holocene raised shorelines on the hatay coasts turkey palaeoecological and tectonic implications abstract the marks of two emerged shorelines superimposed erosional notches and in situ bioconstructed rims with the vermetid dendropoma on both sides of the orontes delta near the border between turkey and syria are interpreted as representing the occurrence of two rapid uplifts during the late holocene rather than representing eustatic fluctuations of climatic origin as claimed by previous authors in other areas of the eastern mediterranean the upper shoreline which has an elevation of about 2 0 m south of the delta and which increases from 2 5 m to 3 0 m between 2 and 8 km north of the delta has been radiocarbon dated four dates to between 5170 190 and 2595 100 yrs b p the lower shoreline indicating a former relative sea level situated consistently at about 0 7 to 0 8 m has yielded seven dates between 2910 95 and 1345 70 yrs b p the latter age being that of fossil oyster shells collected in growth position on a quay of the ancient harbour of seleucia pieria if the possible contamination of some oyster shells is taken into account the two uplift movements may be dated at around 2500 100 yrs b p for the upper shoreline and to historical times for the lower shoreline probably in july 551 a d when devastating earthquake damage was reported from all the levant regions the age of the second uplift movement falls within the possible time span of a major tectonic event the early byzantine tectonic paroxysm ebtp which about 1500 yrs b p caused sudden relative sea level changes in various areas of the eastern mediterranean antikythira western crete and alanya area the lebanon northern cyprus etc in the hatay region the effect of the ebtp has been a reactivation of local fault lines probably in connection with movements on the east anatolian fault system this has contributed a new jerk to the long term trend of uplift in this coastal area

alexander the great s tombolos at tyre and alexandria eastern mediterranean tyre and alexandria s coastlines are today characterised by wave dominated tombolos peculiar sand isthmuses that link former islands to the adjacent continent paradoxically despite a long history of inquiry into spit and barrier formation understanding of the dynamics and sedimentary history of tombolos over the holocene timescale is poor at tyre and alexandria we demonstrate that these rare coastal features are the heritage of a long history of natural morphodynamic forcing and human impacts in 332 bc following a protracted seven month siege of the city alexander the great s engineers cleverly exploited a shallow sublittoral sand bank to seize the island fortress tyre s causeway served as a prototype for alexandria s heptastadium built a few months later we report stratigraphic and geomorphological data from the two sand spits proposing a chronostratigraphic model of tombolo evolution

organic matter composition and sulfate reduction intensity in oman margin sediments abstract petrographical and geochemical studies of neogene marine sediments from the oman sea leg 117 sites 720 724 726 and 730 show a close relationship between the nature and amount of the organic matter and the degree of degradation of organic matter by sulfate reduction i e pyritization petrographically three major pyritization types were observed 1 finely dispersed pyrite framboids in sediments from oman margin and indus fan enriched in autochthonous marine organic matter 2 infilling of pores by massive pyrite crystals in oman margin sediments with a low toc and a high microfossil content 3 pyrite mineralization of lignaceous fragments in organic depleted sediments from the indus fan leading to more massive pyrite geochemically we can define a sulfate reduction index sri as the percentage of initial organic carbon versus that of residual organic carbon finely laminated pliocene pleistocene sediments from the oman margin exclusively contain organic matter deriving from organic phytoplankton for which the quantity toc positively correlates with the geochemical quality hydrogen index we think that the occurrence of this residual organic matter is linked mainly to a high primary paleo productivity the intensity of sulfate reduction is constant for sediments with toc up to 2 and becomes more important when organic input decreases this degradation process can destroy up to 50 of the initial organic matter but is not sufficient to explain some of the encountered very low toc values it can be seen that sharp increases of certain plankton species with mineral skeletons are responsible for a pronounced degradation of organic matter due to increased sulfate reduction in that case the organic matter may be strongly degraded high sri although deposited in an oxygen depleted environment conversely miocene pliocene sediments contain an autochthonous organic matter that is typical of both low productivity and oxic processes their very low sulfate reduction index indicates that very little metabolizable organic matter was initially present

modes and rates of horizontal deformation from rotated river basins application to the dead sea fault system in lebanon partitioning of horizontal deformation between localized and distributed modes in regions of oblique tectonic convergence is in many cases hard to quantify here we use the geometry of river basins and numerical modeling to evaluate modes and rates of horizontal deformation associated with the arabia sinai relative plate motion in lebanon we focus on river basins that drain mount lebanon to the west and are bounded by the yammouneh fault a segment of the dead sea fault system that transfers left lateral deformation across the lebanese restraining bend we quantify a systematic counterclockwise rotation of these basins and evaluate drainage area disequilibrium using the metric the analysis indicates a systematic spatial pattern whereby tributaries of the rotated basins appear to experience drainage area loss or gain with respect to channel length a kinematic model reveals that since the late miocene 23 31 of the relative plate motion parallel to the plate boundary has been distributed along a wide band of deformation to the west of the yammouneh fault taken together with previous shorter term estimates the model indicates little variation of slip rate along the yammouneh fault since the late miocene kinematic model results are compatible with late miocene paleomagnetic rotations in western mount lebanon a numerical landscape evolution experiment demonstrates the emergence of a similar pattern of drainage area disequilibrium in response to progressive distributed shear deformation of river basins with relatively minor drainage network reorganization

holocene sea level changes along the mediterranean coast of israel based on archaeological observations and numerical model local sea level curves reflect global eustatic changes regional isostatic adjustments of the crust to changing ice and ocean volumes and tectonically controlled crustal movements in this study we evaluate the relative contribution of each of these factors to the holocene sea level curve of the mediterranean coast of israel we use archaeological data as constraints on palaeo sea levels and we then compare the observational limits with isostatic models for sea level change across the region the isostatic model includes the contribution arising from the relative minor increase in ocean volumes for the past 6000 years due to residual melting of ice sheets the effect of the changing shape of the ocean basin the time dependence of shorelines as sealevel changes and the changing surface area occupied by ice sheets differences if significant between the observed and predicted change are interpreted as being of tectonic origin the archaeological observations and the model sea level curve along the mediterranean coast of israel were found to be generally consistent and any discrepancies lie within the uncertainties of both values our model predicted that 8000 years ago sea level at the israel coast was at about 213 5 2 m whereas the archaeological data place it at 216 5 1 m by 7000 bp the predicted level has risen to about 27 1 m consistent with the archaeological evidences according to both observations and predictions sea level was still lower than 2 3t o24 5 m at 6000 bp and remained below its present level until about 3000 2000 bp the comparison between the model sea level curve and the archaeological observations also enable to conclude that the average rate of vertical tectonic movement for the last 8000 years at the carmel coast israel has been less than 0 2 mm year q 2001 elsevier science b v all rights reserved

a climate change event detected in visean oil shales from devon island arctic canada abstract important depositional characteristics indicative of climate change has been discovered in 50 m sedimentary succession consisting of oil shales with a marlstone and carbonate matrix of the visean shales from the lower carboniferous emma fiord formation on devon island canada s arctic archipelago older carboniferous tournaisian shales are however absent from devon island but elsewhere such as big marsh nova scotia tournaisian shales show no comparable evidence for climate change the techniques used include reflected light microscopy rockeval analyses instrumental neutron activation analysis inaa for elemental concentration indeed visean shales from the lower part the emma fiord formation from devon island have a marlstone matrix with abundant algal matter the matrix also has low carbonate 32 and total organic carbon toc content between 33 3 and 55 6 moreover the toc show a positive correlation with authigenic uranium and mo which suggests a high productivity due to the high rain deeper water lacustrine depositional environment other visean oil shales from the emma fiord formation on devon island have somewhat different characteristics from those with marlstone matrix indeed they have a high 75 carbonate content with calcified algal matter and low toc 1 14 17 4 a very low correlation between toc and authigenic u and mo most importantly very high oil generation 98 413 l t potential of marlstones as compared to low yield of carbonate mudstones 4 1 17 0 l t shows a dramatic climatic shift to low precipitation and much dryer conditions such a drastic climatic condition has not been detected for the tournaisian oil shales

