recent sediment accumulation and origin of shelf mud deposits in the yellow and east china seas abstract modern last 100 yr accumulation rates of shelf mud deposits in the yellow and east china seas were investigated using the distribution of excess 210pb 210pbex in sediment core samples compilation and merger of new and previously published data helped clarify sediment accumulation in these seas the estimated accumulation rates together with data of suspended sediment concentrations provided findings on the sediment budget origin and transport pathway of the mud deposits the overall accumulation distribution in the yellow and east china sea shelf revealed a general cross shelf decreasing trend along the sediment dispersal system away from the rivers except for the south sea ssm and southeastern yellow sea seysm mud patches found along the korean coast notably 210pbex activity profiles within the ssm and the seysm yielded a relatively high accumulation rate of 2 5 mm yr implying a sedimentation rate of 4 15 107 tons per year in this coastal zone such an annual accumulation rate is about one order of magnitude greater than the total sediment discharge 6 20 106 tons yr from korean rivers suggesting an additional offshore source the distribution pattern of the well defined suspended plume clearly showed the possible transport and exchange of fine grained sediments between the ecs shelf and the coastal area of korea especially during winter such a high accumulation in korean coastal areas is attributable to the sediments supplied from the mud deposit of the ecs i e swcim with origins in chinese rivers therefore the korean coastal area may be an important sink for some of chinese river sediments being transported from the south by the yellow sea warm current

niveo aeolian sand deposition in subarctic dunes eastern coast of hudson bay quebec canada aeolian sand transport during winter and the snow free season was assessed quantitatively by direct year round field measurements along transects on the lee side of parabolic dunes in subarctic quebec in 1987 1988 niveo aeolian deposition was more important than aeolian sedimentation in three of the four study sites and contributed 75 of the total annual accumulation in exposed sites and 25 in protected forest sites the maximum depth of interstratified snow and sand deposits 3 5 m was recorded in march semi permanent snow lenses may persist longer than 2 years in the aeolian sediments after dissipation of snow 22 cm of sand as a maximum accumulated on the slipface of the most active dunes whereas only minor sand accumulation occurred in distant areas from active sand erosion wind driven sand was dispersed over 7 4 km2 in the whapmagoostui kuujjuarapik area the acumulation of snow and sand during the snow season together with spring thaw and collapse of the niveo aeolian deposit caused different types of injuries to trees especially in 1985 and 1987 when a maximum of torn branches was recorded over the last 10 year period

magnetic properties of muddy sediments on the northeastern continental shelves of china implication for provenance and transportation mud deposits are widespread in estuaries and on continental shelves and contain important information regarding interactions between terrestrial and coastal processes magnetic properties of muddy sediments from the northeastern continental shelves of china including shelves close to korean coasts were analyzed using bulk and size fractionated samples to elucidate muddy sediment sources and transport types concentration and granulometry of magnetic minerals were determined and all samples were found to be dominated by magnetite muddy sediments from the zhemin coast off the zhejiang and fujian coasts have the highest magnetic susceptibility and saturation isothermal remanent magnetization sirm values while those from the central and southeastern south yellow sea and the western korea strait have lower values reflecting lower magnetic mineral concentrations single domain ferrimagnetic grains dominate the magnetic particles in the central south yellow sea while superparamagnetic sp grains contribute significantly to the magnetic grains in the bohai sea sp and coarse multi domain md grains dominate magnetic grain assemblages in the north yellow sea and along the zhemin coast rock sediment particle size is not a major factor affecting the magnetic properties of the mud deposits in the study area rather terrigenous inputs and hydrodynamic transport processes primarily control the magnetic properties and sediments from the changjiang and huanghe rivers make the most significant contribution this observation applies to the whole study area although terrigeneous magnetic mineral concentrations decrease with increasing distance from the river mouths due to both sorting and mixing with other sediments with weak magnetic signatures bacterial magnetosomes also play a role in the central south yellow sea

provenance discrimination of last deglacial and holocene sediments in the southwest of cheju island east china sea abstract the ultimate provenance of muddy sediment in the southwest of cheju island east china sea remains enigmatic thus far in this study rare earth elements rees were used to investigate sediment provenances of cores e03 6 e03 10 and e03 11 taken from the mud patch discrimination plots based on ree fractionation parameters and trace elements suggest that the sediments deposited during the last deglacial period 15 ka were derived predominantly from the paleo huanghe yellow river which might have delivered sediments directly into the northeastern east china sea during the lowstand of sea level the coarse grained sediments deposited at transgressive stage 15 6 ka were primarily sourced from the changjiang yangtze river and partly from the korean peninsula probably transported by tidal currents in comparison the clayey sediments deposited at highstand stage

physical and acoustic properties of inner shelf sediments in the south sea korea abstract core sediment sampling has been conducted to investigate the physical and acoustic properties of inner shelf sediments in the south sea korea thirty two piston core samples were analyzed for sediment texture grain size as well as fractions of sand silt and clay physical properties porosity water content bulk density grain density and shear strength and acoustic properties compressional wave velocity and attenuation the sediments in the study area consist mostly of homogenous mud the study area can be divided into two different areas south of namhae island and southeast of naro island by texture and physical and acoustic properties the mean grain size generally decreases seaward from the mouth of yeosu sound and eastward in the southeast area of naro island the compressional wave velocity decreases southeastward from 1500 to 1480 m s and then increases to 1520 m s due to relict sediments deposited in mid shelf of the south sea porosity water content and bulk density show an inverse pattern to velocity the geoacoustic properties of the study area are generally similar to those of continental terrace sediment studied by hamilton in the north pacific the area south of namhae island area matches hamilton s model better than the area southeast of naro island this result is believed to be related to the higher silt and sand contents as well as lower clay content than southeast of naro island

a review on the provenance discrimination of sediments in the yellow sea the yellow sea has been extensively studied for the understanding of dispersal patterns and limits of sediments from neighboring countries including china and korea although sedimentological mineralogical and geochemical approaches have been tried to solve the problems especially including the identification of sediment sources in and around the yellow sea the published results are not enough for understanding them suggestions on sediment origins budgets sediment accumulation rates mineralogical and geochemical compositions are not coincident to each other and sometimes even controversial for example conflicts on the distribution patterns of smectite and calcium carbonate the provenance of the southeastern yellow sea mud and sedimentation rates in there the ratios of v al and mn al in korea and china river sediments the origin of ba and pb in sandy sediments of the northeastern yellow sea and so on various geochemical indicators from the literature for the provenance discrimination in the yellow sea are reviewed here in depth and corresponding discussions are described separately research topics for the future study also are suggested for the proper access to the understanding of the origin and dispersal patterns of the yellow sea sediments especially focusing on the geochemical approaches d 2003 elsevier science b v all rights reserved

partitioning of transgressive deposits in the southeastern yellow sea a sequence stratigraphic interpretation abstract the last glacio eustatic sea level fluctuation in the southeastern part of the yellow sea formed a number of unconformity bounded sedimentary sequences these sequences comprise 1 regressive to transgressive incision fills unit c 2 transgressive sand ridges and swales unit b and 3 transgressive to highstand muds lower mud unit a2 upper mud unit a1 the sequence boundary between unit c and the lower unit comprises erosional surface which can be traced for the entire study area the even and sharp boundary between the incision fills unit c and the sand ridges unit b represents a transgressive surface of erosion the depositional boundary between the lower mud unit a2 and the upper mud unit a1 suggests a change in oceanographic conditions the boundary is confined landward and correlated offshore with the top of units b and c that is exposed on the seafloor these transgressive deposits show partitioning controlled by currents tides and sediment supply as well as physiography of the seafloor

sediment distribution dispersal and budget in the yellow sea abstract information on the surface sediment distribution in the yellow sea is newly compiled based on all available data produced by chinese and korean workers and is used to refine the dispersal patterns and budget of sediments derived from the adjoining landmass the central yellow sea is largely covered with fine grained sediments originating from the huanghe river 2 2 10 8 t yr about 20 of the total discharge thick sediment accumulation exceeding 5 mm yr occurs in the gulf of bohai and around the shandong peninsula about two thirds of the total huanghe river discharge the old huanghe delta suffers from reworking by strong tides and waves and forms a mud patch southwest of cheju island accumulation rate 2 10 7 t yr more than half of the sediments derived from the changjiang river are deposited along the coast of the east china sea the remainder accumulate on the inner shelf off the river mouth in the southeastern yellow sea the keum river dominates sediment discharge forming a holocene mud belt along the southwestern coast of korea accumulation rate 5 10 6 t yr turbid water plumes occur nearshore throughout the year and their suspended sediments are transported along the tip of the peninsula to the western coastal embayments in the south sea the nakdong river discharge of 1 10 7 t yr is responsible for the eastern nearshore mud of the south sea relict sands occur in the northern part of the yellow sea in the northern east china sea and in the korea strait

niveo aeolian deposits and denivation forms with special reference to the great kobuk sand dunes northwestern alaska the geomorphology lithology and chronostratigraphy of extensive late pleistocene inland and river dune sands aeolian sand sheets cover sands and loess deposits of periglacial origin in northwestern europe are well known however the idea that some of these aeolian sediments result from niveo aeolian processes is still an open question as no diagnostic sedimentary features have yet been reported moreover actual niveo aeolian sediments and related denivation forms reported from various cold climate regions are not suitable analogues recent observations in active dune fields in northwestern alaska indicate that interstratification of wind driven snow and sand preferentially occurs on slip faces of transverse barchanoid or parabolic dune ridges annual denivation forms develop e g snow ramparts sinkholes snow hummocks snow meltwater fans and tensional cracks the surface consists of a cracked wet sand layer with a dimpled surface and spongy structure although the preservation potential of these features is low in this specific case similar features may be observed in ancient sediments elsewhere and provide useful palaeoclimatic indicators the niveo aeolian concept should therefore not specifically be related to late pleistocene cover sand deposition in northwestern europe as previously assumed

