about 14 of the total predicted strike slip motion within the lebanese restraining bend and it should be considered a potential seismogenic fault for seismic hazard estimates in lebanon

seismic evidence for neogene and active shortening offshore of lebanon shalimar cruise 1 lebanon located on a 160 km long transpressional bend of the left lateral levant dead sea fault system lfs has been the site of infrequent but large earthquakes including one submarine tsunamigenic event the main objective of the shalimar marine survey was to characterize and map active deformation offshore of lebanon using a range of geophysical techniques particularly seismic reflection profiling the cruise results clearly establish the presence of young submarine thrust faults and folds and clarify the structure of this part of the levant margin a submarine fold belt bounded by thrusts and lateral ramps and extending up to 30 km from the shoreline is interpreted as the foreland thrust system of the actively growing mount lebanon range there is no large fault extending into the levant basin toward cyprus which indicates that thrusting only absorbs local transpression resulting from the lebanese restraining bend both the miocene and plio quaternary sedimentary sequences are affected by shortening with landward dipping blind thrusts and associated growth strata the presence of the messinian evaporites creates complex deformation patterns including normal faults due both to folding accommodation and to gravity spreading all well imaged in the seismic reflection profiles because the evaporite layer acts as a decollement level shortening extends farther out seaward through a series of thrust imbricates or duplexes the strongest shortening observed between beirut and batroun decreases toward the south between saida and tyre north of tripoli the passive margin is not affected by neogene deformation and is well preserved we propose that since the miocene the northward propagating lfs interacted with margin structures inherited from the mesozoic rifting phase and was deviated along the more rigid oceanic crust flooring the levant basin a process which led to the formation of the lebanese restraining bend of the lfs and consequently to the offshore shortening we document here such coastal transpression has resulted in local 100 km inversion of the passive margin which might eventually evolve into a new subduction zone

characterization of the monte arci sardinia obsidian sources in the western mediterranean obsidian from four volcanic island sources was used beginning in the neolithic period the geological sources on lipari palmarola and pantelleria have been located and chemically characterized until now however the monte arci source in sardinia was better known from the analysis of archaeological rather than geological specimens the results of a comprehensive field survey and characterization study of the obsidian sources in sardinia are presented here and finally allow all obsidian artefacts of western mediterranean origin to be attributed to specific sources using minimally destructive and relatively inexpensive methods of analysis five chemically distinct sources in the monte arci region were exploited with their location and the physical properties of the obsidian itself contributing to chronologically and spatially diverse frequency of use patterns

application of non destructive xrf method to the study of the provenance for archaeological obsidians from italian central european and south american sites abstract this paper presents the results of the attribution of approximately 1700 artifacts from italian central european and south american sites to the geological obsidian sources the provenance was determined using the non destructive x ray fluorescence xrf analytical method based on the secondary x ray intensity proposed by crisci et al 1994 and optimized by de francesco et al 2008 in the first phase of the research to test the non destructive xrf method the analysis on entire obsidian fragments similar to archaeological waste was initially carried out on 60 samples representative of all the geological outcrops in the mediterranean region the secondary x ray intensities obtained by non destructive xrf on whole pieces were compared with the results using the xrf method on powders carried out on the same samples major elements and selected trace elements such as nb y zr rb and sr as exhaustively described in de francesco et al 2008 these five trace elements were sufficient to characterize by both methods the different places of obsidian origin because they are particularly indicative of the genetic processes that produced obsidian the provenance of the obsidian artifacts was determined by comparing the x rays intensity ratios of the selected elements with those obtained on the entire fragments of the obsidian sources in the mediterranean the purpose of this paper is to show the results obtained in almost two decades of the application of the non destructive xrf method about 1700 archaeological obsidian fragments from numerous italian corsican central european romanian and south american central western argentina and central chile archaeological sites have been analyzed by non destructive xrf and assigned to obsidian sources the provenance of 97 of the obsidian artifacts was successfully determined the results demonstrate that the non destructive xrf method thanks to its sensitivity low cost and high speed is an extremely valuable tool for the attribution of the provenance of archaeological obsidian in the areas under consideration

gps measurements of near field deformation along the southern dead sea fault system 1 analysis of short term deformation along the southern part of dead sea fault dsf provides a systematic view of kinematics this part of the continental transform the southern dsf consists of two principal segments the wadi araba and jordan valley faults in addition to other regional continuous gps data this study uses new data from 25 survey sites and 4 continuous gps stations in jordan for improved near field observations resulting velocities are reported with 1 uncertainties ranging from 0 4 1 0 mm yr application of elastic dislocation models yields estimates of slip rates for wadi araba and jordan valley faults are 4 9 0 4 mm yr and 4 7 0 4 mm yr respectively modeling also suggests different depths of effective fault locking with 15 5 km and 8 5 km for the wadi araba and jordan valley faults respectively these slip rates are generally consistent with the upper end of the range of slip rates estimated from late quaternary geology spatial variations in effective fault locking generally correspond with a heterogeneous mantle lithosphere a similar observation can be observed along the southern san andreas fault and this may reflect the influence of heterogeneity in the uppermost mantle on crustal faulting processes

geochemical characteristics of soil radon and carbon dioxide within the dead sea fault and karasu fault in the amik basin hatay turkey abstract the study area is close to the boundary of three tectonic plates anatolian arabian and african plates and is characterized by important tectonic lineaments which consist mainly of the dead sea fault dsf the karasu fault and the east anatolian fault eaf systems to understand the origin of soil gas emanation and its relationships with the tectonics of the amik basin hatay a detailed soil gas sampling was systematically performed together with co2 flux measurements 220 soil gas samples were analyzed for rn and co2 concentrations the distribution of soil rn kbq m3 co2 concentration ppm and co2 flux g m2 day in the area appears as a point source spot and or diffuses halo anomalies along the buried faults fractures due to crustal leaks the results revealed that rn and co2 concentrations in the soil gas show anomalous values at the specific positions in the amik basin the trace of these anomalous values is coincident with the n s trending dsf co2 is believed to act as a carrier for rn gas based on the rn and co2 concentrations of soil gases at least three gas components are required to explain the observed variations in addition to the atmospheric component two other gas sources can be recognized one is the deep crust component which exhibits high rn and co2 concentrations and is considered the best indicator for the surface location of fault fracture zones in the region the other component is a shallower gas source with high rn concentration and low co2 concentration moreover he isotopic compositions of representative samples vary from 0 94 to 0 99 ra illustrating that most samples have a soil air component and may have mixed with some crustal component without significant input of the mantle component based on the repeated measurements at a few sites soil gas concentrations at the same site were observed to be higher in 2014 than in 2013 which may be associated with the activity of the dsf in 2013 2014 this suggests that soil gas variations at fault zone are closely related to the local crustal stress and hence are suitable for monitoring fault activities