high resolution stratigraphy and multiple luminescence dating techniques to reveal the paleoseismic history of the central dead sea fault yammouneh fault lebanon abstract continuous sedimentation and detailed stratigraphy are key parameters for a complete paleo earthquake record here we present a new paleoseismological study across the main strike slip fault branch of the dead sea fault in lebanon we aim to expand the current knowledge on local paleoseismicity and seismic behavior of strike slip plate boundary faults and to explore the limitations of paleoseismology and dating methods the trench dug in the jbab el homr basin reveals a succession of remarkable very thin 0 1 to 5 cm palustrine and lacustrine layers ruptured by at least 17 earthquakes absolute ages of 4 samples are obtained from three luminescence dating techniques targeting fine grain minerals blue green stimulated luminescence bgsl on quartz and post infrared infrared stimulated luminescence at 225 c on polymineral aliquots led to consistent ages while ages from infrared stimulated luminescence at 50 c on polymineral aliquots appeared underestimated the quartz bgsl ages are 26 9 2 3 ka at 0 50 m depth and 30 8 2 9 ka at 3 65 m depth during this time period of 3 9 ka 0 9 1 ka 14 surface rupturing events occurred with a mean return time of 280 years 0 650 years and probable clustering this return time is much shorter than the 1127 135 years return time previously determined at the yammouneh site located 30 km south although fault segmentation and temporal variations in the earthquake cycle remain possible causes for such different records we argue that the high resolution stratigraphy in jbab is the main factor enabling us to record small deformations related to smaller magnitude events that may have been missed in the rougher strata of yammouneh indeed focusing only on larger events of jbab we obtain a mean return time of 720 years 0 1670 years that is compatible with the yammouneh record

early holocene and late pleistocene slip rates of the southern dead sea fault determined from 10be cosmogenic dating of offset alluvial deposits 1 two sites located along the wadi araba fault waf segment of the dead sea fault are targeted for tectonic morphological analysis 10be cosmogenic radionuclide crn dating of embedded cobbles is used to constrain the age of offset alluvial surfaces at the first site a 48 7 m offset alluvial fan for which 10be crn model ages average 11 1 4 3 ka yield a slip rate of 5 4 2 7 mm a with conservative bounds of 1 3 16 4 mm a at the second site the scattered distributions of the 10be crn ages from an offset bajada attest to the complex processes involved in sediment transport and emplacement there two offsets were identified the 160 8 m offset of an incised alluvial fan dated at 37 5 ka shows a slip rate of 4 5 0 9 mm a with a conservative minimum value of 3 2 mm a a larger offset 626 37 m is derived from a prominent channel incised into the bajada cobbles from the bajada surface have ages from 33 to 141 ka with a mean of 87 26 ka a slip rate of 8 1 2 9 mm a is derived from the mean age with conservative bounds of 3 8 22 1 mm a these results and other published slip rates along the linear waf segment from gps to geological time scales lack the resolution to fully resolve the question of temporal variations versus consistency of the fault slip rate of the waf yet given the uncertainties they are not inconsistent with each other

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

the holocene drowned reef of les saintes plateau as witness of a long term tectonic subsidence along the lesser antilles volcanic arc in guadeloupe abstract resulting from the interplay between tectonics and eustatism reef terraces are powerful markers of vertical movements at a scale of 1000 to 100 000 years in the lesser antilles they grow around every island of the archipelago and record both local and subduction related tectonics the recent acquisition and interpretation of very high resolution bathymetry of les saintes submarine plateau french west indies together with seismic reflection profiles are a unique opportunity to study one of these submarine structures at metric to kilometric scales addressing the questions of its nature age and growth environment but also of the control of active tectonics on its formation the 20 km wide les saintes reef plateau lies at about 45 mbsl it is crosscut by nw se striking north dipping normal faults that belong to les saintes fault system and graben which produced a mw 6 3 earthquake in 2004 the plateau is composed of four 20 m thick reef units piled up in layer cake morphology down to 110 mbsl the upper unit has a fresh morphology and presents typical reef features like barrier and lagoon spurs and grooves pinnacles etc from its morphology we propose that it grew during the holocene last transgression below the three other units likely formed during pleistocene sea level highstands and were eroded during the low stands as evidenced in seismic reflection profiles this scenario would imply that les saintes plateau formed in a context of subsidence with a rate we evaluate to be of the order of tenths of mm yr probably linked to local tectonics we believe that this deformation is also related to plate scale subduction processes similarly to deformations occurring on the other islands of the guadeloupe archipelago

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

active thrusting offshore mount lebanon source of the tsunamigenic a d 551 beirut tripoli earthquake on 9 july a d 551 a large earthquake followed by a tsunami destroyed most of the coastal cities of phoenicia modern day lebanon tripoli is reported to have drowned and berytus beirut did not recover for nearly 1300 yr afterwards geophysical data from the shalimar survey unveil the source of this event which may have had a moment magnitude mw of 7 5 and was arguably one of the most devastating historical submarine earthquakes in the eastern mediterranean rupture of the offshore hitherto unknown 100 150 km long active east dipping mount lebanon thrust deep towed sonar swaths along the base of prominent bathymetric escarpments reveal fresh west facing seismic scarps that cut the sediment smoothed seafloor the mount lebanon thrust trace comes closest 8 km to the coast between beirut and enfeh where as 13 14c calibrated ages indicate a shoreline fringing vermetid bench suddenly emerged by 80 cm in the sixth century a d at tabarja the regular vertical separation 1 m of higher fossil benches suggests uplift by three more earthquakes of comparable size since the holocene sea level reached a maximum ca 7 6 ka implying a 1500 1750 yr recurrence time unabated thrusting on the mount lebanon thrust likely drove the growth of mount lebanon since the late miocene

molybdenum accumulation in cariaco basin sediment over the past 24 k y a record of water column anoxia and climate molybdenum mo concentrations in a sediment core from the cariaco basin on the venezuelan continental shelf can be partitioned between a marine fraction and a terrigenous fraction the accumulation rate of the marine fraction of mo increased abruptly 15 000 calendar years ago 15 ka from 2 yr 1 to 4 g cm 2 yr 1 and then decreased abruptly at 9 ka the accumulation rate remained high throughout this 6 k y period but exhibited maxima at 15 14 and 12 5 ka corresponding in time to meltwater pulse ia into the gulf of mexico and the onset of the younger dryas cold event respectively the marine fraction of mo is interpreted in terms of redox conditions of bottom water as dictated by both the flux of settling organic matter and bottom water residence time correspondence between geochemical extremes in this core with changes in sea level and global climate demonstrates the high degree to which this ocean margin basin has responded to the paleoceanographic regime throughout the past 24 k y

