correlation of fluvial sequences in the mediterranean basin over the last 200 ka and their relationship to climate change macklin mark fuller i c lewin j maas g a 2002 correlation of fluvial sequences in the mediterranean basin over the last 200 ka and their relationship to climate change quaternary science reviews 21 14 15 pp 1633 1641 rae2008

fossils from quaternary fluvial archives sources of biostratigraphical biogeographical and palaeoclimatic evidence fluvial sedimentary archives have the potential to preserve a wide variety of palaeontological evidence ranging from robust bones and teeth found in coarse gravel aggradations to delicate insect remains and plant macrofossils from fine grained deposits over the last decade advances in quaternary biostratigraphy based on vertebrate and invertebrate fossils primarily mammals and molluscs have been made in many parts of the world resulting in improved relative chronologies for fluviatile sequences complementary fossil groups such as insects ostracods and plant macrofossils are also increasingly used in multi proxy palaeoclimatic and palaeoenvironmental reconstructions allowing direct comparison of the climates and environments that prevailed at different times across widely separated regions this paper reviews these topics on a regional basis with an emphasis on the latest published information and represents an update to the 2007 review compiled by the flag inspired igcp 449 biostratigraphy subgroup disparities in the level of detail available for different regions can largely be attributed to varying potential for preservation of fossil material which is especially poor in areas of non calcareous bedrock but to some extent also reflect research priorities in different parts of the world recognition of the value of biostratigraphical and palaeoclimatic frameworks which have been refined over many decades in the core regions for such research particularly for the late middle and late pleistocene of nw europe has focussed attention on the need to accumulate similar palaeontological datasets in areas lacking such long research histories although the emerging datasets from these understudied regions currently allow only tentative conclusions to be drawn they represent an important stage in the development of independent biostratigraphical and palaeoenvironmental schemes which can then be compared and contrasted

characterization of site specific gps errors using a short baseline network of braced monuments at yucca mountain southern nevada 1 we use a short baseline network of braced monuments to investigate site specific gps effects the network has baseline lengths of 10 100 and 1000 m baseline time series have root mean square rms residuals about a model for the seasonal cycle of 0 05 0 24 mm for the horizontal components and 0 20 0 72 mm for the radial seasonal cycles occur with amplitudes of 0 04 0 60 mm even for the horizontal components and even for the shortest baselines for many time series these lag seasonal cycles in local temperature measurements by 23 43 days this could suggest that they are related to bedrock thermal expansion both shorter period signals and seasonal cycles for shorter baselines to rep2 the one short braced monument in our network are correlated with temperature with no lag time differences between rep2 and the other stations which are deep braced should reflect processes occurring in the upper few meters of the ground these correlations may be related to thermal expansion of these upper ground layers and or thermal expansion of the monuments themselves even over these short distances we see a systematic increase in rms values with increasing baseline length this and the low rms levels suggests that site specific effects are unlikely to be the limiting factor in the use of similar gps sites for geophysical investigations

the quaternary evolution of the gulf of corinth central greece coupling between surface processes and flow in the lower continental crust abstract the gulf of corinth in central greece is an active normal fault zone with particularly clear evidence of isostatic footwall uplift constrained by quaternary marine terraces and hanging wall subsidence and sedimentation it is bounded to the south by a pliocene to early pleistocene sedimentary basin which is now eroding into the gulf previous work has suggested that the relief across this region has increased dramatically since the early pleistocene due to the isostatic response to increased rates of footwall erosion and hanging wall sedimentation it is indeed assumed here that incision accompanying the draw down of global sea level at 0 9 ma during the first major pleistocene glaciation initiated the erosion of the basin south of the gulf of corinth and so abruptly increased the sedimentation rate in the gulf the resulting transient thermal and isostatic response to these changes is modelled with the subsiding depocentre and eroding sediment source coupled by flow in the lower continental crust the subsequent enhancement of relief involving an increase in bathymetry from near zero to 900 m and 500 m of uplift of the eroding land surface in the sediment source is shown to be a direct consequence of this change the model is sensitive to the effective viscosity of the lower crust and can thus resolve this parameter by matching observations a value of 6 1019 pa s is indicated suggesting a viscosity at the moho no greater than 1018 pa s similar transient topographic effects caused by increased rates of sedimentation and erosion are likely to be widespread within the geological record suggesting that this coupling process involving flow in the weak lower crust may be of major geological and geomorphological importance

crustal deformation rates in central and eastern u s inferred from gps analysis of continuous gps observations between 1996 and 2000 at 62 stations distributed throughout the central and eastern united states suggests that the area is generally stable seven of the 62 stations show anomalous velocities but there is reason to suspect their monument stability assuming the remaining 55 stations are stable with respect to interior north america we have found the north america itrf97 euler vector 1 88 1 04 n 77 67 0 39 w 0 201 0 004 myr 1 that minimizes the rms station velocity referred to fixed north america all of these velocities are less than 3 2 mm yr 1 motion of several stations suggests the mississippi embayment may be moving southward away from the rest of the continent at a rate of 1 7 0 9 mm yr 1 the motion of the embayment produces a large gradient in velocity which in turn implies the highest seismic moment accumulation rate that we found although the highest rate is only marginally significant the fact that it occurs near new madrid where earthquake risk is thought to be high argues that the anomaly may be real nevertheless the identification of the anomaly remains tentative

secondary fabrics revealed by remanence anisotropy methodological study and examples from plutonic rocks summary the fabric of fine grained magnetite is isolated by partial remanence anisotropy paar measurements that combine cycles of anhysteretic remanence acquisition and alternating frequency af tumbling demagnetization of the low coercivity fraction since remanence intensities of the most coercive fine grained magnetite are very weak rarely exceeding 10 per cent of the measured remanence in the studied samples a methodological study is presented that defines optimal measurement schemes and examines the role of gyroremanence and background remanences due to hard remanence carriers this procedure is applied to some reddened granites from tana corsica and wichita oklahoma and to the tellnes ilmenite rich norite norway the paar fabrics for fine grained magnetites are compared to the fabrics of the coarse grained primary magnetite grains as shown by both the anisotropy of magnetic susceptibility ams and the remanence anisotropy of the low coercivity fraction in tellnes fine grained magnetite is believed to be of secondary origin this is strongly suggested by the correlation between the paar fabrics and the orientations of sets of microfractures decorated by oxides in the reddened granites although no direct correlation between paar fabrics and microstructures could be evidenced the comparison between unaltered specimens and hydrothermally altered ones reveals changes in magnetic properties and fabrics that are ascribable to this secondary geological process

kinematics of the amanos fault southern turkey from ar ar dating of offset pleistocene basalt flows transpression between the african and arabian plates

kinematics of active left lateral faulting in se turkey from offset pleistocene river gorges improved constraint on the rate and history of relative motion between the turkish and arabian plates in the arabian platform of se turkey abundant evidence exists of fluvial incision by c 110 10 m since the late early pleistocene starting in or around marine oxygen isotope stage 22 at 870 ka this incision which has accompanied regional surface uplift as the isostatic response to regional erosion has progressively locked rivers into their gorges in landscape that formerly had much lower relief we use this effect to estimate 4 44 0 06 km of left lateral slip on this time scale on the golbasi turkoglu fault a segment of the east anatolian fault zone from offset river gorges giving a slip rate of 5 10 0 07 mm a 1 piercing points indicate that this fault has slipped a total of 19 km making its age 3 73 0 05 ma a total of 33 km of relative motion between the turkish and arabian plates is documented on this time scale in the vicinity of golbasi at an overall time averaged rate of 8 85 0 12 mm a 1 the estimated euler vector for relative motion between these plates being 0 89 0 01 ma 1 about 33 4 n 42 3 e this method can be readily applied to determine slip rates time averaged since the late early pleistocene on other strike slip fault zones worldwide

river terrace systems in north west europe an archive of environmental change uplift and early human occupation abstract staircases of large scale aggradational river terraces are a notable feature of many valleys in the temperate lattitudes particularly in areas beyond the reach of the erosive activities of pleistocene ice sheets it is now recognized that the cyclic fluctuations of climate during the quaternary have driven the generation of terraces through the direct and indirect influence of both temperature and precipitation on fluviatile activity where fossiliferous deposits are preserved within terrace sequences it is often possible to date these and to correlate them with the oceanic record thus providing an important framework for the evidence of environmental change on land middle and late pleistocene terraces in different areas can commonly be seen to have formed in synchrony with glacial interglacial cycles or with longer periodicity megacycles climatic forcing alone is insufficient to cause terraces to form however uplift is also necessary so that terrace sequences can provide a useful record of crustal movement in northwest europe where some of the best known studies of river terrace sequences have been carried out the fluviatile deposits are also an important repository for palaeolithic artefacts from which a record of early human occupation can be reconstructed

stratigraphic and tectonic settings of early paleolithic of north west armenia the quaternary stratigraphy and tectonic development of the southern javakheti upland and the adjacent upper akhurian and lori uplifted basins in nw armenia lesser caucasus and geological position of the early and middle acheulian lithic industries were studied using a multi method approach studies of sedimentary sections petrological and geochemical correlation of lavas and tuffs k ar dating of volcanic rocks and sims 238u 206pb dating of tuffs examination of obtained fossils and pollen analysis and determination of remanent magnetic polarity of volcanic rocks and clastic sediments have been used to compile the stratigraphic scheme and to estimate the age of units the low mountain topography was differentiated to ridges and basins to the beginning of quaternary the eruptions of basalts and basaltic andesites evened topography of the upper akhurian and lori basins in the gelasian the lava flows spread along big river valleys at tens of kilometers at the late gelasian the eruptions of basaltic trachyandesites trachyandesites and dacites replaced the basaltic eruptions the latter dammed the akhurian river flowing to the south and the upper akhurian river found the flowing to the east via the valley like depression of the karakhach pass to the dzoraghet debed valley the course grained tuffaceous clastic karakhach unit was deposited during the olduvai subchron not earlier than 1 9 1 85 ma and the earliest calabrian the water transit between the upper akhurian and lori basins was interrupted later because of rise of the karakhach pass volcanic activity renewed for a short time in the early calabrian 1 7 and 1 5 1 4 ma the end calabrian and earliest middle pleistocene sedimentation 1 0 5 ma occurred in stagnant water partly lacustrine conditions this was expressed by formation of the relatively fine grained kurtan unit during the last 0 5 ma the region underwent flexure fault deformation and tectonic uplift at 350 800 m the epoch of formation of the karakhach unit was characterized by middle mountain topography and humid climate not later than 1 85 ma the region was occupied by the earliest hominines producing lithic industries of the early acheulian aspect they contained crude hand axes and other macro tools made of local dacite and basalt sites of karakhach muradovo and agvorik early appearance of these industries might be caused by natural parting of dacite and basalt to tabulated fragments that gave a possibility to make such macro tools the middle acheulian artifacts were found in the kurtan i section of the kurtan unit

