multiple climatic cycles imprinted on regional uplift controlled fluvial terraces in the lower yalong river and anning river se tibetan plateau abstract the development of fluvial systems on the southeastern margin of the tibetan plateau is linked to significant and rapid late cenozoic uplift the relatively complete fluvial terrace sequence preserved along the yalong river valley and that of its tributary the anning river provides an excellent archive for studying the development of terraces in rapidly uplifting mountainous areas this study reveals that terrace development is predominantly controlled by multiscale climate cycles and long term uplift as shown by terrace dating sedimentary characteristics and incision rates at least six alluvial terrace units were identified in 20 transverse sections through the terraces along about a 600 km length of river and were dated using electron spin resonance esr and optically stimulated luminescence osl the climatostratigraphic positions of the terrace deposits and their respective age constraints suggest that fluvial aggradation was concentrated during marine isotope stages mis 32 22 18 4 2 and the younger dryas yd and that incision occurred during the succeeding cold to warm transitions the changes in fluvial style marked by terraces 6 5 and 4 predominantly occurred in synchrony with the 100 ka milankovitch climate cycles while terraces 3 and 2 were controlled by the obliquity driven 41 ka climate cycles finally the aggradation of terrace t1 occurred in response to the yd stadial during the intervening time between 0 72 and 0 063 ma terraces either did not form or were not preserved which may suggest that uplift rates varied through time and influenced terrace formation preservation the progressive valley incision recorded by these fluvial terraces cannot be entirely explained by climate cycling alone temporal and spatial variations in incision rates indicate that the continuing long term incision has been driven by uplift the temporal distribution of the incision rates reveals two rapidly uplifting stages in the southeastern tibetan plateau including an accelerated uplift that has been taking place since 0 06 ma the spatial distributions of differing incision rates reflect the geomorphological response to crustal shortening and differential uplift in this region

long term fluvial archives in hungary response of the danube and tisza rivers to tectonic movements and climatic changes during the quaternary a review and new synthesis abstract the paper discusses the quaternary evolution of the danube and tisza rivers and their main tributaries in the context of evolution of the entire pannonian basin which is europe s largest intramontane basin within the alp carpathian orogen the palaeo drainage reconstruction of the pannonian basin for the pre quaternary period is outlined in connection with the gradual regression of lake pannon since the late miocene deltas of rivers that entered the basin from the northwest and northeast were gradually transformed into extended alluvial plains thus the earliest possible ancestor of the danube coming southeastwards from the alps could be as old as late miocene by the pliocene the whole lake pannon was infilled the former extensional basin formation was replaced by a compresional stress field which resulted in an uplift of the marginal flanks and late stage subsidence anomalies the increasing relief led to the formation of the quaternary drainage pattern the actively subsiding young basins were filled by fluvial sediments transported by the danube and tisza river systems from the uplifting mountains between the subsiding regions of the little and great plains the danube has formed an antecedent valley with terrace staircases between the uplifting sections of the transdanubian range and the north midmountains the formation of the terraces is attributed to periodic climate changes during the pleistocene combined with differences in the uplift rate the paper gives a complex overview of the classical chronology of the six terraces based on various data sources mostly dating of loess paleosol sequences travertines aeolian sand and tephra strata overlying the fluvial sediments complemented by scattered vertebrate faunal data and archaeological evidence directly from the terrace sediments the quaternary drainage pattern evolution of the great plain with a strong tectonic control is discussed in detail rivers originating from the uplifting marginal areas were drawn towards the subsiding depressions which served as local base level changes in subsidence rates in space and time throughout the quaternary resulted in the evolution of a complex drainage pattern a special emphasis is placed on the late pleistocene holocene development of the middle tisza region and the koros basin where the berettyo koros rivers form an eastern tributary system of the tisza river a comparative evaluation of these two areas is especially relevant as they provide insights into large scale late pleistocene avulsion of the tisza river osl dating complemented with inferred transport directions determined from heavy mineral analysis of fluvial sediments in the koros basin has revealed an ancient large meandering river system that can be identified with the palaeo tisza which was flowing along a tectonically controlled depression during the late pleniglacial successions in the middle tisza region have allowed differentiation between the older channels of the palaeo bodrog river and the sajo hernad alluvial fan and the younger meander belts of the new course of the tisza in the tisza system changes in river style braided to various scales of meandering show correspondence to millennial scale climate changes of the last 25 ka while in the koros basin the effects of tectonics are overprinted onto the regional climatic signals

long term bedload mobility in gravel bed rivers using iron slag as a tracer abstract bedload dispersion is evaluated in gravel bed rivers using slag elements from ironworks established along rivers in the ardenne region between the fourteenth and the nineteenth centuries large quantities of slag were dumped close to these rivers or even directly into the channels for centuries slag elements were dispersed in the bedload and transported by floods of varying importance consequently slag may be considered as a reliable tracer to analyze bedload dispersion over several centuries the size of slag elements was studied along 16 ardenne rivers the longitudinal size trend of the largest slag particles allows the effective competence of these rivers to be determined between 19 and 129 mm for rivers where specific stream power for the bankfull discharge ranges between 20 and 134 w m a direct relationship doesn t exist between these two parameters as the size of slag elements must be considered with regard to the d 50 of the bed selective transport was analyzed directly downstream of the input sites the sorting distance varies from river to river and depends on the velocity of the coarse elements introduced into the river since the inception of the iron industry downstream of two metallurgic sites the slag propagation fronts were located as the periods of activity at these sites are known from historical studies the virtual velocity of bedload movement in these rivers was estimated to be 2 4 km century