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

the permo triassic extinction the end permian mass extinction brought the palaeozoic great experiment in marine life to a close during an interval of intense climatic tectonic and geochemical change improved knowledge of latest permian faunas coupled with recent advances in isotopic studies and biostratigraphy have greatly enhanced our understanding of the events of 250 million years ago and have begun to provide answers to many questions about the causes of extinction

an early carboniferous visean lacustrine oil shale in canadian arctic archipelago the lower carboniferous visean emma fiord formation in the canadian arctic archipelago is an oil shale of lacustrine origin composed of black carbonaceous shale siltstone and marlstone with interbedded sandstone conglomerate and oolitic and algal limestones at kleybolte peninsula on ellesmere island the emma fiord formation was deposited on the tectonically active northwestern rim of the sverdrup basin it is now thermally overmature and well beyond the dry gas zone of organic maturation vitrinite reflectance approx 5 0 in contrast the emma fiord sequence on grinnell peninsula devon island near the southern edge of the sverdrup basin is immature to marginally mature vitrinite reflectance 0 26 0 44 and is composed predominantly of liptinite rich oil sha e these kerogen rich rocks contain a high volume of microcrystalline calcite and compositionally are marlstones the emma fiord lake system probably was a closed basin and may have been thermally and chemically stratified meromictic seasonal or continuous high organic productivity by phytoplankton and bacteria in the epilimnion resulted in accumulation of lipid rich calcareous sediment below an anoxic hypolimnion the emma fiord oil shales on grinnell peninsula contain both autochthonous and allochthonous organic material two types of oil shales are recognized in this sequence 1 alginite rich oil shales with a clay carbonate matrix in which liptinite content may be as high as 93 of the organic matter the hydrogen oxygen index indicates kerogen of intermediate composition between types i and ii these oil shales are hydrogen rich and oxygen poor 2 alginite poor oil shale with a carbonate matrix relatively hydrogen poor and oxygen rich the hydrogen oxygen index indicates kerogen of intermediate composition between types ii and iii the emma fiord oil shales were deposited in lakes formed immediately prior to or possibly synchronous with the initiation of rifting in the sverdrup basin syntectonic red bed conglomerates derived from uplifted horst blocks directly overlie the emma fiord rocks a few beds of conglomerate and sandstone in the upper part of the emma fiord formation possibly record the onset of faulting the formation closely resembles contemporaneous sequences in northern alaska yukon territory greenland and spitsbergen clearly similar tectonic and paleoclimatic factors influenced sedimentation over this area in the early carboniferous with the sverdrup basin locations lying within 10 15 of the paleoequator

the timing and extent of the eruption of the siberian traps large igneous province implications for the end permian environmental crisis we present new high precision 40ar 39ar ages on feldspar and biotite separates to establish the age duration and extent of the larger siberian traps volcanic province samples include basalts and gabbros from noril sk the lower tunguska area on the siberian craton the taimyr peninsula the kuznetsk basin vorkuta in the polar urals and from chelyabinsk in the southern urals most of the ages except for those from chelyabinsk are indistinguishable from those found at noril sk cessation of activity at noril sk is constrained by a 40ar 39ar age of 250 3 1 1 ma for the uppermost kumginsky suite the new 40ar 39ar data confirm that the bulk of siberian volcanism occurred at 250 ma during a period of less than 2 ma extending over an area of up to 5 million km2 the resolution of the data allows us to confidently conclude that the main stage of volcanism either immediately predates or is synchronous with the end permian mass extinction further strengthening an association between volcanism and the end permian crisis a sanidine age of 249 25 0 14 ma from bed 28 tuff at the global section and stratotype at meishan china allows us to bracket the p tr boundary to 0 58 0 21 myr and enables a direct comparison between the 40ar 39ar age of the traps and the permo triassic boundary section younger ages 243 ma obtained for basalts from chelyabinsk indicate that volcanism in at least the southern part of the province continued into the triassic

the kinematics of central southern turkey and northwest syria revisited central southern turkey nw syria and adjacent offshore areas in the ne mediterranean region form the boundary zone between the turkish african and arabian plates a great deal of new information has emerged in recent years regarding senses and rates of active crustal deformation in this region but this material has not hitherto been well integrated so the interpretations of key localities by different teams remain contradictory we have reviewed and synthesised this evidence combining it with new investigations targeted at key areas of uncertainty this work has led to the inference of previously unrecognised active faults and has clarified the roles of other structures within the framework of plate motions provided by gps studies roughly one third of the relative motion between the turkish and arabian plates is accommodated on the misis kyrenia fault zone which links to the study region from the kyrenia mountain range of northern cyprus much of this motion passes nne then eastward around the northern limit of the amanos mountains as previously thought but some of it splays northeastward to link into newly recognised normal faulting within the amanos mountains the remaining two thirds of the relative motion is accommodated along the karasu valley some of this component steps leftward across the amik basin before passing southward onto the northern dead sea fault zone dsfz but much of it continues southwestward past the city of antakya then into offshore structures ultimately linking to the subduction zone bounding the turkish and african plates to the southwest of cyprus however some of this offshore motion continues southward west of the syrian coast before linking onshore into the southern dsfz this component of the relative motion is indeed the main reason why the slip rate on the northern dsfz measured geodetically is so much lower than that on its southern counterpart in some parts of this region notably in the karasu valley it is now clear how the expected relative plate motion has been accommodated on active faults during much of the quaternary rather than constant slip rates on individual faults quite complex changes in the partitioning of this motion on timescales of hundreds of thousands of years are indicated however in other parts of the region it remains unclear whether additional major active faults remain unrecognised or whether significant relative motions are accommodated by distributed deformation or on the many smaller scale structures present

a paleoseismic record of earthquakes for the dead sea transform fault between the first and seventh centuries c e nonperiodic behavior of a plate boundary fault we present new results from a paleoseismic trenching campaign at a site across the jordan gorge fault jgf the primary strand of the dead sea transform in northern israel in addition to the previously recognized earthquakes of 1202 and 1759 c e we observe evidence for eight surface rupturing earthquakes prior to the second millennium c e the past millennium appears deficient in strain release with the occurrence of only two large ruptures when compared with the preceding 1200 years assuming gutenberg richter magnitude frequency distribution there is a dis crepancy between measured rate of small magnitude earthquakes m 4 from instrumental records and large earthquake rates from paleoseismic records the in terevent time of surface rupturing earthquakes varies by a factor of two to four during the past 2 ka at our site and the fault s behavior is not time predictable the jgf may be capable of rupturing in conjunction with both of its southern and northern neigh boring segments and there is tentative evidence that earthquakes nucleating in the jordan valley e g the 749 c e earthquake could either rupture through the stepover between the faults or trigger a smaller event on the jgf we offer a model of earth quake production for this segment in which the long term slip rate remains constant while differing earthquake sizes can occur depending on the segment from which they originated and the time since the last large event the rate of earthquake occurrence in this model does not produce a time predictable pattern over a period of 2 ka as a result of the interplay between fault segments to the south and north of the jgf online material high resolution photomosaic logs of trench walls probability density function pdf and table of unit descriptions for channels 3 and 4

bathymetry of the levant basin interaction of salt tectonics and surficial mass movements abstract a new high resolution bathymetric map of the levant basin between israel and the eratosthenes seamount reveals previously undetected folds faults and channels the map facilitates a regional map view analysis of structures that were previously examined only in cross section the systematic mapping of morpho structural elements in the entire basin is followed by a kinematic interpretation that distinguished between two main processes sculpting the seabed from bottom and top salt tectonics and sediment transport we show that the contractional domain related to salt tectonics is far more complex than previously thought ridges previously interpreted as contractional folds are in fact surficial undulations of the seabed reminiscent of sediment waves moreover other folds previously interpreted as downdip contraction of the westward gliding plio quaternary section are in some parts of the basin caused by updip climbing of this section eastwards as a result of the regional pattern of salt flow away from the nile cone in the context of sediment transport we show that the northern sinai continental slope is covered by a dense net of turbidite channels whereas the levant slope has no channels at all particularly interesting is the levant turbidite channel described and named here for the first time this feature begins at the southeastern corner of the mediterranean at water depths of 1100 m continues along the valley between the sinai and levant slopes and reaches the deepest part of the basin in water depths of 2500 m northeast of the eratosthenes seamount however this prominent feature cannot be explained by the current drainage consisting of two minor rivers that enter the basin at that point and thus most likely reflects periods of wetter climate and or lower sea level when these rivers were more active and possibly connected to the submarine channel system