interaction between fault and off fault seismic sources in hazard analysis a case study from israel abstract in this study seismic source characterization ssc for purpose of seismic hazard analysis sha is explored with a focus on the moment balance and interaction between on fault and off fault seismicity for the purpose of this study a homogenous uniform earthquake catalog for israel is first compiled and de clustered gridded seismicity is calculated based on the de clustered catalog using a fixed kernel as well as an adaptive kernel the main faults are represented as planar features and their magnitude frequency distribution is adjusted to match both the geological and the seismological available data a full probabilistic seismic hazard analysis psha is then conducted for the entire state of israel results are presented both in terms of the full spatial distribution in the form of hazard maps as well as at specific point locations near and far from the main sources our results show that based on the available data and balancing seismic moment the characteristic portion of the main seismic sources in israel is larger than the classical 94 suggested by youngs and coppersmith 1985 and is about 96 98 depending on the fault this suggests that the exponential model as currently used in the building code leads to a significant underestimation of hazard we further show that as long as the moment is balanced hazard results are only mildly sensitive to model choices such as size of kernel or type of cutoff between on fault and off fault sources finally we suggest using the adaptive kernel with the fault extract interaction which we believe is the best representation of the currently available geological seismological and geodetic information

quaternary tectonic evolution of the northern gulf of elat aqaba along the dead sea transform the northern gulf of elat aqaba is located in the transition between the deep marine basins of the gulf and the shallow onland basins of the arava valley interpretation of 500 km of high resolution seismic reflection data collected across the northern shelf reveals the tectonic structure and evolution of this transition six nne trending faults and one e w trending transverse fault are mapped slip rates are calculated based on measured offsets and age determination based on a radiocarbon calibrated sedimentation rate and a quaternary age model the most active fault is the evrona fault that absorbs most of the left lateral slip within the basin with an average sinistral slip rate of 0 7 0 3 mm yr through the late pleistocene and 2 3 3 4 mm yr during the holocene two intrabasin faults east of the evrona fault that have been inactive for the last several tens of thousands of years were mapped and motion from these faults has likely transferred to the evrona fault the basin is flanked on the west by the elat fault and on the east by the aqaba fault both faults are marked by large bathymetric escarpments based on displaced seismic reflectors we calculate a holocene vertical slip rate of 1 0 0 2 and 0 4 0 1 mm yr for the elat and aqaba faults respectively the geometry slip rates and slip history of the northern gulf of elat aqaba faults show that during the late pleistocene several intrabasin faults became dominant across the basin but that during the holocene the evrona fault accommodates most of the strike slip

modelling tectonic deformation along the north anatolian fault in the sea of marmara abstract using analogue techniques we attempted to model the complex tectonic deformation pattern observed along the north anatolian fault in the sea of marmara from morpho bathymetry and seismic reflection images in particular this paper focuses on the so called cinarcik segment of the fault connecting the eastern izmit segment which entirely ruptured during the mw 7 4 1999 earthquake to the western segment of the central high the cinarcik segment potentially loaded after the izmit earthquake is expected to rupture during an earthquake occurring in the near future possibly the next decades with a high potential to affect the istanbul metropolitan area our analysis suggests that the development of the observed structures accommodating strike slip transtensional and transpressional deformations could be explained by changes in the geometry of fault segments within a right lateral strike slip tectonic regime tectonic deformations were reproduced in the analogue model by imposing a small about 10 and sharp difference in the relative orientations of the strike slip segments at the edges of a major releasing bend in the model slower strain accumulation occurs along the analogue of the cinarcik segment than along the analogue of the izmit segment of the fault this would predict a delay for earthquakes triggered by stress transfer between the izmit and cinarcik segments the model further predicts that most of the deformation in the cinarcik basin is controlled by the sharp changes in the geometry of the fault itself

present day kinematics in the eastern mediterranean and caucasus from dense gps observations abstract the eastern mediterranean and caucasus are located among the eurasian african and arabian plates and tectonic activities are very complex in this paper the kinematics and strain distribution in these regions are determined and investigated from dense gps observations with over 1000 stations and longer observations the elastic block model is used to constrain present day plate motions and crustal deformation the relative euler vectors between the nubian arabian caucasus anatolian and central iranian plates are estimated the arabian eurasia anatolian eurasia nubian eurasia caucasus eurasia and central iranian euler vectors are 0 584 0 1 myr 1 0 825 0 064 myr 1 0 35 0 175 myr 1 0 85 0 086 myr 1 and 0 126 0 016 myr 1 the strain rate in the east mediterranean and caucasus has been estimated from the gps velocity field the results show that the thrust dominated areas the eastern mediterranean middle east caucasus and zagros have negative dilatation and the western anatolia region has positive 2d dilatation rate with significant rotation the west anatolian shows the extension in nw se with about 150 199 nstrain yr in the w e direction the central anatolia shows compression rate below 50 nstrain yr and extensional strain rate adjacent to east anatolian fault and dead sea fault is about 0 100 nstrain yr the contraction strain rate is higher in zagros and caucasus between 100 150 nstrain yr and contraction orientation is along the ne sw direction in caucasus the north part of iran shows less contraction rate below 50 nstrain yr but north east zagros mountains tabriz fault and chalderan fault show extensional rate between 50 110 nstrain yr and principal axes rotation in the n s direction the maximum contraction observed in the kopek dag is about 100 194 nstrain yr and orientated in the ne sw direction east zagros mountain and makran subduction zone have a large clockwise rotation with 70 85 nradian and principal axes remains mostly along the n s direction the observed extension is along n s by about 0 100 nstrain yr with counter clockwise rotation in dead sea fault the sinai block shows shortening rate in the range of 0 100 nstrain yr

