long term fluvial archives in the fen wei graben central china and their bearing on the tectonic history of the india asia collision system during the quaternary abstract staircases of large scale river terraces are striking features of the landscape in the fen wei graben adjacent to the qinling orogenic belts central china field investigations indicate that all five river terraces are composed of a basal channel gravel and an overlying thick loess palaeosol succession as chinese loess stratigraphy has been well studied it favours age determination of these terraces and their correlation with the marine oxygen isotope stages our research indicates that the ages of the five terraces are approximately 2 6 1 2 0 9 0 65 and 0 15 ma respectively the formation of these river terraces within the fen wei graben has been attributed to nw se crustal extension associated with left lateral displacement between the north and south china blocks in response to the northward movement of india towards asia since cenozoic time thus the stepped terraces in the fen wei graben reflects elements of the india asia collision systems in which terraces define episodes of accelerated northward movement of india towards asia during the quaternary

sedimentary characteristics of the gravel sand transition in the river rhine abstract a gravel bed river often changes abruptly into a sand bed river the causes of such so called gravel sand transitions have been elucidated in recent years but detailed observations of gravel sand transitions in large rivers are scarce the present study fills this knowledge gap by investigating the sedimentary characteristics of the gravel sand transition in the river rhine data on bed composition and flow characteristics are used in combination with a novel method for the evaluation of the bed structure the analysis shows that in contrast to common belief the bed structure in the gravel sand transition zone does not change from fully clast supported to fully matrix supported instead there is a strong cross stream variation in bed structure especially upstream of the transition zone the analysis also shows that the downstream decrease in gravel mobility in the gravel sand transition zone which is usually attributed to the change in bed structure and the so called patchiness effect is at least partly caused by the larger scale bend sorting process which concentrates gravel in outer bends where it is only infrequently mobile dune sorting which has been suggested to have an effect on the gravel mobility similar to that of bend sorting was found to be relatively unimportant in the rhine partly because it is strongly counteracted by armoring processes that affect an uncommonly thick sediment layer the gravel sand transition in the rhine with its length of 50 km is much less abrupt than the gravel sand transitions of smaller rivers reported on in the literature although the dependence of the transition length on river size intuitively is correct the exact causes remain unclear

cadomian terranes wrench faulting and thrusting in the central europe variscides geophysical and geological evidence sixty five per cent of the paleozoic basement of western and central europe is hidden by a sedimen tary cover and or sea this work aims to remove that blanket to detect new structures which could used to build a more comprehensive model of the variscan or ogeny it is based on the interpretation of various forms of data a published gravity maps corrected for the ef fects of the crust mantle boundary topography and light sedimentary basins b aeromagnetic maps c measurements of densities and d induced and rema nent magnetizations on rocks from paleozoic outcrops of the upper rhenish area from the northern b ohem ian massif to the eastern paris basin the saxothurin gian is characterized by a 500 km long belt of gravity highs the most important being the kraichgau high most of the corresponding heavy bodies are buried un der a post early visdan cover they are interpreted as relics of late proterozoic terranes overlain by an early to middle paleozoic sequence equivalent to the bo hemian t errane in the bohemian massif the most probable continuation of these dense bohemian ter ranes toward the west is the southern channel north ern brittany cadomian terrane the gravity lows are correlated with variscan granites and pre and early variscan metagranites gravity and magnetic maps demonstrate large scale displacement in devonian early carboniferous times along the parallel and equidistant nw se striking vistula elbe bavarian bray and south armorican dextral wrench faults in the vosges schwarzwald and central massif the faults continue with the east west striking lalaye lubine ba den baden and marche faults and with south vergent thrusts the bavarian faults shift the kraichgau terrane by 150 km relative to the bohemian terrane whereas the offset of the north ern brittany cadomian relative to the northern vosges kraichgau terranes is estimated at 400km along the bray fault sinistral wrench faults are the ne sw striking sillon houiller rheingraben rodl vitis and diendorf faults the southern vosges schwarzwald devonian dinanti an basin is interpreted as a pull apart basin at the south easterly extremity of the bray fault the bohemian and kraichgau body form allochthonous terranes which were thrust over the saxothuringian crust thrusting to the north west was accompanied by back thrusting and led to the forma tion of pop up structures contemporaneous dextral and sinistral wrench faulting resulted in transpressive strain during collision the zonal structure of the varis cides in the sense of kossmat 1927 is relevant only to the rhenohercynian foreland belt kossmat 1927 al ready spoke of a moldanubian region because it dis plays no real zonal structure the saxothuringian zone was formed by terrane accretion their apparent zonal structure is not a pre collisional feature but only the result of accretion and collision

the continental rift system of the rhinegraben structure physical properties and dynamical processes abstract the geophysical investigation of the continental rift system of the rhinegraben by various methods has progressed to such a stage that details of structure physical properties and seismic activity and relations between these features can be recognised differences in the nature of the crust mantle boundary inside and outside the graben proper seem to be a typical property of continental rifts asymmetries of structure seismic activity temperature in the crust and physical properties in the lithosphere are an important clue to the understanding of rift dynamics these asymmetries indicate that the formation of the rift cannot be explained by the updoming of an asthenolith alone but that taphrogenesis took place in the foreland of the continent continent collision in the alpine mediterranean zone a number of future key experiments is proposed

chronology of the yellow river terraces at qingtong gorge ne tibet insights into evolution of the yellow river since the middle pleistocene abstract the formation and abandonment of fluvial terraces provide key records of past climatic changes and regional tectonics that reflect the evolution of rivers at the northeastern periphery of the tibetan plateau the yellow river flows through the qingtong gorge a deep canyon incised through the niushou shan a flight of 8 fluvial terraces preserved along the canyon four of which t2 t3 t6 and t8 were dated using osl and cosmogenic nuclide exposure dating the results show that the four terraces were formed at 51 6 2 9 ka 60 7 14 4 8 3 ka 346 1 30 27 3 ka and 580 640 ka respectively precise measurement of terrace heights suggests that the average incision rate of the yellow river over the past 350 ka was 200 m ma and increased significantly in the past 60 ka analysis of the relationship between the observed incision histories with regional climatic records and local tectonics suggests that climatic variations since the late quaternary drove cutting and abandonment of the terraces during progressive tectonic growth of the niushou shan our results provide constraints on the timing of incision and linkage of various segments of the modern yellow river fluvial network

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

palaeostress analysis a contribution to the understanding of basin tectonics and geodynamic evolution example of the permian cenozoic tectonics of great britain and geodynamic implications in western europe abstract microtectonic analysis in association with tectonic sedimentological observations enables us not only to define palaeostress tensors but also to date each of them such a study carried out in central and northeastern england and in southernmost wales has permitted us to point out several tectonic stages during the permian cenozoic period 1 inferred from syn sedimentary faulting in the late permian series the permian early triassic tectonic regime is characterised by a nnw sse oriented extension 2 during the late triassic to the early late jurassic an e w to ene wsw oriented extension was acting as suggested by syn sedimentary normal faulting in keuper lias and middle dogger sediments and post sedimentary normal faulting in oxfordian sediments 3 the following tectonic event probably started during the malm and was particularly active during the early cretaceous it was characterised by a n s to nne ssw oriented extension and was associated with an e w to wnw ese oriented strike slip tectonic regime transtension 4 a locally observed nw se oriented transpressional strike slip tectonic regime is thought to correspond to the laramide inversion phase of the middle paleocene 5 the later tectonic event is characterised by a n s oriented transpressional strike slip regime and affects a paleocene tholeiitic dyke cleveland dyke it is supposed to be synchronous with the so called eocene pyrenean to the early miocene helvetic compressional stages these paleostress tensors are compared with others defined in france the benelux countries and germany and are also collated to the tectonic evolution of oil basins assessed from geophysical analyses these comparisons raise discussions about the paleostress distribution within the geodynamic evolution of the west european shelf

the rhinegraben extension subsidence and shoulder uplift abstract we apply a numerical model of the thermal evolution of a continental lithosphere undergoing extensional deformation to the rhinegraben using reasonable parameters the results of computations are in agreement with the present configuration of the rift and of its shoulders as well as with their evolution since the oligocene contrasting evolutions are reconstructed in the northern and southern rhinegraben whereas the northern history is accounted for by a simple model of homogeneous stretching of the lithosphere the history of the southern rhinegraben cannot be explained without introducing two main periods of heterogeneous stretching the results are locally supported by structural analyses of extensional patterns factors of extension average 1 2 in the axial portion of the rhinegraben and 1 15 for the whole rift section suggesting that the total amount of e w extension reaches 6 km

rhinegraben horizontal stylolites indicating stress regimes of earlier stages of rifting abstract buchner f 1981 rhinegraben horizontal stylolites indicating stress regimes of earlier stages of rifting in j h illies editor mechanism of graben formation tectonophysics 73 113 118 tectonic stylolites horizontal columns and their statistical distribution in middle triassic and jurassic limestones on both flanks of the rhinegraben are described and their relation to the rhinegraben taphrogenesis is discussed a generation of pre middle miocene nne striking horizontal stylolites and a subsequent generation of post lower miocene nw striking horizontal stylolites have been recognized the first generation stylolites indicates a horizontal compression in the nne ssw direction while the second generation indicates a compression in the nw se direction average maxima of joints parallel to the two horizontal stylolite maxima were found joints and their corresponding horizontal stylolites were formed under the same stress regime

a deep reflection seismic line across the northern rhine graben abstract two reflection seismic lines across the tertiary rhine graben in central europe were recorded in 1988 as a joint venture of the french ecors and the german dekorp deep seismic reflection programs in this paper the line across the northern graben is presented the main results are the asymmetry of the graben as documented by the sedimentary fill is accompanied by asymmetric features throughout the entire deep crystalline crust a thin 3 7 s twt reflective lower crust in the east a thick 5 5 s twt relatively transparent lower crust in the west total crustal thicknesses of 8 7 s twt in the east vs 10 5 s twt in the west provided a laterally homogeneous crust existed prior to rifting significant differences in upper and lower crustal thinning must be postulated extension occurred along localized shear zones that are located in the upper crust and at the crust mantle boundary the entire lower crustal layer acts as a decoupling zone

suspended sediment and bed load problems of the upper rhine summary the regulation of the southern upper rhine by dams down to iffezheim has considerably changed the sediment balance of the stream in the impounded sections fine grained sediments are deposited narrowing the cross section and thus impeding high water discharge concluding from the high illite content of the suspended material a considerable part of the settling sediment is derived from the waste waters of the alsatian potassium mining in the freely flowing rhine downstream of iffezheim in turn erosion occurs although the degradation of the riverbed downstream of the iffezheim dam is prevented successfully by artificial addition of gravel this has no positive influence on the erosion reaches farther northwards this becomes apparent both in the petrographic composition of the bed load material as well as in its particle size distribution medium grained to coarse gravel with high carbonate rock content are already deposited upstream of speyer downstream of speyer sand and fine gravel rich in crystalline components are taken up from the river bottom this situation might probably be improved by appropriate addition of sand and fine gravel downstream of iffezheim