submarine fault scarps in the sea of marmara pull apart north anatolian fault implications for seismic hazard in istanbul earthquake scarps associated with recent historical events have been found on the floor of the sea of marmara along the north anatolian fault naf the marmarascarps cruise using an unmanned submersible rov provides direct observations to study the fine scale morphology and geology of those scarps their distribution and geometry the observations are consistent with the diversity of fault mechanisms and the fault segmentation within the north marmara extensional step over between the strike slip ganos and izmit faults smaller strike slip segments and pull apart basins alternate within the main step over commonly combining strike slip and extension rapid sedimentation rates of 1 3 mm yr appear to compete with normal faulting components of up to 6 mm yr at the pull apart margins in spite of the fast sedimentation rates the submarine scarps are preserved and accumulate relief sets of youthful earthquake scarps extend offshore from the ganos and izmit faults on land into the sea of marmara our observations suggest that they correspond to the submarine ruptures of the 1999 izmit mw 7 4 and the 1912 ganos ms 7 4 earthquakes while the 1999 rupture ends at the immediate eastern entrance of the extensional cinarcik basin the 1912 rupture appears to have crossed the ganos restraining bend into the sea of marmara floor for 60 km with a right lateral slip of 5 m ending in the central basin step over from the gulf of saros to marmara the total 1912 rupture length is probably about 140 km not 50 km as previously thought the direct observations of submarine scarps in marmara are critical to defining barriers that have arrested past earthquakes as well as defining a possible segmentation of the contemporary state of loading incorporating the submarine scarp evidence modifies substantially our understanding of the current state of loading along the naf next to istanbul coulomb stress modeling shows a zone of maximum loading with at least 4 5 m of slip deficit encompassing the strike slip segment 70 km long between the cinarcik and central basins that segment alone would be capable of generating a large magnitude earthquake mw 7 2 other segments in marmara appear less loaded

flip convergence across the phoenician basin through nucleation of subduction abstract modern examples of active subduction nucleation are scarce hence knowledge is derived from reconstructions of old subduction zones and numerical modeling here we present a rare analog of induced subduction nucleation occurring today along the northeastern mediterranean continental margin geological evidence gathered here suggests that plate convergence between africa sinai arabia and eurasia anatolia since the pliocene led to fragmentation of the northern sinai plate into the phoenician and northern levant micro plates currently convergence is in the process of shifting from subduction cessation beneath the eastern cyprus arc to reactivation of the northern levant margin this shift induces the nucleation of an embryonic subduction zone through polarity reversal it re defines the front of plate convergence

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

historical and pre historical tsunamis in the mediterranean and its connected seas geological signatures generation mechanisms and coastal impacts abstract the origin of tsunamis in the mediterranean region and its connected seas including the marmara sea the black sea and the sw iberian margin in the ne atlantic ocean is reviewed within the geological and seismotectonic settings of the region a variety of historical documentary sources combined with evidence from onshore and offshore geological signatures geomorphological imprints observations from selected coastal archeological sites as well as instrumental records eyewitnesses accounts and pictorial material clearly indicate that tsunami sources both seismic and non seismic e g volcanism landslides can be found in all the seas of the region with a variable tsunamigenic potential local regional and basin wide tsunamis have been documented an improved map of 22 main tsunamigenic zones and their relative potential for tsunami generation is presented from west to east the most important tsunamigenic zones are situated offshore sw iberia in the north algerian margin in the tyrrhenian calabria and messina straits in the western and eastern segments of the hellenic arc in the corinth gulf of central greece in the levantine sea offshore the dead sea transform fault and in the eastern side of the marmara sea important historical examples including destructive tsunamis associated with large earthquakes are presented the mean recurrence of strong tsunamis in the several basins varies greatly but the highest event frequency 1 96 years is observed in the east mediterranean basin for most of the historical events it is still unclear which was the causative seismic source and if the tsunami was caused by co seismic slip by earthquake triggered submarine landslides or by a combination of both mechanisms in pre historical times submarine volcanic eruptions i e caldera collapse massive pyroclastic flows volcanogenic landslides and large submarine landslides caused important tsunamis although little is known about their source mechanisms we conclude that further investigation of the tsunami generation mechanisms is of primary importance in the mediterranean region inputs from tsunami numerical modeling as well as from empirical discrimination criteria for characterizing tsunami sources have been proved particularly effective for recent well documented aseismic landslide tsunamis e g 1963 corinth gulf 1979 cote d azur 1999 izmit bay 2002 stromboli volcano since the tsunami generation mechanisms are controlled by a variety of factors and given that the knowledge of past tsunami activity is the cornerstone for undertaking tsunami risk mitigation action future interdisciplinary research efforts on past tsunamis are needed

gas emissions due to magma sediment interactions during flood magmatism at the siberian traps gas dispersion and environmental consequences we estimate the fluxes of extremely reduced gas emissions produced during the emplacement of the siberian traps large igneous province due to magma intrusion in the coaliferous sediments of the tunguska basin using the results of a companion paper iacono marziano et al submitted to epsl and a recent work about low temperature interaction between magma and organic matter svensen et al 2009 we calculate co ch4 dominated gas emission rates of 7 1015 2 1016 g yr for a single magmatic volcanic event these fluxes are 7 to 20 times higher than those calculated for purely magmatic gas emissions in the absence of interaction with organic matter rich sediments we investigate by means of atmospheric modelling employing present geography of siberia the short and mid term dispersion of these gas emissions into the atmosphere the lateral propagation of co and ch4 leads to an important perturbation of the atmosphere chemistry consisting in a strong reduction of the radical oh concentration as a consequence both co and ch4 lifetimes in the lower atmosphere are enhanced by a factor of at least 3 at the continental scale as a consequence of 30 days of magmatic activity the short term effect of the injection of carbon monoxide and methane into the atmosphere is therefore to increase the residence times of these two species and in turn their capacity of geographic expansion the estimated co and ch4 volume mixing ratios i e the number of molecules of co or ch4 per cm3 divided by the total number of molecules per cm3 in the low atmosphere are 2 5 ppmv at the continental scale and locally higher than 50 ppmv the dimension of the area affected by these high volume mixing ratios decreases in the presence of a lava flow accompanying magma intrusion at depth complementary calculations for a 10 year duration of the magmatic activity suggest i an increase in the mean ch4 volume mixing ratio of the whole atmosphere up to values 3 to 15 times higher than the current one and ii recovery times of 100 years to bring back the atmospheric volume mixing ratio of ch4 to the pre magmatic value thermogenic methane emissions from the siberian traps has already been proposed to crucially contribute to end permian early triassic global warming and to the negative carbon isotopic shift observed globally in both marine and terrestrial sediments our results corroborate these hypotheses and suggest that concurrent high temperature co emissions also played a key role by contributing to increase i the radiative forcing of methane and therefore in its global warming potential and ii the input of isotopically light carbon into the atmosphere that generated the isotopic excursion we also speculate a poisoning effect of high carbon monoxide concentrations on end permian fauna at a local scale