the river orontes in syria and turkey downstream variation of fluvial archives in different crustal blocks the geomorphology and quaternary history of the river orontes in western syria and south central turkey have been studied using a combination of methods field survey differential gps satellite imagery analysis of sediments to determine provenance flow direction and fluvial environment incorporation of evidence from fossils for both palaeoenvironments and biostratigraphy uranium series dating of calcrete cement reconciliation of palaeolithic archaeological contents and uplift modelling based on terrace height distribution the results underline the contrasting nature of different reaches of the orontes in part reflecting different crustal blocks with different histories of landscape evolution upstream from homs the orontes has a system of calcreted terraces that form a staircase extending to 200 m above the river new u series dating provides an age constraint within the lower part of the sequence that suggests underestimation of terrace ages in previous reviews this upper valley is separated from another terraced reach in the middle orontes by a gorge cut through the late miocene early pliocene homs basalt the middle orontes terraces have long been recognized as a source of mammalian fossils and palaeolithic artefacts particularly from latamneh near the downstream end of the reach this terraced section of the valley ends at a fault scarp marking the edge of the subsiding ghab basin a segment of the dead sea fault zone which has been filled to a depth of 1 km by dominantly lacustrine sediments of pliocene quaternary age review of the fauna from latamneh suggests that its age is 1 2 0 9 ma significantly older than previously supposed and commensurate with less uplift in this reach than both the upper and lower orontes two localities near the downstream end of the ghab have provided molluscan and ostracod assemblages that record somewhat saline environments perhaps caused by desiccation within the former lacustrine basin although they include fluvial elements the ghab is separated from another subsiding and formerly lacustrine depocentre the amik basin of hatay province turkey by a second gorge implicit of uplift this time cut through palaeogene limestone the ne sw oriented lowermost reach of the orontes is again terraced with a third and most dramatic gorge through the northern edge of the ziyaret dagi mountains which are known to have experienced rapid uplift probably again enhanced by movement on an active fault indeed a conclusion of the research in which these various reaches are compared is that the crust in the hatay region is significantly more dynamic than that further upstream where uplift has been less rapid and less continuous

preservation of miocene glacier ice in east antarctica antarctic climate during the pliocene has been the subject of considerable debate one view holds that during part of the pliocene east antarctica was largely free of glacier ice and that vegetation survived on the coastal mountains1a 4 an alternative viewpoint argues for the development of a stable polar ice sheet by the middle miocene which has persisted since then5a 10 here we report the discovery of buried glacier ice in beacon valley east antarctica which appears to have survived for at least 8 1 million years we have dated the ice by 40ar 39ar analysis of volcanic ash in the thin overlying glacial till which we argue has undergone little if any reworking isotope and crystal fabric analyses of the ice show that it was derived from an ice sheet we suggest that stable polar conditions must have persisted in this region for at least 8 1 million years for this ice to have avoided sublimation

geodesy using the swedish permanent gps network effects of snow accumulation on estimates of site positions we have observed variations at the several centimeter level in estimates of the vertical coordinate of site position the estimates are obtained from our analysis of data acquired from the swedish permanent global positioning system gps network the observed variations are strongly correlated with changes in the indirectly inferred accumulation of snow which we assume collects on the radomes and pillars the gps sites could not be observed directly due to their remoteness numerical simulations which assume a simple geometry for the snow cover are used to study the effects of snow accumulation on gps phase observables and hence on estimates of the vertical coordinate of site position obtained from these observables our results indicate that the variations in the vertical coordinate of site position can be fully explained by reasonable accumulations of snow which retard the gps signals and enhance signal scattering effects

regional power and local ecologies accumulated population trends and human impacts in the northern fertile crescent archaeological data tend to be gathered at the local level human agency also operates at this scale by combining data from multiple surveys conducted within a larger area it is possible to use local datasets to obtain a perspective on regional trends in settlement population and human activity here we employ data derived from nine archaeological surveys in the northern and western regions of the fertile crescent west and north syria se turkey and northern iraq to show how local trends aggregate to create a general proxy record of settlement and regional population in addition we use geoarchaeological data from a region extending from homs in the west to northern iraq in the east to outline historical trends in alluvial fill development both settlement and alluviation trends are then related to palaeoclimate proxy data from soreq cave and lake van settlement geoarchaeological signatures and climate are then examined side by side in order to assess long term human interactions

displacement of surface monuments vertical motion several measurements of vertical ground motion at pinon flat observatory california indicate the overall weakness and instability of the earth s weathered surface with respect to the underlying rock cumulative long period motions of order 0 5 mm per year dominate these records though smaller elastic deformations caused by precipitation loading atmospheric loading and tidal strains are evident at higher frequencies all of these help to characterize the near surface material the long period records suggest that near surface weathering is the dominant influence on monument motion at least at this site on crystalline rock in a semi arid environment rainfall loading gives an average vertical modulus of 2 6 gpa for the material in the uppermost 26 m of the ground compared with 88 gpa for granite under moderate confining stress atmospheric loading gives similar results but indicates the ground is permeable to airflow at periods longer than a few hours earth tide records show poisson s ratio to be 0 09 in contrast to the normative range of 0 2 0 25 establishing that horizontal strains couple only weakly into vertical ones so that vertical strains near the surface are a poor measure of areal strain the form of the ground surface displacement power spectrum indicates that analyses of geodetic surveys would be improved with the inclusion of a monument positioning error budget that increases with time because of ground instability and the generally small rate of crustal tectonic motions deeply emplaced monuments will be needed for observational programs designed to detect short term changes in crustal deformation over baselengths of order 10 km and less

the geological problems of the large dams constructed on the euphrates river turkey abstract in order to use the energy and irrigation potential of the euphrates river a series of dams have been designed upstream to downstream keban karakaya karababa ataturk birecik and karkamis the first three of these dams have been completed construction on the birecik and karkamis dams is underway the initial plans involved a 60 m high golkoy dam downstream of the karakaya dam with the ataturk dam 60 m lower than it is currently in the belief that the cost of irrigation by the ataturk dam s water would be high the increase of the height of ataturk dam was preferred to the construction of the golkoy dam the keban dam s basement is formed by karstic rock named keban marble from the author and his colleagues studies it has been shown that water would leak from the left side of keban dam reservoir forming a spring in the keban creek in order to prevent this water leakage an intensive grouting programme was applied in spite of this when the reservoir was filled 26 30 m3 s of water leaked from the keban creek a more recent study on the volume of leakage showed it to be reduced to 7 8 m3 s with this amount remaining constant the karakaya dam is constructed on metamorphic rocks thus only allowing minimal water leakage however on the downstream side of the right slope the tillo bego senketo landslides have been an important risk to the dam if such landslides cause an artifical lake by blocking the euphrates river the karakaya hydroelectric power station could be flooded limestone forms the foundations for the ataturk dam on and around the damsite there is epithermal water 24 26 c below the aquifer deeper than 300 m with the level of the grouting curtain down to 180 200 m the grouting curtain would not be able to prevent the leakage because the level of karstification extends below the grouting curtain in february 1993 the total volume of leaking water from the damsite and its vicinity reached 10 m3 s when the reservoir level was 517 m when the reservoir is full 542 m the volume of leaking water is expected to increase under the clay core of the dam extending from the surface to 30 40 m depth high grouting pressure could not be applied so water leaked at this part of the grouting curtain and thus the amount of leaked water could not be measured

tectonic development of the eastern mediterranean region the eastern mediterranean region is a classic area for the study of tectonic processes and settings related to the development of the tethyan orogenic belt the present set of research and synthesis papers by earth scientist from countries in this region and others provides an up to date interdisciplinary overview of the tectonic development of the eastern mediterrenean region from precambrian to recent key topics include continental rifting ophiolite genesis and emplacement continental collision extensional tectonics crustal exhumation and intraplate deformation e g active faulting alternative tectonic reconstructions of the tethyan orogen are presented and discussed with important implications for other regions of the world the book will be an essential source of information and interpretation for academic researchers geologists and geophysicists advanced undergraduates and also for industry professionals including those concerned with hydrocarbons minerals and geological hazards e g earthquakes

dating quaternary volcanism and incision by the river tigris at diyarbakir southeast turkey new high precision ar ar dating of basalt underlying the city of diyarbakir southeast turkey constrains the quaternary incision history of the river tigris strengthening the pre existing chronology based on magnetostratigraphy and k ar dates the basalt which overlies tigris terrace gravel 70 m above the river is part of the karacadag shield volcano complex centred ca 60 km to the southwest the reverse magnetised diyarbakir basalt one of relatively few flow units to reach the tigris valley axis has been dated to 1196 19 ka 2 two lower terraces have been recognised in the diyarbakir area 46 and 32 m above the present river with at least one other further downstream from this evidence the rate of middle late pleistocene incision by the tigris can be estimated it probably reached ca 0 07 mm a 1 reflecting the characteristic global increase in uplift rates observed at that time copyright 2007 john wiley sons ltd