mid pleistocene acheulean like stone technology of the bose basin south china stone artifacts from the bose basin south china are associated with tektites dated to 803 000 3000 years ago and represent the oldest known large cutting tools lcts in east asia bose toolmaking is compatible with mode 2 acheulean technologies in africa in its targeted manufacture and biased spatial distribution of lcts large scale flaking and high flake scar counts acheulean like tools in the mid pleistocene of south china imply that mode 2 technical advances were manifested in east asia contemporaneously with handaxe technology in africa and western eurasia bose lithic technology is associated with a tektite airfall and forest burning

the jura mountains an active foreland fold and thrust belt abstract recently completed in situ stress measurements using the borehole slotter at 33 new test sites within the swiss and french jura mountains combined with previously published stress data allow a detailed description of the contemporary state of stress in this fold and thrust belt and the adjacent foreland five stress provinces can be recognized with two different general orientations of maximum horizontal stress sh 1 the central and southwest provinces with a nnw sse to nne ssw orientation 2 the east northwest and southeast provinces with an e w to nw se orientation stress magnitudes are in general higher in the southern than in the northern jura mountains characteristic of the northern jura is an e w trending zone of low stress magnitudes which can be traced from the bresse depression south of besancon to the eastern end of the jura northwest of zurich boundaries of stress provinces show poor agreement with boundaries of tectonic units in the jura in addition stress provinces extend beyond the boundaries of the jura mountains into their foreland furthermore palaeo stress orientations show large discrepancies with respect to the contemporary stress orientation these findings are considered to indicate a termination of jura thin skinned foreland tectonics which probably took place some time between 9 and 4 ma according to palaeontological and tectonic evidence it is suggested that a new style of tectonics has commenced in the jura mountains deforming both the basement directly below the jura fold and thrust belt and the cover rocks in a similar mode

evolution of the stress field pattern in the south of the rhine graben from the eocene to the present a stress field evolution from the eocene to the present is proposed for the southern part of the rhine graben stress tensor determinations are supported by striated microfaults and calcite twin lamellae analyses both methods lead to the determination of 1 a an e w extension contemporaneous with the opening of the graben and 2 b a n s compressive event which may be related with alpine tectonics it is shown that a n s compressive event occurred prior to the oligocene extension a permutation between the 1 and 2 axes is proposed to explain the transition between compression and extension a 1 2 inversion during the oligocene is compatible with compression in the southern part of the rhine graben infilling horizontal 1 and extension vertical 1 more to the north during the miocene the jura emplacement corresponds to a n s compression in this area there is no significant variation of the 1 direction south of the rhine graben from the eocene to the late miocene the 1 direction only turns to a n140 direction during the pliocene or the quaternary

equilibrium or indeterminate where sediment budgets fail sediment mass balance and adjustment of channel form green river downstream from flaming gorge dam utah and colorado this study examines bed and bank adjustment in the 105 km reach of the green river immediately downstream from flaming gorge dam by the use of historical aerial and oblique photographs analysis of current and abandoned stream gaging records and field observations although this segment has been previously characterized as sediment deficient these data show that sediment is accumulating in all reaches and that the bed has not degraded at any location where historical data are available adjustment is occurring through a combination of deposition of post dam sediment and stabilization of pre dam deposits resulting in a 10 30 reduction in average width of the channel all post dam surfaces are colonized by woody riparian vegetation the style of channel adjustment varies between geomorphically defined reaches in canyons dominated by debris fans and gravel bedded restricted meandering reaches gravel bars have become inactive and accumulated fine sediment in the sand bedded meandering reaches existing islands have increased in size and new mid channel islands have formed in all of these types of reaches post dam deposits line the banks and sediment has accumulated in side channels that previously separated islands from the bank these findings demonstrate that sediment budgets that show a balance between inputs and outputs cannot necessarily be interpreted to indicate channel equilibrium a sediment mass balance for 150 km reach between the dam and the first long term gage indicates approximate balance of inputs and outputs for the pre and post dam periods when uncertainty in budget components is considered the mass balance is indeterminate although the green river may have been in approximate equilibrium in the pre dam period we have shown that channel width is decreasing in the post dam period the post dam deposits constitute a small but a significant component of the sediment budget upstream from the first major tributary sediment is supplied to this reach by small tributaries and to a lesser extent erosion of pre dam alluvium downstream from the study area the volume of the post dam deposits is tiny relative to the volume of sediment input from the first major tributary d 2005 elsevier b v all rights reserved

upper pleistocene holocene geomorphic changes dictating sedimentation rates and historical land use in the valley system of the chifeng region inner mongolia northern china this study focuses on the late quaternary landscape evolution in the chifeng region of inner mongolia china its relations to the history of the pleistocene holocene loess accumulation erosion and redeposition and their impact on human occupation based on 57 optically stimulated luminescence osl ages of loess sediments fluvial sand and floodplain deposits accumulated on the hill slopes and floodplains we conclude that during most of the pleistocene period the region was blanketed by a thick layer of aeolian loess as well as by alluvial and fluvial deposits the loess section is divided into two main units that are separated by unconformity the osl ages at the top of the lower reddish loess unit yielded an approximate age of 193 ka roughly corresponding to the transition from mis 7 to 6 though they could be older the upper gray loess unit accumulated during the upper pleistocene glacial phase mis 4 3 at a mean accumulation rate of 0 22 m ka parallel to the loess accumulation on top of the hilly topography active fans were operating during mis 4 2 at the outlet of large gullies surrounding the major valley at a mean accumulation rate of 0 24 m ka this co accumulation indicates that gullies have been a long term geomorphic feature at the margins of the gobi desert since at least the middle pleistocene during the holocene the erosion of the pleistocene loess on the hills led to the burial of the valley floors by the redeposited sediments at a rate that decreases from 3 2 m ka near the hills to 1 0 4 m ka1 in the central part of the chifeng valley this rapid accumulation and the frequent shifts of the courses of the river prevented the construction of permanent settlements in the valley floors a situation which changed only with improved man made control of the local rivers from the tenth century ad copyright 2010 john wiley sons ltd

human induced changes in bed shear stress and bed grain size in the river waal the netherlands during the past 900 years human impact has changed the flow characteristics and bed sediment characteristics of lowland rivers affecting channel stability flood risk navigability and biodiversity we analysed the effect of human activities on the flow and bed sediment characteristics of the river waal the netherlands the objectives were a to reconstruct the historical change in bed shear stress during the past 900 years b to reconstruct the contemporary change in bed grain size and c to identify the main causes of these changes various data types were used such as borehole descriptions historical river maps and modern hydraulic data it was found that the bed shear stress in the river waal strongly increased during the past 900 years in the same period the gravel content of the sandy river bed increased causing a coarsening of the river bed before ad 1870 the shear stress increase and bed coarsening were mainly due to embankment artificial levee construction after ad 1870 the shear stress increase and bed coarsening were mainly due to river narrowing and dredging the systematic grain size difference between present day and historical rivers should be taken into account in river restoration projects copyright 2009 john wiley sons ltd

rapid fluvial incision and headward erosion by the yellow river along the jinshaan gorge during the past 1 2 ma as a result of tectonic extension abstract in north china the ordos block located northeast of the tibetan plateau is regarded as a stable craton surrounded by the yinchuan graben to the west the hetao graben to the north and the fenwei graben to the southeast the major tectonic structure around this block in the cenozoic reflects intensive extension as a response to the eastward extrusion of the tibetan plateau intermittent downcutting by the yellow river starting from the planation surface level on the ordos block and penetrating the bedrock resulted in the formation of the jinshaan gorge a series of well preserved fluvial terraces was identified along this gorge providing new insight into the far field effect of the eastward extrusion of the tibetan plateau magnetostratigraphic records from the planation surface and uppermost terrace suggest that this gorge has been entrenched over its total length in the period from 3 7 to 1 2 ma a preliminary explanation is proposed here for the morphological evolution of the yellow river in the jinshaan gorge on the basis of terrace correlation between seventeen geomorphic sections multiwave headward erosion initiated by the yellow river along this gorge has been reconstructed this process may be attributed to the lowering of the base level the fenwei graben this graben has been formed during the cenozoic as the tibetan plateau extruded eastwards resulting in accelerated ground subsidence a combined approach of magnetostratigraphy pedostratigraphy and optically stimulated luminescence osl was adopted to establish a new geochronology for terraces in the gorge at 1 2 ma 1 1 ma 787 ka 412 ka 245 ka 128 ka 29 ka and 11 ka these ages provide an excellent framework for calculating the extension within the fenwei graben the average incision rate appears to be enhanced significantly since 412 ka indicating a rapid extension within the fenwei graben during this time

on the origin of the southern permian basin central europe abstract a detailed study of the structural and stratigraphic evolution of the southern permian basin during latest carboniferous to early jurassic times supported by quantitative subsidence analyses and forward basin modelling for 25 wells leads us to modify the conventional model for the rotliegend zechstein development of this basin the late permian early jurassic tectonic subsidence curves are typical for a permian to early triassic extensional stage that is followed by thermal subsidence however a purely extensional model is extremely problematic because active faulting during this time is minor and generally hard to document using inverse techniques to model the subsidence curves we quantitatively show that a significant component of late permian and triassic tectonic subsidence can be explained by thermal relaxation of early permian lithospheric thinning and by delayed infilling of paleo topographic depressions that developed during the early permian in this interpretation stephanian autunian wrenching resulted in thermal destabilisation of the lithosphere deep fracturing of the crust disruption and erosion of its sedimentary cover and regional uplift of the area of the future southern permian basin upon termination of wrench tectonics and associated volcanism towards the end of the autunian the southern permian basin began to subside in response to thermal contraction of the lithosphere the evolving basin was isolated from the world oceans and had subsided possibly up to some 700 m below their level at the beginning of upper rotliegend sedimentation after catastrophic flooding of this paleo topographic depression at the beginning of the zechstein changing sea level sedimentation and subsidence rates remained essentially in balance although the effects of triassic rifting overprinted parts of the southern permian basin its overall subsidence pattern persisted well into the jurassic in contrast to the remainder of the southern permian basin permian and triassic crustal extension contributed significantly to the subsidence of the polish trough