an integrated assessment of a type euxinic deposit evidence for multiple controls on black shale deposition in the middle devonian oatka creek formation an integrated lithologic paleontologic and multi proxy geochemical study of the middle devonian oatka creek formation a black shale in the northern appalachian basin indicates that a number of different factors contributed to organic carbon rich black shale deposition conditions leading to this organic rich sedimentary deposit were ultimately controlled by a relative sealevel rise dominantly eustatic but with possible contributions from local tectonics which cut off the supply of carbonate to the basin geochemical proxy evidence such as mo ti fe ti corg spy and 34spy suggests that as sealevel continued to rise after the carbonate supply was cut off a threshold was crossed at which point conditions in the basin shifted from dominantly anoxic to dominantly euxinic anoxic sulfidic bottom waters concurrent with the shift to dominantly euxinic conditions the supply of siliciclastic sediments was cut off resulting in a condensed horizon as evidenced by the elemental ratios of si al and k fe mg and the relative concentration of eolian silt as determined petrographically and from scanning electron microscopy sediment starvation in the basin appears to have facilitated the biogeochemical re cycling of c n and p specifically the elemental ratios of c n and p and the stable carbon isotope composition of organic matter suggest that the preferential regeneration of p under anoxic conditions and of n during the oxic phase of oxic anoxic oscillation led to enhanced primary production in surface waters thereby maintaining euxinic conditions in the bottom waters through respiration of settling organic matter finally it is observed that though conditions in the basin seem to have remained consistently anoxic sulfidic for some time after the initial shift to euxinic conditions a progressive increase in siliciclastic sedimentation led to a corresponding decrease in the enrichment of various redox related elements illustrating the overriding control that sedimentation can have on geochemical proxy records

four thousand years of seismicity along the dead sea rift a study of major earthquake occurrence along the dead sea transform 35 5 36 5 e 27 2 37 5 n during the past four millenia has been attempted geological archaeological biblical historical and seismological evidence were integrated in an effort to quantify the space time distribution of seismicity in the said province the overall earthquake activity in the conterminous near east indicates a stable pattern and appeared to have been stationary over the examined time window about 110 earthquakes in the magnitude range 6 7 ml 8 3 affected the area during the past 2500 years of these 42 originated along the dead sea fault system itself while 68 were imported from the helenic cyprian arcs and the anatolian elburz zagros fault systems these events were responsible for the repeated destruction of many cultural centers in the dead sea region proper the major seismic activity since 2100 b c e before christian era has been confined to the vicinity of its eastern shore with extremal seismicity at its southern tip near the prehistorical site of bab a dara a 31 15 n 35 32 e this may constitute the first solid evidence that the biblical cities of the plain sodom gommorah etc were located there recent studies of earthquake deformations in the lisan deposits near bab a dara a agree with our findings at the present time a magnitude 6 earthquake is pending at the northern edge of the levant rift with its average recurrence interval 83 years exceeded by one standard deviation 32 years

multimodal method for coseismic landslide hazard assessment abstract regional scale coseismic landslide hazard assessments have traditionally been based on infinite slope analyses considering only a single mode of failure inventories and landslide reconnaissance work have shown a diverse range of coseismic landslide modes with significantly different consequences of failure this paper presents a multimodal approach for regional scale coseismic landslide hazard assessment through a two step procedure the multimodal method explicitly accounts for four general landslide types commonly observed during earthquakes rock slope failures disrupted soil slides coherent rotational slides and lateral spreads first the susceptibility to each landslide mode is evaluated based on topography second coseismic landslide hazards are assessed using mode specific geotechnical models a trial multimodal landslide assessment is presented for the seismically active country of lebanon results show that the computed coseismic landslide hazard closely matches field verified slope activity across different regions of the country exhibiting a range of failure modes these results qualitatively demonstrate the efficacy of the procedure and suggest that multimodal coseismic landslide hazard analysis is especially well suited for regions with varying terrain and where landslide inventories are not available

tectono stratigraphic evolution of the northern levant basin offshore lebanon abstract seismic interpretation constrained by a detailed assessment of the levant paleogeography allowed subdividing the sedimentary infill of the northern levant basin offshore lebanon in eight major seismic packages fifteen seismic facies have been identified with distinctive characteristics the levant basin architecture is pre determined by a late paleozoic early mesozoic rift that led to the formation of a passive margin dominant aggrading carbonate platforms are observed along the levant margin and deepwater mixed settings i e carbonates and siliciclastics are suggested to prevail in the basin the collision of afro arabia with eurasia led to the development of a flexural basin in the northernmost offshore lebanon since the late cretaceous a southward migration of this flexural depocenter in the miocene is hindered by the change in the stress field along the latakia ridge and by the westward escape of the anatolian plate in late miocene and pliocene times interplay between major geodynamic events as well as sea level fluctuations in the mesozoic and cenozoic induced important marginal uplifts and emersion sediments sourced from the erosion of nubian siliciclastic material and from the exposed granitic red sea rift shoulders and arabian shield were driven into the levant basin the sediment sources diversity the mechanisms of sediment transport through varied pathways i e the levant margin canyons the latakia region and the nile delta deep sea cone are expected to strongly impact the reservoir characteristics and prospectivity of the northern levant basin

first direct observation of coseismic slip and seafloor rupture along a submarine normal fault and implications for fault slip history properly assessing the extent and magnitude of fault ruptures associated with large earthquakes is critical for understanding fault behavior and associated hazard submarine faults can trigger tsunamis whose characteristics are defined by the geometry of seafloor displacement studied primarily through indirect observations e g seismic event parameters seismic profiles shipboard bathymetry coring rather than direct ones using deep sea vehicles we identify for the first time a marker of coseismic slip on a submarine fault plane along the roseau fault lesser antilles and measure its vertical displacement of 0 9 m in situ we also map recent fissuring and faulting of sediments on the hangingwall along 3 km of rupture in close proximity to the fault s base and document the reactivation of erosion and sedimentation within and downslope of the scarp these deformation structures were caused by the 2004 m w 6 3 les saintes earthquake which triggered a subsequent tsunami their characterization informs estimates of earthquake recurrence on this fault and provides new constraints on the geometry of fault rupture which is both shorter and displays locally larger coseismic displacements than available model predictions that lack field constraints this methodology of detailed field observations coupled with near bottom geophysical surveying can be readily applied to numerous submarine fault systems and should prove useful in evaluating seismic and tsunamigenic hazard in all geodynamic contexts

geochemistry of recent toc rich sediments from the gulf of california and the black sea major and minor elements incl ag as ba cd co cr cu mn mo ni pb sr v zn have been determined in recent sediments from the gulf of california upwelling area and black sea sapropels in order to reinterpret their chemical composition in view of reliable seawater and plankton data the chemistry of the gulf of california sediments reflects regeneration processes which occur in the water column i e only a small fraction 10 of elements like cd which in seawater are coupled to the labile nutrients c n p is buried in the sedimentary column in contrast elements like the more resistant nutrients si undergo a deeper regeneration cycle ba several trace metals which are present in comparatively higher concentrations in seawater as mo u v and at the same time are reactive under reducing conditions and or are able to form stable sulfides are fixed in the sediments during early diagenesis the early diagenetic behavior of ba is closely related to bacterial sulfate reduction the formation of barite concretions is discussed anoxic conditions in the water column act as ideal traps for a number of redox sensitive and or stable sulfide forming elements a simple trace metal balance calculation shows that the chemical composition of black sea sapropels is controlled by fluvial and mediterranean seawater element input and the accumulation rate of terrigenous detrital material

ancient harbors and holocene morphogenesis of the ras ibn hani peninsula syria abstract ras ibn hani peninsula a wave dominated tombolo 800 1000 m on the syrian coast provides evidence for significant holocene changes that can be linked to geological inheritance rising post glacial sea level sediment supply and human impacts initial development of ras ibn hani s coastal system began 8000 years ago when shallow marine environments formed in a context of rising post glacial sea level following relative sea level stabilization 6000 cal yr bp beach facies trace the gradual formation of a wave dominated sandbank fronted by a 2300 500 m palaeo island whose environmental potentiality was attractive to bronze age societies a particularly rapid phase of tombolo accretion is observed after 3500 cal yr bp characterised by a two to fourfold increase in sedimentation rates this is consistent with i a pulse in sediment supply probably driven by bronze age iron age soil erosion in local catchments and ii positive feedback mechanisms linked to regionally attested neotectonics archaeological remains and radiocarbon datings confirm that the subaerial tombolo was probably in place by the late bronze age these data fit tightly with other eastern mediterranean tombolo systems suggesting that there is a great deal of predictability to their geology and stratigraphy at the regional scale