coseismic growth of sedimentary basins along the yammouneh strike slip fault lebanon summary the left lateral yammouneh fault yf is the main active branch of the dead sea transform fault dstf within the lebanese restraining bend despite the overall transpressional setting a series of sedimentary basins have developed along the trace of the yf consequently palaeoseismic studies within these basins provide an opportunity to study the processes of coseismic growth of the basins as well as elucidate earthquake behaviour of the fault in general geodetic measurements of contemporary fault slip within the lebanese restraining bend indicate that the yf accommodates most of the expected left lateral strike slip motion despite the apparent lack of present day seismicity we studied the yf using combined investigations of remote imagery geomorphology and palaeoseismology the active fault trace along a 51 km strip was delineated as relatively young surface ruptures and fault scarps that affect holocene deposits with intermittent offset geomorphic markers seven closed basins that occur along strike of the yf were found to be related to faulting with at least three of them displaying evident pull apart settings we concentrated our work on the rhombohedral yammouneh basin an actively evolving example of pull apart basins which is presently obliquely cut by the active fault with an apparently young age of 1 4 0 3 myr 3 d correlation and analysis of palaeoseismic investigations exposed a composite shear zone with a total subsidence that exceeds 1 6 m over the past 4000 4400 yr stratigraphic and geochronological constraints suggest the occurrences of at least five large faulting events during that period by correlating the stratigraphy and ages of this trench with a previously published study located nearby a combined palaeoseismic history for the past five events is constructed this suggests a mean recurrence period of 1020 1175 yr for large earthquakes along this section of the yf our results suggest a subsidence rate due to faulting of about 0 36 0 40 mm yr 1 within the yammouneh pull apart basin the geometrical relationship between the active fault trace and the older fault traces suggests that the basin may have evolved in a two stage process in which the original releasing fault bend developed a cross cutting fault accommodating most of the subsequent strike slip displacement the role of the yf in controlling basin evolution is further supported by the correspondence of the active fault with the boundary of the present depocentre our results highlight the interrelation between active strike slip faulting and the coseismic incremental evolution of fault related sedimentary basins which may provide a conceptual model with broader implications on analogous tectonic systems worldwide

ancient obsidian sources on pantelleria italy abstract neolithic and late bronze age obsidian tools with a sodic peralkaline composition but which are measurably different from those of this chemical type studied previously have been found for the first time in sicily since all these peralkaline obsidians are believed to originate on pantelleria this finding poses the problem of the number of obsidian sources on that island the elemental composition of a series of 143 obsidians collected on pantelleria and consisting of both archaeological and various geological samples have been investigated it is concluded that there are at least five different obsidian sources on pantelleria although the exact location of some of these is uncertain finally the lower i e at sea level obsidian from balate dei turchi has never been used in tool making at least not during the bronze age of the island of pantelleria

geomechanical model of the marmara sea region i 3 d contemporary kinematics summary we investigate by means of a 3 d geomechanical model the relationship between structural elements and contemporary kinematics in the marmara sea region northwest turkey the recently imaged fault system beneath the marmara sea is incorporated into the model as frictional surfaces with varying strike and dip the main marmara fault is implemented as through going and is accompanied by mostly non vertical second order faults topography basement topography and the moho become mechanically effective through changes in density and elastic parameters across these horizons the model is subjected to gravity and kinematic boundary conditions the ultimate goal of this study is to set up a 3 d model that is consistent with both kinematic observations and stress data the stress results are presented in a complementary paper in this paper we present the modelled long term 3 d kinematics in terms of fault slip rates rotations vertical motion and sense of fault slip the model results agree with global positioning system velocities geological fault slip rates palaeomagnetic measurements and with the observed pattern of subsidence and uplift furthermore our tectonically driven vertical velocities can be linked to landscape and basin evolution and to features of sedimentation our results indicate that the main marmara fault can be interpreted as a through going fault that slips almost purely in a strike slip sense nevertheless and not contradictory to the previous statement there is significant dip slip motion at some sections of the main marmara fault the agreement of the modelled 3 d kinematics with model independent observations supports that the main structural details of the fault system are accounted for sensitivity analysis of model parameters reveals that changes in rock properties and the initial stress state have minor influence on the 3 d kinematics we conclude that the 3 d structure of the fault system is the key control of the kinematics the slip rate of the main marmara fault from our model is lower than previous estimates and shows high variability along strike 12 8 17 8 mm a 1 the latter indicates that stress accumulation is non uniform along strike

structural evolution of the whipple and south mountains shear zones southwestern united states the whipple and south mountains of the southwestern united states have undergone a strikingly similar sequence of deformations in both ranges gently dipping mylonitic fabrics have been overprinted by successively more brittle structures associated with a low angle detachment fault kinematic indicators reveal that the mylonitic rocks brittle structures and detachment faults are kinematically coordinated and were all formed by top to the northeast shear the structural evolution of both areas can be explained in terms of major shallow dipping shear zones that accommodated tertiary crustal extension we suggest that detachment faults and associated zones of brecciation cataclasis and seismic slip were originally continuous downdip along the low angle shear zones into mylonitic gneisses formed below or near the ductile brittle transition as the mylonites were drawn out from beneath the brittlely extending upper plate they were progressively uplifted above the ductile brittle transition and were overprinted by successively more brittle structures

evolving deformation along a transform plate boundary example from the dead sea fault in northern israel 1 we analyzed geologic structures adjacent to the dead sea fault dsf along the margins of the sinai and arabian plates in northern israel in order to investigate the style and sequence of deformation associated with a transform plate boundary the field area located between the hula basin in northern israel andthelebaneserestrainingbendinsouthernlebanon is divided into distinct structural blocks by a series of distributed faults that comprise this approximately n s trending section of the dsf cretaceous and tertiary rocks within and adjacent to the structural blocks are folded into broad anticlines and synclines with more intense localized shortening manifested by tight folds and thrust duplexes kinematic analyses of folds faults and veins provide evidence for two directions of regional shortening 1 nw se shortening responsible for the formation of ne sw trending fold axes and left lateral strike slip motion along n s trending faults and 2 e w shortening as indicated by n s trending fold axes n s striking thrust faults and extensional calcite filled veins that strike e w crosscutting relations and u th ages of the vein material suggest that the e w phase of transform normal shortening represents the most recent and presently active phase of deformation the structural analysis provides evidence for the transition from an early miocene lower pliocene phase of pure strike slip motion to a late pleistocene to recent phase of convergent strike slip the latter phase is characterized by strain partitioning which is manifested by discrete left lateral strike slip motion across weak n s faults and the development of a fold thrust belt in response to transform normal shortening analogous to the strain partitioning observed in southern california we suggest that blind thrust faults adjacent to the dsf in the study area may pose a seismic risk to populations in northern israel and southern lebanon citation weinberger r m r gross and a sneh 2009 evolving deformation along a transform plate boundary example from the dead sea fault in northern israel tectonics 28 tc5005 doi 10 1029 2008tc002316