40ar 39ar dating of a tephra layer in the pliocene seneze maar lacustrine sequence french massif central constraint on the age of the reunion matuyama transition and implications on paleoenvironmental archives the sedimentary sequence cored in the seneze maar velay france is very favourable for magnetostratigraphy of the late pliocene and for studying the paleoenvironmental changes that occurred during that period the magnetostratigraphic studies revealed that the sediments from this lacustrine sequence were deposited during the matuyama reverse period except for the upper part where a short normal polarity episode was recorded a tephra layer interbedded in the sediments contemporaneous with this normal polarity event is dated at 2 10 0 01 ma by the 40ar 39ar method using this chronological marker it can be inferred that the normal polarity episode recorded in the seneze sequence corresponds to the reunion event and that the age of the normal reverse transition closing this event is ca 2 09 ma these chronological constraints also permit to 1 demonstrate that the villafranchian mammal fauna found in the seneze maar is younger than 2 09 ma and 2 correlate the climatic events recorded in the seneze sequence to the marine d18 o records this suggests that the seneze pollen sequence 5 120 m depth ranges from isotopic stage 85 to 76

the fluvial system research perspectives of its past and present dynamics and controls abstract during the conference the fluvial system past and present dynamics and controls held at the department of geography of bonn university from 16 to 22 of may 2005 the participants organised in 12 international organisations working in the fluvial environment were asked about their opinions about the main aspects to be considered for sustainable progress in future research projects the individual comments can be grouped by the following headlines integration and application of experiences considering system analytical approaches considering effects of climate and global change interdisciplinary work regarding extreme events and their frequencies and quantification of human impact detailed explanations and selected references of previous studies initially considering the mentioned aspects are given as a review

interaction of fluvial and eolian sedimentation processes and response to climate change since the last glacial in a semiarid environment along the yellow river interactions of fluvial and eolian processes are prominent in dryland environments and can significantly change earth surface morphology here we report on sediment records of eolian and fluvial interactions since the last glacial period in the semiarid area of northwest china at the limit of the southeast asian monsoon sediment sequences of last glacial and holocene terraces of the yellow river are composed of channel gravels overlain by flood sands eolian dunes and flood loams these sequences dated by optically stimulated luminescence record interlinks between fluvial and eolian processes and their response to climate change sedimentologic structures and grain size analysis show flood loams consisting of windblown sediment deposited from floodwater suspended sediment the gravel and sand were deposited during cold periods during transitions from cold to warm phases the river incised and dunes were formed by deflation of channel and floodplain deposits 70 and 21 16 ka dunes also formed at 0 8 ka probably after human intervention after dune formation flood loam covered dunes without erosion during peak discharges at the beginning of the subsequent warm period the fluctuations of the southeast asian monsoon as a moisture transporting agent have perhaps been the driving force for interactions between fluvial and eolian processes in this semiarid environment

comment on how plausible are high frequency sediment supply driven cycles in the stratigraphic record by s castelltort and j van den driessche 2003 sedimentary geology 157 3 13

linking morphology across the glaciofluvial interface a 10be supported chronology of glacier advances and terrace formation in the garonne river northern pyrenees france abstract the garonne river drains an important part of the northern pyrenees and its northern foreland we investigated the middle reaches of the garonne river establishing a detailed morphogenetic profile of its foreland terrace staircase and the preserved palaeoglacier margins we particularly focussed on the glaciofluvial interface linking also genetically the fluvial sediment archives in the foreland with the terminal glacial basin upstream of the pyrenees mountain front using cosmogenic nuclide 10be analyses two terrace exposures have been dated including a prominent fluvioglacial outwash fan at the foreland transition we identified three terminal margins of late pleistocene glacier advances the prominent garonne staircase consists of three major terrace complexes comprising eight individual terrace levels results indicate a young age of the lower terrace complex of the garonne staircase mis 4 2 the morphogenetic relationships and the new 10be exposure age constraints suggest that during the last glaciation wurmian the garonne glacier reached its maximum extent at the north pyrenean mountain front apparently already during mis 4 two different ice margins were associated with mis 2 indicating close to maximum ice extent during early mis 2 lgm and relatively stationary ice recession in the late mis 2 the extensive garonne terrace complexes formed under cold climate conditions and were abandoned by incision during major glacial interglacial transitions during warm cold climate transitions lateral erosion caused the reworking of previously abandoned palaeofloodplains the long term quaternary incision of the garonne and other north pyrenean rivers indicates that the proximal aquitaine foreland basin experienced uplift however non uniform lateral course migrations and valley asymmetries of the north pyrenean piedmont rivers indicate that uplift magnitude is variable with maximum amounts in the centre of the molasse fan of lannemezan rivers on the western part of the fan were tilted toward the west whereas rivers in the eastern part like the garonne were tilted to the east

faunal remains from the oldowan site of muhkai ii in the north caucasus potential for dating and palaeolandscape reconstruction abstract the results of study of faunal materials unique for the north eastern caucasus are published deriving from layer 80 of the oldowan site of muhkai ii twenty six specimens of four species of carnivorous mammal and six species of herbivorous mammal were identified in this material in addition the remains of small mammals reptiles and amphibians were identified which are indicators for the dating of the assemblage and the establishment of the specific characteristics of the natural environment at the time of usage of the oldowan site while in the modern day the investigated region consists of a belt of medium high mountains during the chronological period under study open landscapes of savannah type with small areas of forest vegetation dominated based on a combination of data from palaeomagnetic analysis and faunal determinations the time of existence of the complex is established as no later than the lower limit of the olduvai episode during the matuyama palaeomagnetic epoch

sedimentary basins tectonic recorders of sediment discharge from drainage catchments the sedimentary basin is to geology what the drainage system is to geomorphology with sediment flux being a unifying link between the two features and disciplines the global sediment discharge from contents to oceans contributes to major mass recycling associated with plate subduction major plate reorganization is accompanied by small fluctuations in continental volumes due to recycling of sediment stored along the sink like passive margins in continental sedimentary basins the sediment preservation ratio sepra depends upon the tectonic drawdown of sediment flux preserved in the subsurface until basin inversion major unsteadiness in sediment discharge arises from teconic or climatic causes the latter prominent in the quaternary to holocene record contrasting trends in sediment discharge reflect both the nature of climate and vegetation change and source rock lithology 1997 by john wiley sons ltd