ice sublimation as a geomorphic process a planetary perspective abstract sublimation plays a role in the shaping of landforms of planetary surfaces where ice is present as frost as polar caps or in the subsurface this review is focused primarily on the geomorphologic consequences of sublimation a summary of the suite of landforms that have been observed on the surface of various planetary bodies and whose formation is attributed to sublimation is presented this includes the sublimation of a range of different ices that are found on planetary bodies water ice carbonic ice etc at least four groups of landforms are distinguishable independent of the planetary body i residual lags that are depleted in ice which form after sublimation loss such residual lags isolate deeper ice from sublimation and thus can have an important impact on planetary volatile cycles ii landforms due to differential sublimation resulting from enhanced sublimation in low albedo warmer areas of the planet and preservation of ice in the high albedo regions iii landforms due to differential sublimation initiated by fractures or ground heterogeneities for example sublimation enhanced polygonal cracks iv pitted terrains that occur in a relatively homogeneous ice bearing subsurface or as an effect of local ice enrichment or segregation in the ground

distribution of suspended sediment in the korea strait and southeastern yellow sea onset of winter monsoons abstract high energy conditions in the yellow sea begin each year with the onset of monsoon winds in late october these transitional season surges of cold air initiate sediment resuspension vertical mixing of suspended sediments and a wind driven coastal current that flows to the south during the summer to winter transition suspended sediment concentrations in the southeastern yellow sea range from 5 100 mg l 1 at the surface and 5 500 mg l 1 at the bottom the highest concentrations occur off the southwest tip of the korean peninsula and the lowest occur in the central part of the korea strait the rate of transitional season destratification may depend on the timing and intensity of monsoonal surges whereas a late onset of monsoon winds allows waters to remain longer in their moderately stratified summer condition an early onset of monsoon winds tends to destratify the water column by mid november resulting in a nearly uniform high concentration of suspended sediments from surface to bottom the band of more turbid coastal water ends abruptly 25 50 km offshore as a turbidity front in waters 20 80 m deep a wind driven residual flow to the south appears to transport large volumes of this turbid water into the korea strait and perhaps as far as the sea of japan

evidence of widespread cretaceous remagnetisation in the iberian range and its relation with the rotation of iberia a palaeomagnetic investigation has been carried out at 13 sites of jurassic age in the iberian range northern spain two components of remanent magnetisation have been found at each site a primary high temperature component shows an average counterclockwise rotation with respect to the north of 33 2o clockwise about a vertical axis corresponding to the absolute rotation of the iberian plate since the jurassic a secondary low temperature component shows a systematic declination difference of 16 4o with respect to the primary component this indicates that a rotation of iberia must have occurred between the two acquisition times comparison of the magnetisation directions with previous palaeomagnetic data and with sea floor spreading data constrains the age of the remagnetisation between 95 and 125 ma the remagnetisation may be associated with the extensional phases in the iberian basin in the early cretaceous barremian early albian or late cretaceous cenomanian a principal characteristic of the remagnetisation is its widespread character in the iberian range 1998 elsevier science b v all rights reserved

polytypism of cookeite in low grade metapelites of the cameros basin spain lack of correlation of well ordered polytypes with pressure cookeite occurs in low grade chloritoid bearing metapelites of the cameros basin northern iberian range spain as thin coatings on poikiloblastic pyrite crystals 25 cm on edge textural relations imply formation via hydrothermal fluids in a syn to late regional metamorphic environment selected area electron diffraction patterns of cookeite display a wide range of stacking order disorder from patterns with streaking parallel to c in k 3 n reflections to sharply defined reflections having one two and greater than two layer periodicities well ordered polytypes in crystals up to 0 1 m thick are of type ia as determined by powder x ray diffraction coexisting chamosite likewise displays a range of order in polytypism from complete disorder to the well ordered iib polytype which is typical of low grade metamorphism contrary to assertions that ordered cookeite polytypes are indicators of medium to high pressure metamorphism the occurrence of ordered stacking sequences is direct evidence that although ordered cookeite may occur in medium to high p environments it is equally indicative of low p environments it can therefore not be used as an indicator of high pressure the occurrence of several ordered and disordered polytypes in the same sample is compatible with the generally accepted notion that free energy differences between polytypes are too small to be indicators of specific stable equilibrium p t conditions the general occurrence of semirandom stacking is attributed to a lack of equilibrium in structure that is generally characteristic of phyllosilicates in low p t environments of formation

niveo aeolian sedimentation of loess and sand an experimental and micromorphological approach the concept of a niveo aeolian influence on the genesis of northwest european pleistocene aeolian sand and loess deposits has been advocated in the past both to explain the presence and the absence of lamination field experiments were carried out on artificially deposited alternating layers of sand and snow and of loess and snow to investigate the role of a niveo aeolian mode of deposition on resulting sedimentary structures field observations of sand plots revealed minor changes in surface morphology typical of denivation surfaces the thin sections showed a characteristic porous structure deformations of the depositional structure and indications for erosion and redeposition were limited however the originally smooth aeolian sedimentary surface of the loess changed considerably the thin sections showed also a porous spongy structure indications were found for disturbances by frost action liquefaction during melting of the snow and ice and redeposition of loess by meltwater the experimental results strongly suggest that sand and loess deposited as niveo aeolian material are characterized both by a porous structure and that the original sedimentary structure of the sand is not affected by snowmelt whereas loess becomes non laminated thus the intercalation of snow during sedimentation of sand and loess does not in itself induce a laminated structure

depositional development of an isolated mound and adjacent area in the southern yellow sea during the last postglacial sea level rise abstract a detailed analysis of the chirp 2 7 khz profiles core sediments and 14c ages from an isolated mound and adjacent area in the southern yellow sea off the jiangsu coastal area reveals a highly complex development of transgressive and highstand deposits during the last postglacial sea level rise in water depths of 50 60 m the terrace consists of thin transgressive sediments directly above transgressive surface the isolated mound 40 7 km long and 29 6 km wide occurs above 40 50 m in water depth and is detached from the jiangsu and east china sea tidal sand ridges it comprises the sse ward prograding sandy unit pu and the overlying muddy flank unit fu at the outer margin the terrace with thin transgressive sediments was most likely formed when sea level rose rapidly from 58 to 45 m around about 11 6 ka as rate of sea level rise was attenuated from 45 to 36 m between ca 11 6 and 9 6 ka the nearly flat lower boundary of the pu was produced at water depths of 37 42 m by a ravinement process subsequent rapid sea level rise from 36 to 16 m between ca 9 6 and 9 1 ka created accommodation for deposition of the pu sea level rise stagnated from 16 to 10 m between ca 9 1 and 7 5 ka during which the huanghe river apparently shifted south of the shandong peninsula and discharged directly into the western yellow sea the combination of slow sea level rise and sediment supply from the early holocene huanghe delta by the southward flowing coastal currents most likely favoured the formation of the sse ward prograding transgressive sandy pu the highstand muddy fu overlying the pu was accumulated after ca 7 5 when sea level approached its present position and the huanghe river shifted back to the north development of transgressive and highstand deposits in the study area during the last postglacial sea level rise was highly variable in time and space in response to changes in rate of sea level rise together with variations in sediment supply caused by the shifting of the huanghe river

is climate change affecting rates of dune migration in antarctica antarctica is the coldest driest and windiest continent on earth and contains sand dunes like deserts elsewhere the structure and age of the cold climate dunes found in the victoria valley antarctica are described in the light of changing climate in the ross sea region of antarctica during the late holocene ground penetrating radar gpr was used to image sand dune stratigraphy and optically stimulated luminescence osl was used to determine when the sands were deposited the timing of sand dune accretion identified from the gpr stratigraphy ranges from the present day to ca 1 3 kyr b p the osl ages were used to calculate end point migration rates of 0 05 1 5 m yr lower than migration rates from photogrammetry and field surveys undertaken over the past 50 yr the earliest recorded dune development ca 1 3 kyr b p was probably controlled by intensification of circumpolar westerlies at that time as well as by drier conditions and lower temperatures that promoted dune stabilization the dune reactivation ca 300 yr ago coincides with cooling ca a d 1700 1850 and strengthening of southern circumpolar westerlies the increase in rate of dune migration after this period and especially the past 200 yr may coincide with the modern rise in co 2 and the warmest temperatures in antarctica during the past 800 kyr

criteria for recognition of localization and timing of multiple events of hydrothermal alteration in sandstones illustrated by petrographic fluid inclusion and isotopic analysis of the tera group northern spain stratigraphic relations detailed petrography microthermometry of fluid inclusions and fine scale isotopic analysis of diagenetic phases indicate a complex thermal history in tithonian fluvial sandstones and lacustrine limestones of the tera group north spain two different thermal events have been recognized and characterized which are likely associated with hydrothermal events that affected the cameros basin during the mid cretaceous and the eocene multiple stages of quartz cementation were identified using scanning electron microscope cathodoluminescence on sandstones and fracture fills primary fluid inclusions reveal homogenization temperatures th from 195 to 350 c in the quartz cements of extensional fracture fillings the high variability of th data in each particular fluid inclusion assemblage is related to natural reequilibration of the fluid inclusions probably due to cretaceous hydrothermal metamorphism some secondary fluid inclusion assemblages show very consistent data th 281 305 c and are considered not to have reequilibrated they are likely related to an eocene hydrothermal event or to a retrograde stage of the cretaceous hydrothermalism this approach shows how multiple thermal events can be discriminated a very steep thermal gradient of 97 214 c km can be deduced from 18o values of ferroan calcites 18o 14 2 11 8 v pdb that postdate quartz cements in fracture fillings furthermore illite crystallinity data anchizone epizone boundary are out of equilibrium with high fluid inclusion th these observations are consistent with heat flux related to short lived events of hydrothermal alteration focused by permeability contrasts rather than to regional heat flux associated with dynamo thermal metamorphism these results illustrate how thermal data from fracture systems can yield thermal histories markedly different from host rock values a finding indicative of hydrothermal fluid flow