towards an astrochronological framework for the eastern paratethys mio pliocene sedimentary sequences of the focsani basin romania abstract a reliable geological timescale for the neogene sedimentary deposits of the romanian carpathian foredeep did not exist so far due to the lack of accurate isotopic datings and straightforward magnetostratigraphic correlations here we present a new chronology for the upper miocene to pliocene deposits of the westernmost part of the eastern paratethys based on high resolution magnetostratigraphic data from the focsani basin the thick and continuous river sections of putna 2 35 km and rimnicu s rat 7 32 km yield excellent magnetostratigraphic results and allow an unambiguous correlation to the polarity timescale for the interval between 7 and 2 5 ma the new age control permits the calculation of accumulation rates for each polarity zone which shows a significant increase at approximately 5 8 6 my the upper miocene to pliocene sedimentary rocks of the focsani basin display cyclic alternations of sandy units and finer intervals the calculated values for the average duration of the observed sedimentary cycles are very close to the average duration of precession 21 7 ky which indicates that the sedimentary cycles from the eastern carpathian foredeep deposits are astronomically forced we show that the usage of the unambiguous time control offered by magnetic polarity stratigraphy would give a more realistic picture of the processes that have taken place in this tectonically active region

reply to comment by riccardo caputo and marcello bianca on late cenozoic uplift of southern italy deduced from fluvial and marine sediments coupling between surface processes and lower crustal flow by rob westaway and david bridgland improved uplift modelling of the gulf of taranto marine terraces the well developed pleistocene marine terrace staircase along the gulf of taranto coastline southern italy has been extensively studied over many decades the rivers in this region have also formed long timescale terrace staircases our paper late cenozoic uplift of southern italy deduced from fluvial and marine sediments coupling between surface processes and lower crustal flow quaternary international 175 86 124 presented original field observations aimed at testing contradictory hypotheses for the mode of origin of this marine terrace staircase and developed age models for the marine and fluvial successions we also proposed on the basis of physics based numerical modelling that the quaternary uplift of this region is primarily the isostatic response to erosion and has thus been driven by climate which has forced the erosion despite the location within a plate boundary zone however bianca and caputo quaternary international 204 98 102 have questioned our use of the data and disputed the logic of our numerical modelling notwithstanding minor corrections and updating from which we present revised uplift modelling we uphold the substantial content of our original paper as valid and consider it to be a tenable interpretation of the terrace record in the study region we also discuss underlying issues including strategies for age control and the causes of fluvial terrace development

large scale global surface mass variations inferred from gps measurements of load induced deformation 1 detrended crustal deformation measurements from a global network of up to 200 continuous global positioning system gps tracking sites are inverted for low degree and order n m 6 spherical harmonic series of surface mass variations an independent geophysical model of the atmosphere oceans and water and snow on land is also used to guide the spherical harmonic truncation and to evaluate aliasing errors in the results inversion uncertainties decrease significantly as spatial coverage and data quality improve with time especially in the last few years consequently gps inverted seasonal geocenter and low degree zonal harmonics converge to those determined by measurements from satellite laser ranging slr significant n 1 and non zonal variations have also been found

pliocene early pleistocene history of the euphrates valley applied to late cenozoic environment of the northern arabian plate and its surrounding eastern turkey abstract the pliocene quaternary paleogeography of the euphrates river valley changed due to sinistral movements on the east anatolian fault zone eafz and the taurus ridge rise by movements on the south taurus thrust evidence of these changes is based on studies of the pliocene quaternary deposits of the euphrates river basin to the north and to the south of the taurus ridge and the late cenozoic deformation including offsets on the eafz combination of methods was used to date the pliocene quaternary deposits it includes geological and geomorphic analysis and correlation of sections determination of remanent magnetization paleontological and archaeological finds pollen analysis and k ar dating of volcanic rocks to the north of the taurus ridge the late miocene tectonic depressions were filled by lakes connected by braided streams in the early pliocene the euphrates and murat river valleys formed and the euphrates flew to the south westwards of its recent position via the graben like trough of the sultan suyu river valley and farther to the erikdere that are recent euphrates tributaries the flow was interrupted later because of some desiccation and rise of the taurus ridge the flow recommenced in the end gelasian early calabrian via the goksu cayi and erikdere valleys consecutively and was interrupted again at the end of calabrian 0 8 0 9 ma the euphrates waters found the recent way via the taurus ridge and the former upstream bottoms of the euphrates and its tributaries valleys became a vast upper terrace after this the taurus ridge rose by more than 330 m lower terraces were formed because of the tectonic uplift that was more intense to the north of the taurus ridge 0 13 0 16 mm year than to the south of it 0 1 mm year the new formed segment of the euphrates valley was offset on the eafz at 12 km that gives the slip rate of 13 15 mm year

climate driven deformation of the solid earth from grace and gps 1 grace data indicate large seasonal variations in gravity that are assumed to be related to climate driven fluxes of surface water seasonal redistribution of surface mass should deform the earth and our calculations using grace data suggest vertical deformations of 13 mm in the region of greatest flux the amazon river basin to test the grace gravity hydrology connection we analyzed gps data acquired from sites in this region after accounting for degree 1 variations not observable with grace we find that annual deformation measured with gps correlates highly with predictions calculated from grace measurements these results confirm the variations in surface water sensed by grace which are significantly larger than those predicted by some hydrology models the results also demonstrate that grace can be an important tool for monitoring deformation of the earth and suggest that combined analysis of grace and gps may be a useful approach for estimation of geocenter variations

fluvial deposits as an archive of early human activity progress during the 20 years of the fluvial archives group fluvial sedimentary archives are important repositories for lower and middle palaeolithic artefacts throughout the old world especially in europe where the beginning of their study coincided with the realisation that early humans were of great antiquity now that many river terrace sequences can be reliably dated and correlated with the globally valid marine isotope record potentially useful patterns can be recognized in the distribution of the find spots of the artefacts that constitute the large collections that were assembled during the years of manual gravel extraction this paper reviews the advances during the past two decades in knowledge of hominin occupation based on artefact occurrences in fluvial contexts in europe asia and africa as such it is an update of a comparable review in 2007 at the end of igcp project no 449 which had instigated the compilation of fluvial records from around the world during 2000 2004 under the auspices of the fluvial archives group an overarching finding is the confirmation of the well established view that in europe there is a demarcation between handaxe making in the west and flake core industries in the east although on a wider scale that pattern is undermined by the increased numbers of lower palaeolithic bifaces now recognized in east asia it is also apparent that although it seems to have appeared at different places and at different times in the later lower palaeolithic the arrival of levallois technology as a global phenomenon was similarly timed across the area occupied by middle pleistocene hominins at around 0 3 ma

active crustal shortening in ne syria revealed by deformed terraces of the river euphrates the africa arabia plate boundary comprises the red sea oceanic spreading centre and the left lateral dead sea fault zone dsfz however previous work has indicated kinematic inconsistency between its continental and oceanic parts the palmyra fold belt pfb splays ene from the dsfz in sw syria and persists for 400 km to the river euphrates but its significance within the regional pattern of active crustal deformation has hitherto been unclear we report deformation of euphrates terraces consistent with quaternary right lateral transpression within the pfb indicating anticlockwise rotation estimated as 0 3 ma 1 about 36 0 n 39 8 e of the block between the pfb and the northern dsfz relative to the arabian plate interior the northern dsfz is shown to be kinematically consistent with the combination of euler vectors for the pfb and the red sea spreading resolving the inconsistency previously evident the sw pfb causes a significant earthquake hazard previously unrecognized to the city of damascus

displacement of surface monuments horizontal motion measurements of tectonic deformation depend on both accurate instrumentation and adequate coupling of the apparatus to the earth s crust existing techniques capable of resolving the signals of interest strain rates of 10 n yr are mainly observatory based the limitation in the baselength of these instruments 1 km results in a requirement that the reference monuments be exceptionally stable 10 tzm yr however records from pition flat observatory california show that the actual horizontal displacements for massive near surface monuments eraplaced in competent weathered granite are of the order of 50 tzm yr the low noise level of the strain measurements at this site indicates that this magnitude of monument displacement is abnormally small until high accuracy geodetic techniques are developed sophisticated monuments or monument monitoring devices will be necessary to record faithfully continuous crustal deformation

late cenozoic surface uplift revealed by incision by the river euphrates at birecik southeast turkey incision by the river euphrates has created a dramatic erosional landscape in the northern arabian platform in se turkey we obtain accurate heights of its terrace deposits in the birecik area using differential gps and summarise evidence regarding heights of late miocene basalt flows and low altitude wetland sediments we thus estimate 600 m of uplift since the early late miocene 9 ma represented by 270 m of fluvial incision the difference reflecting downstream channel lengthening as the coastline has retreated to the persian gulf 1400 km away the oldest recognised sediments inset below this level form a thick aggradation between 100 and 130 m above the present level of the euphrates we estimate that this accumulated during 5 3 ma when uplift rates were low such that aggradation was necessary to maintain a downstream channel gradient in response to the coastal retreat palaeolithic artefacts have been reported locally in euphrates deposits up to 80 m above present river level which we tentatively date to 1 8 ma the euphrates subsequently incised to within 10 m of its present level before aggrading 45 m higher in the late early pleistocene the final 55 m of incision reflects the increase in uplift rates observed worldwide in the early middle pleistocene following the mid pleistocene revolution