fluvial terrace formation along wyoming s laramie range as a response to increased late pleistocene flood magnitudes abstract this study evaluates the potential climatic mechanisms involved in fluvial terrace genesis along wyoming s laramie range we used optical dating methods to determine depositional ages for fluvial fills and to calculate incision rates for terrace suites along two of the region s larger rivers optical ages were determined for the five lowest terrace levels t5 t1 which were deposited at 59 6 39 2 26 3 22 7 and 18 5 ka and incision rates calculated for the two rivers were 0 29 0 34 m kyr over the last 60 kyr the formation of fluvial terraces in the central rocky mountains is commonly attributed to climatically induced changes in sediment input according to most studies relatively low incision rates existed during the colder periods of the pleistocene due to high stream sediment loads but terraces were formed during warmer interglacial periods when reduced sediment availability facilitated higher incision rates however this conceptual model cannot explain the incision records presented here which show that the streams incised 9 10 m in two to three events during oxygen isotope stage 2 but only 1 2 m during the warmer climates of the last 18 5 ka the stream power model we adapted to this setting suggests that late quaternary streams operated under two basic states during the colder conditions of the pleistocene higher flood magnitudes resulted in higher lateral erosion and incision rates however the lower stream discharge common to the warmer interglacial periods resulted in relatively inactive streams when both lateral erosion and incision rates were lowered this model can explain the high incision rates during the cold conditions of oxygen isotope stage 2 the occurrence of terrace fill ages near cold to warm transitions and the apparent acceleration in incision rates toward the end of the last glacial cycle finally this study suggests that terrace fill ages and incision rates are similar for the distally glaciated laramie river nonglaciated sybille creek and the proximally glaciated streams that drain the wind river range this implies that rivers responded synchronously to late quaternary climate changes regardless of their influence by alpine glaciation

a magnetostratigraphic record of landscape development in the eastern ordos plateau china transition from late miocene and early pliocene stacked sedimentation to late pliocene and quaternary uplift and incision by the yellow river abstract a continuous fluviolacustrine record provides the geochronological framework to reconstruct the fluvial landscape evolution of the middle reach of the huanghe yellow river magnetostratigraphic records from six sections at the north of the jinshaan gorge indicate that an isolated fluviolacustrine system occupied this gorge from 8 3 to 3 7 ma local fluvial incision initiated at the lake margin around 5 3 4 9 ma and concomitant fluvial deposits intruded laterally into fine lacustrine strata increasing the sedimentation rate ca 3 1 cm ky within the isolated lake the temporal coincidence of the onset of uplift driven valley incision at 3 7 ma along the yellow river and the onset of basin excavation suggest that uplift possibly played an important role in the late pliocene quaternary drainage evolution consequently incision of the yellow river upstream in the jinshaan gorge initiated at 3 7 ma

strath terraces of jinshaan canyon yellow river and quaternary tectonic movements of the ordos plateau north china studies of the strath terraces in jinshaan canyon where the yellow river cuts through the ordos plateau in the continental interior of china provide an opportunity to solve some of the critical problems associated with quaternary tectonic movement of the plateau six strath terraces indicate that five episodes of regional epeirogenic uplift affected the ordos plateau during the quaternary the local tectonic deformation is superimposed on the regional epeirogenic uplift expressed either as faulting or as non uniform uplift induced by local arching the results have important implications for understanding the relationship between the regional epeirogenic uplift of the ordos plateau and the uplift of the qingzang plateau time lines of climate change in the regional epeirogenic uplift landscape and the genesis of strath terraces associated with the through flowing plateau drainage in the continental interior

anthropogenic landforms and sediments from dredging and disposing sand along the apalachicola river and its floodplain abstract the apalachicola river which begins at the confluence of the chattahoochee and flint rivers near the georgia florida state line has multiple human impacts water inputs declined due to upstream irrigation and urbanization in georgia sediment trapped by numerous small to large dams including construction of jim woodruff dam in 1954 near the apalachicola chattahoochee flint acf confluence has increased degradation shortly thereafter the river was modified for a navigation project with 29 6 10 6 m 3 dredged between 1957 and 2002 from the apalachicola alone this study investigates how historic dredging coincides with the modern morphology of the channel and how historic dredging disposal and other activities have modified the floodplain landforms and sediments this analysis of the navigation impacts in the middle apalachicola river river miles 40 to 65 ties spatial and temporal variations of dredging field derived bathymetry historic maps patterns of floodplain disposal of dredge spoil from lidar imagery and modern point bar channel change of the apalachicola river floodplain mounds of coarse material built from out of bank disposal constitute 800 000 m 3 in the study area approximately 7 7 10 6 m 3 of sediment was dredged within the study reach roughly 11 of the volume dredged remains on the floodplain sand bars were disposal sites thus their increased area of 263 is partly tied to this practice thus the legacy of dredging affects the modern sedimentology and morphology of the floodplain and channel findings show that a failed navigation project could have been pre empted with better geomorphic geologic and hydrologic study and suggest that vegetative restoration of point bars would help in narrowing and stabilizing this dynamic system

characterization of organic rich material in an evaporitic environment the lower oligocene of the mulhouse basin alsace france evaporitic sediments from the max borehole mulhouse potash basin southern rhine graben were studied over an interval of about 40 m in the vicinity of sylvite beds total organic carbon toc analyses of 450 samples showed that marly layers interbedded within the evaporites have toc values that fluctuate in a rhythmic manner the highest values are found near the top of the clay anhydrite layers and the lowest values are recorded near the top of the halite rich beds geochemical elemental analysis of kerogen gas chromatography of bitumen and palynological studies of 26 samples showed that the organic matter is mainly of algal origin a and b groups a third category of organic material c group may have been derived from a mixture of continental supply and in situ bacterial productivity

assessing tectonic and climatic controls for late quaternary fluvial terraces in guide jianzha and xunhua basins along the yellow river on the northeastern tibetan plateau abstract this study focused on well preserved fluvial terrace sequences that span the past 100 ka in the guide jianzha and xunhua basins along the yellow river that drained the northeastern tibetan plateau new geomorphic stratigraphic sedimentologic and chronologic data from twelve depositional sequences within terraces yielded better constraints on rates of incision degradational and aggradational phases for the yellow river age control was established by sixteen osl ages on quartz grains from fluvial sediments three fluvial aggradational phases were identified between 100 and 80 ka 53 and 40 ka and 21 and 12 ka associated with terrace levels respectively at 120 to 95 61 to 45 and 25 to 15 m above river level these aggradational phases reflect multiple processes including enhanced fluvial discharge sediment availability with glaciation deglaciation and increased monsoonal precipitation the initiation of fluvial degradation was linked to mega floods released from landslide dammed lakes at ca 76 38 and 16 ka though these changes may also reflect variations in sediment load discharge relations with climate change the apparent net incision rate is 1 13 0 11 mm yr for the past 100 ka and is consistent with late cenozoic tectonic uplift rates 0 5 2 mm yr and recent gps based rates the fluvial dynamics of the upper reach of the yellow river was variably controlled by climate induced changes in discharge sediment load relations on stadial to interstadial timescales episodic mega floods from the breach of landslide dams and with net incision in the past 100 ka in response to tectonic uplift of the tibetan plateau

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

the evolution of the shiwanghe river valley in response to the yellow river incision in the hukou area shaanxi china abstract tributary response to mainstream incision is an important landscape evolution process the objective of this study is to examine tributary valley evolution in response to mainstream incision the shiwanghe river a tributary of the yellow river in the hukou area was chosen for a case study the terraces and knickpoints of the shiwanghe river were investigated and correlated to those of the mainstream optically stimulated luminescence osl was applied to date fluvial terraces longitudinal profiles of river and terraces were used to analyze valley evolution the terrace sequence of the shiwanghe river near their confluence is almost identical to the yellow river terraces at the hukou area this suggests that terrace formations of the tributary and the mainstream are synchronous and influenced by similar factors but the formation age of the same tributary terrace varies from downstream to the upper reaches of the river valley for such terraces their formation should be controlled by knickpoint migration a sudden drop in base level caused by the yellow river incision would trigger the formation of a knickpoint in the tributary a new terrace would be formed as the knickpoint propagated upstream throughout the tributary valley due to the different erodibility of bedrock a set of interbedded sandstone and shale the major knickpoint would disassemble into a cluster of small ones during its propagation the age of terrace formation with various valley segments depends on knickpoint migration rate and distance from the confluence vertical incision of the yellow river results in knickpoint recession of its tributaries the migration rate of knickpoints was affected by climate lithologic variation and to some extent structural control

dating fluvial sediments by optically stimulated luminescence selection of equivalent doses for age calculation fluvial sediments are not an ideal material for optical dating because of insufficient or and uneven exposure to daylight prior to burial the equivalent doses for a sample obtained using the single aliquot regenerative dose method usually show a large scatter which may be attributed to many factors here we developed a technique to evaluate the contributions from each factor using this technique relatively well bleached aliquots were identified and the average of their equivalent doses was taken for age calculation

lithospheric cross sections of the european cenozoic rift system abstract the lithospheric structure of the european cenozoic rift system ecris is presented in transects through the southern rhine graben and the rhenish massif hessen depression emphasizing the geophysical structure of the lithosphere based on seismic refraction reflection investigations teleseismic tomography electromagnetic depth sounding models and gravity aeromagnetic earthquake uplift subsidence and heat flow data the rift is clearly expressed in the rhine graben but is not evident at the surface in the area of the rhenish massif where its existence is indicated by seismicity it is characterized by abnormal crustal and upper mantle structures which vary considerably in horizontal direction for example under the rhine graben the crust is thinned to 25 km but at 40 km depth anomalously high velocities are observed in contrast beneath the rhenish massif the crust is thickened to 35 37 km and under its eastern part a high velocity thin upper mantle slice is seen at 30 km depth within the lower crust which towards the hessen depression is gradually replaced by normal variscan mantle with the moho near 30 km depth under the western part of the rhenish massif p and s wave velocities are reduced below 50 km depth which is not seen east of the rhine river under the rhine graben the existence of a low velocity upper mantle above 100 km cannot be generalized but is restricted to confined regions

the evolution of a terrace sequence along the yellow river huanghe in hequ shanxi china as inferred from optical dating abstract investigations of river terraces are often seriously hindered by difficulties in dating the formation of terraces using conventional and well established methods such as 14c dating in this paper recently developed optical dating techniques were applied to a yellow river terrace sequence in the hequ area shanxi province china based on field investigations four terraces were identified systematic sampling for optical dating was carried out on these terrace deposits the single aliquot regenerative dose method was used to determine equivalent dose by analyzing the degree of bleaching of fluvial samples maximum and minimum optical ages were obtained for these samples the minimum optical dates obtained are geomorphologically and stratigraphically consistent with each other suggesting that the dates are reliable the formation ages of the four terraces are 3 4 10 20 25 30 and 90 ka respectively on the basis of these optical dates the geomorphological evolution of the terrace sequence was established and the factors affecting the terrace development discussed