massive volcanism at the permian triassic boundary and its impact on the isotopic composition of the ocean and atmosphere abstract bulk carbonate and conodonts from three permian triassic p t boundary sections at guryul ravine kashmir abadeh central iran and pufels bula bulla italy were investigated for 13 c and 18 o carbon isotope data highlight environmental changes across the p t boundary and show the following features 1 a gradual decrease of 4 to more than 7 starting in the late permian changhsingian c bachmanni zone with two superimposed transient positive excursions in the c meishanensis h praeparvus and the m ultima s mostleri zones 2 two 13 c minima the first at the p t boundary and a higher occasionally double minimum in the lower i isarcica zone it is unlikely that the short lived phenomena such as a breakdown in biological productivity due to catastrophic mass extinction a sudden release of oceanic methane hydrates or meteorite impact s could have been the main control on the latest permian carbon isotope curve because of its prolonged 0 5 ma duration gradual decrease and the existence of a 1 positive shift at the main extinction horizon the p t boundary 13 c trend matches in time and magnitude the eruption of the siberian traps and other contemporaneous volcanism suggesting that volcanogenic effects such as outgassed co 2 from volcanism and even more thermal metamorphism of organic rich sediments as the likely cause of the negative trend

3d effects of sedimentary wedges and subsurface canyons ground motion amplification in the israeli coastal plain abstract we study the propagation of seismic waves the resulting ground motions and their amplification atop sedimentary structures underlying continental passive margins we employ a set of generic models with increasing complexity within a framework of a 3d numerical scheme the basic geological structure and velocity model were derived from the subsurface of the israeli coastal plain where soft sediments form a wedge over the stiffer bedrock and fill subsurface canyons that incise deep into the bedrock ground motions were modeled for both seaside and landside seismic sources we show that for a landside source peak ground velocities pgvs atop a sedimentary wedge are amplified by a maximum factor of 2 6 and on average by a factor of 1 6 relative to a reference model this amplification is mainly due to the ellipticity of rayleigh waves in the soft sediment layer spatial distribution of amplification factors shows that sedimentary wedges do not exhibit a prominent edge effect atop sediment filled canyons and landside source pgv are amplified by a maximum factor of 3 3 relative to a reference model along the exposed part of the canyon the pgv amplification factor in the canyon relative to adjacent hard rock site is up to 2 4 pgv amplification atop the sediment filled canyons is mainly due to the geometrical focusing of sh waves based on our findings we present a simplified ground motion amplification map for the israeli coastal plain electronic supplement animations of the three components of the ground motion models

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

anthropogenic accumulation of metals and metalloids in carbonate rich sediments insights from the ancient harbor setting of tyre lebanon the antique and byzantine sediments of the northern harbor of tyre lebanon store high amounts of metals and metalloids as the result of a millennial anthropogenic contamination as well as of efficient trapping and immobilization processes geochemical and mineralogical analyses reveal the contrasted patterns for the accumulation of trace metal loid s in the sedimentary sequence recovered by coring the inner part now emerged of the ancient harbor lead sn cu and ag concentrations can be as high as 3000 150 1000 and 1 2 g g respectively enrichment factors were calculated with respect to 1 th and 2 the chemistry of the substratum and appear to be driven by anthropogenic inputs indeed a drastic change in both excess concentrations and concentration ratios is observed through roman and byzantine times pointing to major intensification of the trade and use of metals in tyre coherent with historical data good preservation of the archeological signal despite 1 sediment disturbances that have caused age depth inversions and 2 the large time lapse since the time of deposition of anthropogenic trace metal loid s is probably due to the reducing character of the sediments tyre s sedimentary sequence provides an interesting analog for modern carbonate rich harbor environments in which a millenary accumulation of trace metal loid s has been overall well preserved and suggests a restricted mobility of anthropogenic contamination for a period of time in excess of 1500 years

latest permian chars may derive from wildfires not coal combustion the permian triassic boundary extinction event was the largest biological crisis of the phanerozoic one of the principle triggers for the mass extinction is thought to be greenhouse warming resulting from the release of ch 4 from basalt coal interaction during the extensive siberian traps russia eruptions observations of organic matter interpreted to be coal combustion products fly ash in latest permian marine sediments have been used to support this hypothesis however this interpretation is dependent upon vesicular chars being fly ash coal combustion derived and not formed by alternative mechanisms here we present reflectance microscopy images of vesicular chars from russian permian coals and chars from modern tundra peatland and boreal forest fires to demonstrate that despite a difference in precursor fuels wildfires are capable of generating vesicular chars that are morphologically comparable to end permian fly ash these observations coupled with extensive global evidence of wildfires during this time interval call into question the contribution of coal combustion to the end permian extinction event

catastrophic dispersion of coal fly ash into oceans during the latest permian extinction the eruption of the siberian trap flood basalts resulted in the heating and combustion of coals and organic rich sediments at the time of the permian mass extinction the presence of char in distant lake sediments linked to the eruption suggests that fly ash could have been generated by the coal combustion and then dispersed globally creating toxic marine conditions

eastern mediterranean tectonics and tsunami hazard inferred from the ad 365 earthquake historical accounts describe an earthquake and tsunami on 21 july ad 365 that destroyed cities and drowned thousands of people in coastal regions from the nile delta to modern day dubrovnik the location and tectonic setting of this earthquake have been uncertain until now here we present evidence from radiocarbon data and field observations that western crete was lifted above sea level by up to 10 m synchronously with the ad 365 earthquake the distribution of uplift combined with observations of present day seismicity suggest that this earthquake occurred not on the subduction interface beneath crete but on a fault dipping at about 30 within the overriding plate calculations of tsunami propagation show that the uplift of the sea floor associated with such an earthquake would have generated a damaging tsunami through much of the eastern mediterranean measurement of the present rate of crustal shortening near crete yields an estimate of 5 000 yr for the repeat time of tsunamigenic events on this single fault in western crete but if the same process takes place along the entire hellenic subduction zone such events may occur approximately once every 800 yr in the year ad 365 an earthquake and tsunami destroyed much of the eastern mediterranean coastal regions the distribution of uplift at the time suggests that the earthquake occurred on a fault within the overriding plate at the subduction zone beneath crete and not on the subduction interface itself

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

methane release from igneous intrusion of coal during late permian extinction events abstract unusually large and locally variable carbon isotope excursions coincident with mass extinctions at the end of the permian period 253 ma and guadalupian epoch 260 ma can be attributed to methane outbursts to the atmosphere methane has isotopic values 13c low enough to reduce to feasible amounts the carbon required for isotopic mass balance the duration of the carbon isotopic excursions and inferred methane releases are here constrained to 10 000 yr by counting annual varves in lake deposits and by estimating peat accumulation rates on paleogeographic maps the most marked carbon isotope excursions form linear arrays back to plausible methane sources end permian siberian traps and longwood bluff intrusions of new zealand and end guadalupian emeishan traps of china intrusion of coal seams by feeder dikes to flood basalts could create successive thermogenic methane outbursts of the observed timing and magnitude but these are unreasonably short times for replenishment of marine or permaf