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

ar ar dating of late cenozoic basaltic volcanism in northern syria implications for the history of incision by the river euphrates and uplift of the northern arabian platform 1 ar ar dating of basalt flows capping terrace deposits of the river euphrates in northern syria has provided a new quantitative chronology for the late cenozoic evolution of this important river system and for the associated history of surface uplift of the northern arabian platform through which it flows a region of relatively strong crust that has experienced only slow deformation notably fluvial deposits 65 m above the euphrates are overlain by basalt dated to 2717 20 ka those 45 m above the river are overlain by basalt dated to 2116 39 ka and those 8 9 m above the river are overlain by basalt dated to 402 11 ka these new dates require the previous dating scheme based on paleolithic archaeology to be revised the euphrates terrace deposits and the associated incised valley are much older than was previously thought rates of incision by the euphrates providing a proxy for regional surface uplift that is inferred to be the isostatic response to regional erosion have varied significantly over the past 3 ma with indications that between 1 2 and 0 9 ma there was regional subsidence which gave rise to fluvial aggradation this unusual pattern involving reversals in the sense of vertical crustal motions is interpreted to be a consequence of a relatively cold and thin mobile lower crustal layer no more than 5 km thick evidently due to the presence of a much thicker underlying layer of mafic underplating at the base of the crust this study thus indicates previously unsuspected complexity in the isostatic response to regional erosion in an area of high crustal stability

dating and correlation of the quaternary fluvial terraces in syria applied to tectonic deformation in the region abstract new data on location height and composition of terraces of the el kabir and orontes rivers in syria are represented by combined use of paleontological archaeological paleomagnetic and radio isotopic methods ages of these river terraces are estimated and they are correlated with the euphrates river terraces the age of the terraces is defined more precisely by evidence of synchronism of the el kabir alluvial terraces and the marine terraces of the mediterranean coast the average rates of incision during different time intervals were estimated in the studied valleys and their segments using relative height of the terraces this gives the possibility of approximately estimating a rate of the quaternary uplift in different tectonic provinces of syria as well as rates of vertical movements on the lattaqieh the el kabir valley hama the orontes valley and euphrates the euphrates valley faults the rates of incision were usually small in the earlier stages of the valley formation and increased later the middle and late pleistocene rates of the valley incision reach 220 280 mm ky in the el kabir valley the coastal range anticline 80 130 mm ky in the orontes valley and the euphrates upstream of the assad reservoir the mobile platformal aleppo block and 25 30 mm ky in the euphrates valley downstream of the assad reservoir southwestern side of the mesopotamian foredeep

noise in gps displacement measurements from southern california and southern nevada 1 time series of position changes estimated from data from 236 continuously recording gps receivers operating in southern california and southern nevada are evaluated for noise models that characterize their temporal correlations the lengths of the time series range between 3 5 and 10 years after adjusting these data for postseismic deformation offsets and annual periodicities i find that about one half of the time series have temporal correlations that are categorized as either flicker or random walk noise the remaining time series can be best categorized as either a combination of flicker and random walk power law noise first order gauss markov plus random walk noise or power law plus broadband seasonal noise a variety of geodetic monuments are used in southern california and nevada including deeply braced designs cement piers pins drilled in outcrop and buildings when i evaluate the noise for each time series in terms of an estimate of the standard error in velocity i find that the sites with the smallest errors are those located in nevada using deeply braced monuments sites that are installed within regions of active pumping both for groundwater and oil had the largest standard errors in velocity comparison of monument stability as measured by standard error in rate with average annual rainfall nearby indicates a marginally significant correlation in addition even though regional filtering removed much of the common mode signals in these time series there still remains a common mode seasonal signal which can and should be removed

geodesy using the global positioning system the effects of signal scattering on estimates of site position analysis of global positioning system gps data from two sites separated by a horizontal distance of only 2 2 m yielded phase residuals exhibiting a systematic elevation angle dependence one of the two gps antennas was mounted on an 1 m high concrete pillar and the other was mounted on a standard wooden tripod we performed elevation angle cutoff tests with these data and established that the estimate of the vertical coordinate of site position was sensitive to the minimum elevation angle elevation cutoff of the data analyzed for example the estimate of the vertical coordinate of site position changed by 9 7 0 8 mm when the minimum elevation angle was increased from 10 to 25 we performed simulations based on a simple ray tracing multipath model with a single horizontal reflector which demonstrated that the results from the elevation angle cutoff tests and the pattern of the residuals versus elevation angle could be qualitatively reproduced if the reflector were located 0 1 0 2 m beneath the antenna phase center we therefore hypothesized that the elevation angle dependent error was caused by scattering from the horizontal surface of the pillar located a distance of 0 2 m beneath the antenna phase center we tested this hypothesis by placing microwave absorbing material between the antenna and the pillar in a number of configurations and by analyzing the changes in apparent position of the antenna the results indicate that 1 the horizontal surface of the pillar is indeed the main scatterer 2 both the concrete and the metal plate embedded in the pillar are significant sources of scattering and 3 the scattering can be reduced greatly by the use of microwave absorbing materials these results have significant implications for the accuracy of global gps geodetic tracking networks which use pillar antenna configurations identical or similar to the one used for this study at the westford wfrd gps site

correlated errors in geodetic time series implications for time dependent deformation analysis of frequent trilateration observations from the two color electronic distance measuring networks in california demonstrate that the noise power spectra are dominated by white noise at higher frequencies and power law behavior at lower frequencies in contrast earth scientists typically have assumed that only white noise is present in a geodetic time series since a combination of infrequent measurements and low precision usually preclude identifying the time correlated signature in such data after removing a linear trend from the two color data it becomes evident that there are primarily two recognizable types of time correlated noise present in the residuals the first type is a seasonal variation in displacement which is probably a result of measuring to shallow surface monuments installed in clayey soil which responds to seasonally occurring rainfall this noise is significant only for a small fraction of the sites analyzed the second type of correlated noise becomes evident only after spectral analysis of line length changes and shows a functional relation at long periods between power and frequency of 1 where is frequency and 2 with 2 this type of correlated noise is termed random walk noise and its source is mainly thought to be small random motions of geodetic monuments with respect to the earth s crust though other sources are possible because the line length changes in the two color networks are measured at irregular intervals power spectral techniques cannot reliably estimate the level of 1 noise rather we also use here a maximum likelihood estimation technique which assumes that there are only two sources of noise in the residual time series white noise and random walk noise and estimates the amount of each from this analysis we find that the random walk noise level averages about 1 3 mm yr and that our estimates of the white noise component confirm theoretical limitations of the measurement technique in addition the seasonal noise can be as large as 3 mm in amplitude but typically is less than 0 5 mm because of the presence of random walk noise in these time series modeling and interpretation of the geodetic data must account for this source of error by way of example we show that estimating the time varying strain tensor a form of spatial averaging from geodetic data having both random walk and white noise error components results in seemingly significant variations in the rate of strain accumulation spatial averaging does reduce the size of both noise components but not their relative influence on the resulting strain accumulation model

late cenozoic surface uplift basaltic volcanism and incision by the river tigris around diyarbakir se turkey we document the staircase of terraces of the river tigris in the diyarbakir area of se turkey in the northern arabian platform and improve control on the ages of these terrace deposits by dating of overlying basalt flows using the unspiked k ar technique these fluvial terraces are formed of polymict gravel including clasts derived from the anatolian metamorphic terrane farther north as well as of local basalt at least 9 tigris terraces have been recognised so far the highest of which 200 m above present river level marks the local transition from stacked deposition to fluvial incision the timing of which is bounded between the mid late miocene and the middle pliocene our k ar dating indicates a hiatus in fluvial incision in the late early pleistocene as basalts dated to 1 22 0 02 and 1 07 0 03 ma overlie tigris gravels at very similar levels 60 70 m above the present river the lower terraces record the subsequent entrenchment of the modern tigris valley following an increase in incision rates in the early middle pleistocene evident from the disposition of younger basalt dated to 0 43 0 02 ma capping fluvial gravel only 21 22 m above the present river level numerical modelling can account for the observed uplift history as the response to coupling between surface processes and induced flow in the lower crust with the mobile lower crust thin 5 7 km thick consistent with the known presence of a thick layer of mafic underplating at the base of the crust beneath the arabian platform

slip rate increase at parkfield in 1993 detected by high precision edm and borehole tensor strainmeters on two of the instrument networks at parkfield california the two color electronic distance meter edm network and borehole tensor strainmeter btsm network we have detected a rate change starting in 1993 that has persisted at least 5 years these and other instruments capable of measuring crustal deformation were installed at parkfield in anticipation of a moderate m6 earthquake on the san andreas fault many of these instruments have been in operation since the mid 1980s and have established an excellent baseline to judge changes in rate of deformation and the coherence of such changes between instruments the onset of the observed rate change corresponds in time to two other changes at parkfield from late 1992 through late 1994 the parkfield region had an increase in number of m4 to m5 earthquakes relative to the preceding 6 years the deformation rate change also coincides with the end of a 7 year period of sub normal rainfall both the spatial coherence of the rate change and hydrological modeling suggest a tectonic explanation for the rate change from these observations we infer that the rate of slip increased over the period 1993 1998

high sediment yields and cool wet winters test of last glacial paleoclimates in the northern mediterranean opposing models have been proposed for last glacial paleoclimates in the mediterranean area to discriminate between the alternative models we calculate variations in sediment yield within a high resolution stratigraphic framework developed for the alkyonides basin central greece latest quaternary highstand deposits are distinguised from lowstand lake corinth deposits on the basis of seismic reflection data and micropaleontological and palynological analyses of drop cores after depth conversion and calculation of solid sediment masses in successive time slices sediment discharge rates during the last glacial lowstand interval ca 70 12 ka are shown to have exceeded discharge rates during the preceeding interglacial highstand interval ca 128 70 ka by 60 implying enhanced seasonality during the glacial period with cool dry summer and wet winter conditions in the region sediment yield calculations can thus provide an empirical test of paleoclimate models and offer input to sequence stratigraphic models

tectonics of strike slip restraining and releasing bends restraining and releasing bends are common but enigmatic features of strike slip fault systems occurring in all crustal environments and at regional to microscopic scales of observation regional scale restraining bends are sites of mountain building transpressional deformation and basement exhumation whereas releasing bends are sites of topographic subsidence transtensional deformation basin sedimentation and possible volcanism and economic mineralization because restraining and releasing bends often occur as singular self contained domains of complex deformation they are appealing natural laboratories for earth scientists to study fault processes earthquake seismology active faulting and sedimentation fault and fluid flow relationships links between tectonics and topography tectonic and erosional controls on exhumation and tectonic geomorphology this volume addresses the tectonic complexity and diversity of strike slip restraining and releasing bends with 18 contributions divided into four thematic sections 1 a topical review of fault bends and their global distribution 2 bends sedimentary basins and earthquake hazards 3 restraining bends transpressional deformation and basement controls on development 4 releasing bends transtensional deformation and fluid flow

noise properties of continuous gps data from concrete pillar geodetic monuments in new zealand and comparison with data from u s deep drilled braced monuments 1 reducing noise levels in geodetic data is critical for the interpretation and modeling of geophysically interesting signals in this paper i estimate noise properties of continuous gps time series collected on concrete pillar monuments and compare them with similar data from deep drilled braced monuments that are considered the most stable three dimensional monuments available i show that the time series noise properties are very similar between the monument types at least for time series up to 4 5 years duration differences between the monument types are therefore not a dominant influence on these time series implying that the less expensive concrete pillar monuments are a valid choice for recording many signals of geophysical interest