slip rate and locking depth from gps profiles across the southern dead sea transform 1 the dead sea transform is a major strike slip fault bounding the arabia plate and the sinai subplate on the basis of two gps campaign measurements 6 years apart at 17 sites distributed in israel and jordan complemented by israeli permanent stations we compute the present day deformation across the southern segment of the dead sea transform the wadi araba fault elastic locked fault modeling of fault parallel velocities provides a slip rate of 4 9 1 4 mm a and a best fit locking depth of 12 km this slip rate is slightly higher than previous results based only on israeli permanent gps stations data which are located west of the fault it is in good agreement with results based on offset geomorphologic and geologic features that average longer periods of time 10 ka to 1 ma projection in itrf2000 reference frame allows using our data combined with results published earlier to further study the kinematics between arabia nubia and sinai systematic combination of euler poles available in the literature in addition to our new set of data shows that a wide range of arabia sinai pole positions and angular velocities predict reasonable slip rate on the dead sea fault we highlight uncertainties of calculating such poles due to the small size of the blocks and their slow relative motion along a short and almost straight strand of the transform fault which lead to a large trade off between pole location and angular velocity

current stress and strain rate fields across the dead sea fault system constraints from seismological data and gps observations abstract the stress and strain rate fields characterizing the dead sea fault system are investigated by using seismological and geodetic observations in order to assess spatial variations in the regional stress field we compiled a multidisciplinary dataset of well constrained horizontal indicators by merging all available data reported in literature with the data obtained in this study through weighted stress inversions of focal plane solutions our findings indicate that the state of stress is characterized by the coexistence of a normal faulting stress regime with the primarily strike slip one according to the regional frame illustrated by previous geological and seismological observations an updated velocity field computed from new observations and earlier published data depicts the general left lateral motion of the dead sea fault system well in agreement with previous studies we detected some differences in the slip rate pattern between the northern and the southern sectors of the fault system the geodetic strain rate field highlights how much of the deformation is accommodated along the fault system itself in a narrow region the comparison between the stress and the strain rate directions reveals that both orientations are near parallel clearly indicating that present day crustal stress and ground deformation patterns are chiefly driven by the same tectonic processes

a non active fault within an active restraining bend the case of the hasbaya fault lebanon abstract the hasbaya fault is a 50 km long fault branch of the dead sea transform fault within the lebanese restraining bend it lies within the intersection zone of mount lebanon and anti lebanon chains along the western flank of mount hermon it is little studied its tectonic behavior is unknown and its role among the other active fault branches of the restraining bend is the least defined it was mapped as a discontinuous array of fault segments with minor displacements and tectonically undisturbed basaltic cover we studied the hasbaya fault with detailed field mapping and combining geomorphology structural geology and active tectonic investigations the results reveal little and localized faulting along the entire length of the fault with no signs of tectonic correlation between the drainage network evolution and the tectonic activity of the fault the absence of active tectonic surface features along the hasbaya fault trend indicates that it does not manifest enough surface evidence to be classified as a tectonically active structure within the lebanese restraining bend and subsequently does not appear to be a major source of seismic hazard in the region it may be related to the subsurface structure that controls the monocline that forms the western flank of mount hermon or it may represent the remnant of an old suture zone between mount lebanon and anti lebanon as a part of the regional compression imposed across the restraining bend our results shed light on the role of the non active hasbaya fault in a zone of active faults within a restraining bend which may provide a case with broader implications on comparable tectonic settings worldwide

fission track dating obsidians in central and northern anatolia twenty obsidian samples from central and north anatolia were dated by the fission track method split samples analyzed in two different laboratories give consistent results data presented refer to three volcanic fields and are summarized as follows orta sakaeli northern anatolia obsidians with ages from 21 23 ma gollu dagi dome complex near ciftlik central anatolia has given ages between 1 33 0 98 ma acigol caldera central anatolia shows three age groups 1 eruptions of precaldera bogazkoy obsidians with ages 0 18 0 15 ma 2 formation of the large intracaldera dome kocadag taskesiktepe at about 0 08 ma uncorrected apparent age of 0 075 ma and 3 acigol peripheral obsidian domes with plateau ages of 0 020 and 0 019 ma and an additional uncorrected age of 0 018 ma form a distinct age group this fission track parameters discriminate between the various obsidian sources of prehistoric obsidian artifacts

review of the seismotectonic setting of the gulf of aqaba with respect to the 27 june 2015 and the 16 may 2016 earthquake sequences the gulf of aqaba is one of the most active places around egypt with several earthquake sequences having occurred there through ancient and modern times in the last century four earthquake sequences took place in the gulf 1983 1990 1993 and 1995 recently on 27 june 2015 a sequence of 96 earthquakes with local magnitudes ranging from 0 7 to 5 2 was recorded by the egyptian national seismological network ensn on 16 may 2016 another earthquake sequence started and continued for several consecutive days with 95 events with local magnitudes ranging from 1 6 to 5 5 being centered south of the 27 june 2015 sequence in this paper we analyse the complete waveform and polarity data set of both earthquake sequences to determine their focal mechanisms and to update our knowledge of the stress field in the gulf of aqaba through the results obtained we conclude that the gulf of aqaba is affected by a primary structure of a left lateral strike slip fault with a minor normal component in most segments our study also infers the presence of a secondary structure which is indicated to be a right lateral strike slip with a minor reverse component

almost a sharp cut a case study of the cross point between a continental transform and a rift based on 3d gravity modeling abstract transform faults displace older structures crossing their paths marking a visible shift between the two sliding plates the fate of these pre transform structures within the damage zone is less understood and so is the dynamics of plate boundaries and their changes through time to what extent are they preserved and what structural heritage do they dictate the current study focuses on a crossing region between the oligo miocene nw trending irbid rift and the n trending miocene to recent dead sea transform dst the structural heritage aspect is examined through 3d forward modeling of gravity data across the kinneret kinarot beit she an kkb basin complex of the dst the model includes pre senonian to recent formations highlighting key volcanic and evaporitic units by modeling the depth thickness and 3d density distribution of each lithological unit the study constructs the volumetric geometry of the sub basins and suggests central stages in its geological development the southern beit she an basin began as part of the irbid rift and was later hijacked by the younger dst at the transform rift cross region the transform displacement initiated en echelon mini basins from the beit she an basin northwards to form the proto kinarot and kinneret sea of galilee basins volcanic phases record the deformation leaving a reliable time frame for the subsidence mode faulting and the role of salt tectonics during the late miocene the lateral displacement formed a trishear structure that evolved by the plio pleistocene into the kinneret kinarot beit she an complex bounded by longitudinal faults stemming from a single deep rooted fault