overbank sand deposition in relation to transport volumes during large magnitude floods in the dutch sand bed rhine river system using aerial photographs and field measurements sandy overbank deposits formed by the large magnitude floods of 1993 94 and 1995 were quantified along two branches of the dutch rhine river system the waal 1993 94 and 1995 and the ijssel 1995 these deposits were laid down intermittently all along the length of these rivers on the top and landward slope of the natural levees and covered about 4 per cent of the embanked floodplain on the waal and about 1 per cent on the ijssel the overbanks and transport mechanism is basically convective by nature the spatial variability of overbank sedimentation points to the important role played by helicoidal currents in determining overbank deposition the presence of embankments and training works appears to influence the sand transport to and morphological development of the floodplains along the dutch rhine river system overbank deposition volumes about equal present estimates of sand transport during a large magnitude flood it appears that studies on sand transport in the dutch rhine carried out so far underestimate sand transport during floods 1998 john wiley sons ltd

the hydromorphological evaluation tool hymet abstract river engineering structures such as bank protection or bed sills act as constraints on the hydromorphology of rivers and limit morphodynamic processes accordingly the deviations of a river s morphology from a natural reference condition have been attributed to the degree of artificiality in the observed river section and river restoration works mainly aimed at reducing artificial constraints within the river reach less attention has been drawn to alterations of the sediment continuum between sediment production in the river s catchment and downstream river reaches however the sediment supply from upstream is strongly reflected in the morphodynamics such as bar formation or the reworking of the riverbed any alteration of sediment supply may affect the morphological appearance of a reach and determine its deviation from an undisturbed condition we introduce the hydromorphological evaluation tool hymet which accounts in a hierarchical procedure for sediment supply and sediment transfer as catchment and river network based preconditions for sustainable morphodynamics in river reaches at the reach scale artificiality and the sediment budget are assessed in contrast to existing evaluation methods for assessing hydromorphological state no reference condition is needed for determining hydro morphological alterations here with re established sediment supply and reduced artificiality a river reach is expected to develop morphodynamics that approach a morphodynamically and ecologically sustainable condition application to the drau river showed that the alteration of sediment supply strongly affects the hydromorphological condition and thus the evaluation result of a restored reach indicating the remaining potential for the re initiation re establishment of morphodynamics through catchment wide restoration plans

development of the alluvial and lacustrine terraces on the northern margin of the hetao basin inner mongolia china implications for the evolution of the yellow river in the hetao area since the late pleistocene abstract terrace formation processes can reflect the evolution of large rivers the hetao basin is a floodplain of the yellow river and there are two to three terraces that extend e w on the northern margin based on a detailed field geological survey and measurement of the terrace sections combined with sedimentological and chronological analyses we reconstructed the developmental processes of the three terraces and inferred that three river terraces were formed by the yellow river the osl dating results show that the time of deposition of terrace 3 was prior to 118 ka bp subsequently the terrace began to experience incision and formed the geomorphic surface of terrace t3 similarly terrace 2 and terrace 1 were mainly deposited from 109 and 59 ka respectively and began to be incised prior to 71 and 46 ka respectively the three terraces in the northern hetao basin are the products of the combined actions of climatic shifts and tectonic uplift the yellow river s evolutionary history in the hetao area since the late pleistocene is discussed before about 120 ka bp the yellow river may have flowed through the northern hetao basin between 110 and 70 ka bp the yellow river experienced at least two changes between river and lake sedimentation from 60 to 50 ka a very large river connected lake of the yellow river was developed in the hetao basin after 50 ka the hetao river connected paleolake of the yellow river gradually dried

the significance of hiatus beds in shallow water mudstones an example from the middle jurassic of switzerland abstract limestone beds formed in nearly carbonate free shallow water mudstones by discontinuous sedimentation and erosion are called hiatus beds anaerobic oxidation of organic matter by microbes provided excess alkalinity inducing carbonate precipitation a multiphase history of such beds is documented from the swiss jurassic by several cementation and dissolution phases four cement types occur micrite as earliest cement 13c 10 to 20o oo stellate calcite between micrite cemented parts 13c 5 to 10o oo fibrous calcite cement in dissolution cavities 13c 30o oo and blocky calcite in remaining pores 13c 5o oo except for the late blocky cement all cements contain pyrite indicating carbonate precipitation within the sulfate reduction zone after early cementation by micrite the beds moved relatively upwards into a shallower geochemical zone and some even to the seafloor because of erosion cavities formed during reburial by dissolution in the upper part of the sulfate reduction zone and in the upper part of the methanogenic zone strongly reduced sedimentation rates provided the requisite stable geochemical conditions for at least several thousands of years which permitted precipitation and dissolution of carbonate by biochemical processes and diffusion this happened on short lived swells caused by differential subsidence and rotation along listric faults when basement structures became reactivated during the extensional stress regime from opening of the tethys during the jurassic and cretaceous breakup of pangea the shelf area increased and differential subsidence on these newly formed shelves was the main factor responsible for the observed post paleozoic maximum in hiatus beds and hiatus concretions

optical dating of holocene sediments from a variety of geomorphic settings using single grains of quartz this paper presents an improved method for the optical dating of holocene sediments from a variety of geomorphic settings we have measured the equivalent dose de in individual grains of quartz using green laser light for optical stimulation and have simulated the de distributions for multiple grain synthetic aliquots using the single grain data for 12 samples of known independent age we show that application of a minimum age model to the single grain and small 10 grain aliquot de data provides the most accurate estimate of the burial dose for nine of the samples examined 3 aeolian 5 fluvial and 1 marine the weighted mean de as obtained using the central age model gives rise to burial age overestimates of up to a factor of 10 for these nine samples whether single grains small aliquots or large 100 grain aliquots are used for the other three samples two aeolian and one fluvial application of either the minimum age model or the central age model to the single grain small aliquot and large aliquot de data yields burial ages in accord with the independent age control we infer that these three samples were well bleached at the time of deposition these results show that heterogeneous bleaching of the optical dating signal is commonplace in nature and that aeolian transport offers no guarantee that the sample will be well bleached at the time of deposition we also show that grains sensitive to infrared ir stimulation can give rise to low de values which will result in significant underestimation of the burial dose and hence of the age of deposition we demonstrate that use of a modified single aliquot regenerative dose protocol incorporating ir stimulation prior to green light stimulation deals effectively with contamination by ir sensitive grains we conclude that application of the modified protocol to single grains or small aliquots of quartz using the lowest de population to estimate the burial dose is the best means of obtaining reliable ages for holocene sediments from a wide range of depositional environments d 2003 elsevier b v all rights reserved

optical dating of an offset river terrace sequence across the karakax fault and its implication for the late quaternary left lateral slip rate abstract the karakax fault is one of the largest left lateral strike slip faults at the rim of the northwestern tibetan plateau in this study the optical dating techniques were applied to the taersayijilega river terraces which were transversely cut and offset by the karakax fault six fluvial sand samples from the river terraces were collected and dated the results show that the terraces t2 t5 have ages of 14 5 1 0 ka 21 2 1 2 ka 28 5 1 7 ka and 39 7 2 5 ka respectively by interpreting high resolution satellite images the horizontal displacements of the four river terraces are estimated at 160 m 235 m 260 m and 365 m respectively based on the ages and offsets of the terraces the average left lateral slip rate of the karakax fault was estimated at 7 8 1 6 mm a during the late quaternary such rate of the karakax fault is significantly higher than that of the longmu gozha co fault suggesting that the karakax fault plays an important role in accommodating eastward movement of the tibetan plateau at the northwest during the late quaternary

the evolution of the south hunsruck and taunus borderzone abstract the main fabric development of the south hunsruck and taunus borderzone htb occurred during late variscan homoaxial backfolding of an early variscan stack of thrust sheets in a narrow wsw ene trending zone several hundred kilometres long rotation and uplift of the southern rhenohercynian zone was accompanied by the subsidence of the southward adjacent northernmost parts of the saxothuringian zone and the development of the saar nahe basin during the latest carboniferous changing stress conditions gave rise to the development of normal faults along the htb and an extensive tholeiitic and rhyolitic volcanism contemporaneous uplift of the hunsruck is reflected by coarse elastics in the saar nahe basin subsequently the htb became covered by latest carboniferous early permian and mesozoic sediments cretaceous uplift of the rhenish shield caused their erosion the faultzone separating the rhenohercynian hunsruck and taunus from the permo carboniferous saar nahe basin is characterised by reverse and normal faults conjugate shear indicated by slickensides on steep oblique fracture planes as well as slight folding and small scale thrusting in post variscan sediments may be attributed to compressional foreland deformation reactivating variscan joint fabrics and fault systems timing of these deformations is ambiguous and could partly be related to dextral shear during the cenozoic subsidence of the rhine graben cenozoic sediments of the upper rhine graben overstep the northeastern parts of the htb seismic investigations indicate that the htb is associated with a system of southeast hading listric planes extending beneath the moho occasional dip slip earthquakes occur along these fractures

today s sediment budget of the rhine river channel focusing on the upper rhine graben and rhenish massif abstract the river bed of the rhine river is subject to severe erosion and sedimentation such high geomorphological process rates are unwanted for economical ecological and safety reasons the objectives of this study were 1 to quantify the geomorphological development of the rhine river between 1985 and 2006 2 to investigate the bed erosion process and 3 to distinguish between tectonic hydrological and human controls we used a unique data set with thousands of bedload and suspended load measurements and quantified the fluxes of gravel sand silt and clay through the northern upper rhine graben and the rhenish massif furthermore we calculated bed level changes and evaluated the sediment budget of the channel sediment transport rates were found to change in the downstream direction silt and clay loads increase because of tributary supply sand loads increase because of erosion of sand from the bed and gravel loads decrease because of reduced sediment mobility caused by the base level control exerted by the uplifting rhenish massif this base level control shows tectonic setting in addition to hydrology and human interventions to represent a major control on morphodynamics in the rhine the rhine bed appears to be in a state of disequilibrium with an average net bed degradation of 3 mm a sand being eroded from the bed is primarily washed away in suspension indicating a rapid supply of sand to the rhine delta the degradation is the result of an increased sediment transport capacity caused by nineteenth and twentieth century s river training works in order to reduce degradation huge amounts of sediment are fed into the river by river managers bed degradation and artificial sediment feeding represent the major sources of sand and gravel to the study area only small amounts of sediment are supplied naturally from upstream or by tributaries sediment sinks include dredging abrasion and the sediment output to the downstream area large uncertainties exist about the amounts of sediment deposited on floodplains and in groyne fields compared to the natural situation during the middle holocene the present day gravel and sand loads seem to be lower whereas the silt and clay loads seem to be higher this is probably caused by the present day absence of meander migration the deforestation and the reduced sediment trapping efficiency of the floodplains even under natural conditions no equilibrium bed level existed