crustal displacements due to continental water loading the effects of long wavelength 100 km seasonal variability in continental water storage on vertical crustal motions are assessed the modeled vertical displace ments arm have root mean square rms values for 1994 1998 as large as 8 mm with ranges up to 30 mm and are predominantly annual in character regional strains are on the order of 20 nanostrain for tilt and 5 nanostrain for hori zontal deformation we compare arm with observed global positioning system gps heights aro which include ad justments to remove estimated effects of atmospheric pres sure and annual tidal and non tidal ocean loading for 147 globally distributed sites when the aro time series are ad justed by arm their variances are reduced on average by an amount equal to the variance of the arm of the aro time series exhibiting a strong annual signal more than half

kinematic consistency between the dead sea fault zone and the neogene and quaternary left lateral faulting in se turkey a revised quantitative kinematic model has been determined for the dead sea fault zone dsfz and the left lateral fault zones in se turkey the relative motions of the african and arabian plates across the dsfz are represented by relative rotation about 31 1 n 26 7 e at 0 40 0 02 ma 1 the northern dsfz in syria and southern turkey is interpreted for the first time as a series of transpressional stepovers along which the left lateral slip rate is substantially less than the rate of relative plate motion because this slip is oblique to the plate motion the slip rate on the east anatolian fault zone eafz is estimated as 8 mm a 1 restoring its observed slip thus requires its age to be 4 ma the previous phase of deformation which involved slip on the malatya ovacik fault zone mofz before the eafz came into being is thus dated to 7 4 ma suggesting initiation of the north anatolian fault zone nafz at 7 ma not 5 ma as previously thought the total left lateral slip on the northern dsfz in southernmost turkey is estimated as at least 65 km partitioned with 45 km on the amanos fault 10 km on the east hatay fault and a further 10 km on the kirkpinar fault farther east much of this slip is inferred to have occurred during the miocene before the modern geometry of this plate boundary zone developed when it first formed the af ar plate boundary was relatively complex it initially reactivated preexisting structures in the palmyra foldbelt in syria and in the gaziantep region of southern turkey which were significantly misaligned relative to the plate motion requiring major components of shortening as well as left lateral slip the transition from this initial rather diffuse geometry to the present localised geometry of the dsfz across western syria occurred within the miocene the predicted rate of relative motion between the stable interiors of the turkish and african plates in the vicinity of their common boundary onshore of iskenderun gulf in southern turkey is estimated as westward at 9 mm a 1 however this promontory of the african plate is itself moving westward relative to the stable interior of this plate at 7 8 mm a 1 the rate of localised left lateral slip on the onshore part of this boundary the ne trending yakapinar goksun fault is thus estimated as only 2 mm a 1 this locality can also be regarded as within the distributed boundary zone between the turkish and arabian plates the estimated relative motion between these plates is at 8 7 mm a 1 towards the ssw partitioned between localised left lateral slip at 2 mm a 1 on the yakapinar goksun fault and at least 1 mm a 1 on the amanos fault and 2 5 mm a 1 on east hatay fault with at most distributed left lateral simple shear at 3 2 mm a 1 across the amanos mountains in between however the combined slip on left lateral faults east of the amanos mountains may be as high as 6 mm a 1 with slip at 1 7 mm a 1 on the amanos fault and at 4 3 mm a 1 on the east hatay fault and any active faults farther east this requires no more than 0 7 mm a 1 of distributed simple shear across the amanos mountains raising the possibility that this component of deformation may in fact be zero this small nonzero estimate possibly indicating a closure error arising from minor errors in predicted values of other relative motion vectors it is proposed that this boundary between the turkish and african plates first developed at the same time as the mofz and nafz but its original geometry involving left lateral slip on the karatas osmaniye fault has since become locked by the presence of relatively strong ophiolitic crust within this fault zone this quantitative kinematic model demonstrates for the first time how it is possible for the left lateral faulting accommodating the nnw sse relative motion between the arabian and african plates in nw syria to dovetail into the left lateral faulting accommodating the wsw ene relative motion between the turkish and arabian plates in se turkey

pliocene and quaternary regional uplift in western turkey the gediz river terrace staircase and the volcanism at kula abstract along the upper reaches of the gediz river in western turkey in the eastern part of the aegean extensional province the land surface has uplifted by 400 m since the middle pliocene this uplift is revealed by progressive gorge incision and its rate can be established because river terraces are capped by basalt flows that have been k ar and ar ar dated at present the local uplift rate is 0 2 mm a 1 uplift at this rate began around the start of the middle pleistocene following a span of time when the uplift was much slower this was itself preceded by an earlier uplift phase apparently in the late late pliocene and early early pleistocene when the uplift rate was comparable to the present the resulting regional uplift history resembles what is observed in other regions and is analogously interpreted as the isostatic response to changing rates of surface processes linked to global environmental change we suggest that this present phase of surface uplift amounting so far to 150 m is being caused by the nonsteady state thermal and isostatic response of the crust to erosion following an increase in erosion rates in the late early pleistocene most likely as a result of the first large northern hemisphere glaciation during oxygen isotope stage 22 at 870 ka we suggest that the earlier uplift phase responsible for the initial 250 m of uplift resulted from a similar increase in erosion rates caused by the deterioration in local climate at 3 1 ma this uplift thus has no direct relationship to the crustal extension occurring in western turkey the rate and sense of which are thought not to have changed significantly on this time scale our results thus suggest that the present often deeply incised landscape of western turkey has largely developed from the middle pleistocene onwards for reasons not directly related to the active normal faulting that is also occurring the local isostatic consequences of this active faulting are instead superimposed onto this background of regional surface uplift modelling of this surface uplift indicates that the effective viscosity of the lower continental crust beneath this part of turkey is of the order of 1019 pa s similar to a recent estimate for beneath central greece the lower uplift rates observed in western turkey compared with central greece result from the longer typical distances of fluvial sediment transport which cause weaker coupling by lower crustal flow between offshore depocentres and eroding onshore regions that provide the sediment source

palaeohydrological corridors for hominin dispersals in the middle east 250 70 000 years ago abstract the timing and extent of palaeoenvironmental connections between northeast africa the levant and the arabian peninsula during the middle and late pleistocene are critical to debates surrounding dispersals of hominins including movements of homo sapiens out of africa although there is evidence that synchronous episodes of climatic amelioration during the late middle and late pleistocene may have allowed connections to form between northern africa and western asia a number of palaeoclimate models indicate the continued existence of an arid barrier between northern arabia and the levant here we evaluate the palaeoenvironmental setting for hominin dispersals between and within northeast africa and southwest asia during marine isotope stages mis 7 5 using reconstructions of surface freshwater availability as an environmental proxy we use remotely sensed data to map palaeohydrological features lakes wetlands and rivers across the presently hyper arid areas of northern arabia and surrounding regions integrating these results with palaeoclimate models palaeoenvironmental proxy data and absolute dating to determine when these features were active our analyses suggest limited potential for dispersals during mis 7 and 6 but indicate the formation of a palaeohydrological corridor the tabuk corridor between the levant and the arabian interior during the mis 6 5e glacial interglacial transition and during mis 5e a recurrence of this corridor following a slightly different route also occurred during mis 5a these palaeohydrological and terrestrial data can be used to establish when proposed routes for hominin dispersals became viable furthermore the distribution of arabian archaeological sites with affinities to levantine assemblages some of which are associated with homo sapiens fossils and the relative density of middle palaeolithic assemblages within the tabuk corridor are consistent with it being utilised for dispersals at various times

late palaeogene neogene evolution of the triple junction region near maras south central turkey the marao region of turkey includes the anatolian arabian african triple junction the african arabian margin is marked by left lateral transtension along the dead sea kara su rift motion on the anatolian arabian boundary is partitioned between the left lateral east anatolian fault and a fold thrust belt termed the engizek zone equivalent to the bitlis suture further east the african anatolian boundary lies along the cyprus misis andirin trend and is expressed near the triple junction as the aslantao iskenderun zone now undergoing slow left lateral transtension the neogene evolution of these boundaries is largely recorded in the stratigraphy and structure of the basins that lie along the anatolian arabian lice basin and anatolian african aslantao iskenderun basin boundaries these basins appear to have developed in the early miocene along major strike slip zones large half graben in the pre neogene 9basement9 of the western misis andirin block developed contemporaneously with motion on the anatolian african boundary these extensional features evolved subsequent to the intense shattering of the mesozoic carbonate sequence in the misis andirin block and its mixing with panels of deep water palaeogene strata to form an extensionally disrupted assemblage transpression and conversion of both anatolian african and anatolian arabian boundaries to fold thrust belts occurred in the late miocene transpression continues along the anatolian arabian boundary but transtension has recurred along the anatolian african boundary since the pliocene

an integrated global model of present day plate motions and plate boundary deformation summary in this paper we present a global model gsrm 1 of both horizontal velocities on the earth s surface and horizontal strain rates for almost all deforming plate boundary zones a model strain rate field is obtained jointly with a global velocity field in the process of solving for a global velocity gradient tensor field in our model we perform a least squares fit between model velocities and observed geodetic velocities as well as between model strain rates and observed geological strain rates model velocities and strain rates are interpolated over a spherical earth using bi cubic bessel splines we include 3000 geodetic velocities from 50 different mostly published studies geological strain rates are obtained for central asia only and they are inferred from quaternary fault slip rates for all areas where no geological information is included a priori constraints are placed on the style and direction but not magnitude of the model strain rate field these constraints are taken from a seismic strain rate field inferred from normalized focal mechanisms of shallow earthquakes we present a global solution of the second invariant of the model strain rate field as well as strain rate solutions for a few selected plate boundary zones generally the strain rate tensor field is consistent with geological and seismological data with the assumption of plate rigidity for all areas other than the plate boundary zones we also present relative angular velocities for most plate pairs we find that in general there is a good agreement between the present day plate motions we obtain and longterm plate motions but a few significant differences exist the rotation rates for the indian arabian and nubian plates relative to eurasia are 30 13 and 50 per cent slower than the nuvel1a estimate respectively and the rotation rate for the nazca plate relative to south america is 17 per cent slower on the other hand caribbean north america motion is 76 per cent faster than the nuvel 1a estimate while crustal blocks in the india eurasia collision zone move significantly and self consistently with respect to bounding plates only a very small motion is predicted between the nubian and somalian plates by integrating plate boundary zone deformation with the traditional modelling of angular velocities of rigid plates we have obtained a model that has already been proven valuable in for instance redefining a no net rotation model of surface motions and by confirming a global correlation between seismicity rates and tectonic moment rates along subduction zones and within zones of continental deformation