provenance of obsidian artifacts from the natural protected area laguna del diamante mendoza province argentina and upper maipo valley chile by la icp ms method abstract by means of inductively coupled plasma mass spectrometry associated with laser ablation la icp ms we analyzed several obsidian artifacts from the natural protected area laguna del diamante mendoza argentina and upper maipo valley chile this analytical method almost non destructive is a powerful tool for the determination of trace elements and is very useful in characterizing and determining the provenance of obsidian fragments of archeological interest although care must be taken to avoid or account for heterogeneities within obsidian such as microcrysts in the macro region of study two types of sources can be differentiated on the basis of their primary location high altitude sources emplaced in the andes range 2500 m a s l including laguna del diamante laguna del maule and las cargas sources and low altitude 1500 m a s l extra andean sources situated on the eastern plains cerro huenul and el peceno in addition while the primary location of arroyo paramillos source is currently unknown we consider it as a sub source of laguna del diamante since its wide archaeological distribution has a main core within laguna del diamante area and in the upper maipo river basin considering this pattern the assignation of provenances presented here improves the basis for assessing the use of high andean environments from both sides of the mountain range in addition we will also improve the geochemical discrimination between the two sources arroyo paramillos and las cargas that based on only previous xrf analysis are chemically overlapping leading to an incorrect interpretation of their pattern of archaeological distribution the better characterization of the obsidian sources of the laguna del diamante and neighboring regions allows discussions of mobility exchange and human use of this lithic resource in the highland of central western argentina central chile

what triggered the early to mid pleistocene tectonic transition across the entire eastern mediterranean abstract subduction plays a fundamental role in plate tectonics and when interrupted it may trigger a series of geodynamic and sedimentary responses synchronous structural modifications recorded across the entire eastern mediterranean region are dated to a relatively short period early to mid pleistocene these deformations are documented within plates e g arabian sinai and african plates along plate boundaries e g dead sea and north anatolian faults and cyprus arc and in the mediterranean basin during the same period the northward subduction of the sinai plate was interrupted when the eratosthenes seamount cyprus arc collision initiated subduction collision processes of the eastern mediterranean serve as a unique modern analogue for similar settings worldwide understanding their association with accompanying neo tectonic processes is therefore predominantly important by fostering a detailed and comprehensive approach this research provides a coherent tectonic picture for the eastern mediterranean early to mid pleistocene tectonic transition in order to explore its triggering mechanisms since the neogene convergence across the eastern mediterranean was accompanied by eurasian indentation by arabia northward motion westwards anatolia escape and southwards aegean propagation this semi counterclockwise plate motion was temporarily interrupted by the incipient seamount arc collision which is suggested here as a trigger of the early to mid pleistocene tectonic transition

crustal deformation in northwestern arabia from gps measurements in syria slow slip rate along the northern dead sea fault summary new global positioning system gps measurements in nw syria provide the first direct observations of near field deformation associated with the northern dead sea fault system dsfs and demonstrate that the kinematics of the northern section of this transform plate boundary between the arabian and sinai plates deviate significantly from plate model predictions velocity estimates based on gps survey campaigns in 2000 2007 and 2008 demonstrate left lateral shear along the northern dsfs with 1 uncertainties less than 0 7 mm yr 1 these velocities are consistent with an elastic dislocation model with a slip rate of 1 8 3 3 mm yr 1 and a locking depth of 5 16 km this geodetically determined slip rate is about half of that reported farther south along the central section lebanese restraining bend and the southern section jordan valley and wadi araba of the transform and consequently requires some deformation to occur away from the transform along other geological structures the factor of two difference in slip rates along the transform is also consistent with differing estimates of total fault slip that have occurred since the mid miocene 20 25 km along the northern dsfs in nw syria versus about 45 km along the southern dsfs segment some of the strain deficit may be accommodated by north south shortening within the southwestern segment of the palmyride fold belt of central syria additionally a distinct change in velocity occurs within the sinai plate itself these new gps measurements when viewed alongside the palaeoseismic record and the modest level of present day seismicity suggest that the reported estimates of recurrence time of large earthquakes m 7 along the northern section of the dsfs may be underestimated owing to temporal clustering of such large historical earthquakes hence a revised estimate of the earthquake hazard may be needed for nw syria

anomalous magnetic properties in rocks containing the mineral siderite paleomagnetic implications sampling and magnetic measurement of a 1 m bed in a new road cut of the upper cretaceous austin chalk northeastern texas has yielded anomalous magnetic results initial measurement of the anisotropy of magnetic susceptibility ams indicated unusually high anisotropies and low bulk susceptibilities characteristic of a magnetocrystalline anisotropy which might be expected for siderite feco3 natural remanent moments nrm for these samples were low 1 10 4 a m2 and directions were typical for samples which had acquired a normal geomagnetic field overprint at the site periodic remeasurement of the nrm yielded an increase in moment for some samples and periodic reversals of rm in a direction parallel or antiparallel to the ambient field in the laboratory isothermal remanent moments of these samples saturates at low induction values 200 mt ams remeasurement over a period of weeks to months revealed a general decrease in the anisotropy magnitudes an increase in susceptibility and a change in principal axis orientations these data were compared with heating oxidation experiments on austin chalk siderite ore and clastic sediments with siderite cements all of these results are consistent with the x ray diffraction and mossbauer data which indicate the presence of siderite in the austin chalk samples the mossbauer spectra of the samples obtained at room temperature and 78 k indicate the presence of approximately 80 pyrite 10 siderite and 10 of a clay component possibly chlorite when only the iron bearing mineral components are considered after sampling exposure to the air and subsequent oxidation in the laboratory the siderite in austin chalk samples appears to have altered to fe2o3 maghemite or fe3o4 magnetite increasing the magnetic moment and changing the nrm and ams directions in the samples the continuing changes appear to reflect a conversion from the less stable fe2o3 to fe2o3 hematite or oxidation of fe3o4 to fe2o3 we infer from our study that oxidation of siderite bearing limestone e g during the formation of unconformities or due to low magnitude tectonic events may produce a very stable secondary magnetic moment in the rock such changes may be very important when interpreting paleomagnetic data from limestones