dispersal of fine grained sediments in the southeastern yellow sea a steady state model a large portion of the yellow sea is floored by fine grained clastics derived largely from the hwangho and yangtze rivers in the southeastern yellow sea however coarse grained sediments prevail derived probably from the short and steep korean rivers farther east the coarse grained sediments contain substantial amounts of fine fractions near the keum estuary detrital clays such as kaolinite and chlorite are abundant in the free fractions and this trend extends for about 120 km both toward the northwest and the southwest illite appears to be dominant in the rest of the yellow sea the data suggest that the bulk of fine grained sediments in the southeastern yellow sea originates from the keum river the sediments are subsequently transported by prevailing nearshore currents both northwestward during summer and southwestward in winter the tidal currents may also play a role the close correspondance between the oceanographic data and the mineralogic evidence suggests that the dispersal of fine grained sediments in the southeastern yellow sea occurs largely under the steady state conditions

seismic stratigraphy and depositional history of late quaternary deposits in a tide dominated setting an example from the eastern yellow sea abstract analysis of high resolution seismic profiles and sediment data from the eastern yellow sea reveals that the late quaternary deposits comprise six seismic units interpreted as transgressive and highstand systems tracts formed since the lgm each unit was deposited during distinctive portions of the sea level curve associated with hydrodynamic conditions during the lgm 19 ka bp the study area was completely exposed resulting in subaerial erosion associated with paleo channel incision by the huanghe and korean rivers as the shelf was flooded the incised channels were backfilled fluvial or coastal sediments forming incised channel fill deposits su1 the paleo river may have supplied abundant terrigenous sediments to the study area around the paleo river mouth and adjacent area these sediments were trapped within the paleo estuary and formed su2 regarded as an estuarine deposit two types of serial sand ridges su3 and su5 which correspond to transgressive deposits developed su3 on the southern part west of jeju island 80 110 m deep is regarded as a moribund type mainly formed during the early to middle stage of transgression these are thought to have ceased growing and remobilizing in contrast su5 occurring 30 50 m deep off the korean peninsula is generally regarded as active sand ridges deposited during the late stage of transgression and is partly modified by modern tidal currents as the transgression continued the near surface sediments were reworked and redistributed by shelf erosion resulting in a thin veneer of transgressive sands su4 the uppermost unit su6 formed the heuksan mud belt hmb which is one of the most prominent mud deposits in the yellow sea the lower part of the hmd corresponds to shelf mud deposited during the late stage of transgression whereas the upper part consists of a recent shelf delta developed after the highstand sea level at about 7 ka bp

intraplate deformation in the nw iberian chain mesozoic extension and tertiary contractional inversion the iberian chain developed within the iberian plate during the palaeogene and early miocene as a result of convergence between the african and eurasian plates it is a fold and thrust belt which involves the hercynian basement and the mesozoic and cenozoic cover a generalized cross section of the nw part of the chain of 195 km length is presented mesozoic basins developed on the hercynian basement display thickness variations across normal faults that bounded them and that can be recognized in the field the tertiary contraction deformed and inverted the mesozoic basins and it is inferred to have produced a thrust sheet about 5 km thick in its frontal northeastern part which thickens to the sw the total tertiary shortening in the section is 66 6 km 26 the structure and the crustal shortening and thickening of the iberian chain are explained by a major upper crustal thrust system with simple flat and ramp geometry which may branch to the pyrenees or the betics this is combined with internal deformation of the thrust sheet the contribution of the iberian chain shortening to the convergence of the african and eurasian plates during the tertiary is about one half of that of the pyrenees and should be taken into account in any reconstruction of the kinematics of these plates

remagnetizations as a tool to analyze the tectonic history of inverted sedimentary basins a case study from the basque cantabrian basin north spain 1 in this work we use syntectonic remagnetization data to determine the synrift geometry of inverted basins this methodology analyzes remagnetization directions in order to obtain the tilting of beds at the moment of the acquisition of the overprint filtering the subsequent compressional deformation we collected samples from jurassic and lower cretaceous limestones and red beds cabuerniga and pas groups in the cabuerniga basin one of the most important mesozoic basins developed near the iberia europe mesozoic plate boundary in northern spain that later inverted during the uplift of the pyrenees these deposits represent the synrift sequence linked to a widespread extensional stage in the iberian basins during the mesozoic all sampled rocks show a normal polarity remagnetization fold and conglomerate tests indicate that remagnetization postdates the main extensional stage of basin formation late jurassic barremian and was acquired before the subsequent compressional deformation the analysis of these overprinted directions allows the basin geometry of the studied area to be restored at the moment of acquisition of the remagnetization this approach represents a powerful tool to study basinal evolution and uplift of sedimentary basins to be tested in other inverted basins with syn extensional related secondary overprints

diachronous pervasive remagnetization in northern iberian basins during cretaceous rotation and extension article i nfo northern iberia exposes a series of mesozoic sedimentary basins whose final formation history is tied to a rotation episode of iberia during the aptian related to the opening of the bay of biscay many of these basins experienced widespread remagnetization previously loosely tied to a mid cretaceous thermal event here we make use of the improved apparent polar wander path apwp of iberia to narrowly constrain the age of their remagnetization to show that several basins experienced a regional diachronous remagnetization we apply the small circle intersection sci method to reconstruct the paleomagnetic field direction during remagnetization in the organya basin in the southern pyrenees spain where the age of remagnetization is stratigraphically well dated to around the barremian aptian boundary and where the paleomagnetic direction during remagnetization has been well established the resulting direction of d i 316 8 5 7 54 8 3 3 where the uncertainty in declination is approximated by 95 cos i and the error in inclination by 95 correspondscloselytoarecently improvedapwpofiberia providingsupportfortheapplicabilityof thismethod applicationofthescimethodallowsustoshowthattheolderportionoftheremagnetizedbedswasalreadytilted

grid mapping the northern plains of mars using morphotype and distribution of ice related landforms to understand multiple ice rich deposits in utopia planitia this work in utopia planitia is the first continuous regional mapping of ice related landforms integrated into an effort to study the three main basins arcadia acidalia utopia planitiae in the northern plains the distribution and morphotypes of these landforms sharad detections and crater size frequency distribution measurements 50 m in diameter were used to understand the permafrost cryolithology and its past evolution in relation to climate in utopia planitia three assemblages of landforms were identified based on their spatial correlation and correlation with mola surface roughness along a strip from 30 n to 80 n at 30 38 n the assemblage is formed by km scale polygons high albedo mounds and thumbprint terrains this assemblage is associated with a lobate deposit of 30 m in thickness with a crater retention age of 1 ga at 38 47 n the assemblage is comprised of large scallops 100 m diameter polygons pits and mantled deposits this assemblage is correlated with a deposit of 80 m in thickness containing excess ice 50 85 by volume with a crater retention age of about 10 ma at 47 78 n the assemblage is composed of mantled deposits textured terrains and 30 m diameter polygons this assemblage is related to the ice rich debris covered latitude dependent mantle that has a crater retention age of about 1 5 ma utopia planitia appears to be a region of combined depositions of sediment and continuous cold climatic conditions that leaded to a complex distribution of ground ice

aeolian dune field development in a water table controlled system skeiđararsandur southern iceland aeolian dune fields characterized by partly vegetated bedforms undergoing active construction and with interdune depressions that lie at or close to the water table are widespread on skei ararsandur southern iceland the largest aeolian dune complex on the sandur covers an area of 80 km2 and is characterized by four distinct landform types i spatially isolated aeolian dunes ii extensive areas of damp and wet flooded interdune flat with small fluvial channels iii small aeolian dune fields composed of assemblages of bedforms with simple morphologies and small predominantly damp interdune corridors and iv larger aeolian dune fields composed of assemblages of complex bedforms floored by older aeolian dune deposits that are themselves raised above the level of the surrounding wet sandur plain the morphology of each of these landform areas reflects a range of styles of interaction between aeolian dune interdune and fluvial processes that operate coevally on the sandur surface the geometry scale orientation and facies composition of sets of strata in the cores of the aeolian dunes and their relationship to adjoining interdune strata have been analysed to explain the temporal behaviour of the dunes in terms of their mode of initiation construction pattern of migration style of accumulation and nature of preservation seasonal and longer term flooding induced changes in water table level have caused episodic expansion and contraction of the wet interdune ponds most of the dunes are currently undergoing active construction and migration and although sediment availability is limited because of the high water table substantial aeolian transport must occur especially during winter months when the surface of the wet interdune ponds is frozen and sand can be blown across the sandur without being trapped by surface moisture bedforms within the larger dune fields have grown to a size whereby formerly damp interdune flats have been reduced to dry enclosed depressions and dry aeolian system accumulation via bedform climb is ongoing despite regional uplift of the proximal sandur surface in response to glacial retreat and unloading over the past century sediment compaction induced subsidence of the distal sandur is progressively placing aeolian deposits below the water table and is enabling the accumulation of wet aeolian systems and increasing the likelihood of their long term preservation wet dry and stabilizing aeolian system types all co exist on skei ararsandur and the dunes are variously undergoing coeval construction accumulation bypass stabilization and destruction as a result of interactions between localized factors