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

estimating small permanent rotation from strong motion records what is comparison with external measurements telling us abstract modern strong motion accelerometers record instruments translational accelerations as well as their rotation based on a detailed analysis of the low frequency content of acceleration records javelaud et al 2011 removed the permanent tilt information from strong motion records the accuracy of permanent rotation angles derived from acceleration time histories can be checked by comparison with external rotation information in practice this can be done at exceptional sites that experience earthquake induced permanent rotation and where the permanent rotation is recorded by various instruments situated above a hidden fault and located 4 km from the epicenter during the 2000 m j 7 3 western tottori earthquake in japan kasho dam experienced very strong shaking and a homogeneous tectonic rotation of about 1 5 10 4 rad over the dam and its reservoir areas because the dam is well instrumented plumb line strong motion seismometers pre and post earthquake ground surveys it makes an ideal site to check the accuracy of tectonic permanent rotation estimated from records of the strong motion seismometer located at the dam s foundation as a result of this benchmark the permanent rotation obtained from the analysis of strong motion acceleration time histories is consistent with external measurements which validates the methodology used and that strong motion time histories can be used to estimate permanent rotation

a 40 ka record of temperature and permafrost conditions in northwestern europe from noble gases in the ledo paniselian aquifer belgium the ledo paniselian aquifer in belgium offers unique opportunities to study periglacial groundwater recharge during the last glacial maximum lgm as it was located close to the southern boundary of the ice sheets at that time groundwater residence times determined by 14c and 4he reveal a sequence of holocene and pleistocene groundwaters and a gap between about 14 and 21 ka indicating permafrost conditions which inhibited groundwater recharge in this paper a dataset of noble gas measurements is used to study the climatic evolution of the region the derived recharge temperatures indicate that soil temperatures in the periods just before and after the recharge gap were only slightly above freezing supporting the hypothesis that permafrost caused the recharge gap the inferred glacial cooling of 9 5 c is the largest found so far by the noble gas method yet compared to other palaeoclimate reconstructions for the region recharge temperatures deduced from noble gases for the cold periods tend to be rather high most likely this is due to soil temperatures being several degrees higher than air temperatures during periods with extended snow cover thus the noble gas derived glacial cooling of 9 5 c is only a lower limit of the maximum cooling during the lgm some samples younger than the recharge gap are affected by degassing possibly related to gas production during recharge in part of the recharge area especially during times of melting permafrost the findings of this study such as the occurrence of a recharge gap and degassing related to permafrost and its melting are significant for groundwater dynamics and geochemistry in periglacial areas copyright 2010 john wiley sons ltd

climate related river activity at the weichselian holocene transition a comparative study of the warta and maas rivers huvial systems from the dutch and polish lowlands are compared for their evolution during the weichselian deglaciation period in both regions the pleniglacial braided river pattern changed to a meandering pattern in the beginning of the lateglacial several transitional stages between braided and high sinuosity meandering systems have been recognized a difference in fluvial activity is found during the younger dryas when the maas transformed to a braided pattern while the warta maintained its meandering pattern phases of erosion and aggradation are more or less synchronous in the different river basins but their intensity may differ greatly the major characteristics of the fluvial systems are obviously a response to the general climatic evolution and related to changes in vegetation the regional differences are of minor importance and can be explained by site specific factors threshold values within the latter factors define the changes in river dynamics

late quaternary linkage of sedimentary records to three astronomical rhythms and the asian monsoon inferred from a coastal borehole in the south bohai sea china abstract the bohai sea was formed by subsidence during the cenozoic some 2000 3000 m of fluvial lacustrine and marine sediments has been deposited in this basin previous studies focused mainly on the transgression history with little examination of orbital variation in relation to other areas within the asian monsoon domain here we present the late quaternary results of a new borehole in the south bohai sea optically stimulated luminescence and radiocarbon dating which provide concordant age estimates were employed to generate an initial chronology for the borehole after refining the chronology through astronomical tuning the results showed that 1 the grain size variation represents asian monsoon intensity which was dominated by both solar insolation major and global ice volume minor forcing 2 the magnetic susceptibility indicates river incision processes which were sensitive to orbital tilt with influence from solar insolation 3 the vegetation coverage responded to global ice volume coupled obliquity changes and that 4 neither external nor internal factors could dominate the paleoenvironmental evolution on orbital timescales in an independent way and they are both integrated in a complex pattern we conclude that three different astronomical rhythms have affected coastal evolution and that the sedimentary records in the south bohai sea china result from the nonlinear interaction and the complex response to driving processes

holocene floodplain sediment storage and hillslope erosion within the rhine catchment the response of fluvial systems to land use and climate change varies depending on catchment size while forcing response mechanisms of small catchments are reasonably well understood the response of larger drainage basins is less clear in particular the impact of land use and climate change on the rhine system is poorly understood because of the catchment size 185 000 km 2 and the long history of human cultivation which started approximately 7500 years ago a sediment budget is calculated to specify the amount of alluvial sediment that was deposited during the holocene and to estimate long term soil erosion rates the results suggest that 599 14 10 9 t of holocene alluvial sediment is stored in the non alpine part of the rhine catchment south and central germany eastern france the netherlands about 50 of holocene alluvial sediment is deposited along the trunk valley and the delta upper rhine lower rhine coastal plain while the rest is stored along the tributary valleys the floodplain sediment storage corresponds to a mean erosion rate of 0 559 0 16 t ha per yr 38 59 10 7 mm kyr across the rhine catchment outside the alps this holocene averaged estimate amounts for sediments that were delivered to the channel network and is at the lower limit of erosion rates from other studies of different methodology

a quantitative approach for estimating coseismic displacements in the near field from strong motion accelerographs the translational accelerations recorded by strong motion seismometers are often contaminated by baseline offsets that prevent recovering theground displace ments by double integration detailed analysis of the k net95 strong motion seis mometer and the improvement of the visual display of the recorded accelerations fourier transform by addition of long zero pads to the acceleration records made it possible to distinguish the origins of the long period noise that contaminate the translational accelerations recorded in the near field of two studied earthquakes the 2004 niigata ken chuetsu earthquake and the 2007 niigata ken chuetsu oki earthquake japan they are the residual rotation of the instrument residual tilt or the 1 f digital semiconductor noise the quantification of these two terms allows us to discuss the low frequency content of the records and to describe when it is possible to obtain realistic displacement time histories it happens when the residual tilt is removed in the time domain or when the 1 f semiconductor noise overshadows the translational acceleration records up to sufficiently small frequencies as a check of the method displacement time histories obtained from acceleration records are compared with nearby 1 hz gps data good similitudes are obtained in the near field for collocated instruments online material figures showing acceleration velocity and displacement time series and acceleration spectra for 18 records