bedrock river incision response to basin connection along the jinshan gorge yellow river north china abstract the jinshan gorge of the yellow river connecting the hetao and the fenwei basins is a key area for understanding the formation and evolution of the drainage system in response to bedrock river incision we have measured fluvial terraces along the gorge in the field in detail the longitudinal profile and published dating of terraces indicate that rapid river incision occurred in the late pleistocene the deactivated boundary faults and uniform lithology of the gorge have no measurable influence the incision changes in precipitation are consistent with incision rate in late pleistocene rapid in mis5 and low in mis3 whereas appearing inconsistent in mis7 when high rainfall was associated with low incision rates we infer the variation of discharge to large paleolakes drainage in response to connection of the hetao and fenwei basins revealed by lacustrine platform in these two basins fast paleolake regressions took place approximately at 0 22 ma in the fenwei basins leading to base level fall and then 0 10 ma in the hetao basins causing an abrupt increase in discharge these two events made major contributions to the rapid bedrock river incision

subsidence analysis and modelling of the roer valley graben se netherlands abstract the roer valley graben southeastern netherlands forms the most northern branch of the european cenozoic rift system sedimentary backstripping of exploration wells provides control on vertical tectonic motions during the complex post paleozoic geodynamic evolution of the area the roer valley graben evolved by repeated reactivation of permo carboniferous fracture systems at least three episodes of extension related subsidence are recorded these occurred during the late permian early triassic 255 240 ma the middle jurassic 168 165 ma and the late cenozoic 36 0 ma a late jurassic early cretaceous stretching phase is weakly inferred from incomplete data crustal stretching values calculated from the tectonic subsidence curves can account for the reflection seismic controlled crustal configuration of the roer valley graben area results demonstrate a close relationship between the roer valley graben and the basins in the north sea during the mesozoic in contrast the cenozoic evolution of the roer valley graben is independent from that of the north sea and is related to the development of the rhine graben

the upper rhenish shield basement vosges upper rhinegraben and schwarzwald main structural features deduced from magnetic gravimetric and geological data abstract interpretation of magnetic and gravimetric data and correlations with geological observations on outcrops and in boreholes have enabled the construction of a geological sketch map of the pre westphalian basement in the area of the upper rhenish shield the map demonstrates the contrast between the heavy and magnetic saxothuringian characterized by palaeozoic units metamorphosed to varying degrees and intruded by early carboniferous basites and the lighter moldanubian consisting mainly of gneisses and granites geological structures and tectonic features are recorded beneath the mesozoic and cenozoic cover the present picture of the basement is mainly the result of late visean early namurian structural features represented by a linear arrangement of magmatic bodies and the distribution of strike slip and thrust faults the major structural features are the e w vittel lalaye lubine baden baden fault that marks the border between saxothuringian and moldanubian the n35 left lateral wrench fault system running along the present rhinegraben the n60 grain of the northern vosges and the saar basin and the s verging crustal thrusts of moldanubian

sediment budgets for a sediment laden river the lower wei river in the period 1960 1990 fluvial sediment delivery is the main form of sediment transfer from the land to the sea but this process is currently undergoing significant variations due to the alteration of catchment and base level controls related to climate change and human activities especially the widespread construction of dams using the lower wei river as an example and an integrated approach this study investigates the variation of fluvial sediment delivery as well as the connectivity under the effects of both controls based on hydrological records and channel cross section surveys sediment budgets were constructed for two periods 1960 1970 1970 1990 after the dam was closed in 1960 in the period 1960 1969 due to the elevated base level 327 2 1 62m caused by the dam the aggradation rate was 0 451x10 8 tyr 1 in the channel and 0 716x10 8 tyr 1 on the floodplain indicating that the positive lateral connectivity between these locations was enhanced as a consequence serious sediment storage resulted in a sediment delivery ratio sdr that was smaller than that occurring before 1960 in the period 1970 1990 sweeping soil and water conservation swc measures were implemented resulting in a reduction of the connectivity between the trunk and tributaries and a decrease of similar to 31 in the mean sediment input in addition together with the base level fluctuation in the range of 327 47 0 49m the annual variation in sediment storage was primarily dependent on the water sediment regime affected by the swc the negative lateral connectivity was enhanced between the channel and floodplain via bank erosion consequently the aggradation rate was reduced by 89 on the floodplain and by 96 in the channel sediment output continued to decrease primarily due to the swc practices and climate changes in this period whereas the sdr increased due to the enhanced longitudinal connectivity between the upstream and downstream copyright c 2014 john wiley sons ltd

fluvial sediment budget of a modern restrained river the lower reach of the rhine in germany abstract the rhine river is a restrained river which is intensely used for navigation its river bed is subject to human induced erosion and sedimentation processes for river management information on the amount type source transport mode and fate of the sediments moving through the rhine is indispensable the objective of this study was to quantify the downstream fluxes of clay silt sand gravel and cobbles through the rhine between 1991 and 2010 and to identify the sources and sinks of these sediments this was done by analysing a unique dataset containing thousands of sediment transport measurements and by evaluating the sediment budget the river bed of the rhine was found to be subject to a net bed degradation of 3 mm a between 1991 and 2010 bed degradation has been induced by 18th 20th century river training works and nowadays is concentrated in areas with tertiary sands close to the bed surface in areas with mining induced subsidence and in the gravel sand transition zone sediment transport was found to be dominated by suspended clay and silt morphologically relevant however are only the sand gravel and cobble fractions despite the armoured gravely river bed sand is the main morphological agent sediment loads change in the downstream direction sand and fine gravel loads increase due to erosion of the bed whereas coarse gravel and cobble loads decrease due to a reduced sediment mobility caused by the downstream decreasing bed slope approximately one third of the sand and gravel load comes from upstream rhenish massif one third is supplied by bed degradation and one third is supplied artificially by humans for bed stabilisation purposes or as substitute for natural bed load slightly more than one half of the sediment was transported downstream into the north sea basin rhine delta a small amount was lost by abrasion and the remainder must have been deposited in groyne fields on floodplains or in ports the transfer of sand gravel and cobbles from the hinterland towards the rhine delta equalled 0 66 mt a 26 despite the long history of human impact this rate does not differ significantly from the holocene rate of sediment transfer to the rhine delta

eocene oligocene tectonics and kinematics of the rhine saone continental transform zone eastern france a tectonic analysis of brittle deformaton was performed in the rhine saone transform in order to decipher and understand the deformation processes in a typical continental hansfer zone cenozoic major and minor fault patterns are described and brittle structures are interpreted in terms of paleostress orientations the eocene n s compression related to africa eurasia convergence is marked mainly by strike slip faults it was followed by a major phase of crustal extension mainly oligocene in age related to the west european rifting this extensional phase is expressed by normal faults tension gashes and extensional strike slip faults which are especially abundant in the transform zone these two events are found to be quite different in terms of distribution of horizontal shess trajectories the trend of ol axes is very homogeneous for the n s compression whereas o3 orientations associated with the major extension vary from e w in most of the rift system to i v se within the transform zone finally the mio pliocene tectonic emplacement of the jura fold and thrust belt is marked in the field by strike slip faults associated with a well defined trend of ol oriented w iiw e se to nw se the preexisting basement fracture pattern between the grabens was also considered in order to estimate which faults were likely to have been reactivated during the oligocene transform kinematics and the theoretical shear motion on these inherited fault surfaces when submitted to e w extension was calculated left laterauextensional reactivation of a preexisting 60 n trending fault system in the brittle upper crust is likely to have accommodated the shear strain arising between the rift segments in response to crustal stretching two independent numerical modelings based on distinct element and finite element analyses respectively enabled us to verify and to refine the hypothesis of transform kinematics related to e w extension and inducing regional perturbations of extensional stress trajectories the overall mechanism and the transtensional kinematics of the rhine saone transform zone are thus tightly conshained the inherited crustal anisotropy the large scale perturbations of extensional stress trajectories and the development of distributed brittle deformation within the sedimentary cover are found to play a major role in the tectonic evolution of continental rift transform systems

successive post variscan stress fields in the french massif central and its borders western european plate comparison with geodynamic data abstract structural analysis and particularly microtectonic methods have made it possible to define the different stages of brittle deformation of the massif central basement and the surrounding sedimentary cover from the end of the hercynian orogeny to the end of the tertiary during the stephanian a compressional tectonic regime prevailed regional faults appeared or were react vated reactivation as a result of initial n s compression becoming nw then e w these regional strike slip faults caused local extension which led to the formation of small coal bearing basins this compressional regime which marked the end of the formation of pangea was followed by a series of extension episodes permian triassic extension oscillating around n s e w to nw se extension in the early and middle jurassic and finally n s to ne sw extension in the late jurassic to cretaceous the normal faults formed during these episodes strongly influenced the distribution of emerging continents and sedimentary basins from the campanian 75 ma to the present the convergence of africa and eurasia involved the distribut on of stresses in the west european plate several tectonic episodes are distinguished in the massif central during the eocene approximately n s compression predominated general e w extension in the late eocene oligocene resulted in grabens with general northerly strike mainly in the centre of the massif central and on its east and southeast borders lastly compression varying from nw se to e w in the north and south of the massif central prevailed during the alpine orogenic phase at the end of the miocene these successive stages of brittle deformation are interpreted in the context of the evolution of the west european plate and its displacement in relation to the african plate the correspondences between the major geodynamic periods and the distribution of stresses over the west european continent are noted as well as the problems which remair to be resolved