laboratory apparatus for calibrating optical suspended solids sensors abstract an apparatus for testing and calibrating miniature to medium sized optical suspended solids sensors is described stable suspensions of sedimentary particles ranging in size from 10 6 to 4 10 3 m can be produced in water with concentrations exceeding 100 g 1 1 flow velocities in the test volume can be varied continuously from 0 1 to 1 5 m s 1 and samples of suspensions can be withdrawn directly with a peristaltic pump for gravimetric and particle size analyses the apparatus has been used to evaluate the effects of particle size flow speed and air bubbles on the performance of optical backscatterance sensors and transmissometers

debris flows on the great kobuk sand dunes alaska implications for analogous processes on mars abstract we observed niveo aeolian deposits denivation features and small meltwater induced debris flows that had formed at the great kobuk sand dunes northwestern interior alaska in late march 2010 this high latitude cold climate dune field is being studied as a planetary analog to improve our understanding of factors that may trigger debris flows on the lee slopes of martian aeolian dunes debris flows consisted of a sand and liquid water mixture that cascaded down the lee slopes of two barchanoid dunes on days when measured ground surface temperatures were below freezing we hypothesize that relatively dark sand on snow caused local hot spots where solar radiation could be absorbed by the sand and conducted into the underlying snow enabling meltwater to form and sand to be mobilized this investigation provides insights into the interactions between niveo aeolian deposition slope aspect and insolation thawing and initiation of alluvial processes these debris flows are morphologically similar to those associated with seasonal gullies or erosion tracks visible on the slopes of mid to high latitude dune fields in both martian hemispheres localized heating and thawing at scales too small for orbital sensors to identify may yield martian debris flows at current climate conditions

high resolution acoustic characteristics of epicontinental sea deposits central eastern yellow sea abstract large amounts 45390 line km of closely spaced 2 2 4 4 km high resolution subbottom profiles chirp 2 7 khz made it possible to identify detailed echo types and their distribution in an epicontinental shelf environment on the basis of seafloor morphology surface bedforms and subbottom acoustic characters 10 echo types were identified in the uppermost sedimentary sequence of the central eastern yellow sea flat seafloor with sharp bottom echoes echo types 1 1 1 2 and 1 3a transgressive sediment sheets or relict sands is widespread in the offshore area and underlain to the west by an acoustically transparent wedge echo type 1 3b highstand muds mounded seafloor with either smooth surface or superposed bedforms echo types 2 1 2 2 and 2 3 tidal ridges and flat seafloor with regularly spaced wavy bedforms echo type 1 4 large scale dunes are dominant in the eastern nearshore area large scale mounds with continuous inclined internal reflectors echo type 2 4 giant mud bank occur in the southeastern nearshore area various scale eroded seafloor echo types 3 1 and 3 2 channels and flat seafloor with regularly spaced wavy bedforms echo type 1 4 large scale dunes are present in the northern part of the sea the distribution pattern of echo types in the central eastern yellow sea reflects depositional processes and sediment dispersal systems during the holocene transgression and highstand period 1 development of tidal ridges and large scale dunes in response to strong tidal currents and waves in the eastern nearshore area 2 construction of transgressive to highstand mud bank huksan mud belt by deposition of muds derived from the keum river in the southeastern nearshore area 3 active erosion due to intensified currents in the northern part and 4 highstand mud deposition derived from the huanghe river on the transgressive sediment sheets in the offshore area

effects of temperature and humidity upon the transport of sedimentary particles by wind aeolian transport of sedimentary particles is a well recognized phenomenon in cold regions but the effect of low temperature t and specific humidity q upon particle entrainment has not previously been investigated this study reports on wind tunnel experiments 12 c t 32 c and 1 g kg 1 q 10 g kg 1 that suggest the aerodynamic drag required to entrain sand sized particles can be 30 lower in cold or high latitude settings as compared to hot deserts for any given regional wind velocity this effect will increase the wind strength index and thereby the proportion of time a surface is active at low temperature

exhumation of the sierra de cameros iberian range spain constraints from low temperature thermochronology we present new fission track and u th he data from apatite and zircon in order to reconstruct the exhumation of the sierra de cameros in the northwestern part of iberian range spain zircon fission track ages from samples from the depocentre of the basin were reset during the metamorphic peak at approximately 100 ma detrital apatites from the uppermost sediments retain fission track age information that is older than the sediment deposition age indicating that these rocks have not exceeded 110 c apatites from deeper in the stratigraphic sequence of the central part of the basin have fission track ages of around 40 ma significantly younger than the stratigraphic age recording the time of cooling after peak metamorphic conditions apatite u th he ages in samples from these sediments are 31 40 ma and record the last period of cooling during alpine compression the modelled thermal history derived from the uppermost sediments indicates that the thermal pulse associated with peak metamorphism was rapid and that the region has cooled continuously to the present the estimated palaeogeothermal gradient is around 86 c km 1 and supports a tectonic model with a thick sedimentary fill c 8 km and explains the origin of the low grade metamorphism observed in the oldest sediments

tectono stratigraphic evolution of an inverted extensional basin the cameros basin north of spain the cameros basin is a part of the mesozoic iberian rift it is an extensional basin formed during the late jurassic and early cretaceous in the mesozoic iberian rift context and it was inverted in the cenozoic as a result of the alpine contraction this work aims to reconstruct the tectono stratigraphic evolution of the basin during the mesozoic using new and revised field geophysical and subsurface data the construction of a basin wide balanced section with partial restorations herein offers new insights into the geometry of the syn rift deposits field data seismic lines and oil well data were used to identify the main structures of the basin and the basin forming mechanisms mapping and cross sectional data indicate the marked thickness variation of the depositional sequences across the basin suggesting that the extension of the depositional area varied during the syn rift stage and that the depocentres migrated towards the north from field observation and seismic line interpretation an onlap of the depositional sequences to the north over the marine jurassic substratum can be deduced in the last few decades the structure and geometry of the basin have been strongly debated the structure and geometry of the basin infill reconstructed herein strongly support the interpretation of the cameros basin as an extensional ramp synclinal basin formed on a blind south dipping extensional ramp the gradual hanging wall displacement to the south shifted the depocentres to the north over time thus increasing the basin in size northwards with onlap geometry on the pre rift substratum the basin was inverted by means of a main thrust located in a detachment located in the upper triassic beds keuper which branched in depth with the mesozoic extensional fault flat the reconstruction of the tectono stratigraphic evolution of the cameros basin proposed herein represents a synthesis and an integration of previous studies of the structure and geometry of the basin this study can be used as the basis for future basin scale research and for modelling the ancient petroleum system of the basin

holocene palaeosols and aeolian activities in the umimmalissuaq valley west greenland aeolian sand sheets and active dunefields preserve an ancient holocene land surface represented by palaeosols that occur around the present ice margin in the kangerlussuaq area west greenland to determine the relation between holocene aeolian activities and periods of soil formation both substantially dependent on the deglaciation history palaeosols aeolian sand sheets and dunefields were analysed using field data grain size analyses optically stimulated luminescence dating and ams 14c data in an area of about 15 km2 of the umimmalissuaq valley palaeosols are developed close to the ice margin 60 wt are comparable with aeolian sand sheets currently formed at greater distances 4 5 km from the present ice margin we propose a transport distance for fine aeolian sediments in which the palaeosols are formed of at least 4 km from inboard of the present ice margin soil for

annual to decadal morphodynamics of the foredune system at greenwich dunes prince edward island canada the purpose of this study was to quantify relationships between season sediment availability sediment transport pathways and beach foredune morphology at greenwich dunes pei this was done for periods ranging from a few days to multiple decades using erosion pins bedframe measurements annual surveys and digital photogrammetry using historical aerial photographs the relative significance of seasonal annual processes versus response of the foredune system to broader geomorphic controls e g relative sea level rise storms etc was also assessed the data show that there are clear seasonal differences in the patterns of sand supply from the beach to the foredune at greenwich and that there are differences in sediment supply to the foredune between the east and west reaches of the study area resulting in ongoing differences in foredune morphology they also demonstrate that models that incorporate wind climate alone or even models that include other factors like beach moisture would not be able to predict the amount of sediment movement from the beach to the foredune in this environment unless there were some way to parameterize system morphology especially the presence or absence of a dune ramp finally the data suggest that the foredune can migrate landward while maintaining its form via transfers of sediment from the stoss slope over the crest and onto the lee slope although the rate of foredune development or recovery after disturbance changes over time due to morphological feedback the overall decadal evolution of the foredune system at greenwich is consistent with and supports the davidson arnott 2005 conceptual model of dune transgression under rising sea level copyright 2012 john wiley sons ltd