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

seismic refraction profiles between cyprus and israel and their interpretation summary a long seismic refraction profile was carried out between southern israel and cyprus the seismic energy was generated by 33 sea shots each of 0 8 t explosives and was recorded by land stations in israel and cyprus and by ocean bottom seismographs deployed along the profile the results showed that the continental crust of southern israel thins towards the mediterranean underneath a northward thickening sedimentary cover cyprus is underlain by a 35 km thick continental crust thinning south wards and extending to mt eratosthenes between mt eratosthenes and the israel continental shelf the crystalline crust is composed of high velocity 6 5 km s 1 material and is about 8 km thick it is covered by 12 14 km of sediments and may represent a fossil oceanic crust

variable slip rate and slip per event on a plate boundary fault the dead sea fault in northern israel abstract we resolved displacement on buried stream channels that record the past 3400 years of slip history for the jordan gorge jgf section of the dead sea fault in israel based on three dimensional 3d trenching slip in the past millennium amounts to only 2 7 m similar to that determined in previous studies whereas the previous millennium experienced two to three times this amount of displacement with nearly 8 m of cumulative slip indicating substantial short term variations in slip rate the slip rate averaged over the past 3400 years as determined from 3d trenching is 4 1 mm yr which agrees well with geodetic estimates of strain accumulation as well as with longer term geologic slip rate estimates our results indicate that 1 the past 1200 years appear to significantly lack slip which may portend a significant increase in future seismic activity 2 short term slip rates for the past two millennia have varied by more than a factor of two and suggest that past behavior is best characterized by clustering of earthquakes from these observations the earthquake behavior of the jordan gorge fault best fits is a weak segment model where the relatively short fault section 20 km bounded by releasing steps fails on its own in moderate earthquakes or ruptures with adjacent segments

first indications of high slip rates on active reverse faults nw of damascus syria from observations of deformed quaternary sediments implications for the partitioning of crustal deformation in the middle eastern region recent research on rates of crustal shortening within the palmyra fold belt pfb in syria has drawn attention to the possibility that reverse faults near the city of damascus which adjoins the sw pfb have significant slip rates we infer that the damascus fault directly adjacent to the city has developed a throw of 2500 m and report the discovery of the en echelon bassimeh fault with a throw of 1000 m this fault being revealed by warping of the local bedrock and of a terrace of inferred late pleistocene age of the river barada we estimate that this set of faults became active circa 0 9 ma synchronous with changes to the pattern of faulting previously reported farther southwest in the northern jordan valley vertical slip rates on the bassimeh and damascus faults of 1 1 and 2 8 mm a 1 respectively are thus estimated we also infer that large historical earthquakes previously attributed to left lateral faulting farther west on the dead sea fault zone dsfz probably occurred on this set of reverse faults these faults thus represent a significant hazard to the city of damascus our observations indicate that as much as half of the northward motion of the arabian plate relative to the african plate may be absorbed by crustal shortening within the pfb potentially explaining the low slip rate recently measured geodetically on the northern dsfz in western syria

inland jump of the arabian northwest plate boundary from the levant continental margin to the dead sea transform 1 while the breakup of arabia and africa began in the early oligocene the northwestern boundary of the arabian plate along the dead sea transform dst formed 10 15 myr later early middle miocene during the early stage of breakup the red sea rift continued propagating northwestward forming the suez rift the present 45 northward twist of the plate boundary from the red sea toward the gulf of eilat aqaba still did not exist what happened at the northern tip of the suez rift at that time how was strain distributed to its surroundings and where did the plate boundary continue from there here we describe an abandoned segment of the arabian northwestern plate boundary that extended from the northern tip of the suez rift northeastward along the levant margin seismic data collected offshore israel support a subsurface deep rooted fault zone running along the base of the continental slope these faults indicate oligocene transpressional lateral shearing we propose that during the early stage of continental breakup a left lateral strike slip motion of 10 km took place along this embryonic plate boundary such deep rooted tectonism implies that unlike the passive situation of the israel sinai continental margin witnessed presently and before the oligocene during the early stage of the africa arabia breakup this part of the continental margin was reactivated we further suggest that the inland jump of the plate boundary toward the dst was not immediate and that during the transitional period the israel sinai triangular block was an independent subplate with deformation all around it

contrasting sulfur geochemistry and fe al and mo al ratios across the last oxic to anoxic transition in the cariaco basin venezuela an abrupt transition from oxic to anoxic sulfidic euxinic marine bottom waters occurred in the cariaco basin in response to increasing productivity resulting from the late pleistocene post glacial rise in sea level and corresponding increase in surface water nutrient availability the microlaminated sediments of the euxinic interval which span the last f14 5 ky suggest a predominance of water column syngenetic pyrite formation based on 1 high pyrite sulfur spy concentrations in the surficial sediment layers 2 values for degree of pyritization dop that generally do not increase appreciably with increasing burial 3 ratios of total iron fet to al that are elevated above the continental baseline recorded in the underlying oxic sediments and 4 spy isotope trends that largely mimic the d 34 shsof the modern water column intermediate dop values in the microlaminated deposits and fet al ratios that are slightly above continental levels indicate an iron reservoir controlled by scavenging during syngenetic pyrite formation in combination with intermediate rates of fe bearing siliciclastic accumulation as predicted from the relative rates of siliciclastic delivery fet al and dop data lie between end member values observed in the modern black sea as viewed broadly fet al and dop relationships in euxinic sediments reflect the balance between syngenetic fe scavenging and temporal and spatial gradients in siliciclastic input pyrite concentrations are generally low in the underlying oxic marine deposits because of limitations in the supply of organic carbon corg however the upper 80 cm of the fe rich corg poor bioturbated sediment show evidence for a strong diffusional hsoverprint from the overlying fe limited euxinic marine environment this post glacial transition manifests in pyrite overprints that are strongly 34 s depleted relative to those in restricted presently euxinic marine settings elsewhere in the world such as the black sea where the sedimentary sequence spanning the last glacial interglacial transition begins with a shift from freshwater to corg poor oxic marine deposition and thus dominantly sulfate diffusion trends for mo al ratios in the microlaminated sediments suggest that mo is enriched by roughly two orders of magnitude above the continental levels recorded in the oxic deposits organic matter plays a role by enhancing hsproduction and or by providing a substrate for mo scavenging significant mo enrichment via diffusion into the upper portion of the bioturbated zone was not observed despite hs rich pore waters as recorded in the heavy iron sulfide overprint we have

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

geochemical study of organic matter rich cycles from the kimmeridge clay formation of yorkshire uk productivity versus anoxia abstract in this contribution we study two meter scale cycles from the kimmeridge clay formation cored near marton yorkshire which shows cyclic organic matter om distribution our aim is to try to understand the factors responsile for om accumulation the first cycle called lower cycle shows a total organic carbon toc content between 1 and 10 whereas the second called upper cycle shows a toc content varying between 5 and 35 the geochemical composition major elements and trace elements the organic geochemistry toc hi palynofacies and mineralogy of the sediments have been determined in both cycles the cyclicity is expressed through variations in the nature and in the relative abundance of the various types of organic matter constituents furthermore dilution effects by inorganic components of the sediment cannot account for the toc cyclicity for lower cycle the mo v and u content is low and little variable as is the intensity of the oxidation which om suffered from this indicates that variations in phytoplanktonic productivity may be held responsible for the cyclicity in steady and mildly reducing redox conditions in the upper cycle cyclicity also appears to depend on productivity but variations in the concentration of mo v and u and in the oxidation state of the om suggest the environment was temporarily more reducing it is proposed that larger amounts of h 2 s were released into marine bottom waters as a result of initial om decomposition forced the oxic anoxic boundary to rise in the water column and thus favoured om storage the main driving force for variations in the om concentration was the productivity of organic matter walled phytoplankton redox conditions of the depositional environment could have had a positive action but only by acting as a positive feedback effect