flow in the lower continental crust as a mechanism for the quaternary uplift of south east england constraints from the thames terrace record abstract the sequence of terraces of the river thames in south east england has been shown to date from the early pleistocene onwards and to provide an indication of the quaternary uplift history of the region using this evidence supplemented by altitudes of pliocene and early pleistocene marine sediments we have determined the pliocene and quaternary uplift histories of five representative localities clacton colchester and dartford for the lower thames and cookham and reading for the middle thames these uplift histories have been modelled using a physics based technique which calculates the isostatic response involving flow in the lower continental crust induced by cyclic loading at the earth s surface our results suggest that the late pliocene and early pleistocene part of the uplift history of our study region was initiated following the deterioration in climate starting at 3 1 ma which marked the start of upland glaciation elsewhere in europe the later increase in uplift rates in the middle pleistocene followed the start of intensified cyclic loading by very large continental ice sheets during and after oxygen isotope stage ois 22 at 0 87 ma dartford cookham and reading in the interior of south east england are all shown to have begun to uplift quite rapidly at rates of up to 0 1 mm a 1 following the start of forcing at 3 1 ma they have since uplifted by distances which increase gradually westward from 200 to 250 m of which a uniform 70 m has occurred since ois 22 at 0 87 ma in contrast clacton and colchester near the present north sea coastline experienced slow subsidence until the late early pleistocene but have nonetheless uplifted since ois 22 by similar distances to the other sites

improved stability of a deeply anchored geodetic monument for deformation monitoring a test of two different monument designs used in geodetic networks shows that monuments installed to depths of 5 to 10 meters and laterally braced exhibit less environmentally caused displacement than those installed to 2 meters depth at parkfield california we have been monitoring the lengths of 17 baselines over the past decade with a 2 to 3 day interval between measurements using a two color geodimeter with a nominal precision of 0 5 mm over 5 km long baselines significant variations are observed on many of these baselines which appear to be related to the seasonally occurring rainfall with the larger variations approaching 10 mm over the past decade to test whether we could improve upon the measurements on some of the more susceptible lines at two sites we installed new monuments within about 30 meters of the original monuments after 1 5 years of measurements it is evident that the new monuments significantly attenuate the seasonal displacements to less than 1 mm the use of deeply anchored monuments should improve the ability of fault scale geodetic monitoring arrays to detect small tectonic displacements

a numerical modelling technique that can account for alternations of uplift and subsidence revealed by late cenozoic fluvial sequences abstract alternations between fluvial incision and aggradation in response to switches between uplift and subsidence and occurring over timescales of many hundreds of thousands of years have been documented in many regions worldwide contrasting markedly with the monotonic histories of uplift or subsidence evident elsewhere it has been noted that this pattern of reversals in vertical crustal motion is only observed in regions where the mobile lower crustal layer is thin 6 km thick suggesting a cause and effect connection with the physical properties of the underlying continental lithosphere it is proposed that these reversals result from the interplay between the isostatic responses to erosional unloading by lower crustal flow and by mantle lithosphere relaxation estimates of the characteristic timescale for relaxation of the continental mantle lithosphere range from several hundred thousand years in regions of cold crust with a thin mobile lower crustal layer to a few tens of thousands of years in regions of hot crust where the mobile lower crustal layer is thicker in regions of hot crust relaxation of the mantle lithosphere requires a shorter characteristic timescale than flow within the lower crust the complex interaction between these processes means that isostatic compensation of crustal thickening in regions of hot crust will typically involve surface uplift the development of a lower crustal root and thinning of the mantle lithosphere the observation of alternations between uplift and subsidence in long timescale fluvial sequences and the proposed physical interpretation demonstrate the importance of fluvial records for providing unique high resolution control on deformation of the continental lithosphere and for constraining its layered rheology

contributions of thermal expansion of monuments and nearby bedrock to observed gps height changes 1 long term continuous global positioning system gps observations have become an important tool for studying the various geodynamic processes to fully study the geodynamic processes at gps stations the temporal movements of gps monuments and nearby bedrock induced by thermal expansion need to be considered in this paper we extend a theoretical model to estimate the thermal expansions of gps monuments and nearby bedrock for 86 globally distributed gps stations based upon measurements of surface air temperatures the results show that annual temperature variations are the dominant contributors for the thermal expansion of gps monuments and nearby bedrock the contributions of thermal expansion to gps height changes display largely spatial variations and can reach to a few millimeters citation yan h w chen y zhu w zhang and m zhong 2009 contributions of thermal expansion of monuments and nearby bedrock to observed gps height changes geophys res lett 36 l13301 doi 10 1029 2009gl038152

cenozoic epeirogeny of the arabian peninsula from drainage modeling it is generally accepted that the arabian peninsula has been uplifted by subcrustal processes positive residual depth anomalies from oceanic crust in the red sea and in the gulf of aden suggest that a region surrounding this peninsula is dynamically supported admittance calculations surface wave tomography studies and receiver function analyses all imply that regional topography is generated and maintained by some combination of mantle convective circulation and lithospheric thickness changes despite these significant advances the spatial and temporal uplift rate history of the arabian peninsula is not well known here we show that a regional uplift rate history can be obtained by jointly inverting 225 longitudinal river profiles that drain this peninsula our strategy assumes that shapes of individual river profiles are controlled by uplift rate history and moderated by erosional processes we used local measurements of incision rate to calibrate the relevant erosional parameters in our inverse algorithm uplift rate is permitted to vary smoothly as a function of space and time but upstream drainage area remains invariant we also assume that knickzone migration is not lithologically controlled implications of these important assumptions have been investigated our results suggest that the arabian peninsula underwent two phases of asymmetric uplift during the last 20 30 ma at rates of 0 05 0 1 mm a 1 the southwestern flank of the peninsula has been uplifted by 1 5 2 5 km regional stratigraphic constraints the age and composition of volcanism paleosol formation incised peneplains emergent marine terraces and thermochronometric measurements corroborate our calculated patterns of uplift progressive development of three domal swells along the western margin of the peninsula is consistent with localized upwelling of hot asthenospheric mantle

river terrace development in the ne mediterranean region syria and turkey patterns in relation to crustal type it is widely recognized that the optimal development of river terraces globally has been in the temperate latitudes with nw and central europe being areas of particular importance for the preservation of such archives of quaternary environmental change there is also a growing consensus that the principal drivers of terrace formation have been climatic fluctuation against a background of progressive but variable uplift nonetheless river terraces are widely preserved in the mediterranean region where they have often been attributed to the effects of neotectonic activity with a continuing debate about the relative significance of fluctuating temperature glacials interglacials and precipitation pluvials interpluvials research in syria and southern central turkey specifically in the valleys of the tigris and ceyhan in turkey the kebir in syria and the trans border rivers orontes and euphrates has underlined the importance of uplift rates in dictating the preservation pattern of fluvial archives and has revealed different patterns that can be related to crustal type the ne mediterranean coastal region has experienced unusually rapid uplift in the late quaternary the relation between the kebir terraces and the staircase of interglacial raised beaches preserved along the mediterranean coastline of nw syria reinforces previous conclusions that the emplacement of the fluvial terrace deposits in the mediterranean has occurred during colder climatic episodes

choice of optimal averaging radii for temporal grace gravity solutions a comparison with gps and satellite altimetry summary one of the initial challenges of the gravity recovery and climate experiment grace mission is to validate the accuracy of the time variable gravity fields these gravity fields contain both spatially correlated systematic and random noise and hence spatial averaging needs to be implemented before the fields may be interpreted optimum averaging radii need to be determined through comparison with independent data we compare time series of vertical solid earth deformations computed from 22 approximately monthly grace gravity fields covering 2002 3 until 2004 6 with vertical displacements measured using a global gps network of 63 sites about half of which are located on small islands the gps data were processed using a precise point positioning approach using fiducial free orbits and attempting to minimize propagated systematic errors the optimum mean correlations were obtained at 500 km averaging radii for continental sites r 0 55 2000 km for island sites r 0 3 subtracting the grace displacement time series from the gps ones revealed a mean variance reduction of 14 per cent to supplement the gps data at the island sites we also computed displacements based on topex poseidon t p sea surface height data between 2002 3 and 2004 corrected for steric effects correlations reached a maximum at 2000 km with a correlation of 0 38 increasing to 0 47 after the removal of six outlying sites overall we conclude that optimum averaging radii are 500 km for continental sites and 2000 km over the oceans but that the measurement precision of gps and t p may be inflating these values

aliased tidal signatures in continuous gps height time series 1 coordinate time series are often derived from continuous gps data processed as discrete 24 hour solutions under this regimen residual semi diurnal and diurnal crustal tide signatures are under sampled resulting in aliased periodic signals in the coordinate time series a secondary aliasing effect well known from satellite altimetry studies but generally ignored in gps analysis arises from the repeat period of the satellite orbits being longer than the nyquist period of the semi diurnal and diurnal tidal signatures this paper derives the theoretical periods for these two aliasing effects for the principal semi diurnal and diurnal tidal constituents the presence of both types of aliased signals in gps time series is then demonstrated using simulated gps data and also considered for time series derived from real gps data it is shown that the beating of the two aliased signals invariably results in spurious signatures in the time series with semi annual and annual periods