meteorological controls on sand transport and dune morphology in a polar desert victoria valley antarctica the hyperarid polar desert of the mcmurdo dry valleys contains an abundance of aeolian sedimentary deposits the largest in antarctica providing a unique setting for studying cold climate aeolian processes and dune morphology meteorological controls on sand transport and changes in dune morphology were monitored for 11 days in november december 2004 on a barchan dune in the victoria valley mcmurdo dry valleys sand transport in this environment was found to be influenced by 1 interparticle cohesion ice bonding 2 diurnal variations in the speed of thermally driven easterly valley winds due to reduced solar heating by night and 3 topographically modified foehn southwesterly winds the threshold entrainment velocity during easterly valleys winds was 5 3 m s at 0 4 m 0 21 m s warm dry and gusty foehn southwesterly winds were found to promote aeolian processes by dislodging surface sediments with dune morphology responding rapidly importantly no diurnal signal in sand transport was observed under these conditions when wind speed and sand transport occurred independently of solar heating measured changes in dune morphology indicate that the dune field of the victoria valley under current environmental conditions is in dynamic equilibrium with frequent up valley sand transport by thermally generated valley winds balanced by less frequent but greater magnitude down valley sand transport by moderate to strong foehn southwesterlies this results in little net movement of dunes and subsequent change in the position of the dune field accordingly we believe that regional scale shifts in climate that cause change in the synoptic circulation patterns of the ross sea region that affect the frequency of either the up valley easterlies or down valley foehn winds will result in a net change in the morphology of the victoria valley s dune field such change in circulation may become apparent early as change in the morphology of the victoria valley sand dunes we therefore suggest this site should be monitored as an indicator site for identifying change in regional weather and climate

sublimation and aeolian sand movement from a frozen surface experimental results from presqu ile beach ontario abstract recent aeolian literature has indicated that sand movement can and does take place on frozen surfaces the winter aeolian process is influenced by the pore ice which binds the sand grains together and increases the surface resistance to wind action sublimation of the frozen moisture provides loose grains of sand which subsequently can be entrained by the wind field experiments carried out on the presqu ile beach ontario in the 1992 1993 winter provide some data on variables which affect sand loss from frozen surfaces because of sublimation sand moisture content determines the resistivity of the surface to sublimation induced sand loss frozen surfaces with higher moisture contents experience less sand loss the existing literature has indicated that temperature plays an important role in the occurrence of sublimation higher temperatures i e temperatures which are closer to 0 c result in higher rates of sublimation however the presqu ile experiments show that wind speed is more strongly correlated with sublimation induced particle loss than temperature or relative humidity higher wind speeds allow sand from the surface and sublimation produced water vapour to be removed from the area thus providing an incentive for further sublimation and sand loss to take place information on the variables which affect sublimation induced sand loss from frozen surfaces can be used to increase understanding of the processes involved in sand movement on frozen surfaces under subzero temperatures

early cenozoic sedimentation in the hammerfest basin abstract using seismic stratigraphy combined with information from 24 wells a detailed history of the early cenozoic sedimentation of the hammerfest basin in the southwestern barents sea has been revealed during the early paleocene the hammerfest basin was subject to non deposition or minor erosion and sedimentation in the basin was initiated after a transgression in the mid paleocene coeval erosion on the basin margin ceased as the transgression gradually spread in the late paleocene and a south southwesterly sediment input from the loppa high to the hammerfest basin was initiated during the late paleocene the late paleocene early eocene environment was dominated by ssw directed progradation from the loppa high and westward progradation in the central part of the basin the early tertiary sedimentation of the hammerfest basin is speculated as mirroring reactivation of older fault regimes and transpression and transtension along the western margin during the latest phase of rifting and earliest phase of spreading in the norwegian greenland sea are indicated mid eocene to pliocene sediments have not been found in the hammerfest basin it seems however that sedimentation continued in the basin in post early eocene time during the oligocene and miocene accumulation and erosion alternated in the hammerfest basin the erosion increased during the late miocene and pliocene and culminated with the pleistocene glaciations

kinetic energy transfer through impact and its role in entrainment by wind of particles from frozen surfaces while extensive aeolian deposits are associated with glaciation little is known of the mechanisms which produced them observation of glaciofluvial sediments in pangnirtung pass n w t indicates that peak deflation occurs in the fall and winter months so that the nature of sediment transport involving frozen surfaces greatly differs from warm environments laboratory experiments indicate that such surfaces are mobilized through abrasion and are most susceptible at low volumetric water content less than 20 and low temperature 20 c stable surfaces have volumetric water contents in excess of 30 and temperatures of 15 c surface stability also increases with decreasing particle size density and possibly transport load collisions with frozen surfaces are relatively elastic with significantly greater kinetic energy transfer to ejected surface grains than observed for loose dry surfaces saltation transport in cold environments could therefore be sustained at lower windspeeds than for dry surfaces provided that some loose particles are available initially but do not accumulate at the surface

physical processes and fine grained sediment dynamics coast of surinam south america abstract the prograding holocene mud wedge between the amazon and orinoco rivers in the trade wind belt of northeastern south america provides a modern day example of muds accumulating under moderate wave energy conditions gigantic shore attached mudbanks 10 km 20 km composed partly of thixotropic fluid mud gel front this coast every 30 60 km to form a buffer to wave attack and a temporary storage for fine grained sediments this mesotidal coast tide range 2 0 m with gentle offshore slope 0 0006 allows the exposure twice a day of extensive tidal flat deposits which are backed by mangrove swamps on a well developed chenier plain complex field experiments were conducted in surinam du ing 1975 and 1977 to provide new information on process form relationships in this interesting but unusual muddy environment simultaneous measurements of waves currents tide elevation suspended sediment concentration and variations in mud density show that soft intertidal and subtidal muds are suspended at both tide and wave frequency suspended sediment concentrations typically exceed 1 000 mg l at the surface as incoming solitary like waves partially disperse fluid mud into overlying water on a falling or rising tide redeposition of mud may occur near time of high tide the strong attenuation of shallow water waves by these muds provides conditions that are favorable for further sedimentation high concentrations of suspended fluid mud together with solitary like waves from the northeast throughout the year can lead to extraordinarily high net sediment transport rates in the nearshore zone calculations based on solitary wave theory and on data obtained from this study indicate that 15 65 106 m3 of mud can move along shore each year without involving breaking waves the concept of radiation stress and a nearshore circulation cell or bedload transport farther offshore outside the zone of wave dominance wind driven currents and the guiana current combine to transport muds to the northwest consistent with the observed direction of mudflat migration

destruction of a fluvial reservoir by hydrothermal activity cameros basin spain abstract this study provides an example of a high quality fluvial hydrocarbon reservoir that was completely destroyed by hydrothermal processes the reservoir unit was deposited in the cameros basin located in the nw sector of the iberian chain spain the basin was filled with clastic fluvial deposits sandstones and conglomerates between late berriasian and early aptian times provenance of sands was mainly from coarse crystalline rocks a humid tropical climate produced intense weathering of k feldspar during transport from source to basin thus a mineralogically mature rigid framework with high porosity existed at the time of deposition which would have constituted a high quality hydrocarbon reservoir at present however the porosity of the reservoir is negligible porosity was reduced by a sequence of diagenetic processes 1 mechanical compaction i e crushing of metamorphic lithic grains and chemical compaction 2 kaolinite and siderite cementation and 3 early quartz cementation hydrocarbon emplacement probably occurred between phases 2 and 3 a low grade metamorphic hydrothermal event reaching greenschist facies took place during the late cenomanian it dramatically reduced the remaining porosity of the reservoir and destroyed the hydrocarbon charge hydrothermal processes which affected the sandstones include 1 re compaction 2 late quartz cementation and silicification of remaining feldspars 3 carbonate cementation 4 chloritization of feldspars metamorphic lithic fragments and intrabasinal argillaceous grains and 5 growth of pyrite and chloritoid crystals on argillaceous material of intrabasinal extrabasinal or even diagenetic origin hydrocarbons that migrated to the margins of the basin escaped these hydrothermal modifications and were preserved the results of this study may be used to predict the diagenetic and hydrothermal evolution of other potential reservoirs in similar tectonic settings

comment on gonzalez acebron et al criteria for the recognition of localization and timing of multiple events of hydrothermal alteration in sandstones illustrated by petrographic fluid inclusion and isotopic analysis of the tera group northern spain int j earth sciences 2011 100 1811 1826 the paper by gonzalez acebron et al 2011 deals with both regional and methodological problems about the timing of thermal events in one of the best known and controversial basins in the iberian microplate the late jurassic early cretaceous cameros basin the aforementioned paper contains invaluable data about the thermal evolution of the basin and it is an important contribution to the understanding of the post sedimentary pre inversion processes in this strongly subsiding basin it will undoubtedly add new evidence to the knowledge of hydrothermal processes in general and particularly to the paleothermal evolution of the basin however in our opinion there are some problems involving important matters within the paper namely 1 the interpretation of the data obtained which are too constrained within a univocal line of thinking without considering other simpler and more viable options that in the discussed paper are aprioristically rejected 2 the second problem deals with referencing to previous papers and acknowledgement of previous works by other authors we must say that this aspect does not refer to this paper alone but it is recently becoming a commonplace for many scientific papers in this field on the side of the references to previous works it must be stated that

sediment accumulation in a modern epicontinental shelf setting the yellow sea sediment accumulation in the yellow sea epicontinental shelf environment is investigated on 100 yr and 1000 yr time scales using 210pb and 14c geochronologies the distribution of modern 210pb accumulation rates in the yellow sea reveals that the loci of modern huanghe sediment accumulation are the topset 1 2 mm yr foreset 4 9 mm yr and proximal bottomset deposits 2 4 mm yr of the shandong subaqueous delta which extends south from the shandong peninsula 210pb rates in the distal bottomset deposits of the subaqueous delta in the central and southern yellow sea are generally low 0 3 0 9 mm yr a sediment budget demonstrates that between 9 15 of the annual huanghe discharge is accumulating in the yellow sea about two thirds of this sediment is accumulating in the topset foreset and proximal bottomset deposits of the shandong subaqueous delta with the remaining third accumulating as widespread distal bottomset deposits 14c age dates of subaqueous delta sediments indicate that the thick 40m clinoform structure formed predominantly between 6200 and 4060 yrs b p at rates approaching 20 mm yr observations in the yellow sea as well as on the amazon and ganges brahmaputra shelves demonstrate that subaqueous deltaic stratigraphy is the general rule where major rivers enter energetic shelves whether epicontinental or pericontinental the development of extensive bottomset deposits may be restricted to epicontinental shelf environments and may be diagnostic of sedimentation in this type of setting