climatic vs tectonic controls on peat accretion in non marine setting an example from the žacleř formation yeadonian bolsovian in the intra sudetic basin czech republic abstract the acle coalfield in the western part of the intra sudetic basin is an example of coal accumulation in an alluvial valley deposited under a long term 3 m y stable tectonic regime with climatic oscillations possibly operating on several time scales the resulting sedimentary record about 600 m thick encompasses about 60 coal bearing cycles formed in a relatively small and localized part of the valley whereas elsewhere a higher clastic input and or lower rate of subsidence resulted in deposition of strata with very little coal available data suggest that tectonics produced accommodation for sediments and via changes in topography and or size of the source area affected the volume and dispersal patterns of clastic material transported to the depocentre areas with long term tectonic stability were suitable places for recognition of climatic signals in the sedimentary record modified by the intensity of local clastic input climatic fluctuations generated coal bearing cycles probably through a variable intensity of precipitation which affected the density of vegetation cover across the landscape along with evaporation and groundwater table these factors influenced the intensity of chemical weathering and hence regulated the volume and composition of clastics delivered to the depocentre this in turn resulted in alternation of short periods of bedload dominated deposition during the seasonally dry part of the cycle with periods of dominantly suspended load and organic peat deposition during the more humid everwet part of the cycle estimated duration of the basic cycles 46 k y approximates the orbitally driven axial tilt cyclicity basic cycles are arranged into two larger scale cyclic patterns lasting for 270 k y and 1 5 m y respectively which broadly correspond with the timing of glacial maxima and minima inferred from high latitude glacial deposits of gondwanan basins all the coals of the acle coalfield display similar petrographic composition dominated by collotelinite and field observations as well as detailed petrographic study show that they formed in planar rheotrophic peat swamps where long lasting peat accretion was episodically interrupted only by major floods on a century to millennial scale

differentiating pleistocene tectonically driven and climate related fluvial incision the sanggan river datong basin north china the sanggan river is an alluvial river flowing through a graben basin system of the northern shanxi rift zone north china during pleistocene times the river reach in the datong basin was affected successively by various external variables such as invasion by basaltic flow along valley faulting and climatic change therefore it provides excellent constraints for differentiating tectonically driven and climate related fluvial incision in the context of tectonic subsidence based on equilibrium profile analysis k ar dating of basalts 0 74 0 41 ma studies of the river terrace and of stream action history we present a conceptual model for differentiating fault driven and climate related fluvial incision by the river the results show that fluvial incision induced by tectonic lowering of the base level due to along valley movement on the sanggan river fault is equal to fault displacement the amount of post basalt fluvial incision of the reach upstream from the lava dam is 23 to 25 m of which the fault driven and climate related incisions are 15 m and 8 to 10 m respectively the former predominating over the latter the total amount of incision in the lava dam reach is 40 to 47 m of which the fault driven and climate related incisions are 10 m and 30 37 m respectively here the latter is predominant over the former since 0 41 0 10 ma the rate of fluvial incision of the lava dam reach of the river has reached 98 115 m ma which is 1 5 2 times as great as those of the reaches upstream and downstream from the lava dam the higher rate of fluvial incision can be attributed to high water levels supplied by the onset and maintenance of backwater conditions in the reach upstream from the lava dam due to the long period of warm and humid climate in this region plucking abrasion and knickpoint migration appear to be the primary erosional processes in the lava dam reach

interpreting drivers of change in fluvial archives of the western mediterranean a critical view abstract fluvial archives in particular late glacial to holocene floodplain records may provide valuable information regarding past environmental conditions and stages of landscape evolution in view of the high significance of floodplain dynamics for the development of entire landscapes the number of studies that have been performed on floodplain sediments remains comparatively low especially regarding the western mediterranean region however one of the reasons could be seen in the high complexity and diversity of processes and factors that control and influence fluvial activity that often hampers a straightforward interpretation of floodplain dynamics therefore a basic demand on fluvial archive research is to address the complexity of the factors that control the characteristics of fluvial sequences in order to provide a robust basis for their interpretation as a starting point for discussion this paper aims to give an overview of fluvial dynamic patterns in the western mediterranean for the last 15 ka in order to examine their relevance for palaeoenvironmental reconstructions the basis for this is provided by previous investigations on four different river systems in spain and northern africa the results of which are herein synthesized in order to propose a regional late pleistocene and holocene fluvial history for the western mediterranean realm basic results are related to alluvial floodplain deposits and visible features within them such as alluvial soils incision marks and aggradation phenomena since fluvial systems are open systems we discuss our findings against the background of different influencing factors that could modify fluvial architecture and may restrict palaeoenvironmental reconstructions a more comprehensive interpretation focuses on signals that are common to each of the studied river systems in this respect we critically discuss the customary nature of cumulative probability functions for the identification of regional flooding episodes and point out the benefits of a stratigraphy supported approach for characterizing regional floodplain dynamics finally three alluvial soil formation periods were found in all settings a first phase after 15 ka ending with the younger dryas event a second one from 7 to 5 ka with a break between 6 5 and 5 5 ka and a third phase between 3 and 2 ka these soil formation periods were interrupted and framed by fluvial dynamic phases accompanied by channel aggradation floodplain deposition floodplain erosion and or river incision in particular after 5 ka around 1 6 and at 1 ka and during the little ice age lia floodplain aggradation affected river systems in iberia and northern africa as well a cautious assessment of these results and extensive comparisons with secondary archive information prompts us to relate the aggradation periods with climate forcing by means of a supra regional aridification that effected large areas of the western mediterranean in contrast the three mentioned soil formation periods can be linked with landscape stability most probably triggered by favorable climate conditions in the western mediterranean apart from these large scale patterns we discuss the reliability of information emerging from floodplain records against the background of individualistic river behavior and self organization regarding future work we want to emphasize the great potential of yet rarely applied system oriented approaches that also attach importance to sub catchment dynamics as a link between catchment slopes and the main river floodplain