explosive eruption of coal and basalt and the end permian mass extinction the end permian extinction decimated up to 95 of carbonate shell bearing marine species and 80 of land animals isotopic excursions dissolution of shallow marine carbonates and the demise of carbonate shell bearing organisms suggest global warming and ocean acidification the temporal association of the extinction with the siberia flood basalts at approximately 250 ma is well known and recent evidence suggests these flood basalts may have mobilized carbon in thick deposits of organic rich sediments large isotopic excursions recorded in this period are potentially explained by rapid venting of coal derived methane which has primarily been attributed to metamorphism of coal by basaltic intrusion however recently discovered contemporaneous deposits of fly ash in northern canada suggest large scale combustion of coal as an additional mechanism for rapid release of carbon this massive coal combustion may have resulted from explosive interaction with basalt sills of the siberian traps here we present physical analysis of explosive eruption of coal and basalt demonstrating that it is a viable mechanism for global extinction we describe and constrain the physics of this process including necessary magnitudes of basaltic intrusion mixing and mobilization of coal and basalt ascent to the surface explosive combustion and the atmospheric rise necessary for global distribution

late holocene relative sea level changes in lebanon eastern mediterranean twenty nine 14 c dates of precise biological sea level indicators from the lebanese coast show evidence for two significant regional crustal uplift episodes during the past 6000 years we elucidate 1 an upper shoreline at ca 120 to 140 cm which lasted from ca 6000 to 3000 bp and 2 a lower shoreline at 80 40 cm developed between the fifth century bc and the sixth century ad these movements are associated with 1 two major seismic crises along the yammuneh fault and the roum tripoli thrust rtt and 2 subsequent seismic events on a series of second order ene trending dextral transpressive faults vertical movements affected north lebanon whilst the coasts of south lebanon generally underwent crustal downlift this is in contrast with relative stability in northern israel suggesting an area of stationary tectonic conditions west of the dead sea rosh hanikra ras nakoura fault the main 14 c age cluster corresponding to the second uplift event may have resulted from fault movements during the early byzantine tectonic paroxysm ebtp between ca 1750 and 2000 bp relative sea level stabilised to present level around 1000 bp 2006 elsevier b v all rights reserved

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

12 000 year long record of 10 to 13 paleoearthquakes on the yammouneh fault levant fault system lebanon we present results of the first paleoseismic study of the yammouneh fault the main on land segment of the levant fault system within the lebanese restraining bend a trench was excavated in the yammouneh paleolake where the fault cuts through finely laminated sequences of marls and clays first order variations throughout this outstanding stratigraphic record appear to reflect climate change at centennial and millennial scales the lake beds are offset and deformed in a 2 m wide zone coinciding with the mapped fault trace ten to thirteen events are identified extending back more than 12 kyr reliable age bounds on seven of these events constrain the mean seismic return time to 1127 135 yr between 12 ka and 6 4 ka implying that this fault slips in infrequent but large m 7 5 earthquakes our results also provide conclusive evidence that the latest event at this site was the great a d 1202 historical earthquake and suggest that the yammouneh fault might have been the source of a less well known event circa a d 350 these findings combined with previous paleoseismic data from the zebadani valley imply that the parallel faults bounding the beqaa release strain in events with comparable recurrence intervals but significantly different magnitudes our results contribute to document the clustering of large events on the levant fault into centennial episodes such as that during the eleventh through twelfth centuries separated by millennial periods of quiescence and raise the possibility of a m 7 event occurring on the yammouneh fault in the coming century such a scenario should be taken into account in regional seismic hazard assessments and planned for accordingly

quaternary morphotectonic mapping of the wadi araba and implications for the tectonic activity of the southern dead sea fault 1 the dead sea strike slip fault accommodates the northward motion of arabia relative to sinai at a rate of 5 mm yr the southern segment of the fault the wadi araba fault runs along a valley blanketed in quaternary sediments we first focused on understanding the relative and absolute timing of emplacement of the alluvial surfaces we then determined the probable source of the sediments before assessing their lateral offset to constrain the late pleistocene fault slip rate seven successive morphostratigraphic levels were identified at two sites we recognized an alluvial sequence of five to seven successive levels with ages getting younger northward a pattern consistent with the western block moving southward relative to two fixed feeding channels located to the east surface samples were collected for10be cosmogenic radionuclide dating fans f3 and f5 were found to be synchronous from site to site at 102 26 ka and 324 22 ka respectively while f4 could be dated at 163 19 ka at one site only these are minimum ages assuming no erosion of the alluvial surfaces at least two of these periods are correlated with wet periods that are regionally well documented further analyses of tectonic offsets are affected in most cases by large uncertainties due to the configuration of the sites they indicate maximum offsets of 5 5 km for the oldest possibly 1 ma old surfaces they lead to bracketing of the fault slip rate between 5 and 12 mm yr with preferred values of 5 7 mm yr for the last 300 ka

siberian gas venting and the end permian environmental crisis abstract the end of the permian period is marked by global warming and the biggest known mass extinction on earth the crisis is commonly attributed to the formation of the siberian traps large igneous province although the causal mechanisms remain disputed we show that heating of tunguska basin sediments by the ascending magma played a key role in triggering the crisis our conclusions are based on extensive field work in siberia in 2004 and 2006 heating of organic rich shale and petroleum bearing evaporites around sill intrusions led to greenhouse gas and halocarbon generation in sufficient volumes to cause global warming and atmospheric ozone depletion basin scale gas production potential estimates show that metamorphism of organic matter and petroleum could have generated 100 000 gt co2 the gases were released to the end permian atmosphere partly through spectacular pipe structures with kilometre sized craters dating of a sill intrusion by the u pb method shows that the gas release occurred at 252 0 0 4 million years ago overlapping in time with the end permian global warming and mass extinction heating experiments to 275 c on petroleum bearing rock salt from siberia suggests that methyl chloride and methyl bromide were significant components of the erupted gases the results indicate that global warming and ozone depletion were the two main drivers for the end permian environmental crisis we demonstrate that the composition of the heated sedimentary rocks below the flood basalts is the most important factor in controlling whether a large igneous provinces causes an environmental crisis or not we propose that a similar mechanism could have been responsible for the triassic jurassic 200 ma global warming and mass extinction based on the presence of thick sill intrusions in the evaporite deposits of the amazon basin in brazil

crusader castle torn apart by earthquake at dawn 20 may 1202 the crusader castle of vadum jacob an outpost overlooking the jordan river was deformed during a destructive earthquake triggered by motion along the dead sea transform the m 7 earthquake occurred at dawn 20 may 1202 and offset the castle walls by 1 6 m this exceptional precision in dating and estimating displacement was achieved by combining accounts from primary historical sources by excavating the dead sea transform where it bisects the castle and by dating faulted archaeological strata the earthquakes of october 1759 and or january 1837 may account for the remaining 0 5 m out of a total 2 1 m of offset our study exploits the potential embodied in interdisciplinary historical archaeological geological research and illustrates how detailed histories of seismogenic faults can be reconstructed

interactions between active faulting volcanism and sedimentary processes at an island arc insights from les saintes channel lesser antilles arc new high resolution marine geophysical data allow to characterize a large normal fault system in the lesser antilles arc and to investigate the interactions between active faulting volcanism sedimentary and mass wasting processes les saintes fault system is composed of several normal faults that form a 30 km wide half graben accommodating ne sw extension it is bounded by the roseau fault responsible for the destructive mw6 3 21 11 2004 earthquake the roseau fault has been identified from the island of basse terre to dominica it is thus 40 km long and it could generate mw7 earthquakes in the future several submarine volcanoes are also recognized we show that the fault system initiated after the main volcanic construction and subsequently controls the emission of volcanic products the system propagates southward through damage zones at the tip of the damage zones several volcanic cones were recently emplaced probably due to fissures opening in an area of stress increase a two way interaction is observed between active faulting and sedimentary processes the faults control the development of the main turbiditic system made of kilometer wide canyons as well as the location of sediment ponding in turn erosion and sedimentation prevent scarp growth at the seafloor faulting also enhances mass wasting processes since its initiation the fault system has consequently modified the morphologic evolution of the arc through perturbation of the sedimentary processes and localization of the more recent volcanic activity this article is protected by copyright all rights reserved

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