aeolian sand preserved in silver lake a new signal of holocene high stands of lake michigan aeolian sand within lake sediment from silver lake michigan can be used as a proxy for the timing of high lake levels of lake michigan we demonstrate that the sand record from silver lake plotted as percent weight is in phase with the elevation curve of lake michigan since the mid holocene nipissing phase because fluctuations in lake michigan s lake level are recorded in beach ridges and are a response to climate change the aeolian sand record within silver lake is also a proxy for climate change it appears that increases in dune activity and lake sand are controlled by similar climatic shifts that drive fluctuations in lake level of lake michigan high lake levels destabilize coastal bluffs that drive dune sand instability and along with greater wintertime storminess increase niveo aeolian transport of sand across lake ice the sand is introduced into the lake each spring as the ice cover melts

understanding the mesozoic kinematic evolution in the cameros basin iberian range ne spain from magnetic subfabrics and mesostructures abstract analysis of anisotropy of magnetic susceptibility ams and brittle mesostructures hydroplastic synsedimentary faults and tension gashes is applied in this study in order to characterize the mesozoic tectonic events in the cameros basin nw iberian range formed between tithonian and albian times low field ams at room and low temperature lf ams at rt and lf ams at lt respectively together with high field ams hf ams measurements allow separating ferro and paramagnetic fabrics the combination of lf ams at lt and hf ams torque measurements confirms the reliability of both procedures in terms of isolating the paramagnetic contribution to the ams magnetic fabric results combined with the analyses of synsedimentary faults indicate a nw se extension direction during aptian and probably barremian times this extension direction is perpendicular to the main extension direction ne sw prevailing during early and late stages of basin evolution it is also consistent with extension direction deduced from large scale bending folds and tension gashes developed after partial lithification cleavage development during albian enhanced the orientation of the magnetic fabric in lithologies where the previous extensional magnetic lineation is coaxial with the expected one for compression

role of the giant saemangeum dyke in sedimentation at the mouth of an estuarine complex abstract the saemangeum dyke is an enormous offshore structure 33 km long that dams the combined estuary of two rivers on the mid west coast of korea among the numerous environmental issues associated with the dyke construction it has been of special interest whether the tidal flats in the most reentrant area daehangri just outside the beginning part of the dyke will actively grow or not this lies in the center of the arguments about positive negative functions of the dyke field measurements concentrated on hydrodynamics within the bottom boundary layer and sediment transport evaluations were conducted in the coastal areas around the daehangri tidal flats to examine sediment transport and thus source sink relationships of sediments therein deployments of autonomous benthic instruments tisdos during 1 3 weeks indicate that the nearshore sands and muds are transported toward the dyke whereas sands on tidal flats and beaches are transported from the dyke along the shoreline most of the nearshore sediments eventually deposit to form a shallow shoal near the garyuk opening located in the opposite direction to the daehangri tidal flats the rates of sediment transport increase greatly by high waves as compared to those caused by even spring peak tidal currents alone as a result the scheme of sediment transport over the study area clearly rules out the daehangri tidal flats from the newly forming active sinks of the nearshore sediments triggered artificially by the construction of the saemangeum dyke

estimating palaeo water depth from the physical rock record abstract palaeo water depth and its change with time is a key factor in environmental analysis and in sedimentology in general the literature published on this topic and on related subjects however is substantial albeit scattered within and between different communities geologists oceanographers engineers physicists etc here i focus on proxies for palaeo bathymetry as obtained from the physical rock record floral faunal and chemical evidence for palaeo water depth being equally important must be dealt with elsewhere an assessment of the main depth related parameters in actualistic settings is presented and their applicability to the fossil sedimentary record discussed the outcome reveals the full complexity of this topic there is for example no such thing as an average wave base depth applicable to a wide range of fossil case settings this because wave and current climates in general and particularly so in neritic and coastal settings are intriguingly complex furthermore observations from modern oceans are not a priori applicable to fossil ones acknowledging these problems and limitations critically evaluated quantitative proposals for depth indicative facies and features in the sedimentary record are presented and error bars discussed

development of depositional systems in the southeastern yellow sea during the postglacial transgression this study focuses on the development of depositional systems in the southeastern yellow sea during the postglacial transgression based on the analysis of closely spaced high resolution seismic profiles chirp and piston cores transgressive deposits comprise the paralic component of estuarine channel fills seaward prograding wedge and along shore prograding mound and the marine component of sand veneer mud blanket and offshore ridge these transgressive deposits were developed through three distinctive stages in terms of possible sea level position during the early stage tidal sand ridges and sand veneer formed south of jeju island resulting from shoreface erosion associated with a relatively slow transgression the following transgression in the middle stage inundated subaerially formed interfluves along the central part of the sea and affected development of estuarine environments with increasing tidal regime in the eastern part of the sea combined with the strong tidal reworking insufficient sand supply enhanced the formation of erosional ridges short period increase in fluvial discharge affected the deposition of coastal wedge in the western part fine grained sediments from either fluvial discharge or tidal reworking were dispersed seaward to form mud blanket the late stage was characterized by the deposition of veneered sands off the jiangsu coast which was due to relatively slow rise in sea level further offshore along shore prograding mound was constructed by huanghe derived sediment influx and subsequently eroded and redeposited by wave and tide activities thus detached from the proximal source the depositional processes and variability of the transgressive deposits in the southeastern yellow sea were largely controlled by changes in rate of sea level rise during the transgression most likely related to the global flooding events triggered by melt water pulses the changes in shoreline configuration and oceanographic regime have also influenced the distribution and morphology of the transgressive deposits a short period increase in riverine discharge caused the temporal sediment progradation off the jiangsu coast

multidisciplinary approach to an extensional syncline model for the mesozoic cameros basin n spain abstract in this paper we explore the possibility of reconstructing the initial geometry of inverted basins using combined geophysical and geological methods seismic reflection profiles paleomagnetism analogue modelling and 3d geometrical analysis these techniques allow for some unknowns in the geometry and evolution of extensional sedimentary basins mainly the normal drag reverse drag geometrical problem to be solved the example chosen for checking these techniques is the cameros basin northern iberian chain formed during the late jurassic early cretaceous and inverted during the tertiary compressional stage according to the reconstruction proposed the cameros basin can be characterised as a lens shaped syncline basin with maximum thickness of deposits of about 8000 m in its depocenter gradually diminishing toward the north and south the extensional geometry of the cameros basin is defined by 1 a large scale growth syncline over the major basement fault with southward dipping beds in the northern basin margin forming a southward opening sedimentary wedge with upward decreasing dip values large scale normal drag geometry 2 roll over anticlines at the contact between the pre rift series against the normal fault limiting the basin smaller scale reverse drag geometry the combined syncline anticline syn extensional structures were characterised by means of paleomagnetic analysis of a remagnetization acquired at the time of extension analogue models indicate that the development of syncline basin geometries in extensional settings as the one interpreted for the cameros basin is closely related to the presence of a detachment level in the pre rift sequence above the main basement faults

pathways and distances of fluid flow during low grade metamorphism evidence from pyrite deposits of the cameros basin spain new geochemical and sulphur isotopic data are presented for a number of pyrite deposits from the late jurassic early cretaceous cameros basin spain the deposits were formed at or close to the peak of metamorphism and are always related to sandstone units in the mainly metapelite sequence iron remained immobile and conservative pyrite iron being derived by sulphidation of chlorite in the host metapelites reduced sulphur however was supplied from two external sources thermochemical reduction of sulphate and release of s during metamorphism of sedimentary sulphides these sources provided isotopically heavy and light s respectively with variation in pyrite isotopic composition between different deposits resulting from differences in their relative importance at each site during metamorphism the sandstone units acted as aquifers carrying the sulphidic pore waters to locations where permeability provided by syn depositional fractures on a scale of 0 5 5 m allowed its interaction with the metapelites transport distances for sulphide during metamorphism were of the order of hundreds of metres

evidence of a cretaceous remagnetization in the cameros basin north spain implications for basin geometry abstract the paleomagnetic results obtained in 23 sites from red beds of the northern border of the inverted cameros basin northern iberian peninsula prove a cretaceous widespread remagnetization paleomagnetic and rock magnetic analyses indicate that the natural remanent magnetization nrm is dominated by a stable and always normal polarity component carried by haematite two conglomerate test and five fold test indicate that this component is a syn tectonic overprint dated between albian and santonian times most probably albian contemporary with a low grade metamorphism remagnetization was acquired before compressional deformation and post dates the main extensional stage of basin formation berriasian albian incremental fold tests provide best clustering solutions showing dispersed results and far from the expected direction an alternative procedure to obtain fold test solution was applied considering asymmetric limb rotation mean directions obtained from these asymmetric solutions are consistent with the expected direction and yield a statistical value for significant grouping at the 95 confidence level in all fold tests performed this reconstruction allows to determine the tilting of beds at the moment of acquisition of magnetization these original dips were used to reconstruct the original geometry of the northern basin border later modified during the tertiary inversion stage this extensional geometry can be characterised as a large scale syn sedimentary normal fault drag with a minor roll over anticline the procedure developed in this paper should be tested in other inverted basins that also have undergone burial remagnetizations