late cenozoic deep weathering patterns on the fennoscandian shield in northern finland a window on ice sheet bed conditions at the onset of northern hemisphere glaciation abstract the nature of the regolith that existed on the shields of the northern hemisphere at the onset of ice sheet glaciation is poorly constrained in this paper we provide the first detailed account of an exceptionally preserved deeply weathered late neogene landscape in the ice sheet divide zone in northern finland we mine data sets of drilling and pitting records gathered by the geological survey of finland to reconstruct regional preglacial deep weathering patterns within a gis framework using a large geochemical data set we give standardised descriptions of saprolite geochemistry using a variant of the weathering index of parker wip as a proxy to assess the intensity of weathering we also focus on mineral prospects and mines with dense pit and borehole data coverage in order to identify links between geology topography and weathering geology is closely linked to topography on the preglacial shield landscape of northern finland and both factors influence weathering patterns upstanding resistant granulite granite gabbro metabasalt and quartzite rocks were associated with fresh rock outcrops including tors or with thin fines values above 3000 and 4000 beneath valley floors developed along mineralised shear and fracture zones weathering penetrated locally to depths of 50 m and included intensely weathered kaolinitic clays with wip fines values below 1000 late neogene weathering profiles were varied in character tripartite clay gruss saprock profiles occur only in limited areas bipartite gruss saprock profiles were widespread with saprock thicknesses of 10 m weathering profiles included two discontinuities in texture materials and resistance to erosion between saprolite and saprock and between saprock and rock limited core recovery when drilling below the soil base in mixed rocks of the tana belt indicates that weathering locally penetrated deep below upper fresh rock layers such deep seated weathered bands in rock represent a third set of discontinuities incipient weathering and supergene mineralisation also extended to depths of 100 m in mineralised fracture zones the thin weathering crusts found extensively beneath till may represent types of early or middle pleistocene palaeosols we confirm that glacial erosion has been very limited

oblique crustal detachment in the variscan schwarzwald southwestern germany the schwarzwald is part of the central polymetamorphic crystalline belt of the variscan orogen moldanubian belt from north to south it consists of four terranes the metasedimentary zone of baden baden the polymetamorphic central schwarzwald gneiss complex the sedimentary metamorphic zone of badenweiler lenzkirch and the hotzenwald complex the largest of these terranes is the central schwarzwald gneiss complex csgc whose rocks record a history of protracted regional metamorphism and anatectic melt generation during variscan convergence between 350 and 325 ma the csgc became detached from a high temperature lower crustal substratum and was emplaced southeastward over paleozoic clastics volcanic rocks and crystalline slivers of the zone of badenweiler lenzkirch and the hotzenwald complex kinematic indicators suggest that these early convergent movements on retrograde shear zones and the concomitant crustal thickening were superseded by movements on divergent shear zones the ascent of voluminous granitic plutons from a mid crustal zone of melt generation into the upper crust was probably triggered by a change in the crustal kinematics from overall convergence to overall divergence at about 325 ma in detail this process was probably diachronous detachment of upper crust and large scale melt generation in the middle crust of the schwarzwald was probably facilitated by the tectonic stacking of water rich pelitic clastics and gneiss slivers with relatively even proportions of crystalline and pelitic materials

upper rhine graben role of preexisting structures during rift evolution 1 the evolution of the cenozoic upper rhine graben was controlled by a repeatedly changing stress field and the reactivation of a complex set of crustal discontinuities that had come into evidence during permo carboniferous times a comparison of the spatial and temporal thickness distribution of synrift deposits with preexisting fault patterns permits to infer a sequence of distinct basin subsidence phases that can be related to changes in the ambient stress field reactivation of a system of late palaeozoic fault systems outlining troughs and highs controlled the nucleation of initially separated middle and late eocene basins the depocenters of which coincided with a preexisting wsw ene trend during oligocene crustal extension the individual basins coalesced resulting in the development of the ssw nne striking upper rhine graben during the late oligocene chattian change in stress field the upper rhine graben was probably reactivated as a dextral strike slip system with the central graben segment forming a releasing bend during the early miocene aquitanian a major reorientation of the regional stress field is held responsible for the main subsidence phase of the northern parts of the upper rhine graben this is reflected by a counterclockwise rotation and northeastward shift of the depocenter axis and later by the middle miocene uplift and erosion of the southern parts of the upper rhine graben during the plio quaternary the upper rhine graben was reactivated as a sinistral strike slip system with the central graben segment forming a restraining bend

short scale variations of tectonic regimes in the western european stress province north of the alps and pyrenees the data of the european part of the world stress map wsm are used to study the western european stress province north of the alps and pyrenees the study area is characterised by an almost homogeneous n 145 degrees e orientation of the maximum horizont

initial incision of the jinshan gorge of the yellow river china constrained by terrestrial in situ cosmogenic nuclides chronology abstract how post burial terrestrial in situ cosmogenic nuclides tcn production is build up in slow burial condition remains uncertain in this study we dated high fluvial terrace sediments that overlain by loess with a slow deposition rate that is based on the assumption of steady accumulation rate via 26al 10be burial dating method for sample in deep and rapid buried condition prior to slow overlying post burial production shows low component 4 6 in measured concentration however post burial production occupied 39 79 of measured 26al and 10be concentrations which suggests approximately 0 2 0 3 ma underestimation in simple burial dating mode if post burial production is neglected corrected by post burial production we yielded burial ages of two top terraces ca 1 7 2 5 ma and 1 5 ma respectively below the tangxian planation surface along the jinshan gorge of the yellow river implying that the jinshan gorge initially incised at ca 1 7 2 5 ma corresponding well to regional tectonic activities such as extension in the fenwei graben accelerative uplift of the tangxian planation surface vigorous dissection of north china and significant tectonic deformation in northeastern tibetan plateau the slow burial mode is probably a potential method for plateau paleo elevation estimation taking advantage of height sensitivity of tcn production rate if overlying loess magnetostratigraphic age is known

loess deposits in the northern kyrgyz tien shan implications for the paleoclimate reconstruction during the late quaternary article i nfo loess deposits on the northern slopes of the kyrgyz tien shan were examined their particle size characteristics show silt size dominancy n80 with minor contribution from sand 12 and clay 7 the loess was dated using optically stimulated luminescence osl and radiocarbon methods to define the timing of deposition the osl ages of fine and coarse quartz fractions were consistent with each other within 2 uncertainty level ex ceptseveralsamplesdepositedduringmis2 basedontheoslages fourmajorloessdepositionalperiodsarerec ognized in thenorthern kyrgyz tienshan during the late quaternary the holocene mis2 mis3 and mis4 the rate of dust accumulation in the northern tien shan during mis 2 was greater than that during mis 3 or mis 4 this implies that cold dry conditions varied significantly during the late quaternary in the study area the accumulation patterns of the kyrgyz loess deposits in the northern tien shan are closely related to climate fluc tuations during the late quaternary influenced by changes in the mid latitude westerlies asian summer mon soons and siberian high pressure shp systems during which there was no significant cessation of deposition 2013 elsevier b v all rights reserved

paleomagnetic chronology and paleoenvironmental records from drill cores from the hetao basin and their implications for the formation of the hobq desert and the yellow river abstract reconstructing the cenozoic environmental history of hetao basin in the northern part of the ordos plateau in north china is important not only for revealing the evolution of the yellow river but also for understanding the formation of the hobq desert here we present the stratigraphic framework of drill core dr01 with length of 2503 18 m and the results of magnetostratigraphic and esr dating and multi proxy analyses of drill core wedp05 with length of 274 60 m from the hetao basin the magnetostratigraphic and esr results indicate that core wedp05 spans the last 1 68 ma stratigraphic sequence of core dr01 indicates that the hetao area was uplifted and eroded during the early cenozoic before subsiding to form a sedimentary basin subsequently the basin was a fluvio lacustrine environment during the pliocene and then experienced alternating desert and fluvio lacustrine conditions during the quaternary sedimentary facies and multi environmental proxy analyses of core wedp05 indicate that the basin was occupied by a fluvio lacustrine system during the following intervals 1 47 1 30 ma 1 17 1 07 ma 0 68 0 60 ma and from 0 47 ma to the last interglacial and that a desert environment developed during the lake regression phases of 1 30 1 17 ma 1 07 0 68 ma and 0 60 0 47 ma the presence of aeolian sand at the base of core wedp05 suggests that the origin of the hobq desert can be traced back to the early pleistocene and resulted from the erosion and transportation of exposed fluvio lacustrine sediments by near surface winds associated with the asian winter monsoon a large river channel in the hetao basin may have existed as early as the pliocene which was occupied by the yellow river when its upper reaches formed by at least 1 6 ma subsequently at least since 1 2 ma the yellow river formed its drainage system around the hetao basin and controlled the paleoenvironment evolution of the basin

differential impact of small scaled tectonic movements on fluvial morphology and sedimentology the huang shui catchment ne tibet plateau abstract the aim of this paper is to investigate the morphological implications of the interplay between tectonic movements at different rates timescales and spatial extent in a catchment of intermediate size the huang shui river a main tributary of the yellow river in the ne tibet plateau river incision started from a peneplain like surface that developed in post miocene pliocene times at the end of the tertiary a general tectonic uplift of the tibetan plateau initiated river incision this general uplift also caused local fragmentation of the huang shui catchment into blocks kilometers or maximally a few tens of kilometers of local extent that have subsided and or uplifted relative to one another fluvial deposition of 30 m in the subsiding blocks contrasts with erosion and formation of gorges in the uplifted blocks incision into the former peneplain was not continuous but a staircase of terraces developed under climatic influences terrace deposits are sometimes capped by interglacial soils or soil derived material apparently terrace incision occurred at the transition to the next cold period the different rates of uplift and subsidence of the individual blocks resulted in the simultaneous development of erosion and accumulation terraces of different sizes within the same catchment even within the same tectonic block this makes it impossible to connect the terraces of the different blocks except for the three youngest terraces representing the last 300 000 years thus illustrating the uniform tectonic history of the catchment since that time

verification of porosity predictors for fluvial sand gravel deposits 1 although porosity is a key property of sediment mixtures little is known of the natural variations in porosity in fluvial systems porosity predictors can help to generate such information the objective of this study was to determine the accuracy of porosity predictors for fluvial sand gravel mixtures in order to do so porosity measurements were done in the rhine river using a diving bell to allow undisturbed sampling under water in addition laboratory experiments were conducted and porosity data from literature were reanalyzed measured porosity values range from 0 06 to 0 48 our study shows that predictors based on the median grain size the deviation from the fuller curve or the sediment standard deviation are unable to reproduce the observed variation in porosity predictors based on the entire grain size distribution perform better but are biased and have a large prediction error this suggests that they do not account correctly for the grain size effect on porosity on the other hand parameters such as grain shape and the mechanism of deposition probably also have a distinct influence on porosity slightly more accurate predictions can be obtained with tailor made predictors for the river under interest multivariate regression analysis on the rhine data set produced a predictor with two independent parameters the sediment standard deviation and the number of grains smaller than 0 5 mm representing grain mixing effects and adhesion effects respectively despite the shortcomings porosity predictors provide valuable insights in the spatial variation in porosity which is demonstrated in a case study for the rhine river