late glacial sedimentological and morphological changes in a lowland river in response to climatic change the maas southern netherlands the late pleniglacial and late glacial maas valley south of nijmegen contains four terraces three river systems are described based on the morphology of channel scars on these terrace surfaces and by sediment characteristics the river maas reacted to climatic warming at the start of the weichselian late glacial by changing its river system slowly from a braided system to a transitional phase between braiding and meandering and finally to a highly sinuous meandering system the maas reacted rapidly to the younger dryas climate deterioration by again establishing a braiding system at the onset of the holocene the river changed abruptly to a meandering river without a transitional phase the triggering factor for change in the maas river pattern is almost certainly the changing climate in the late glacial gradient lines on the terrace surfaces show that tectonic activity did not modify the morphology of the channels a division of the terraces is shown the morphological sedimentological and petrographical characteristics are presented and the linking of changing fluvial patterns with climatic changes or tectonic movements is discussed 1997 john wiley sons ltd

controls on channel sinuosity changes a case study of the tisza river the great hungarian plain abstract the planform geometry of the tisza the trunk river of the subsiding great hungarian plain is studied by reconstruction of the last pre regulation river course the thalweg sinuosity has been computed for the main alluvial section of the river remarkable sinuosity changes have been found to correlate with discharge and sediment load changes at the inflow of tributaries as well as with active deformation areas like differential subsidence and wrench fault zones analysing the change of the river pattern a new discrimination line has been derived which separates the meandering zone on the classic slope vs discharge diagram into two subzones the first subzone lower slope values corresponds to a range of true self organized meandering the second subzone higher slope values corresponds to a range of unorganized meandering this is a range where river sinuosity decreases although the channel slope increases in the case of the tisza river this subzone equals to the wandering river pattern

the fluvial cycle at cold warm cold transitions in lowland regions a refinement of theory abstract a previously established non linear theory of river cyclicity as a response to climate change states that short phases of fluvial instability occur both at the transition from relatively warm temperate to cold periglacial and from relatively cold to warm periods such instability typically starts with vertical erosion successively followed by sedimentary fill of the erosive scar in spite of frequent confirmation of this theory by geomorphological reconstructions a few problems arise first there are fewer incision phases than climatic transitions secondly remnants of erosion at cold warm transitions are scarce in contrast to obvious erosion relics at warm cold transitions furthermore it appears that the incision style is strikingly different at both kinds of climatic transitions similarly the long stable phases are also expressed in terms of different floodplain development in cold and warm periods these arguments require a modification of the general non linear theory at the transition from relatively temperate to colder conditions rivers transformed gradually from a regular low energy single channel course to a periodically high energy multi channel type the latter braided type is characterized by intense lateral movement rather than by deep vertical erosion this results in a well expressed morphology of wide extensive floodplains and terraces in contrast the linear and constrained meandering channels incise with small width depth ratio and build floodplains of limited lateral extent consequences are twofold 1 the spatial limitation of the deeply incised meandering valleys at the beginning of warm periods counts against their recognition 2 relatively strong lateral migration of the braided rivers removes most traces of previous meandering systems which contrasts with the limited lateral activity of confined meandering channels it means that in a warm cold warm alternation generally only one phase of vertical erosion is preserved the one that is caused by the high energy braided river at the start of the cold period

sensitivity of weichselian fluvial systems to climate change nochten mine eastern germany abstract this paper aims to contribute to the understanding of fluvial system response to climate change during the last glacial interglacial cycle fluvial and aeolian successions have been studied in the opencast brown coal mine nochten in eastern germany an absolute chronology was established by luminescence and 14 c dating enabling to demonstrate the relations between depositional units and changes in sedimentary environment over time with regional climatic and vegetational changes it is concluded that the major climatic periods coinciding with the oxygen isotope stages are generally reflected in the fluvial sequence by distinct fluvial environments major climatic changes oxygen isotope stage boundaries have been preserved in the fluvial record as erosional bounding surfaces and by changes in fluvial style rapid climate changes like the middle pleniglacial dansgaard oeschger cycles are in general not reflected in the fluvial succession these cycles were too short or with too low amplitude to cause a strong vegetational response and related changes in water and sediment supply it is emphasized that also the preservation potential of short lived climatic warming events in high energy fluvial systems is low warming events may however have been preserved in lacustrine successions in former thermokarst lakes a strong cooling event at ca 40 ka leading to continuous permafrost conditions and changes in the water and sediment budget was reflected in the fluvial archive by a change from sandy anabranching to braided river conditions

late pliocene and pleistocene small mammal chronology in the italian peninsula the abundant documentation of small mammals in the italian peninsula collected over recent years furnishes a detailed biochronological sequence mainly from the late pliocene onwards an updated stratigraphic framework is here presented based on the european small mammal biozonation the early villanyian is characterized by mimomys hassiacus m stehlini and later poorly documented m polonicus the late villanyian localities are well characterized with m pliocaenicus m pitymyoides and m tigliensis the older part of the early biharian is documented by assemblages containing microtus allophaiomys ex gr pliocaenicus m pusillus m cf ostramosensis and m tornensis while the later part of the early biharian is characterized by advanced microtus allophaiomys species occurring together with m pusillus or m blanci in the late biharian m savini microtus hintoni gregaloides microtus iberomys ex gr huescarensis brecciensis and terricola arvalidens occur the early toringian with a mosbachensis allocricetus bursae pliomys episcopalis and small sized microtus brecciensis and the late toringian with a terrestris in diversified associations are quoted the most important faunal events are calibrated by independent chronological controls thanks to the record of small mammals from lacustrine deposits several figures illustrate the most significant rodent species occurring in the succession of selected italian localities