development of hybrid aeolian dunes the william river dune field northwest saskatchewan canada observations have been made on the structure morphology and pattern of sand movement on large scale roughly elongate northwest southeast aligned aeolian sand dunes in a desert area of northern saskatchewan canada transverse profiles show steeper northeast flanks the lower parts of which are covered with psammophilous grasses dune structure is dominated by northeast dipping accretion laminae and 14c dates of organic material trapped between such exposed laminae on the southwest flank indicate migration to the northeast at about 0 5 m year in the last few centuries on the other hand there is a progressive increase in height bulk symmetry and peakedness of the dunes from northwest to southeast suggestive of substantial along dune sand movement the present day wind regime shows a potential resultant sand transport vector to the southeast virtually parallel to the dune axis winds from the north northeast and northeast dominate the first 6 months of the year followed by winds from the west so

timing of diagenesis and very low grade metamorphism in the eastern sector of the sierra de cameros iberian range spain a u pb shrimp study on monazite the sierra de cameros is an intracontinental orogen and represents the north western part of the iberian range in northern spain it comprises a thick sequence of syn rift continental sediments mainly sandstones and carbonates deposited during lower cretaceous times a unique characteristic of the sierra de cameros in relation to the rest of the iberian range is the presence of low grade metamorphism in certain parts of the basin an event that predates basin inversion this paper describes the presence textural relationships and geochemical aspects of authigenic and or metamorphic monazite within different lithologies from the deepest parts of the basin sensitive high resolution ion microprobe shrimp u pb dating of monazite records the presence of two age populations the first with 206 pb 238 u ages ranging from 122 to 116 ma which is considered as diagenetic in origin whilst the second is dated at 99 2 ma and postdates the metamorphic climax

sedimentary processes of fine grained material and the effect of seawall construction in the daeho macrotidal flat nearshore area northern west coast of korea abstract sedimentary processes on the lower tidal flat of the reclaimed seosan bay daeho tidal flat at the west coast of korea have undergone significant changes since 1984 when seawalls over 8 km long were constructed at the bay mouth comparison of pre and post construction tidal flow models indicates that in general tidal currents have increased considerably in front of the daeho tidal flat with tidal flow directions having changed from shore normal to shore parallel the 12 h measurements of currents and suspended sediment concentrations at four anchored hydrographic stations show nearshore suspended sediments drifting southward throughout the year bypassing the daeho tidal flat cyclic seasonal variations occur prominently in the grain texture of the tidal flat sediments and associated sedimentation rates in summer fine grained sediments deposit at a rate of 2 6 mm month particularly in sheltered places during the winter monsoon erosional processes are greatly enhanced by the interplay of tidal currents and waves up to 30 mm month this sedimentary seasonality is reflected in the variations in the concentration of nearshore suspended matter the concentration of suspended matter is much higher in winter 60 80 mg l because of vigorous resuspension activities compared with the summer concentration 10 30 mg l the direct effect of seawall construction coupled with strong natural seasonality can be seen from the continuous monitoring of sedimentation rates on the tidal flat the 2 year 1993 1995 measurements indicate that the entire daeho tidal flat was eroded during that period at the abnormally high average rate of 10 cm year the causal blocking of bayward sediment and water movements by any artificial structure might lead to similar erosional conditions to many other bays facing the yellow sea on the both chinese and korean coastlines subjected to energetic winter wave attack

ancient and modern cold climate aeolian sand deposition a review although partly active aeolian sand sheets and dunes cover large areas in the zones of dis continuous permafrost little precise information is available about the influence of cold climate conditions on modern aeolian processes this means that palaeoenvironmental reconstructions in the stabilised mainly late pleistocene dune fields and cover sand regions in the sand belts of the european lowlands and the northern great plains of the usa and canada are necessarily still based on ancient evidence cold climate wind deposits are typically derived from areas of abundant sediment supply like unvegetated flood plains glacial outwash plains till plains and lake shores the common parabolic and transverse dune forms resemble those observed in temperate regions although a variety of periglacial features has been identified in late pleistocene dune and cover sands none of them indicate that permafrost is crucial to aeolian activity specific structures in aeolian strata permit tentative interpretation of the moisture content of depositional sand surfaces the nature of annual sedimentation cycles and the processes by which strata were deposited and or contorted but surprisingly little is known about the role of vegetation in the process of sand accumulation dunes are most informative with respect to reconstructions of past wind regimes which offer important data for verification of palaeoclimatic simulations

fine grained sediment transport and sorting by tidal exchange in xiangshan bay zhejiang china abstract during the winter of 1983 25 h measurements of current speed flow direction water depth and suspended sediment concentration were carried out at six stations located in the inlet section of xiangshan bay during spring and neap tides an analysis of the data obtained shows that tidal exchange in the form of either vertical residual circulation or bay mouth water mixing is responsible for the observed net landward movement of suspended sediment though the ebb currents are stronger than the flood currents in the inlet the analysis suggests also that the tidal exchange processes in combination with the settling behaviour of the suspended sediments and the morphological features of the inlet section lead to marked sorting of the fine grained sediments with the clayey material predominating in the inner part of the bay and the silty material in the outer part

geochemical compositions and provenance discrimination of the central south yellow sea sediments geochemical compositions and sedimentation rates of surface and core sediments in the central south yellow sea were analyzed for the identification of sediment origins the sediment accumulation rates measured by 210 pb geochronology decrease significantly from the western part to the central area calcium carbonate total organic carbon and most elements are more enriched in the western muddy sediments than in the sandy eastern part overall geochemical compositions of the central south yellow sea sediments vary between those of chinese and korean river sediments supplied into the sea although caco3 content exhibits regional variations in the central south yellow sea the discrimination diagram of sc al vs cr th distinctly suggests that the muddy holocene sediments in the central western part are derived ultimately from chinese rivers especially the huanghe river whereas the eastern sandy sediments primarily came from the korean rivers during the postglacial transgression 2007 elsevier b v all rights reserved

origin and dispersal of recent clay minerals in the yellow sea abstract the clay minerals in the by considering the clay minerals supplied by rivers in china the old and present day huanghe river and korea the keum and yeongsan to the yellow sea continental shelf and the spatial variation in the distribution of clay minerals in the yellow sea this study indicates that the provenance of the cysm may be closely related to the old and present day huanghe river system whereas the clay minerals in the seysm seem to be largely associated with the keum and yeongsan rivers in addition smectite may be suggested as an important clay mineral in differentiating between cysm and seysm and understanding the sources of these two mud categories

winter variability of aeolian sediment transport threshold on a cold climate dune abstract changes in surface conditions on cold climate aeolian dunes are pronounced during winter dunes are wet snow covered and or frozen for extended periods of time it is unknown how the critical wind speed for sediment transport threshold varies and how threshold may influence sediment transport predictions although the impact of surface conditions on threshold has been examined in synthetic experiments wind tunnels complicated feedbacks between threshold sand transport and surface conditions that occur in natural environments suggest that a ground based empirical approach may provide enhanced insight in this study we investigate threshold variability for 73 days during fall winter spring surface conditions from 18 november 2008 to 30 may 2009 in the bigstick sand hills of saskatchewan canada simultaneous measurements of threshold and atmospheric variables air temperature relative humidity solar radiation wind speed and direction were used to examine the extent to which surface erodibility was regulated by meteorology time lapse images of the surface from a co located camera were used for quality control and interpreting changes in the surface affecting threshold results reveal that threshold varied throughout the deployment 25 75 quartiles 6 92 8 28 m s 1 mean 7 79 m s 1 threshold variability was especially evident at two scales i event timescale and ii seasonal timescale event scale variability peaked during mid winter in one event the threshold varied by 6 m s 1 in 2 h with freezing and re freezing of the surface and relatively constant atmospheric conditions the causes of event scale variability are complex though qualitatively related to changes of wind direction antecedent meteorological conditions and vertical variations of grain scale bonding agents such as pore ice and moisture seasonal scale changes manifested as an increase in threshold during fall peaking in mid winter and decreasing in spring increased threshold in mid winter was linked to lower insolation and air temperature suggesting low erodibility due to the presence of pore ice correlation coefficients of threshold versus atmospheric variables yielded relatively weak correlations air temperature r 0 322 relative humidity r 0 388 solar radiation r 0 309 that also varied according to wind direction suggesting that the link between atmospheric conditions and surface erodibility on cold climate dunes is complex this contrasts with results from field based studies in warmer climates and controlled wind tunnel experiments which show a more direct link between atmospheric variables temperature and humidity and surface erodibility nevertheless our results do show a seasonal pattern of threshold that could be important for modeling cold climate aeolian sediment transport

origin of inner shelf mud deposit in the southeastern yellow sea huksan mud belt abstract a variety of previous sedimentological results together with newly obtained hydrodynamic data are summarized and reinterpreted with respect to the most likely origin of the huksan mud belt hmb in the southeastern yellow sea the hmb consists of two mud units that have similar grain texture and clay mineralogy but can be differentiated on seismic profiles because the lower unit is generally harder than the watery upper unit the hydrographic measurements together with satellite imagery clearly indicate that the suspended plume covering the hmb originates from the west coast of korea the suspended plume becomes enhanced by winter monsoon winds beginning in late fall most of the studies of clay mineralogy geochemistry and isotherm distribution also suggest that the hmb has been derived from the west coast of korea particularly from the keum river an approximate evaluation of the depositional time for the hmb based on its dimensions and the discharge rate of the keum river suggests a time duration of the order of 14 000 years hydrodynamic measurements across two transects over the northernmost hmb reveal that suspended matter travels southwest toward the main body of the hmb in a well constrained corridor ultimately connected with the keum river time series 12 5 h hydrodynamic measurements at a site over the hmb suggest that the winter season suspended plume carries concentrations of suspended matter one to two orders of magnitude higher than those of the summer silt grains of 5 6 well sorted through numerous resuspension events settle out onto the hmb forming distinctive silt laminae alternating with clay rich laminae