geodetic constraints on present day motion of the arabian plate implications for red sea and gulf of aden rifting 1 five years of continuously recording gps observations in the kingdom of saudi arabia together with new continuous and survey mode gps observations broadly distributed across the arabian peninsula provide the basis for substantially improved estimates of present day motion and internal deformation of the arabian plate we derive the following relative geodetic euler vectors latitude n longitude e rate myr counterclockwise for arabia nubia 31 7 0 2 24 6 0 3 0 37 0 01 arabia somalia 22 0 0 5 26 2 0 5 0 40 0 01 arabia india 18 0 3 8 87 6 3 3 0 07 0 01 arabia sinai 35 7 0 8 17 1 5 0 0 15 0 04 and arabia eurasia 27 5 0 1 17 6 0 3 0 404 0 004 we use these euler vectors to estimate present day stability of the arabian plate the rate and direction of extension across the red sea and gulf of aden and slip rates along the southern dead sea fault south of the lebanon restraining bend 4 5 4 7 0 2 mm yr left lateral 0 8 1 1 0 3 mm yr extension and the owens fracture zone 3 2 2 5 0 5 mm yr right lateral increasing from north to south 1 2 mm yr extension on a broad scale the arabian plate has no resolvable internal deformation weighted root mean square of residual motions for arabia equals 0 6 mm yr although there is marginally significant evidence for n s shortening in the palmyride mountains syria at 1 5 mm yr we show that present day arabia plate motion with respect to eurasia is consistent within uncertainties i e 10 with plate tectonic estimates since the early miocene when arabia separated from nubia we estimate the time of red sea and gulf of aden rifting from present day arabia motion plate tectonic evidence for a 70 increase in arabia nubia relative motion at 13 ma and the width of the red sea and gulf of aden and find that rifting initiated roughly simultaneously 2 2 myr along the strike of the red sea from the gulf of suez to the afar triple junction as well as along the west gulf of aden at 24 2 2 ma based on the present kinematics we hypothesize that the negative buoyancy of the subducted ocean lithosphere beneath the makran and the zagros fold thrust belt is the principle driver of arabia eurasia convergence and that resisting forces associated with arabia eurasia continental collision have had little impact on plate motion

recent kinematics of the tectonic plates surrounding the red sea and gulf of aden this work was funded by the miur prin prot 20125jkany the geodas ship track data used in this study can be found at ngdc http www ngdc noaa gov mgg geodas trackline html

origin and interactions of fluids circulating over the amik basin hatay turkey and relationships with the hydrologic geologic and tectonic settings abstract we investigated the geochemical features of the fluids circulating over the amik basin se turkey syria border which is crossed by the northern extension of the dsf dead sea fault and represents the boundary area of three tectonic plates anatolian arabian and african plates we collected 34 water samples thermal and cold from natural springs and boreholes as well as 8 gas samples bubbling and gas seepage besides the gases dissolved in the sampled waters the results show that the dissolved gas phase is a mixture of shallow atmospheric and deep components either of mantle and crustal origin coherently the sampled waters are variable mixtures of shallow and deep ground waters the latter being characterised by higher salinity and longer residence times the deep groundwaters from boreholes deeper than 1000 m have a ch 4 dominated dissolved gas phase related to the presence of hydrocarbon reservoirs the very unique tectonic setting of the area includes the presence of an ophiolitic block outcropping in the westernmost area on the african plate as well as basalts located to the north and east on the arabic plate the diffuse presence of co 2 enriched gases although diluted by the huge groundwater circulation testifies a regional degassing activity fluids circulating over the ophiolitic block are marked by h 2 dominated gases with abiogenic methane and high ph waters the measured 3 he 4 he isotopic ratios display contributions from both crustal and mantle derived sources over both sides of the dsf although the serpentinization process is generally independent from mantle type contribution the recorded helium isotopic ratios highlight variable contents of mantle derived fluids due to the absence of recent volcanism over the western side of the basin african plate we argue that co 2 rich volatiles carrying mantle type helium and enriched in heavy carbon are degassed by deep rooted regional faults rather than from volcanic sources

magnetic fabric of peridotite with intersecting petrofabric surfaces tinaquillo venezuela abstract two intersecting structural surfaces of different ages and origins are characteristic of the tinaquillo venezuela peridotite an older penetrative mylonitic foliation is cut by younger serpentine veinlets the anisotropy of magnetic susceptibility ams is influenced by both petrofabric components the dominant fabric surface from the ams perspective is defined by serpentine veinlets probably because of the abundant secondary magnetite associated with them the minimum ams axis k 3 is typically orthogonal to the plane of the dominant veinlet set and the maximum k 1 and intermediate k 3 axes lie in the veinlet plane the mylonitic foliation surface also influences the magnetic fabric so that the k 1 axis lies parallel to the line of intersection between the mylonitic foliation and the veinlet plane a macroscopically prominent mineral lineation defined by stretched enstatite laths in the foliation surface shows no ams correlation remanent magnetization directions are multicomponent and show much scatter probably due to the deformation and complex magnetization history of the rock

sources of the large a d 1202 and 1759 near east earthquakes the sources of the may 1202 and november 1759 m 7 5 near east earthquakes remain controversial because their macroseismal areas coincide straddling subparallel active faults in the lebanese restraining bend paleoseismic trenching in the yammouneh basin yields unambiguous evidence both for slip on the yammou neh fault in the twelfth thirteenth centuries and for the lack of a posterior event this conclusion is supported by comparing the freshest visible fault scarps which imply more recent slip on the r chaiya serghaya system than on the yammouneh fault our results suggest that the recurrence of an a d 1202 type earthquake might be due this century as part of a sequence similar to that of a d 1033 1202 possibly heralded by the occurrence of the 1995 mw 7 3 aqaba earthquake the seismic behavior of the levant fault might thus be characterized by millennial periods of quiescence separated by clusters of large earthquakes

anisotropy of magnetic susceptibility sedimentological igneous and structural tectonic applications as was noted by graham 1954 anisotropy of magnetic susceptibility ams data has many applications to the study of geological processes this type of anisotropy expresses directional variation in the magnetization induced in a rock most notably in its iron oxides and especially in its magnetite and hematite the ams is commonly expressed by an ellipsoid of which the principal axes are k1 k2 and k3 from greatest to least this ellipsoid is generally interpreted in terms of the distribution and shape of grains of magnetic minerals in a rock although the ellipsoid determined depends also on magnetocrystalline anisotropy and on factors of instrumental technique ellwood et al in press 1987 the challenge for the geoscientist in analyzing ams data is first to identify the origin of the ams geometry then second to relate that geometry to the natural processes which produced the inferred or measured distribution of magnetic materials

impact of cenozoic strike slip tectonics on the evolution of the northern levant basin offshore lebanon sedimentary basins adjacent to plate boundaries contain key tectonic and stratigraphic elements to understand how stress is transmitted through plates the levant basin is a place of choice to study such elements because it flanks the levant fracture system and the africa anatolia boundary this paper uses new high quality 3 d seismic reflection data to unravel the tectonic evolution of the margin of this basin during the cenozoic the period corresponding to the formation of the levant fracture system part of the africa arabia plate boundary four major groups of structures are identified in the interpreted cenozoic units nw se striking normal faults nne ssw striking thrust faults ene wsw striking dextral strike slip faults and nne trending anticlines we demonstrate that all structures apart of the nw se striking normal faults are inherited from mesozoic faults their reactivation and associated folding started during the late miocene prior to the messinian salinity crisis due to a nw se compressional stress field no clear evidence of shortening at present day offshore lebanon and no large nne ssw strike slip faults parallel to the restraining bend are found indicating that the levant fracture system is mainly contained onshore at present day the intermittent activity of the interpreted structures correlates with the two stages of levant fracture system movement during late miocene and pliocene this paper provides a good example of the impact of the evolution of plate boundaries on adjacent basins and indicates that any changes in the stress field as controlled by the plate boundary will affect immediately the preexisting structures in adjacent basins