european cenozoic rift system abstract the european cenozoic rift system extends from the coast of the north sea to the mediterranean over a distance of some 1100 km it finds its southern prolongation in the valencia trough and a plio pleistocene volcanic chain crossing the atlas ranges development of this mega rift was paralleled by orogenic activity in the alps and pyrenees major rift domes accompanied by subsidence reversal of their axial grabens developed 20 40 ma after beginning of rifting uplift of the rhenish shield is related to progressive thermal lithospheric thinning the vosges black forest and the massif central domes are probably underlain by asthenoliths emplaced at the crust mantle boundary evolution of this rift system is thought to be governed by the interaction of the eurasian and african plates and by early phases of a plate boundary reorganization that may lead to the break up of the present continent assembly

the quaternary uplift history of central southern england evidence from the terraces of the solent river system and nearby raised beaches abstract we have used fluvial solent river system and marine terraces to reconstruct the uplift history of central southern england in the case of the former we make the assumption that fluvial incision has been a direct response to surface uplift with its precise timing controlled by climatic forcing of fluvial activity such that height of terrace gravel above modern river is a consequence of uplift since deposition in the case of the marine sequence we take the height of interglacial raised beaches above a calculated contemporaneous sea level as a measure of uplift the calculation involving an adjustment from modern sea level using the deep oceanic oxygen isotope signal as an indication of global ice volume at the time of deposition this exercise requires some degree of dating constraint which is problematic for both environments the solent terraces have yielded little biostratigraphical evidence whereas the south coast raised beaches have either been poorly exposed in recent years or their ages have been controversial because of disputes between biostratigraphy and geochronological data we have supplemented the evidence available from these sources by using key aspects of the archaeological record as dating constraints in particular the first appearances of levallois technique a marker for mis 9 8 and of bout coupe handaxes mis 3 the first of these has been particularly useful in modelling of the middle pleistocene parts of the river terrace staircases of the solent system in undertaking this reappraisal we have noted several inconsistencies and disagreements between past correlation schemes for the terraces of the solent and its various tributaries we find that versions involving shallower downstream gradients in the main solent river are most likely to be correct and that revisions on this basis solve a number of problems in interpretation encountered previously our results show that most of this region has uplifted by 70 m since the late early pleistocene and by 150 m since the middle pliocene there being a high degree of consistency between uplift histories inferred for river terraces and marine terraces uplift rates increase gradually westward such that along the river frome at the western end of the hampshire basin 80 m of uplift since the late early pleistocene is indicated this variation is interpreted as a consequence of a regional scale variation in crustal properties about 80 m of uplift is also indicated on this timescale by raised beaches in the portsdown area and adjacent terraces of the river test and solent in the vicinity of the portsdown anticline to the north of southampton we interpret this as a consequence of 10 m of vertical slip in the past million years on the blind reverse fault beneath this anticline this dataset thus provides the first clear indication of measurable quaternary structural development in crustal basement in the onshore uk the solent has formed more than a single terrace per 100 ka milankovitch cycle leading us to attribute terraces to isotopic substages potentially improving upon the resolution available from sequences in which terraces formed once per cycle athough the first appearence of levallois technique was initially considered to date from the mis 9 8 transition based on evidence from the thames we found that there was a better modelling fit if this was taken as having occurred slightly earlier in mis 9b perhaps in association with the post mis 9e or 9c marine regression which could have permitted immigration into a previously insular britain of people versed in levallois technology

late quaternary faulting on the manas and hutubi reverse faults in the northern foreland basin of tian shan china abstract the tian shan range lies in the actively deforming part of the india asia collision zone in the northern foreland basin of tian shan the strata were intensively deformed by cenozoic folding and faulting slip rate studies along these faults are important for understanding the dynamics of crustal deformation and evaluating the seismic hazards in the region two reverse faults the manas and hutubi faults in the northern foreland basin were investigated due to past faulting events along these faults the terrace treads along the manas river were ruptured forming fault scarps several meters in height loess deposits were trapped and preserved at the surface ruptures along these scarps the thickness of the trapped loess is dependent on the size of the ruptures the minimum and maximum ages of these scarps are constrained by dating the loess preserved at the surface ruptures and the terrace treads respectively using the quartz optically stimulated luminescence osl dating technique our dating results suggest that the loess trapped at the ruptures was deposited from the early to mid holocene at the hutubi fault and from the mid to late holocene at the manas fault the vertical displacements of the faults were evaluated by measuring the topographic profiles across the investigated fault scarps using the differential global position system dgps our results suggest that during the late quaternary in the studied region the vertical slip rates of the manas fault were between 0 74 mm yr and 1 6 mm yr while the hutubi fault had a much lower vertical slip rate between 0 34 mm yr and 0 40 mm yr the tectonic implications of our results are discussed

the paleolithic site of longwangchan in the middle yellow river china chronology paleoenvironment and implications the longwangchan paleolithic site situated on the yellow river terraces in the hukou area shaanxi province china was found in 2003e2004 and two areas localities 1 and 2 of the site were excavated in 2005e2008 abundant stone artifacts including microliths a grinding stone fragment and a shovel with some animal bones and shells were recovered from locality 1 in this study the cultural deposits from locality 1 were dated using radiocarbon and optical dating techniques and the sediment properties of the deposits were analyzed the results show that the age of the deposits ranges from 29 to 21 ka and most of them were deposited between 25 ka and 29 ka this indicates that corresponds to late marine isotope stage mis 3 and early mis 2 during the human occupation period the climate in this area became colder and drier sediments from beds where the grinding slab and the shovel were found were dated to w25 ka which is the oldest among the grinding stones found in china the microliths and the grinding stone are important evidence for an incipient socio economic process that eventually led to the regional transition from hunting foraging to farming

the late and post variscan tectonic evolution of the western border fault zone of the bohemian massif wbz paleostress analysis and evaluation of the stratigraphic unconformities reveal an extremely polyphase development of one of the most prominent fault zones of central europe usually known as the franconian line fl because the fl is just one fault zone although it is the most important fault zone within a complex fault system a more appropriate term is used herein western border fault zone of the bohemian massif wbz the reconstruction of the paleostress history was carried out by analysing sequences of individual strain increments that belong to the same stratigraphic units e g late variscan granites tertiary basalts a succession of at least 15 paleostress directions and tectonic regimes have been determined since late variscan time

fluvial terrace formation in the eastern fenwei basin china during the past 1 2 ma as a combined archive of tectonics and climate change abstract the key to understanding the fluvial response to climate change and surface uplift is a thorough distinguishing between their roles in terrace formation previous studies have tended to attribute the fluvial behavior of deposit incision alternation to climate cyclicity a preliminary explanation is proposed here for terrace formation in the eastern part of the fenwei basin china the observed fluvial terrace sequence was developed by the yellow river deeply downcutting into the emei platform which was uplifted within the eastern fenwei basin and therefore it probably records the tectonic history of this platform on the basis of the magnetostratigraphy and optically stimulated luminescence osl dating a ca 1 2 ma chronology was established for this terrace sequence pedostratigraphic analysis of the loess deposits accumulated on each tread reveals that the terrace deposits are overlain immediately by a paleosol bed suggesting that the abandonment of these terraces due to fluvial incision occurred at the transitions from glacial to interglacial climates the glacial interglacial climate cycle probably has a temporal control on the fluvial behavior of deposit incision alternation even though the yellow river develops in the subsiding fenwei basin the terrace generation may be sporadic and in the form of unusual stacked pattern before the emei platform was uplifted within the eastern fenwei basin the terrace staircases however formed in synchrony with glacial interglacial climate cycles since this platform began to uplift in the late middle pleistocene this result indicates that uplift may be necessary in large terrace staircase genesis it can force the river system to downcut deeply enough during climatic transitions to separate terrace levels adequately favoring the generation and subsequent preservation of the terrace treads the terrace sequence of the yellow river in the eastern fenwei basin therefore can be considered as a combined archive of climate change and local tectonic activity

the evolution of a terrace sequence along the manas river in the northern foreland basin of tian shan china as inferred from optical dating abstract the tian shan range lies in the actively deforming part of the india asia collision zone the uplift rate and deformation pattern of the tian shan are important for understanding the dynamics of crustal deformation in the region the river terraces in northern tian shan provide key records of past changes in climate and or regional tectonics in this study a terrace sequence along the manas river in a tectonically active zone in the northern foreland basin of tian shan is investigated six river terraces were identified and dated using optically stimulated luminescence osl the results show that the six terraces were abandoned at 0 5 ka 1 4 ka 3 1 ka 4 0 ka 12 4 ka and 19 9 ka respectively together with high resolution global positioning system gps measurements on the terrace treads the fluvial history of manas river is reconstructed from 20 ka to 4 8 ka the height of the fluvial bed of manas river decreased at an average rate of 2 2 0 6 mm yr from 4 8 ka to the present the height of the fluvial bed decreased at an average rate of 13 5 0 6 mm yr corresponding to intensified incision of manas river during the late holocene this accelerated incision is very likely caused by the tectonic forces rather than climatic influences alone suggesting that the tectonic uplift activity was significantly intensified since 4 8 ka in the northern piedmont of tian shan other controlling factors on the incision of manas river are also discussed

engineering impacts on the upper rhine channel and floodplain over two centuries abstract the reconstruction of long term 100 yr channel changes is critical to understanding how natural and anthropogenic factors impact the evolution of river systems it provides information on channel sensitivity and the limitations for channel repair in a functional river restoration context this study presents a two century analysis of the evolution of a large braided and anabranching river the upper rhine downstream of basel which has experienced three phases of engineering works nineteenth century channelization 1930s groyne construction and 1950s damming and by passing we studied historical maps longitudinal profiles and cross sections to investigate changes in the areas and geometries of fluvial features from 1828 to 2009 the results showed a drastic floodplain drying out following nineteenth century channelization 93 reduction of fully connected channels 48 augmentation of partially connected channels augmentation of disconnected water bodies by more than five times and augmentation of terrestrialized channels of more than two times 1828 1925 changes propagated downstream at 280 m yr 1 on the 50 km long river continuum the channel exhibited bed topography of large forms in 1880 with a median pool riffle amplitude of 4 0 m locally reaching 6 6 m among the three phases of engineering works on the upper rhine channelization had the most impact on planform floodplain terrestrialization and vertical 7 cm yr 1 bed degradation adjustments with short reaction times and effects lasting several decades damming had the greatest impact on peak flows and can explain the lower magnitude of the channel changes in the contemporary period we synthetized the complex cause effect relationships between natural anthropogenic controlling factors and hydromorphological processes over the past 200 yr and outlined the evolutionary trend of the main geomorphic variables which can be used as a knowledge framework to evaluate future morphodynamic restoration schemes