interglacial high tide coasts in the bristol channel and severn estuary southwest britain a comparison for the ipswichian and holocene the ipswichian high tide coast in the bristol channel and severn estuary at the time of the highest sea levels 5 10 m od was wave dominated almost everywhere it is defined by raised beaches and inshore sand shoals and only in comparatively long but narrow inlets somerset levels are estuarine conditions evident the modern holocene seaway is wave dominated at high tide only up to and including the inner bristol channel a muddy upper shore typifies the large tide dominated severn estuary to the east and northeast the larger depth and width of the ipswichian seaway may explain its greater wave dominance but it is also possible that differences in the sediment regime also contribute to the contrast observed with water levels continuing to rise the holocene seaway could reach ipswichian depths within a few thousand years and evolve toward greater wave dominance a secondary effect may be the transgression and substantial removal of the holocene estuarine sequence associated with the severn estuary levels copyright 2002 john wiley sons ltd

summertime hydrographic features in the southeastern hwanghae abstract ctd casts in the southeastern hwanghae yellow sea were made in august 1983 and 1984 to describe the spatial structure of the summertime hydrographic features cold coastal water appeared around the southwestern coast of korea which was formed by strong tidal stirring tidal mixing in the study area seems to have been enhanced by the presence of many small islands in the deeper region beyond the tidal front stratification became much stronger and the bottom layer below seasonal thermocline was occupied mostly by the hwanghae cold water characterized by a temperature lower than 10 c and salinity of 32 5 33 0 the northeastward extension of the changjiang diluted water was shown by a tongue like plume of relatively warm fresh water confined to the thin surface layer 10 m thick there was no evidence for the hwanghae warm current carrying high salinity water into the eastern hwanghae along the korean coast the warm current was found to flow in a narrow band close to the west and north coast of chejudo cheju island and then to pass eastward through the cheju strait thus the eastern part of the cyclonic circulation in the surface layer cannot be considered to be a northward continuation of the hwanghae warm current the local salinity maximum in the lower layer off kunsan and the higher salinity on the west side of the central trough than on the east side would imply a northward flow on the west flank of the trough to compensate for the southward intrusion of the hwanghae cold water from which an anticyclonic circulation could be expected in the lower layer

extensional subsidence contractional folding and thrust inversion of the eastern cameros basin northern spain tectonic analysis of the cameros massif northern spain demonstrates the need to integrate detailed structural analysis with stratigraphic studies in order to understand the development of inverted basins the cameros massif underwent three major tectonic events each characterized by different mechanisms of deformation the first event tithonian early albian manifested as continental rifting and formation of the cameros basin and was attended by normal faulting and related folding of pre and syn rift sedimentary sequences up to 9 km thick it corresponded to the beginning of rifting and opening of the bay of biscay to the north of the massif the second event occurred at the end of the early cretaceous the basin underwent contraction manifested as gentle folds containing axial plane cleavage this contraction was due to the migration of the center of rifting away from the basin and toward the northeast and correlates with the onset of oceanic spreading in the bay of biscay deformation happened during a low grade metamorphism period that reached its thermal peak after folding and cleavage formation 90 100 ma the final stage of deformation eocene miocene following a structurally quiescent period of approximately 40 ma occurred during the convergence collision between iberia and europe it formed contractional folds related to large e w striking overthrusts the mesozoic basin was inverted and transported 25 km toward the north during this stage both unfolding and tightening of the former folds occurred as determined from analysis of cleavage orientation associated with the previous shortening

discrimination in magnetic properties of different sized sediments from the changjiang and huanghe estuaries of china and its implication for provenance of sediment on the shelf abstract provenance discrimination of marine sediments is an important topic in marine geology although the catchments of the changjiang and huanghe rivers are regarded as the main sources of sediments on the shelves of the china sea identification of detailed sediment provenance is necessary for understanding sediment transport patterns and the paleoenvironment magnetic properties of both bulk sediment samples and different sized particles from the changjiang and huanghe estuaries are studied to discuss the origin of the sediments the results show that the sediments are dominated by ferrimagnetic magnetite with a minor content of anti ferromagnetic minerals such as hematite and a higher concentration of ferrimagnetic minerals is observed for the changjiang estuary sediments the crystal grains of ferrimagnetic minerals in the changjiang estuary are coarser than those in the huanghe estuary whereas superparamagnetic grains significantly contribute to the huanghe sediments magnetic parameters of sirm soft and arm from different sized particles present more obvious differences than these parameters from bulk particles and s 100 and s 300 for both bulk samples and different sized particles show distinct differences between the sediments from the two estuaries therefore the latter parameters are more useful to distinguish sediment origins a comparison of the magnetic properties of sediments in these two estuaries with those on the shelves of the adjacent china sea also suggests that the analysis of sediment magnetic properties is effective to identify sediment provenances

coastal mudflat accretion under energetic conditions louisiana chenier plain coast usa mudflat accretion on the chenier plain coast of louisiana northern gulf of mexico is anomalous in an area that otherwise experiences widespread land loss due to rapid relative sea level rise accretion is shown to be related to energetic events winter cold fronts and occasional tropical depression storms using a 17 year record of meteorological conditions and aerial surveys the results indicate substantial differences between the behavior of sand and mud dominated coastal systems under energetic conditions comparison of the louisiana chenier plain to other mud rich coasts indicates that certain conditions are necessary for mudflat accretion to occur during energetic atmospheric activity these include an abundant supply of fine grained fluvial sediment and resuspension events that maintain an unconsolidated sea floor dominant onshore wind direction during energetic conditions particularly when onshore winds coincide with high fluvial sediment input to the coastal ocean and a low tidal range

discrimination of sediment provenance in the yellow sea secondary grain size effect and ree proxy this study analyzed grain size and elemental concentrations al mg fe and rare earth elements rees in 91 surface sediments to elucidate sediment provenance in the yellow sea elemental concentrations were normalized by al concentration c element c al to minimize the sediment grain size effect gse however noticeable linear relationships between ai concentration or mean grain size and the ratio e g mg al or fe al appeared unexpectedly in pair diagrams the spatial distribution patterns of fe al and mg al ratios were also similar to the pattern of mean grain size this implies that the gse was not removed completely even after the normalization process thus great care must be taken when applying the ratios of c element c al as a proxy of sediment provenance to improve provenance discrimination of the sediments in the yellow sea the difference between the ree distribution patterns of chinese and korean river sediments expressed as delta delta ree la ree lu was calculated and the spatial distribution patterns of the delta values were mapped the delta values gradually increased from the western to the eastern part of the yellow sea except for low delta values in the southeastern part of the yellow sea this result indicates that the majority of chinese and korean river sediments are accumulating near to their respective coasts except for a deposit along the southwestern coast of korea in which a considerable amount of sediment from chinese rivers has been accumulating c 2016 elsevier ltd all rights reserved

geochemical composition and provenance discrimination of coastal sediments around cheju island in the southeastern yellow sea sediments from the northern coastal area of cheju island south sea of korea southeastern yellow sea were analyzed for grain size composition elemental compositions and clay mineralogy in order to investigate their provenance rare earth element ree compositions and geochemical discrimination diagrams were revealed to be useful indices for identifying the origin of sediments in the study area these indices together with clay mineral compositions suggest that both the sandy and muddy sediments originated from weathering of the volcanic rocks of cheju island whereas sediments originating from the changjiang and huanghe rivers cannot be traced in the study area similarly river borne matter from the korea peninsula has little influence on the sediment deposited therefore the suggestion that fine grained changjiang sediments can reach the nearshore area of cheju island the cheju strait suggested by oceanic circulation patterns in the yellow and east china seas cannot be supported by this study based on geochemical and mineralogical analyses

multielement geochemistry of offshore sediments in the southeastern yellow sea and implications for sediment origin and dispersal abstract in total 116 surface sediments were collected from an offshore area of the southeastern yellow sea including a large mud belt southeastern yellow sea mud seysm and analyzed for grain size and geochemical composition organic carbon and 42 elements principal component analysis revealed that elemental compositions of the offshore sediments were mostly controlled by common aluminosilicate clay minerals and quartz most elements heavy minerals hf zr u th rare earth elements rees biogenic calcium carbonates ca sr feldspar and mica k ba pb and mn oxides mn oxide coatings on sand grains notably total ree concentrations may be associated with heavy minerals possibly zircon and monazite especially in silty grains even though heavy ree hrees concentrations are more strongly controlled by clay minerals in muddy sediments the diagnostic discrimination plots of geochemical compositions e g fe vs al mg vs al light ree vs hree and la lu ucc vs la y ucc suggested that the offshore sediments especially in seysm deposits were composed of a mixture of korean river derived silts and chinese river derived clays this demonstrated that chinese river sediments especially clay particles largely contributed to the formation of the giant mud belt in the korean coastal area furthermore the observed geochemical end members provide new markers of sediment provenance which can be used to track dispersal patterns and sediment limits from chinese and or korean rivers