gps evidence for northward motion of the sinai block implications for e mediterranean tectonics gps survey sites in the sinai peninsula show northerly motion relative to africa nubia at 1 4f0 8 mm yr north and 0 4f0 8 mm yr west continuous igs gps sites in israel west of the dead sea fault show a similar northerly sense of motion relative to nubia 2 4f0 6 mm yr north and 0 04f0 7 mm yr east suggesting that the entire sinai block south of lebanon is characterized by northward translation relative to the nubian plate we develop an elastic block model constrained by the gps results that is consistent with the regional tectonics and allows us to estimate slip rates for sinai bounding faults including the gulf of aqaba southern dead sea fault system 4 4f0 3 mm yr left lateral the gulf of suez 1 9f0 3 mm yr left lateral and 1 5f0 4 mm yr extension and the cyprus arc predominantly convergence at 8 9f0 4 mm yr along the western segment and 6 0f0 4 mm yr left lateral strike slip along the eastern segment these observations imply that the sinai peninsula and levant region comprise a separate sub plate sandwiched between the arabian and nubian plates d 2005 elsevier b v all rights reserved

a braided strike slip model for the northern continuation of the dead sea fault and its implications for levantine tectonics abstract the assumption that the 100 110 km sinistral displacement on the dead sea fault is transmitted northwards along a single structure the yammouneh fault which runs ne sw across lebanon is here reviewed a number of valid objections to this concept exist a more attractive model supported by the limited data available from the area is that the motion is transmitted along a number of faults on this basis the temporary rightward flexure of the levant fracture through lebanon has given rise to a braided strike slip fault complex the yammouneh serrhaya fault system this model overcomes the objections against the older concept and allows the explanation of the mt lebanon bekaa valley anti lebanon complex in terms of transpressive and transtensive blocks a tentative outline of the cenozoic structural evolution of the area in terms of two or more phases of motion along the levant fracture is presented

subduction collision and initiation of hominin dispersal subduction is the main driving force of plate tectonics controlling the physiography of the earth the northward subduction of the sinai plate was interrupted during the early pleistocene when the eratosthenes seamount began to collide with the cyprian arc a series of synchronous structural deformations was triggered across the entire eastern mediterranean and local topography was drastically accentuation along the levantine corridor one of the main pathways of hominin dispersal out of africa however the choice of this preferred pathway and timing of dispersal has not been resolved though causes for dispersal out of africa are in debate we show that the transition from subduction to collision in the eastern mediterranean set the route

a mid pleistocene deformation transition in the hula basin northern israel implications for the tectonic evolution of the dead sea fault the dead sea fault dsf plate boundary has accommodated relative sinistral motion between the sinai and arabian plates since the neogene geologically based models point to a long term 5 0 ma n trending relative motion roughly parallel to the central sector of the dsf gps based calculations of present day relative motion between the sinai and arabian plates indicate a northward increasing convergent component across the dsf suggesting a kinematic change over the plio pleistocene period we study the evolving deformation of the hula rhomb shaped graben situated along the central sector of the dsf in order to examine the possible kinematic change the hula graben is widely accepted as a pull apart basin part of a series of basins extending southward we use a 3 d approach combining mapped surface structures with subsurface seismic reflection profiles 173 km and borehole data 38 boreholes gathered here into a single geographic information systems database results indicate that during the mid pleistocene a major tectonic transition modified the structure of the basin fill a subvertical nnw trending left lateral throughgoing strike slip fault developed diagonally across the basin consequently the basin entered a new geodynamic phase where subsidence was controlled by both the basin bordering faults and the diagonal fault while the vertical displacement across the transverse faults is minor synchronous structural changes recorded in additional localities along the dsf attests to a mid pleistocene 1 ma regional tectonic transition that was associated with a northward increasing convergent component across the central and northern sectors of the dsf

constraints on the post 25 ka slip rate of the yammouneh fault lebanon using in situ cosmogenic 36cl dating of offset limestone clast fans the most active seismogenic structure along the eastern shore of the mediterranean is the n s trending left lateral levant fault system lfs the plate boundary between arabia and africa in lebanon it forms a 160 km long restraining bend responsible for the uplift of mount lebanon the resulting transpression is partitioned between the offshore tripoli roum thrust and the yammouneh strike slip fault there are few quantitative constraints on the quaternary slip rate along the lfs here we present a direct estimate of the 25 ka mean slip rate on the yammouneh fault mapped offsets of alluvial fans at two sites 50 km apart on the eastern flank of mount lebanon range between 24 2 and 80 8 m about 30 limestone cobbles sampled on these fans yield in situ cosmogenic 36cl exposure ages mostly between 6 and 27 ka a statistical assessment of offsets versus ages provides bounds on the late pleistocene holocene slip rate on the fault 3 8 6 4 mm yr these results are consistent with long term geological inferences confirming that the yammouneh fault is the main strike slip branch of the lfs in lebanon they illustrate both the potential and the difficulties of using in situ cosmogenic 36cl dating of limestone clast fan deposits for deciphering tectonic and geomorphic processes in the mediterranean

gps constraints on continental deformation in the africa arabia eurasia continental collision zone and implications for the dynamics of plate interactions 1 the gps derived velocity field 1988 2005 for the zone of interaction of the arabian african nubian somalian and eurasian plates indicates counterclockwise rotation of a broad area of the earth s surface including the arabian plate adjacent parts of the zagros and central iran turkey and the aegean peloponnesus relative to eurasia at rates in the range of 20 30 mm yr this relatively rapid motion occurs within the framework of the slow moving 5 mm yr relative motions eurasian nubian and somalian plates the circulatory pattern of motion increases in rate toward the hellenic trench system we develop an elastic block model to constrain present day plate motions relative euler vectors regional deformation within the interplate zone and slip rates for major faults substantial areas of continental lithosphere within the region of plate interaction show coherent motion with internal deformations below 1 2 mm yr including central and eastern anatolia turkey the southwestern aegean peloponnesus the lesser caucasus and central iran geodetic slip rates for major block bounding structures are mostly comparable to geologic rates estimated for the most recent geological period 3 5 myr we find that the convergence of arabia with eurasia is accommodated in large part by lateral transport within the interior part of the collision zone and lithospheric shortening along the caucasus and zagros mountain belts around the periphery of the collision zone in addition we find that the principal boundary between the westerly moving anatolian plate and arabia east anatolian fault is presently characterized by pure left lateral strike slip with no fault normal convergence this implies that extrusion is not presently inducing westward motion of anatolia on the basis of the observed kinematics we hypothesize that deformation in the africa arabia eurasia collision zone is driven in large part by rollback of the subducting african lithosphere beneath the hellenic and cyprus trenches aided by slab pull on the southeastern side of the subducting arabian plate along the makran subduction zone we further suggest that the separation of arabia from africa is a response to plate motions induced by active subduction