reliable displacement response spectra at long periods in the near field of large earthquakes displacement response spectra defined up to long periods are needed for the design of large structures and to design structures according to displacement based methods the spectra can theoretically be retrieved in the near field of large earthquakes from accelerations recorded by modern strong motion accelerometers difficulties exist due to instrumental limitations long period noise that contaminates the acceleration time histories and record of the tilt simultaneously to the translational accelerations original in this work the effect of the instrument s permanent tilt is investigated and the improvement of the spectra at long periods when the residual tilt is removed from accelerations recorded by modern strong motion seismometers is checked against 1 hz global positioning system gps measurements records of five strong motion accelerometers situated in the near field of the m w 6 8 japanese 2007 niigata ken chuetsu oki earthquake are analyzed in terms of fourier content and displacement response spectra and are then compared to their closest 1 hz gps data the results show that the uncorrected acceleration time histories obtained by simply removing the preevent mean from the raw accelerations recorded by modern strong motion seismometers provide reliable displacement response spectra at periods over 20 s corrected acceleration time histories obtained by removing the permanent tilt from the uncorrected records using the javelaud et al 2011 method may provide reliable response spectra at very long periods until they reach the theoretical peak ground displacement

on baseline corrections and uncertainty in response spectrafor baseline variations commonly encounteredin digital accelerograph records most digital accelerograph recordings are plagued by long period drifts best seen in the velocity and displacement time series obtained from integration of the acceleration time series these drifts often result in velocity values that are nonzero near the end of the record this is clearly unphysical and can lead to inaccurate es timates of peak ground displacement and long period spectral response the source of the long period noise seems to bevariations in the acceleration baseline in many cases these variations could be due to true ground motion tilting and rotation as well as local permanent ground deformation instrumental effects or analog to digital con version very often the trends in velocity are well approximated by a linear trend after the strong shaking subsides the linearity of the trend in velocity implies that no vari ations in the baseline could have occurred after the onset of linearity in the velocity time series this observation combined with the lack of any trends in the pre event motion allows us to compute the time interval in which any baseline variations could occur we then use several models of the variations in a monte carlo procedure to derive a suite of baseline corrected accelerations for each noise model using records from the 1999 chi chi earthquake and several earthquakes in turkey comparisons of the mean values of the peak ground displacements spectral displacements and resid ual displacements computed from these corrected accelerations for the different noise models can be used as a guide to the accuracy of the baseline corrections for many of the records considered here the mean values are similar for each noise model giving confidence in the estimation of the mean values the dispersion of the ground motion measures increases with period and is noise model dependent the dispersion of in elastic spectra is greater than the elastic spectra at short periods but approaches that of the elastic spectra at longer periods the elastic spectra from the most basic proces sing in which only the pre event mean is removed from the acceleration time series do not diverge from the baseline corrected spectra until periods of 10 20 sec or more for the records studied here implying that for many engineering purposes elastic spec tra can be used from records with no baseline correction or filtering

a typology of pleistocene cold based rivers abstract a classification of periglacial rivers is proposed it is based on the generally valid laws relating the ratio of stream power to bed load with fluvial processes and morphology however river patterns may be modified by the special characteristics of the periglacial environment snowmelt especially in areas of continuous permafrost and river ice especially in zones of discontinuous permafrost determine the respective hydrological regimes the frozen state of the subsoil as well as the density of the vegetation cover contributes significantly to the bank cohesion and the sediment load of the rivers these specific periglacial characteristics have a complex influence on the thresholds in river activity resulting in a high diversity of periglacial river types

paleocurrent and fabric analyses of the imbricated fluvial gravel deposits in huangshui valley the northeastern tibetan plateau china abstract gravel deposits on fluvial terraces contain a wealth of information about the paleofluvial system in this study flow direction and provenance were determined by systematic counts of more than 2000 clasts of imbricated gravel deposits in the xining region northeastern tibetan plateau china these gravel deposits range in age from the modern huangshui riverbed to miocene aged deposits overlain by eolian sediments our major objectives were not only to collect first hand field data on the fluvial gravel sediments of the xining region but also to the reconstruct the evolution of the fluvial system these data may offer valuable information about uplift of the northeastern tibetan plateau during the late cenozoic era reconstructed flow directions of the higher and lower gravel deposits imply that the river underwent a flow reversal of approximately 130 180 in addition the lithological compositions in the higher gravel deposits differ significantly from the lower terraces suggesting that the source areas changed at the same time eolian stratigraphy overlying the gravel deposits and paleomagnetic age determination indicate that this change occurred sometime between 1 55 ma and 1 2 ma we suggest that tectonic activity could explain the dramatic changes in flow direction and lithological composition during this time period therefore this study provides a new scenario of fluvial response to tectonic uplift a reversal of flow direction in addition field observation and statistical analyses reveal a strong relationship between rock type size and roundness of clasts

sedimentary history of the western bohai coastal plain since the late pliocene implications on tectonic climatic and sea level changes abstract thick cenozoic deposits from the western bohai coastal plain a tectonic subsiding region provide the potential to study the relations between sedimentary environments and tectonic climatic and sea level changes however sedimentary history of this region extending to the whole quaternary as well as their links to tectonic climatic and sea level changes are still poorly understood mainly because of the lack of long term records with well constrained chronology in this study we present an integrated record based on sedimentology and proxies grain size and color reflectance of a 203 6 m core recovered from the western bohai coastal plain near tianjin the core was chronologically well constrained using paleomagnetic and optically stimulated luminescence dating methods the results show that from the late pliocene 3 3 ma to the late pleistocene 0 10 ma the study region was mainly dominated by fluvial setting and the extensive incursion of sea water into this region began during the last interglacial period 0 10 ma the sedimentology and the color index suggest that tectonic subsidence of the bohai basin during the plio quaternary must have played a significant role in controlling the sedimentary environments in this region the changes in base level because of sea level fluctuations during the quaternary influenced the fluvial development greatly and led to the alternations of coarse crevasse splay channel and finer floodplain deposits in the core sequence in addition climatic changes since the late pliocene also have had significant effects on the sedimentary settings in the bohai coastal plain by influencing the fluvial process with a series of mechanisms