neotectonic deformation in the transition zone between the dead sea transform and the east anatolian fault zone southern turkey a palaeomagnetic study of the karasu rift volcanism in southern turkey ongoing differential impingement of arabia into the weak anatolian collisional collage resulting from subduction of the neotethyan ocean has produced one of the most complex crustal interactions along the alpine himalayan orogen several major transforms with disputed motions including the northward extension of the dead sea fault zone dsfz meet in this region to evaluate neotectonic motion on the amanos and east hatay fault zones considered to be northward extensions of the dsfz the palaeomagnetism of volcanic fields in the karasu rift between these faults has been studied remanence carriers are low ti magnetites and all except 5 of 51 basalt lavas have normal polarity morphological polarity and k ar evidence show that rift formation occurred largely during the brunhes chron with volcanism concentrated at 0 66 0 35 ma and a subsidiary episode at 0 25 0 05 forty four units of normal polarity yield a mean of d i 8 8 54 7 with inclination identical to the present day field and declination rotated clockwise by 8 8 4 0 within the 15 km wide hassa sector of the karasu rift the volcanic activity is concentrated between the amanos and east hatay faults both with left lateral motions which have rotated blocks bounded by nw se cross faults in a clockwise sense as the arabian block has moved northwestwards an average lava age of 0 5 ma yields a minimum cumulative slip rate on the system bounding faults of 0 46 cm year according with the rate deduced from the africa arabia euler vector and reduced rates of slip on the southern extension of the dsfz during plio quaternary times estimates deduced from offsets of dated lavas flows and morphological features on the amanos fault zone tectonophysics 344 2002 207 are lower 0 09 0 18 cm year probably because they are limited to surface fault breaks and do not embrace the seismogenic crust results of this study suggest that most strike slip on the dsfz is taken up by the amanos east hatay afrin fault array in southern turkey comparable estimates of quaternary slip rate are identified on other faults meeting at an unstable fff junction dsfz east anatolian fault zone karatas fault zone a deceleration in slip rate across the dsfz and its northward continuation during plio quaternary times correlates with reorganization of the tectonic regime during the last 1 3 ma including tectonic escape within anatolia establishment of the north and east anatolian fault zones bounding the anatolian collage in mid late pliocene times a contemporaneous transition from transpression to transtension and concentration of all basaltic magmatism in this region within the last 1 ma

adjustments by the charwell river new zealand to uplift and climatic changes major climatic changes and rapid local and regional tectonic movements were common in new zealand during the late quaternary and caused a diversity of adjustments in the drainage basin and piedmont reaches of the charwell river which are separated by the hope fault the onset of semi arid frigid climates during the latest pleistocene probably greatly increased hillslope sediment yields in a periglacial environment and the piedmont reach aggraded as much as 42 m on top of a broad strath with the return of humid mesic climates in the holocene sediment yields decreased as dense forests again mantled the slopes and the piedmont reach degraded as mush as 81 m dating of eleven cut and strath terraces by radiocarbon calibrated weathering rind measurements on greyawake cobbles shows the degradation rates varied greatly during the last 14 ka 1 ka 1000 yr initial degradation rates of 4 m ka 1 increased to 30 m ka 1 by 6 ka ago during a mid holocene climatic optimum since 4 ka ago degradation rates have been only 1 2 m ka 1 comparable to uplift rates in the piedmont reach inferred from marine terrace studies and the river is again cutting a broad strath each broad strath represents equilibrium conditions attained by this powerful stream during interglacial times despite episodes of being overwhelmed by climatically induced sediment yield increases during full glacial climates and having to maintain a long term degradation rate equal to the uplift rate the 75 81 m of degradation since formation of the latest pleistocene fill terrace tread is the sum of the amount of late pleistocene valley floor aggradation and the amount of regional uplift that occurred between the estimated times of major strath formation at about 30 and 0 ka the 39 m of tectonically induced degradation below the pre aggradation strath is sufficiently large that post 30 ka uplift may have doubled holocene degradation rates each of the eleven degradation terraces represents pauses of a few centuries in holocene downcutting brief equilibrium conditions were attained by streambed armoring and concurrent growth of riparian plants both processes progressively increased hydraulic roughness and the shear stresses needed to entrain streambed materials occasional floods possibly from rare cyclones derived from tropical moisture sources destroyed streambed armor and channel downcutting was renewed thus the formation of eleven equilibrium terraces can be accounted for without postulating additional tectonic perturbations or secular climatic changes

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

the somme valley terrace system northern france a model of river response to quaternary climatic variations since 800 000 bp recent research on the somme valley terrace deposits that began in 1987 has resulted in an integrated sequence of geological and geomorphological evidence for this area that is of particular significance for prehistoric investigations this has been achieved using previous evidence and new results from archaeological and geological excavations these include longitudinal profiles cartography and detailed synthesis of sections of alluvial deposits stratigraphy of river deposits and overlying loess sequences the work based on a study of the geometry of the terrace system has resulted in the identification of ninestepped alluvial formations that occur along 70 km of the valley detailed study permits the integration of the various alluvial sequences this suggests that each alluvial sequence results from sedimentation through a single glacial interglacial climatic cycle this hypothesis is confirmed by investigation of soil and loess sequences of the deposits overlying the fluvial sediments the synthesis presented provides a basis for understanding the deposition of the terrace system and an initial chronostratigraphic interpretation for the deposits

uplift driven valley incision and river terrace formation in southern england outside the limits of middle pleistocene glaciation the river basins of southern england contain long cenozoic terrestrial sedimentary records of greatest importance are the river terrace sequences which contain biostratigraphical and sedimentary evidence that testifies to the high amplitude climatic changes of the quaternary however trends in valley development cannot easily be accommodated within the framework of quaternary climatic change it is argued in this paper that episodic incision and terrace development result from uplift a consequence of the interplay between continuing alpine orogenic movements and erosion driven isostasy using a simple linear model height age an uplift rate of ca 7 cm ka 1 is estimated for the terrace sequence in the upper thames valley this preliminary model is evaluated using the records of adjacent basins 1997 john wiley sons ltd

geochronological reconstruction of the pleistocene evolution of the sarre valley france and germany using osl and esr dating techniques abstract this paper focuses upon the pleistocene terraces of the sarre river a right bank tributary of the moselle river ne france and sw germany flowing through the vosges massif the eastern paris basin and the rhenish massif recent research has allowed the recognition of 12 well preserved alluvial terraces sa1 youngest to sa12 oldest between the present floodplain sa0 and 120 m relative height the youngest terraces were dated using optically stimulated luminescence osl a first chronological framework was also provided for older terraces by electron spin resonance esr dating the ages range between the end of the early pleistocene and the last glacial interglacial cycle of the late pleistocene ca 1 1 ma to 50 ka age ranges are consistent with the terrace elevation and stratigraphy allowing correlation of the youngest terraces with established global climate cycles and with the younger terraces in the moselle valley in particular an erosional period was recognised at the end of the saalian end of mis 6 suggesting that the terrace incision occurred at the cold to warm transition this result contrasts with those obtained for the moselle and meurthe rivers where previous studies suggest that major incision took place at the beginning of the cold periods the differences are attributed to a variable fluvial response to climate change which could relate to the presence or absence of glaciers in the upper catchment

gps height time series short period origins of spurious long period signals gps height time series used in geophysical studies are often formed from discrete continuous nonoverlapping 24 hour processing sessions with such a strategy unmodeled periodic ground displacements with approximately semidiurnal and diurnal periods have often been assumed to average close to zero by analyzing several years of continuous gps data from globally distributed sites at which controlled errors were not modeled this paper shows such an assumption to be erroneous it is shown that each unmodeled sub daily periodic displacement can propagate to several spurious long wavelength features in a gps height time series ranging in period from about 2 weeks to 1 year admittances ratio of amplitude of spurious long wavelength output signal in the gps height time series to amplitude of unmodeled periodic ground displacement depend on the coordinate component and the tidal constituent considered for example it is shown that an unmodeled s2 north component periodic ground displacement can propagate to a semiannual height signal with admittance of greater than 100 whereas the height admittance is around 5 10 since model errors in ocean tide loading atmospheric pressure loading and solid earth tide displacement amplitudes can be several millimeters long wavelength spurious signals of up to these amplitudes may be expected to appear in gps height time series this paper provides an indication of how such errors will propagate where such errors are greatest and hence how spurious fortnightly semiannual and in some cases annual effects may be present at some sites copyright 2007 by the american geophysical union

late cenozoic regional uplift and localised crustal deformation within the northern arabian platform in southeast turkey investigation of the euphrates terrace staircase using multidisciplinary techniques we present the results of detailed field investigations of the fluvial succession exposed along the euphrates valley adjoining the ataturk dam in the northern part of the arabian platform within se turkey this work which has used differential gps surveying to obtain accurate heights of deposits and shuttle radar topographic mission imagery for location purposes has included documentation of many fresh sections exposed by quarrying the work has been supplemented by unspiked kar dating of late middle miocene to late miocene basalt flows which are widespread in the region providing a chronology for the early stages of development of this river system following regional emergence above sea level in the early middle miocene for example beside the ataturk dam lake at siverek iskelesi basalt dated to 10 24 0 22 ma 2 caps a polymict euphrates gravel some 80 m above the modern river this is the oldest euphrates terrace currently recognised however amounts and rates of fluvial incision are shown to vary across the northern arabian platform in a complex manner due to the interaction between regional uplift and localised vertical crustal motions caused by slip on active reverse faults beneath anticlines the study reach downstream of the ataturk dam includes the footwall of one such fault beneath the bozova anticline we estimate that the resulting rate of localised subsidence superimposed onto the regional uplift that has also been occurring has been 0 01 mm a 1 during the present phase of crustal deformation which began at 3 7 3 6 ma but was higher maybe 0 03 mm a 1 during the previous phase which began at 6 ma when the pattern of plate motions in the surrounding region was different a large palaeo lake centred north of the present study region around the city of adiyaman is inferred to have existed during this 6 ma to 3 7 3 6 ma phase of plate motion apparently because the relatively rapid localised hanging wall uplift on the northern flank of the bozova anticline dammed the euphrates valley near the site of the modern ataturk dam the uppermost part of a thick fluvial aggradation west of the euphrates near karababa bridge inferred to date from around the mid pliocene reaches 100 m above the modern river and after correction for an estimated 30 m of localised subsidence and by 50 m for subsequent downstream lengthening of the euphrates channel indicates 180 m of subsequent regional uplift the euphrates then incised to within 20 m of its present level by the mid early pleistocene then a switch to regional subsidence accompanied the deposition of a second thick fluvial aggradation the top of which is 70 m above the modern river subsequent renewed regional uplift following the mid pleistocene revolution has resulted in the development of a succession of fluvial terraces typically inset into these older aggradations which are correlated with the cold stages of milankovitch climate cycles the early part of the euphrates chronology constrained mainly by the disposition of basalt flows indicates 800 m of regional uplift since the early middle miocene of which an estimated 330 m is masked by the subsequent downstream lengthening of the river components of localised uplift and subsidence caused by slip on reverse faults beneath anticlines are superimposed onto this regional pattern the hanging wall uplift being much larger in one case roughly five times larger than the footwall subsidence our results provide for the first time detailed documentation of the complex development of the euphrates valley in se turkey during the late cenozoic due to the interaction between regional uplift and localised crustal deformation this work also demonstrates the benefits of applying multidisciplinary techniques to investigate an important but hitherto poorly documented river system