evidence for 830 years of seismic quiescence from palaeoseismology archaeoseismology and historical seismicity along the dead sea fault in syria an edited version of this paper was published in earth and planetary science letters by elsevier science elsevier science retains the copyright to this paper copyright 2003 see also http dx doi org 10 1016 s0012 821x 03 00144 4 http atlas geo cornell edu deadsea publications meghraoui2003 epsl htm

what can we learn from 20 years of interseismic gps measurements across strike slip faults i use gps interseismic velocities and classic 2d elastic half space models with a screw dislocation to estimate the long term fault slip rate locking depth and the offset between the surface fault trace and the location of the dislocation below the seismogenic zone for 13 segments along 8 major strike slip faults using deduced strike slip rates and the position of the dislocation to normalize the interseismic velocities to facilitate comparison of spatial patterns of deformation i show that no substantial differences can be detected ruling out a large asymmetry in interseismic velocities across the 8 faults used in this study only the carrizo plain segment of the san andreas fault shows a significant asymmetry that cannot be explained by shifting the position of the dislocation at depth relative to the fault trace however the resulting perturbation is less than 10 of total strike slip rate fault traces are usually curved defining a concave side when the dislocation at depth is significantly offset from the fault trace the shift is always toward the block on the concave side of the fault trace this suggests that the fault zone in the lower crust may develop a simpler geometry more consistent with relative motion across the fault than its upper seismogenic part constrained by the structural complexity of the brittle crust since the faults used in this study are at different times in their interseismic period comparing the interseismic velocity fields across them allows identification of possible variations of the interseismic velocities with time when normalized by slip rate and dislocation location all the faults show the same interseismic strain with no significant differences between deduced locking depths these comparisons suggest that if temporal variations occur as suggested by some dynamic earthquake cycle models they are small and below the accuracy of the available geodetic measurements

spatial variation in the frequency magnitude distribution of earthquakes under the tectonic framework in the middle east abstract spatial variations of seismic energy released and b value over the middle east region are investigated based on a seismicity catalog from 1995 to 2007 the goal is to use these seismic parameters and based on other geodetic and geophysical observations such as gps measurements strain rate model fault distribution focal mechanism crustal model q model and gravity measurements etc to uncover spatial patterns that seem anomalous areas of high energy released cumulative seem to correspond to the areas of relatively high b values areas of high energy released and high b values seem to correspond very well with the location of continental collision where earthquake activities are high the divergent boundary between arabia and african plates and subduction zone at makran seem to correspond to low to moderate energy release northern pamir azerbaijan caucasus the lower part of zagros mountains eastern turkey owen fracture zone strait of bob el mandeb and south of the sulaiman shear zone seem to correspond to high cumulative energy released high strain rate high b values and high fault density while the central and eastern iran southern zagros northern pakistan gulf of aden alborz southwest of the caspian sea western caucasus and kopeh dagh seem to correspond with lower b values the cross section map for hindu kush shows general decreasing of the b values with depth however a region of high b value is observed underneath pamir at depths from 170 to 230 km this anomaly region can be due to dehydration of pamir crustal slab at depth

archaeological sites tell and road offset by the dead sea fault in the amik basin southern turkey summary the northern end of the dead sea fault dsf in the amik basin southern turkey is investi gated using palaeoseismology archaeoseismology and geophysical prospecting to understand the fault activity during the holocene archaeological sites are largely spread in the area and the fault crosses at least two of them the 5000 bc tell socantarla and 2000 bc ancient road detailed field investigations and geophysical surveys of the tell an ancient road and a roman wall reveal 42 4 1 5 25 3 5 and 9 0 5 m cumulative left lateral movement along the fault and yield an average 6 07 mm yr 1 slip rate in addition palaeoseismic trenching across the fault supports both the exact location of the fault that cut tell and ancient road and recent faulting events related with the 1408 and 1872 large historical earthquakes this work shows the value of faulted archaeological sites that document past earthquakes and may contribute to a better seismic hazard assessment along the northern dsf

the velocity field along the san andreas fault in central and southern california the velocity field within a 100 km broad zone centered on the san andreas fault between the mexican border and san francisco bay has been inferred from repeated surveys of trilateration networks in the 1973 1989 interval the velocity field has the appearance of a shear flow that remains parallel to the local strike of the fault even through such major deflections as the big bend of the san andreas fault in the transverse ranges of southern california across strike profiles of the fault parallel component of velocity exhibit the expected sigmoidal shape whereas across strike profiles of the fault normal component of velocity are flat and featureless no significant convergence upon the fault is observed even along the big bend sector of the fault simple dislocation models can explain most of the features of the observed velocity field but those explanations are not unique about 35 mm yr of relative plate motion is accounted for within the span of the trilateration networks geologic studies indicate that the secular slip rate on the san andreas fault is about 35 mm yr the agreement between these two estimates implies that most of the strain accumulation is elastic and will be recovered in subsequent earthquakes the relative motion observed across the san andreas fault 35 mm yr plus that observed across the eastern california shear zone 8 mm yr accounts for most 43 mm yr of the observed north america pacific relative plate motion 47 mm yr

the miocene to present kinematic evolution of the eastern mediterranean and middle east and its implications for dynamics the present kinematics in the eastern mediterranean and middle east is now well constrained by gps measurements and dominated by a circular counterclockwise motion while arabia rotates rigidly the rotational velocities increase from the levant to aegea causing extension in western anatolia we place the present pattern in light of the post middle miocene geological history and propose that in addition to the effects of the hellenic subduction and zagros collision subduction zones on driving the surface motion an underlying asthenospheric flow is also required this counterclockwise toroidal flow is expected to exist around the eastern edge of the african slab owing to subduction rollback and it helps explain the initiation of the north anatolia fault the extrusion and uplift of anatolia and the mid miocene to recent volcanism in eastern anatolia the afar plume had a similar effect on the acceleration of arabia at 40 mya