late quaternary sedimentation history of the lena delta abstract core and outcrop analysis from lena mouth deposits have been used to reconstruct the late quaternary sedimentation history of the lena delta sediment properties heavy mineral composition grain size characteristics organic carbon content and age determinations 14c ams and ir osl are applied to discriminate the main sedimentary units of the three major geomorphic terraces which form the delta the development of the terraces is controlled by complex interactions among the following four factors 1 channel migration according to the distribution of 14c and ir osl age determinations of lena mouth sediments the major river runoff direction shifted from the west during marine isotope stages 5 3 third terrace deposits towards the northwest during marine isotope stage 2 and transition to stage 1 second terrace to the northeast and east during the holocene first terrace deposits 2 eustasy sea level rise from last glacial lowstand to the modern sea level position reached at 6 5 ka bp resulted in back filling and flooding of the palaeovalleys 3 neotectonics the extension of the arctic mid ocean ridge into the laptev sea shelf acted as a halfgraben showing dilatation movements with different subsidence rates from the continent side differential neotectonics with uplift and transpression in the siberian coast ridges are active both likely have influenced river behavior by providing sites for preservation with uplift in particular allowing accumulation of deposits in the second terrace in the western sector the actual delta setting comprises only the eastern sector of the lena delta 4 peat formation polygenetic formation of ice rich peaty sand ice complex was most extensive 7 11 m in thickness in the southern part of the delta area between 43 and 14 ka bp third terrace deposits in recent times alluvial peat 5 6 m in thickness is accumulated on top of the deltaic sequences in the eastern sector first terrace

modeling the response of the rhine meuse fluvial system to late pleistocene climate change abstract we use a landscape evolution model to infer the effect of late pleistocene climate change on the incision aggradation behaviour of the rhine meuse fluvial system we model the routing of runoff and sediment in the catchment in order to predict grainsize trends and the incision and aggradation behaviour in the downstream reach where we compare it to the sequence of events and grainsize characteristics inferred from borehole corings this sequence starts with an important incision taking place around the mis 3 to mis 2 climatic transition during the coldest part of mis 2 a coarse grained sedimentary unit is deposited that shows an upward increase in the sand gravel ratio the model experiments do not predict an incision at the mis 3 to mis 2 transition therefore the incision should be attributed to other causes most likely effects of glacio isostatic uplift however a relative upward increase in sand content of the sediments is predicted by the model this increase is the result of the difference in transport rates between sand and gravel starting from a homogeneous pre existing mis 3 deposit the gravel content in the active layer increases because the sand is removed quickly and transported further downstream whereas the gravel travels slowly and piles up with gravel originating from immediately upstream resulting in a net accumulation at a later stage sand originating from much further upstream progrades fan like over the gravelly deposits according to the record during the early late glacial warming part of mis 2 bolling allerod interstadial neither incision nor aggradation has taken place this is in accordance with modelling results which show that despite the reduction of sediment input due to re vegetation of hillslopes sufficient sediment remains available for fluvial transport in the channel network itself it takes several thousands of years before effects of sediment depletion in the catchment are noted downstream that is why we argue that the inferred incision at the late late glacial the start of the younger dryas in our downstream study area might reflect depletion effects related to the preceding early late glacial conditions in general our modelling results show that terraces along one large fluvial system are diachronic features in particular terrace surfaces are older upstream compared to downstream in addition complex responses to climate change are likely to occur in a large fluvial system like the rhine meuse and correlation of morphological features in the fluvial record to specific short term palaeo climatic events for example dansgaard oeschger events could be risky without consideration of catchment size characteristics and associated response times

lacustrine fluvial interactions in australia s riverine plains climatic forcing of fluvial systems has been a pre occupation of geomorphological studies in australia since the 1940s in the riverine plain southeastern australia the stable tectonic setting and absence of glaciation have combined to produce sediment loads that are amongst the lowest in the world surficial sediments and landforms exceed 140 000 yr in age and geomorphological change recorded in the fluvial fluvio lacustrine and aeolian features have provided a well studied record of quaternary environmental change over the last glacial cycle the region includes the willandra lakes whose distinctive lunette lakes preserve a history of water level variations and ecological change that is the cornerstone of australian quaternary chronostratigraphy the lunette sediments also contain an ancient record of human occupation that includes the earliest human fossils yet found on the australian continent to date the lake level and palaeochannel records in the lachlan willandra system have not been fully integrated making it difficult to establish the regional significance of hydrological change here we compare the willandra lakes environmental record with the morphology and location of fluvial systems in the lower lachlan an ancient channel belt of the lachlan willandra creek acted as the main feeder channel to willandra lakes before channel avulsion caused the lakes to dry out in the late pleistocene electromagnetic surveys geomorphological and sedimentary evidence are used to reconstruct the evolution of the first new channel belt following the avulsion single grain optical dating of floodplain sediments indicates that sedimentation in the new middle billabong palaeochannel had commenced before 18 4 1 1 ka a second avulsion shifted its upper reaches to the location of the present lachlan river by 16 2 0 9 ka the timing of these events is consistent with palaeohydrological records reconstructed from willandra lakes and with the record of palaeochannels on the lachlan river upstream willandra lakes shows high inflows during the last glacial maximum 22 ka but their subsequent drying between 20 5 ka and 19 ka was caused by river avulsion rather than regional aridity this case study highlights the benefits of combining fluvial with lacustrine archives to build complementary records of hydrological change in lowland riverine plains

comparisons of ground motions from colocated and closely spaced one sample per second global positioning system and accelerograph recordings of the 2003 m 6 5 san simeon california earthquake in the parkfield region the 2003 san simeon california earthquake m 6 5 generated a set of colocated and closely spaced high rate 1 sample per second global positioning system gps positions and ground motions from digital accelerographs in the park field region at epicentral distances of 50 to 70 km the waveforms of displacements derived from the 13 gps receivers in the region have dominant periods between about 7 and 18 sec the waveforms are similar in shape with a systematic change in waveform as a function of distance from the source the gps motions are smaller than the accelerograph motions for periods less than about 2 sec from this we conclude that the 1 sample per sec gps receivers provide a good representation of ground motion at periods longer than about 2 sec perhaps more important for earth quake engineering is that the accelerograph data are similar to the gps data for periods as long as 30 sec if not longer this means that data from digital accelero graphs can provide reliable relative displacement response spectra at the periods needed in the design of large structures at least for earthquakes with magnitudes of 6 5 or above at distances within 70 km we combine the colocated or very closely spaced gps and accelerograph data sets in the frequency domain to obtain a single broadband time series of the ground motion at each accelerograph station these broadband ground motions may be useful to seismologists in unraveling the dynamic process of fault rupture and to engineers for designing large structures with very long period response