climatically controlled terraces in uplifting mountain areas abstract terraces in tectonically active mountains and uplands record both tectonic uplift and rhythmic climatic variations the author discusses the question of how to distinguish the role of both tectonic and climatic factors in central europe with quaternary uplift of the order of 50 100 m climatically controlled terraces are well developed cold stage aggradation is recognised through the interfingering of periglacial alluvial slope and loess deposits erosional activity prevailed in transitional periods then follows a discussion of difficulties connected with the construction of timing and rate of tectonic uplift based on the depth of incision in the bedrock and on facies differentiation the examination of changes in longitudinal profiles of river valleys indicates that unrejuvenated upper valley courses cannot be used for the reconstruction of tectonic uplift finally the author presents several types of adaptation of tectonically determined downcutting and aggradation to quaternary climatic cyclicity

geomorphic evolution of the yangtze gorges and the time of their formation abstract the three gorges of the yangtze link its upper rocky valley to downstream alluvial sections a series of stepped landforms exist in the three gorges area the sichuan basin upstream and the jianghan basin downstream these landforms are characterized by two planation surfaces one erosional surface and up to seven terraces the higher planation surface named the exi surface 1800 2000 m a s l and the lower planation surface 1200 1500 m were probably formed in the tertiary prior to 3 4 3 6 ma b p no correlation seems to exist between the drainage networks of earlier period with the present yangtze system it is suggested that the erosional surface found in the study area at 800 1200 m in elevation above sea level was formed in late pliocene of early pleistocene during this period following the last planation event the ancestral yangtze might have begun to adjust its drainage network the seven terraces well developed along the eastern sichuan basin and the three gorges date from early to late pleistocene 1 16 0 01 ma b p the chronostratigraphic evidence and diagnostic sediments are generally comparable in time and space from the sichuan basin through the three gorges to the jianghan basin therefore the present study proposes that the three gorges were cut not later than the initiation of the earliest terrace the fluvial landforms in the yangtze gorges are characterized also by valley in valley cross sections i e an older u shaped valley cut by a younger v shaped valley a tectonic rise accompanied by a rapid downcutting of the river channels predominated in the region

palaeoclimate and palaeoenvironmental responses in the western mediterranean over the last 140 ka evidence from mallorca spain climatic change in the western mediterranean basin over the last 140 ka has been investigated from sediment and soil sequences along the coast of the northeastern part of mallorca spain palaeoclimate and palaeoenvironments are reconstructed from sediment and soil structures marine and terrestrial molluscan fauna grain size distributions mineral magnetics sediment and soil chemistry sem and oxygen isotope values dating is by osl and amino acid geochronometry along with marine molluscan faunal assemblages all oxygen isotope stages and substages from ois 6 to 1 are recorded mean annual temperatures m a t of c 19 2 c for the climatic optimum of the last interglacial compare with c 17 3 c for the present and are associated with high sea level extensive woodland and stable soils although wide temperature ranges are detected during this stage with values as low as c 10 3 c through ois 5d to 5a m a t fluctuated from 8 2 c to 17 9 c low sea level open vegetation effective river activity and aeolian sand and dust deposition characterize 5d and 5b while relatively high sea level and soil development on stable landscapes dominate ois 5c and 5a ois 4 is represented by m a t of c 4 9 c with aeolian sand and loess deposition limited river activity and weak soil development loess deposition persisted into ois 3 but at this time the m a t was c 13 c and with higher humidity and vegetation growth during the lgm ois 2 m a t was c 8 1 c and effective river slope and aeolian processes along with associated with limited vegetation cover were responsible for the most extensive changes in the landscape major rates of change occur during periods of climatic deterioration when the high levels of geomorphic energy were imposed on a landscape undergoing a breakdown of vegetation cover

climate controlled river terrace formation in the kizilirmak valley cappadocia section turkey inferred from ar ar dating of quaternary basalts and terraces stratigraphy abstract this study was carried out on the cappadocia section of the kizilirmak river valley the longest river completely within the borders of turkey 1355 km a staircase of fifteen terraces found in the valley is maintained against erosion at elevations up to 160 m above the current river level the gulsehir karaburna quatenary basalts four basalt flows which cap four terraces were numerically dated for the first time using the ar ar technique the evren ridge basalt 1 160 m above the river level and capping terrace 1 was dated to 1989 4 38 9 ka the karaburna basalt plateau 2 is 128 m above the river level and caps terrace 4 and was dated to 1228 2 46 4 ka the tuzkoy basalt plateau 3 29 m above the river level and capping terrace 12 was dated to 403 8 9 8 ka and the karniyarik hill basalts 4 at 4 5 m above the river level and capping terrace 15 were dated to 96 0 13 0 ka these basalt ages provide minimum ages for the underlying fluvial deposits on the one hand these data show that kizilirmak river incised its valley by 160 m during the last 2 ma of its evolution on the other hand by using terrace sequences and basalt ages the time averaged incision rate of the river during the last 2 ma was determined as approximately 0 08 mm a 1 but important variations within that time span are also apparent the highest incision rate during this period was determined to be 0 12 mm a 1 between the late early and mid middle pleistocene from the numerical chronology terrace stratigraphy and paleosol records it is suggested that the main incision phases of the kizilirmak river led to terrace formation during the cold periods and the deposition phases occurred during the warm periods including cold warm transitions as a result of assigning terraces to marine oxygen isotope stages it was inferred that nearly all terrace levels had formed during the eccentricity driven climate cycles in association with high uplift rates which were interpreted as being complete in the valley

apparent stability of gps monumentation from short baseline time series 1 long running short 1 km gps baselines offer an insight into the accuracy budget of geophysical estimates inferred from gps coordinate time series in this paper we report on analysis of 10 short baselines using data spanning several years and examine deviations from a constant baseline length annual signals with amplitude 0 5 mm are evident in various coordinate components at 6 of the 10 sites with amplitudes exceeding 2 5 mm on two baselines these signals are largely invariant to elevation cutoff angle multipath and phase center model errors are shown to probably have negligible effects at most sites at annual periods they are therefore likely real monument motions although linear thermal expansion is negligible at most sites linear trends 0 25 mm yr 1 are evident on four baselines in at least one coordinate component subdaily signals are present at all sites at k1 and its higher harmonics time correlated noise possibly in the form of flicker noise dominates despite many common signals being eliminated as a result of the small baseline lengths although it is around 1 order of magnitude smaller than for single site ppp solutions we constrain monument random walk motion to be no more than 0 5 mm yr 1 2 if these baseline motion results were representative of the 300 currently active igs sites 180 would have annual signals 0 5 mm in at least one coordinate component 120 would have linear rates 0 25 mm yr 1 and almost all sites would have subdaily k1 k2 signals of 0 1 mm each solely due to local site effects

a comparison of annual vertical crustal displacements from gps and gravity recovery and climate experiment grace over europe 1 we compare approximately 3 years of gps height residuals with respect to the international terrestrial reference frame with predictions of vertical surface displacements derived from the gravity recovery and climate experiment grace gravity fields for stations in europe an annual signal fit to the residual monthly heights corrected for atmospheric pressure and barotropic ocean loading effects should primarily represent surface displacements due to long wavelength variations in water storage a comparison of the annual height signal from gps and grace over europe indicates that at most sites the annual signals do not agree in amplitude or phase we find that unlike the annual signal predicted from grace the annual signal in the gps heights is not coherent over the region displaying significant variability from site to site confidence in the grace data and the unlikely possibility of large amplitude small scale features in the load field not captured by the grace data leads us to conclude that some of the discrepancy between the gps and grace observations is due to technique errors in the gps data processing this is evidenced by the fact that the disagreement between gps and grace is largest at coastal sites where mismodeling of the semidiurnal ocean tidal loading signal can result in spurious annual signals

validation of ocean tide models around antarctica using onshore gps and gravity data 1 ocean tide models around antarctica are presently only sparsely tested against independent data ocean tide modeling errors along with subsequent ocean tide loading otl displacement modeling errors alias into altimetry and time variable gravity e g gravity recovery and climate experiment grace time series for example to validate various ocean tide models around antarctica gps data from 15 sites have been used to derive three dimensional displacement estimates at eight diurnal and semidiurnal tidal frequencies using hundreds of days of gps data harmonic parameters were estimated on a daily basis then combined these were then compared with otl displacement estimates derived from global and regional ocean tide models in east antarctica where the tides are well defined submillimeter differences are demonstrated in each coordinate component with the lunar n2 and q1 constituents in closest agreement as found in other studies k1 and especially k2 agree less well the spatial variation in the misfits for these two constituents indicates a site dependency with the k2 errors also suggesting an interaction with satellite dependent effects in west antarctica where sites are nearer the largest ice shelves agreement with the older models csr3 and tpxo 2 and nao 99b is poor for all constituents modeled tidal gravity variations were also compared with gravity measurements at the south pole overall the gps and gravity data agree best with newer tide models namely tpxo 6 cada00 10 fes99 and cats02 01 however validation data are lacking at the southern extents of the large ice shelves and hence some uncertainty still exists in all ocean tide models in these regions