mineralogy and geochemistry of the clay fraction of till in northern finland abstract the mineralogy and geochemistry of the clay fraction of till in different moraine types and in different bedrock areas in northern finland have been studied moraine types include ground moraine rogen moraine pulju moraine sevetti moraine and kianta moraine the bedrock is composed of granite granite gneiss and mafic volcanite x ray diffraction differential thermal and thermogravimetric analyses transmission electron microscopy x ray fluorescence and atomic absorption spectrometry were used as analytical methods quartz feldspars and amphibole are the primary rock forming minerals occurring in nearly all the samples of each study area the clay minerals proper include kaolinite vermiculite swelling lattice vermiculite chlorite illite and mixed layer minerals kaolinite occurs most abundantly only in till in the kittilaarea where a preglacial weathering crust has been the source rock poorly crystalline or amorphous fe oxides also abound in till at kittila sodium ca and si have been depleted and al mg fe k ti p and trace elements have been enriched in the clay fraction compared with the fine fraction the contents of si k and na are higher in the granitic areas and the contents of cu co ni and zn are higher in the mafic volcanite areas preglacial weathering has led to the depletion of si mg ca k and na and to the enrichment of al fe ti p and trace elements in the clay fraction of till in the kittilaarea high base metal values in the inari area suggest the possibility of sulphide mineralizations there and high as values in the kittilaarea indicate au potential there the most important factors controlling the mineralogical and geochemical composition of the clay fraction of the tills in northern finland are the composition of the bedrock and the possible occurrence of an old weathering crust the final grain size composition of the tills and consequently the quantitative proportions of the different minerals are often related to the last glacial quarrying and sorting processes therefore the mineralogical composition of the tills is to a certain extent bound also to the respective moraine types

a fluvial terrace record of late quaternary folding rate of the anjihai anticline in the northern piedmont of tian shan china abstract crustal shortening of the tian shan range in northwest china has largely been accommodated by fold and thrust belts that mark the northern and southern mountain boundaries which were formed during the basinward propagation of the deformation front of tian shan investigating the deformation rates of active folds anticlines in the mountain piedmonts within different timescales is important for understanding the mountain building and front propagation processes of the tian shan in this study we investigate the late quaternary folding rate of the anjihai anticline one of the major anticlines in the northern piedmont of tian shan our study is based on optically stimulated luminescence osl dating and topographic measurements of folded river terraces three well preserved fluvial terraces across the anjihai anticline were identified and dated to be 3 6 0 1 ka 9 0 0 6 ka and 53 3 2 2 ka respectively these terrace ages are combined with shortening and uplift of the terraces estimated using an area conservation method and the terrace height profiles to evaluate the average shortening and uplift rates our results show that the minimum shortening rate of the anjihai anticline is 0 4 mm a between 53 ka and 9 ka and 1 1 mm a over the past 9 ka and the corresponding minimum uplift rates are 0 5 mm a and 1 4 mm a respectively if a local sedimentation rate of 0 3 mm a is taken into consideration the shortening rate is 0 7 mm a between 53 ka and 9 ka and 1 3 mm a since 9 ka and the corresponding uplift rates are 0 8 mm a and 1 5 mm a respectively these data suggest that the anjihai anticline has accommodated 20 25 of the total shortening across the whole eastern tian shan 5 mm a in the holocene our results suggest that the holocene is a relatively tectonically active time interval since the late pleistocene the late quaternary shortening rate of the anjihai anticline is much higher than its long term average shortening rate 0 2 mm a since its formation at 7 4 ma a similar situation has also been observed for other active folds in the northern and southern piedmonts of tian shan the higher late quaternary folding rate is possibly attributed to the gradual propagation of the tian shan towards its northern and southern foreland basins in the quaternary

graben inversion in nature and experiments the inversion of crustal scale basement grabens is studied here through laboratory experiments on small scale models and available oil industry seismic lines from the southern north sea two basic configurations are considered first both the basement and the sedimentary cover are brittle and inversion does not involve any potential decollement between them second the basement and sedimentary cover are separated by a weak ductile layer e g salt which can allow decollement of the cover during both extension and later compression and inversion the second configuration is more complicated and can lead to a large variety of geological structures laboratory experiments were carried out on brittle ductile models built with sand to represent brittle layers basement and sedimentary cover and silicone putty to simulate the decollement layer between basement and cover a mechanically based classification of inversion structures is proposed the effects of some crucial parameters are investigated including obliquity between the direction of shortening and normal faults as well as strength profiles and the presence or absence of salt diapirs the experimental investigation leads to the following conclusions 1 the inversion of the graben by reactivation of normal faults implies that the angle between the direction of compression and the graben is less than 45 2 if there is a superficial decollement e g basement cover interface inversion initiates low dipping thrust faults in the cover localized at graben borders 3 salt diapirs or salt walls localized along the graben borders in the cover are preferential sites for the development of thrust faults and 4 when the cover is decoupled from the basement by a decollement layer inversion induced deformation in the cover which is partitioned between thrust faults along the graben borders and strike slip faults within the graben trending oblique to the graben borders experimental results are compared with field examples in particular from the southern north sea

from source to mouth basin scale morphodynamics of the rhine river abstract in this article we present a unique detailed basin wide morphological analysis of the rhine one of the world s larger rivers the objectives of this study were to characterize the basin scale morphodynamics of the rhine river in the period 1991 2010 by quantifying the downstream fluxes of clay silt sand gravel and cobbles from source to mouth and identifying the sources and sinks of these sediments using sediment budget analyses from source to mouth the rhine traverses four sections with fundamentally different morphodynamic behaviour the alpine impounded free flowing and delta section sediment fluxes are discontinuous primarily because of the presence of a glacial lake trapping all sediments from upstream the lake caused sediment fluxes to be discontinuous already before the anthropocene today s sediment fluxes are strongly influenced by dredging and nourishment operations from a global perspective sediment fluxes in the river s headwaters are large whereas sediment output from the rhine towards the sea is small a special feature of the rhine is the fact that more sediment is transported in upstream direction from the sea into the delta than vice versa on a basin scale nourishment represents the biggest source of gravel and cobbles and tributaries the biggest source of clay silt and sand in the lower rhine delta additional large amounts of clay silt and sand are supplied by the sea dredging represents a main sediment sink for all size fractions for silt and clay also floodplain deposition and deposition in ports represent major sinks the rhine is a typical example of a river in disequilibrium large parts of the river are subject to erosion or sedimentation in contrast to other rivers with erosion upstream and deposition downstream the rhine has net deposition upstream and net erosion downstream although human interventions contributed to the disequilibrium the pristine rhine already was in a state of disequilibrium even today natural factors determine the location of the main sedimentation areas the budget analysis shows that the behaviour of the clay silt sand and gravel cobble fractions strongly differ from each other a particularity is that in many reaches gravel is deposited whereas simultaneously sand is being eroded the budget analysis also shows that sediment dynamics in rivers are much higher than is suggested by echosoundings or transport measurements this study provides valuable insights into the basin scale morphodynamics of the rhine helps to see smaller scale studies of parts of the rhine basin in a correct perspective provides a good data basis to improve numerical prediction models and helps to optimize nourishment dredging and monitoring strategies in the rhine furthermore the rhine represents an excellent reference case for other large river systems for which less data are available knowledge gaps of supra regional importance identified in this study relate to a the fundamental disequilibrium of large river systems b the effect of natural and human factors on the future morphodynamic development of the large river systems c the morphodynamic role of sand in gravel bed rivers and d the long term effects of sediment nourishment

regional stress field and rifting in western europe abstract baumann h 1981 regional stress field and rifting in western europe in j h illies editor mechanism of graben formation tectonophysics 73 105 111 in situ stress determination is one possibility to determine stress magnitudes in the earth s crust most measurements especially in the northern alpine foreland have been carried out by using the doorstopper technique stress magnitudes are presented as excess stresses a number of sites where stresses have been determined gave sufficiently high values to statistically determine stress directions for the following tectonic blocks 1 western alps 2 their immediate foreland with the rhinegraben and 3 the rhenish shield bordering on the rift segment of the lower rhine embayment in discussing results of the statistical analyses of stress data it is suggested that stresses measured in the western alps have mainly a topographic origin in the alpine foreland to the north of the rhenish shield topographic stresses are superimposed on active tectonic stress considering the structural and lithological differences the foreland blocks show a different response to the same tectonic stress field which trends for 1 at about 146 this active stress field causes shear rifting in the upper rhinegraben but extensional rifting in the lower rhine embayment in the rhenish shield area only local step faults are observed in direction of 1 due to the ductile behaviour of its basement

discriminating between pore filling load and bed structure load a new porosity based method exemplified for the river rhine sediments contained in the river bed do not necessarily contribute to morphological change the finest part of the sediment mixture often fills the pores between the larger grains and can be removed without causing a drop in bed level the discrimination between pore filling load and bed structure load therefore is of practical importance for morphological predictions in this study a new method is proposed to estimate the cut off grain size that forms the boundary between pore filling load and bed structure load the method evaluates the pore structure of the river bed geometrically only detailed grain size distributions of the river bed are required as input to the method a preliminary validation shows that the calculated porosity and cut off size values agree well with experimental data application of the new cut off size method to the river rhine demonstrates that the estimated cut off size decreases in a downstream direction from about 2 to 0 05 mm covariant with the downstream fining of bed sediments grain size fractions that are pore filling load in the upstream part of the river thus gradually become bed structure load in the downstream part the estimated mass percentage of pore filling load in the river bed ranges from 0 in areas with a unimodal river bed to about 22 in reaches with a bimodal sand gravel bed the estimated bed porosity varies between 0 15 and 0 35 which is considerably less than the often used standard value of 0 40 the predicted cut off size between pore filling load and bed structure load dc p is fundamentally different from the cut off size between wash load and bed material load dc w irrespective of the method used to determine dc p or dc w dc w values are in the order of 10 1 mm and mainly dependent on the flow characteristics whereas dc p values are generally much larger about 100 mm in gravel bed rivers and dependent on the bed composition knowledge of dc w is important for the prediction of the total sediment transport in a river including suspended fines that do not interact with the bed whereas knowledge of dc p helps to improve morphological predictions especially if spatial variations in dc p are taken into account an alternative to using a spatially variable value of dc p in morphological models is to use a spatially variable bed porosity which can also be predicted with the new method in addition to the morphological benefits the new method also has sedimentological applications the possibility to determine quickly whether a sediment mixture is clast supported or matrix supported may help to better understand downstream fining trends sediment entrainment thresholds and variations in hydraulic conductivity