biochronology and biochron boundaries a real dilemma or a false problem an example based on the pleistocene large mammalian faunas from italy abstract reconstructing the neogene quaternary biostratigraphy in continental environments and recognising boundaries between successive mammalian faunal complexes is a problematic task the definition and application of biochronology has been often tainted by references to and inferences from biostratigraphy actually the discontinuities in the continental sedimentary record environmental conditions taphonomic and sampling biases are responsible for the fact that the stratigraphical order of the lowest and highest occurrences of fossil remains stratigraphic datum does not necessarily reflect the temporal order of actual first last appearances of taxa palaeobiological events in time nonetheless the first last appearance bioevents recorded by lowest highest occurrences of fossil remains in fossiliferous levels of different continental stratigraphical successions have been the principal foundation for establishing the biochronological setting of continental mammal faunas therefore from a theoretical point of view boundaries should be defined by the oldest and or youngest historical occurrence of one or more taxa what about an operational approach some examples of the italian faunas are presented focusing on the transition from the villafranchian to the galerian and from the galerian to the aurelian land mammal ages the results obtained indicate the difficulty of defining a stable scheme that can be applied for correlation by the international scientific community

timescales climate and river development abstract in the long term glacial interglacial sequences river development follows general climatic evolution however at the scale of one cold warm cycle it appears that the geomorphological effect of river activity is best expressed at times of climatic change such periods of pronounced fluvial action last only a short time in more detail the internal evolution in a drainage basin after a climatic event results in a delayed response of the morphology and sedimentation pattern finally on the shortest timescale local thresholds may play a decisive role in the reactions of river systems it is concluded that the relation between fluvial development and climate is not a simple one but is fundamentally dependant on the timescale

holocene flooding history of the lower tagus valley portugal the present paper aims to reconstruct the lower tagus valley flooding history for the last ca 6500 a to explore the suitability of pollen based local vegetation development in supporting the reconstruction of flooding history and to explain fluvial activity changes in terms of allogenic climate human impact and autogenic system intrinsic processes the flooding history has been determined by cored sedimentary records located 18 km apart in distal low energy backswamps on both sides of the tagus channel in these low energy backswamps fine grained sediment layers deposited from suspended load of overbank flood water reflect periods with multiple overbank floods by means of a multi proxy approach sedimentology magnetic susceptibility grain size loss on ignition carbonate content and pollen sedimentary and environmental changes were identified at both sites synchronous lithological intervals accumulated suggesting a common origin for the changes in fluvial activity since ca 6500 cal a bp based on lithological changes three phases of high fluvial activity 6500 5500 4900 3500 and 1000 0 cal a bp and two phases of low fluvial activity 5500 4900 and 3500 1000 cal a bp were identified two periods with dominant allogenic controls on fluvial activity in the lower tagus valley were identified relative sea level 6500 5500 cal a bp and human impact 1000 0 cal a bp during the intermediate period changes in fluvial activity may have been caused by climate 5500 1000 cal bp but unambiguous correlations are difficult to make this is due to the way allogenic controls are translated through the fluvial system the geomorphological differences between upstream and downstream studies and autogenic processes the comparison of local vegetation development and flooding phases as reconstructed using sedimentology shows a limited added value of using local palynology as a proxy for fluvial activity 2010 john wiley sons ltd

climatic control on quaternary fluvial sedimentology of a fenland basin river england understanding and interpreting climate response from ancient fluvial deposits requires a combined approach of detailed sedimentological description and interpretation local climate proxies and the accurate comparison of these sequences with further independent climate records application of these multiple lines of evidence is particularly effective in the quaternary period where higher resolution and more detailed palaeoenvironmental reconstruction are possible this paper presents results from a devensian weichselian age sequence in northern fenland england that integrates these approaches detailed sedimentological description has identified three fluvial facies associations overlain by a period of ice wedge cast formation fossil plant and coleopteran material within these sediments have been studied to provide palaeoenvironmental reconstructions for the local landscape including quantitative temperature estimates using the mutual climatic range method on fossil coleoptera in addition joint application of radiocarbon and optically stimulated luminescence osl dating allows this sequence to be compared with the stacked marine isotope record although dates do not agree well at the limit of the radiocarbon technique sedimentological interpretations palaeoenvironments and global ice volume variations a proxy for climatic severity are all in agreement and show clearly how the river nene responded to subtle changes in climate and vegetation cover during the devensian weichselian stage the level of detail possible in this reconstruction shows the importance of this approach in understanding fluvial response to past climate changes

reconstruction of a pleistocene meandering river in east hungary by vhr seismic images and its climatic implications abstract the upper 20 30 m of the pleistocene alluvial sequence on the tisza river hungary is investigated by 200 km of vhr single channel seismic sections frequent internal configurations such as 1 bundles of inclined reflections 2 trough shaped converging and 3 horizontal parallel reflections are interpreted respectively as lateral accretion of point bars abandoned channel fills and floodplain deposits the series of 5 8 m thick inclined strata sets occurring at the same depth throughout the area suggest the presence of a meandering river dated to about 43 47 ka in the late pleistocene according to osl data newly recorded quasi 3d seismic profiles reveal that each 1 3 km long inclined series correlates with an individual point bar continuously migrating in the same direction small deviations in the direction of migration are caused by natural wandering of the meander bend morphometric parameters of point bars are used to calculate ancient channel parameters width and depth of 200 500 m and 5 8 m respectively values imply a channel forming discharge of q 400 900 m 3 s these results imply a greater amount of runoff and supply in the basin during mis3 compared to the present day long lasting meandering indicates the role of local factors and a different fluvial environment compared to the commonly anastomosing systems in nw europe our data support the thesis of the three axis drainage system for the basin new evidence is provided for the antecedent existence of a temporally active third trunk river in addition to the ancestors of danube and tisza rivers contrary to the present day two axis drainage pattern